JP2013221800A - Generation outflow prediction simulation method and program - Google Patents

Abstract

The present invention provides a generation and outflow prediction simulation method capable of sequentially determining the flow rate of water and sediment per minute time due to rain on slopes, valleys, and river channels, and calculating the increase in slopes, valleys, and river channels with high accuracy.
[Solution]
The generated runoff prediction simulation apparatus 100 includes a generated water amount analysis unit 220 and a sediment runoff analysis unit 230, and defines rainfall on the surfaces of the slopes on the left and right banks of the valley, and is generated on this surface, the intermediate upstream layer and the intermediate downstream layer. The total amount of water to be discharged and the amount of earth and sand flowing on the surface of the slope are used as the flow rate to the valley.
[Selection] Figure 1

Description

  The present invention relates to a generated outflow prediction simulation method.

  In mountainous areas, floods suddenly occur in valleys and river channels due to typhoon and guerrilla heavy rains, and at the same time, disasters spread due to sediment discharge. Sediment dams are installed in the valleys to control and manage sediment runoff so that disasters caused by sediment runoff during floods do not occur downstream.

  There is a kinematic wave method (Kinematic Wave method) that calculates the amount of water flowing into rivers and rivers depending on the amount of rainfall in a certain area.

The kinematic wave method (Kinematic Wave method) models virtual slopes and river channels on both sides of a specified length of river (sawa), and calculates the slope flow rate according to the amount of rainfall to calculate the flow rate to the river channel. It is a calculation method.

  On the other hand, there is an outflow prediction system using a kinematic wave method (Kinematic Wave method) (Patent Document 1).

  The outflow prediction system of Patent Document 1 describes that the amount of outflow is determined by determining the permeability of the surface layer, intermediate layer, and underground layer of a slope in a predetermined area. Patent document 1 calculates the flood flow in the arbitrary points of the river channel from the present to several hours ahead.

JP 2009-8651 A

  However, it is not only the amount of water that increases due to the amount of rain, but the soil, sand, and stones that exist on the surface of the slope flow into the valley as the amount of rain increases, and as a result, the soil and sand also flows into the valleys and river channels. Including water volume increases.

For this reason, sediment will accumulate in the downstream area of the river channel. Sediment runoff causes disasters, but stabilizes the downstream riverbed and protects the coast, but in the event of heavy rains due to typhoons or recent guerrilla rainstorms, more sediment than expected is deposited downstream.

Therefore, in the upstream area, a sabo dam with an appropriate position and number should be provided in consideration of the amount of sediment flow in addition to the amount of water, but since only the amount of water is currently considered, an appropriate number of sabo dams are considered. Cannot be proposed.

In addition, it is desirable that the amount of water and sediment generated in the slopes, valleys, and river channels be determined sequentially according to the amount of rainfall that occurs upstream.

  However, it is not only the amount of water that increases due to rainfall, but also the soil, sand, and stones that exist on the slopes and valleys flow down with increasing flow of water, and sediment accumulates in the downstream area of the river channel, causing flood damage. Or earth and sand overflow from the river channel, causing damage to houses, public facilities and roads.

    Therefore, it is necessary to install a sabo dam at an appropriate location in the upstream area and control the sediment runoff during heavy rains. An analysis program that predicts

    In addition, sediment discharge will cause disasters, but it will stabilize the downstream riverbed and protect the coast. Therefore, it is also necessary to maintain the river so that an appropriate amount of sediment flows downstream except during heavy rains. For such management, an analysis program that predicts the amount of sediment runoff associated with rainfall is required.

  However, there is currently only a method for predicting the amount of runoff of water, and no sufficient analysis method has been established to predict the amount of sediment runoff. Therefore, the sabo dam with the appropriate location and number has not been installed, and the maintenance management based on the amount of earth and sand that flows downstream during heavy rain has not been achieved.

  In addition, in the appropriate installation of sabo dams in preparation for landslides during heavy rains and for maintenance management other than during heavy rains, the amount of water and sediment in the slopes, valleys, and river channels also depends on the amount of rainfall that occurs upstream. It is desirable to know the amount of occurrence of each.

  The present invention has been made in view of the above problems, and it is possible to sequentially understand the flow rate of water and earth and sand per minute time due to rainfall in slopes, valleys, and river channels, and to accurately increase the amount of increase in slopes, valleys, and river channels. The purpose is to obtain a simulation method for predicting generation and outflow.

The present invention divides an intermediate flow layer that flows through a predetermined area including a valley connected to a river channel and permeates through the slopes on the left and right sides of the valley into a slope intermediate upstream layer and a slope intermediate downstream layer. The generated outflow prediction simulation method for predicting the flow rate generated in the valley by outputting the obtained calculation result to the valley analysis unit,
A rainfall data storage means for storing a divided rainfall obtained by dividing the rainfall data per unit time in the predetermined area by a finer analysis unit time;
Based on the generated flow analysis basic information including the slope length of the left and right slopes, the valley length of the valley, the thickness of the right and left slope middle upstream layer, the thickness of the right and left slope middle downstream layer, and the slope slope of the left and right A slope model storage means in which left and right slope multilayer models sandwiching a valley are stored in association with the valley number (iv);
Slope parameter storage means in which various parameters for slopes on the left and right slopes for analyzing the amount of water flowing on the slope and the sediment flow are stored in association with the valley number (iv),
Slope flow calculation result storage means for storing calculation result data for each of the left and right slope division blocks in association with the valley number (iv);
With
Computer
(A1). Converting the left and right slope multilayer model into a slope split multilayer model having a slope split block that is split from the surface to the bottom surface of the intermediate flow layer with a constant split width;
(A2). Defining the divided rainfall for each analysis unit time in each slope division block of the slope division multilayer model;
(A3). Means for setting the left or right slope of the slope division multilayer model, and for each setting, sequentially setting the slope division block from the upper side toward the edge of the valley;
(A4). Each time the slope division block is set, the step of designating adjacent slope division blocks on both sides;
(A5) For each of the designated slope division blocks, the divided rainfall of the slope division block is read, and the both sides of the both sides obtained by the division rainfall of the analysis unit time immediately before the analysis unit time are obtained. The water depth (hs) accumulated from the bottom surface of the slope intermediate flow layer in the slope division block set using the water depth of each slope division block, the total flow rate of each water, the slope gradient, and various parameters for the slope. The desired process;
(A6). Each time the water depth (hs) in the designated slope dividing block is obtained, the flow rate of water flowing on the surface of the slope in the slope dividing block based on the water depth (hs), the various parameters of the slope, and the slope gradient. (Qws0), a step of obtaining a total flow rate (qws2) of the slope divided block as a total flow rate (qws2) of water flowing through the slope intermediate upstream layer (qws1) and a flow rate of water flowing through the slope intermediate downstream layer (qws2);
(A7). The slope flow calculation result storage unit stores the slope (hs), the total water flow rate (qws), and the analysis unit time in association with the designated slope division block as slope calculation result data for each slope block. Memorizing process;
(A8). Outputting the total water flow rate (qws) of the slope calculation result data for each slope block at the lowest end in the analysis unit time from the slope flow calculation result storage means to the valley analysis unit as the calculation result; The gist is to do.

The present invention also provides:
Computer
(A9). Defining a parameter for analyzing debris flow included in the various parameters for the slope for each of the slope division blocks;
(A10). Parameters for analyzing the water depth (hs), total water flow rate (qws), and debris flow in the slope divided block, and the both sides obtained by the divided rainfall of the analysis unit time one time before the analysis unit time Calculating the amount of slope sediment (qLs) on the basis of the amount of slope-movable earth and sand (VLs), and storing this in association with the slope calculation result data for each slope block of the slope division block;
(A11). The gist of the present invention is to perform the step of outputting the slope sand flow amount (qLs) of the slope calculation result data for each slope block at the lowest end from the slope flow calculation result storage means to the valley analysis unit as the calculation result.

Furthermore, the present invention provides a computer comprising:
(B1). Analyzing whether the water surface at the depth (hs) obtained in the step (A5) is present in any one of the surface layer, the intermediate upper layer, or the intermediate lower layer;
(B2). The generated outflow prediction simulation method according to claim 1, wherein a step of associating the analysis result with the calculation result data for each slope is performed.

Furthermore, the present invention provides an analysis of the generated flow rate including the valley length of the valley, the width of the valley, the thickness of the intermediate flow flowing through the valley bottom, the thickness of the valley intermediate flow upper layer, the thickness of the valley intermediate flow lower layer, and the valley gradient. A trough model storage means in which a trough multilayer model based on the basic information is stored in association with the trough number as a trough sandwiching the left and right slope multilayer models;
Various parameters for valleys for analyzing the amount of water flowing through the valleys and the sediment flow, parameter storage means for valleys stored in association with valley numbers,
Storage means for trough calculation results in which trough calculation result data is stored;
With
Computer
(C1). A valley division multilayer model having a valley multilayer division mesh divided to the bottom surface of the valley intermediate flow layer at the slope division width; and
(C2). Setting the valley multi-layer divided mesh in order from the most upstream side of the valley division multi-layer model,
(C3). For each of the set valley multi-layer divided mesh, assigning the various parameters for the valley,
(C4). Assigning the total water flow rate (qws) of the slope division block at the lowest end in the output analysis unit time to each of the valley multilayer division meshes instead of the division rain amount;
(C5). For each of the valley division meshes, the both sides of the both sides determined by the total water flow rate (qws) of the water and the total water flow rate (qws) of the lowest end of the analysis unit time one time before the analysis unit time. The total water flow rate of the valley divided mesh, the valley gradient, and the various parameters for the valley are used to determine the water depth (hv) accumulated from the bottom surface of the valley intermediate flow layer in the valley multi-layer divided mesh that has been set. Process,
(C6). Each time the water depth (hv) is obtained, the flow rate (qwv0) of water flowing on the surface of the valley portion in the valley multi-layer divided mesh is read by reading the various parameters of the valley portion and the valley gradient, The total flow rate (qwv) of the water flowing through the set valley multi-layer divided mesh is obtained as the total of the flow rate (qwv1) of the water flowing through the upper part of the middle intermediate flow and the flow rate (qwv2) of the water flowing through the middle intermediate downstream layer. Process,
(C7). The step of storing the water depth (hv) per the valley multi-layer divided mesh, the total flow rate (qwv) of the water, and the analysis unit time in the valley calculation result storage unit as the calculation result data for each valley When,
(C8). And a step of outputting the total flow rate (qwv) of the water in the bottommost multi-layer divided mesh at the analysis unit time of the valley calculation result storage means to the river channel analysis unit. .

  As described above, according to the present invention, the divided rainfall per analysis unit time is defined on the surfaces of the slopes on the left and right banks of the valley, and the total amount of water generated on the surface, the intermediate upstream layer and the intermediate downstream layer, and the slope The amount of earth and sand flowing on the surface is the flow rate to the valley.

For this reason, in the valley, it is possible to accurately notify the amount of water and sediment that flows by divided rainfall every analysis unit time every unit time, so in the downstream area of the river channel it is possible to accurately determine how much sediment is deposited by the rainfall. Can be predicted.

Therefore, when heavy rain occurs, it is possible to accurately predict the generation amount of water and sediment.

In addition, since the amount of water and the amount of earth and sand can be predicted with high accuracy, it is possible to predict how many sediment control dams will be provided to prevent sediment from being deposited downstream.

It is a schematic block diagram of the generated outflow prediction simulation apparatus 100 of this Embodiment. It is explanatory drawing of rainfall data. It is explanatory drawing of valley slope data. It is explanatory drawing of the parameter used for an outflow analysis. This parameter is commonly used in sediment runoff calculation and river bed fluctuation calculation. It is explanatory drawing of the particle size data of earth and sand. It is explanatory drawing of a slope part sediment runoff calculation parameter. It is explanatory drawing of a valley part sediment runoff calculation parameter. It is explanatory drawing of river channel cross-sectional data. It is explanatory drawing explaining the production | generation of a valley slope model. It is explanatory drawing of the input data which an operator inputs. It is a flowchart of calculation of divided rainfall data. It is explanatory drawing of division | segmentation rainfall data. It is a flowchart explaining slope flow analysis. It is a flowchart explaining slope flow analysis. It is explanatory drawing of a slope division | segmentation multilayer model. It is explanatory drawing of the slope flow calculation result data for every slope block. It is explanatory drawing explaining determination of the water depth which generate | occur | produces in each layer of a slope. It is a flowchart explaining the process of the valley part flowing water amount analysis part 220b. It is a flowchart explaining the process of the valley part flowing water amount analysis part 220b. It is explanatory drawing explaining a valley part multilayer model. It is explanatory drawing of the water amount calculation result data for every valley. It is explanatory drawing explaining the determination of the water depth which generate | occur | produces in each layer of a trough. It is a flowchart explaining the analysis process of slope earth and sand movement. It is a flowchart explaining the analysis process of slope earth and sand movement. It is explanatory drawing of a slope debris movement model. It is explanatory drawing of the sediment flow calculation result data for every slope block. It is a flowchart explaining the analysis process of a valley part earth and sand movement. It is a flowchart explaining the analysis process of a valley part earth and sand movement. It is explanatory drawing explaining a valley part earth and sand movement model. It is explanatory drawing of the sediment flow rate calculation result data for every trough in the case of debris flow generation. It is explanatory drawing explaining the data output to a river channel part. It is explanatory drawing explaining the effect by this implementation. It is explanatory drawing explaining the effect by this implementation.

  FIG. 1 is a schematic configuration diagram of a generated flow rate prediction simulation apparatus 100 according to the present embodiment. As shown in FIG. 1, the generated flow prediction simulation apparatus 100 includes a display unit 101, an analysis data generation unit 210, a generated water amount analysis unit 220, a sediment runoff analysis unit 230, a river channel fluctuation analysis unit 240, and the like. Has been.

These are software, stored in a ROM (not shown), and the CPU stores the program in the execution RAM and executes it. In addition, it has a working memory (not shown) and various storage means (memory).

  The various storage units described above include the following storage units.

  Rainfall data database 310 in which rainfall data is stored, basic information database 320 in which basic information for generating flow rate analysis is stored, and a slope model storage in which a slope-by-slope multilayer partition model (also referred to as a slope multilayer partition model) is stored. Means 330; valley model storage means 340 for generating a valley-by-valley multi-layer division model (also referred to as a valley multi-layer division model); and slope water amount calculation result storage means 350 for storing slope-by-slope slope flow calculation result data. Storage unit 360 for calculating the valley water flow amount calculation result stored for each valley generated flow amount calculation result data, slope unit sediment calculation result storage unit 370 storing the slope sediment flow rate calculation data, and for each valley unit It includes a valley sediment flow calculation result storage means 380 for storing sediment flow rate calculation result data, a river cross section data storage means 390 for storing river cross section data, and the like. To have.

  The slope-by-slope flow calculation result data and the slope-by-slope sediment flow calculation data are collectively referred to as slope-by-slope calculation result data. The generated flow rate calculation result data for each valley and the sediment flow rate calculation result data for each valley are collectively referred to as the calculation result data for each valley.

  The slope water amount calculation result storage means 350 and the slope sediment calculation result storage means 370 are collectively referred to as slope flow calculation result storage means.

As shown in FIG. 2, the rainfall data stored in the rainfall data database 310 is associated with the date, time, duration tri, and rainfall. In addition, record numbers Ri (R1, R2,...) Are added to the rainfall data ri. These are information obtained by the operator from the Japan Meteorological Agency or river management offices.

  The basic information for analyzing the generated flow rate stored in the basic information database 320 will be described below.

  The basic information for the generated flow rate analysis is the valley slope data shown in FIG. 3, the parameters related to the slope shown in FIG. 4 (various parameters for the slope) and the parameters related to the valley (various parameters for the valley) (collectively, parameters for valley slope analysis). 5), parameters used for sediment movement shown in FIG. 5, sediment particle size parameter shown in FIG. 6, slope sediment discharge parameter shown in FIG. 7, valley sediment discharge calculation parameter shown in FIG. Is remembered. These are stored in association with the valley number iv.

    Further, the river channel cross-section data is stored in association with the river channel cross-section number (name) as shown in FIG.

  As shown in FIG. 10 (a), the valley slope data shown in FIG. 3 displays a map of the analysis area on the screen of the display unit 101 using a GIS system (not shown), for example. NO2...), And a valley number associated with the river channel section number is generated in a valley existing upstream of the river channel section number.

  That is, as shown in FIG. 3, the river channel section number and valley number iv are associated with the valley length, valley gradient, valley width, slope length (left and right banks), and slope gradient (left and right banks). That is, the valley slope model shown in FIG. 10B is defined. FIG. 10C illustrates the river cross section data shown in FIG.

Moreover, the above-mentioned valley number iv is indicated by a river channel section number and a valley number.

(Description of each part)
As shown in FIG. 11, the analysis data generation unit 210 causes the display unit 101 to display a screen for inputting the right slope, the left slope, and the valley width of the valley.

The input screen shown in FIG. 11 includes an inflow destination river channel section number, a valley number, a slope number Ns, a valley length Ly, a valley width Bv, a valley gradient Iv, a valley intermediate flow layer hydraulic conductivity (upper layer Ks1, It consists of input items such as a lower layer ks1, a valley portion probability coefficient nv, and a valley intermediate flow layer thickness (upper layer dps1, lower layer dps2), etc. These input screens are provided for each of the right slope and the left slope.

In addition, a sub-screen for data set on each slope portion of the valley is displayed. This sub screen is provided for each right bank and left bank. The sub-screen includes a slope length Ls, a slope gradient Is, a slope intermediate flow layer water supply coefficient (upper layer kv1, lower layer kv2), a slope section charge coefficient nv, and a slope section intermediate flow layer thickness (upper layer dpv1, lower layer dpv2). ) And other input items. In addition, a screen for inputting river channel cross section data is displayed and input.

The analysis data generation unit 210 reads these input data and stores each data in the corresponding storage means as shown in FIGS. 3, 4, 5, 6, 7, 8, and 9. FIG.

    As shown in FIG. 1, the generated water amount analysis unit 220 includes a slope flow water amount analysis unit 220a and a valley flow water amount analysis unit 220b.

    The sediment runoff analysis unit 230 includes a slope sediment flow analysis unit 230a, a valley sediment flow analysis unit 230b, and a valley calculation result output unit 230c (not shown).

<Amount of generated water analysis section>
The slope flow water volume analysis unit 220a reads the generated flow rate analysis basic information stored in the basic information database 320, the slope length (right, left), slope length (right, left), slope slope ( (Right, Left) (These are data of the slope multilayer model) and the slope division width (for example, 10 m, 20 m) included in the slope-related parameters, the slope multilayer partition model shown in FIG. To generate.

As shown in FIG. 16B, the upper side of the slope to the end of the valley is divided at a constant width (for example, 10 m) (each is referred to as a slope division block).

Then, the slope water flow analysis unit 220a reads the rainfall data ri (the duration in FIG. 2: 600 seconds, for example) in the input time range Ti, and continues each of the rainfall data ri in the read time range Ti. The divided rainfall rtti per analysis unit time tti obtained by dividing the time tri by the analysis unit time tti (for example, 1 second, 2 seconds, .5 seconds, .10 seconds) is obtained (see FIG. 13), and these are analyzed unit time. Each ti is assigned to each mesh (slope multilayer division mesh) on the surface of the left and right slope multilayer division model.

  Then, for each divided rainfall rtti, the total flow rate of water on the slope generated in each slope division block (qwsx: the total of the surface of each slope division block, the intermediate upper layer, the intermediate lower layer) is obtained, and the slope water flow calculation result Is stored in the storage means 350 (slope block-by-slope block flow calculation result data rtSBi), and the total water flow rate (qwsx) on the slope of the final slope split block is notified to the valley stream water flow analysis unit 220b. The calculation of the total water flow rate (qwsx) on this slope will be described later in detail. These calculations are performed for each of the left and right slopes.

  The valley water flow analysis unit 220b reads the valley number (iv) of the generated flow rate analysis basic information stored in the basic information database 320, the valley length, the valley width, and the valley width included in the valley slope data. The valley multi-layer model defined by various parameters for the valley (thickness of the valley intermediate upstream layer, thickness of the valley intermediate downstream layer, valley gradient, etc.) is defined as the valley division multilayer model shown in FIG. Store in the model storage means 340. In FIG. 21, the mesh divided at 10 m is referred to as a valley multi-layer divided mesh.

  And every time the total flow (qwsx) of the water of the slope of the last slope division block for every division | segmentation rainfall rtti from the slope flow quantity analysis part 220a is output, it has the valley number iv of the calculation result of this slope flow quantity. The valley divided multi-layer model is read, and the total water flow (qwsx: of the slope water included in the total water flow (qwsx) of the slope of the final slope divided block for each divided rainfall rtti from the slope water flow analysis unit 220a. The total water flow rate (qwsx) of the lowermost slope multilayer mesh of the slope partition block is sequentially assigned to the valley multilayer mesh of the corresponding valley partition number instead of the rainfall data.

  Then, the total water flow qwvx per valley flowing through the valley multi-layer divided mesh at the lowest end of the valley is obtained for each valley by obtaining the total water flow qwvx (qwvx: total water flow (qwv) of each multi-layer divided mesh). The stored flow amount calculation result data rtVBi is stored in the valley calculation result storage means 360 and output to the sediment runoff analysis unit 230.

<Sediment runoff analysis department>
The slope sediment flow analysis unit 230a of the sediment discharge analysis unit 230 obliquely reads the slope multilayer division model corresponding to the valley number iv of the slope model storage means 330, and uses the slope division multilayer model for the slope of the basic information for the generated flow rate analysis. Parameters for analyzing debris flows included in various parameters are assigned to the surface of each slope division block.

    Each time the slope block slope flow calculation result data rtSBi per rainfall division data rtti from the generated water quantity analysis unit 220 is input, the total slope sand flow (qLs) of the earth and sand generated in each slope division block is obtained. The slope sediment calculation result storage means 370 stores it as slope block sediment flow rate calculation result data rtSDi and outputs it to the valley sediment flow rate analysis unit 230. These calculations are performed for each of the left and right slopes.

  The trough sediment flow analysis unit 230b adds a trough of the basic information for analyzing the generated flow of the trough number in the basic information database 320 to each mesh of the trough division multilayer model corresponding to the trough number iv of the trough model storage unit 340. Parameters for analyzing debris flows included in various parameters are assigned to the surface of each valley division mesh.

  Then, the total sediment volume (qLv) of the sediment generated in the valley multi-layer divided mesh per divided rainfall data rtti is obtained and stored in the valley calculation result storage means 380 as the per-valley sediment calculation result data rtVDi. And output to the river channel. The calculation of the valley total liquid sand amount (qLv) will be described later in detail.

  The river channel analysis unit 240 obtains the sum of these every time the valley total water flow rate qwvx and the trough flow rate (qLvx), and sequentially stores them in the screen or memory as the flow rate generated in the river channel. .

    Therefore, when the map is displayed on the screen and the total is sequentially displayed, the increase based on the rainfall per unit time is sequentially displayed as an image (using GIS).

(Description of operation)
The operation of the generated flow rate simulation device 100 configured as described above will be described below.

  First, the divided rainfall data rtti will be described. FIG. 12 is a flowchart for explaining the calculation of the divided rainfall data.

As shown in FIG. 12, the slope water flow analysis unit 220a reads rain data ri stored in the rain data database 310 (S1: see FIG. 2).

    Then, the record number Ri of the rainfall data ri is set (pointer) (S2). Next, the preset continuation time tri is read (S3), and the continuation time tri is divided by the preset analysis unit time tti (S4).

Then, the analysis unit time tti is set (S5), and the rainfall amount rui of the rainfall data ri of the record number Ri is divided by the analysis unit time tti (divided rainfall data rtti) (S6).

These are stored in association with the record number Ri as shown in FIG. 13 (S7; 310). As shown in FIG. 13, the duration time tr and the rainfall amount rui are associated with the number Ri of one rainfall data ri, and the divided analysis unit time tti and the divided rainfall amount rtti are associated with the divided rainfall data number rpi. .

Next, it is determined whether there is another analysis unit time tti (S8). If there is another analysis unit time tti, the analysis unit time tti is updated and the process returns to step S2 (S9).

Next, it is determined whether there is another record number Ri. If there is another record number Ri, the record number Ri is updated, and the process returns to step S2 (S10).

   14 and 15 are flowcharts for explaining the calculation of the total slope flow rate (qws) of the slope flow amount analysis unit 220a of the generated water amount analysis unit 220. FIG.

     As shown in FIG. 14, the slope sediment flow analysis unit 230a of the generated water amount analysis unit 220 reads the set valley number (iv) (plural or one) (S11).

   Next, the slope length (right, left), slope length (right, left), slope slope (right, right, slope) of valley slope data included in the basic information for generated flow rate analysis in the basic information database 320 Left) and the slope division width (for example, 10 m) included in the slope-related parameters in the basic information database 320 are read (S12).

Next, the slope sediment flow analysis unit 230a of the generated water amount analysis unit 220 generates a slope multi-layer division model obtained by dividing the vertical section of the slope portion (for example, 10 m) as shown in FIG. 330 is generated (S13).

  In FIG.16 (b), the left slope part is shown, and A arrow directional view is shown in FIG.16 (b). That is, it is a slope multilayer division model divided by ms1, ms2,... Msx (x: indicates the number of the final slope division block). Next, the slope number Mi (right or left) is set (S14a).

  Next, the record number Ri of the rainfall data ri is set (S14b). Then, the slope division number msi of the slope number Mi is set (S15). Initially set to ms1.

  Next, the number rpi (tti) of the divided rainfall data with the record number Ri is set (S16). The divided rainfall data rtti (S17) of the divided rainfall data number rpi (tti), the slope intermediate flow layer thickness (upper layer dps1, lower layer dps2: S19), the slope roughness coefficient ns (S27), the slope intermediate fluid layer. Slopes on both sides adjacent to the slope division block of the set slope division block number msi one step before (tti-1), such as hydraulic conductivity (upper layer ks1, lower layer ks2: S28), slope gradient Is (S29), etc. By reading the water depth hs and flow rate (qws) of the divided block, the slope water depth hs of all layers (surface, upper layer, lower layer) in the set slope division block number msi is obtained (see FIG. 16). Is stored in the slope water amount calculation result storage means 350 as slope block-by-slope flow calculation result data rtSBi (S20: see FIG. 17).

  The above-mentioned one step before means that the slope division block having the set slope division block number msi calculated based on the division rainfall data one previous (tti-1) from the division rain data number rpi set in step S16. Are the water depth hs and the flow rate (qws) of the slope divided blocks on both sides adjacent to. The water depth hs of the upper slope division block with respect to the set slope division block is indicated as hs (msi-1), the flow rate (qws) is indicated as qws (msi-1), and the water depth hs of the lower slope division block is , Hs (msi + 1) and flow rate (qws) are indicated as qws (msi + 1).

As shown in FIG. 17, the water depth hs of all layers is stored in the valley number (iv) in association with the bank number is (left bank: is = 1, right bank: is = 2) and the slope division block number msi. . These are associated with the analysis unit time tti (or rpi). That is, it is stored in the slope water quantity calculation result storage means 350 as slope block slope calculation result data rtSBi for each analysis unit time.

  In FIG. 16A, the height from the middle lower layer (bottom surface of the lower layer) to the water surface is described as the depth hs of all layers.

  The water depth hs is obtained as follows.

(Calculation of slope water depth)
The basic formula for calculating the slope water depth is as follows.

To calculate the slope water depth, Lax-Wendroff method is used, which is a forward-type solution that develops unknowns and substitutes basic equations for each term up to the second order, and explicitly finds the unknowns of the next step at every time step. Use the following formula to calculate.

  Where hs: slope water depth, qws: slope flow rate, r: rainfall.

  Note that m is the slope division number, m-1 is one upstream value, and m + 1 is one downstream value.

Further, n is a time step, and the value obtained at n−1 one step before is used to obtain the value of the current time step n.

The term of F is calculated as follows.

f is calculated as follows.

  Where Is: slope gradient, ns: manning roughness coefficient on slope, dps1: slope middle upstream layer thickness (m), dps2: slope middle upstream layer thickness (m), kps1: slope middle upstream layer , Kps2: permeability coefficient of middle slope of slope, γ: effective porosity of soil layer (0.4).

hs (m ± 1/2, n) is calculated as follows.

  Then, the slope flow water amount analysis unit 220a of the generated water amount analysis unit 220 reads the slope intermediate flow layer thickness (upper layer dps1, lower layer dps1: S19) when the water depth hs of all layers of the slope is obtained (S21), It is determined whether running water is generated in the bed (S22).

    This determination process is shown in FIG.

  18 (a) shows a case where running water is generated in the middle downstream layer, FIG. 18 (b) shows that running water is generated in the upper middle layer and the lower layer, and FIG. In addition, it is determined that running water is generated in the lower layer.

  If it is determined in step S22 that flowing water is generated only in the intermediate downstream layer, the depth hs2 of only the intermediate downstream layer is obtained (S23).

In step S17, when it is determined that flowing water is generated only in the upper intermediate layer and the lower layer, the depth hs1 (hs1 = h-dps2) of the intermediate upper layer and the depth hs2 (hs2 = dps2) of the lower layer are obtained. (S24).

Furthermore, in step S22, when it is determined that water flows only in the surface flow and the intermediate flow upper layer and the lower layer, the surface flow depth hso (h-dps1-dps2) and the intermediate flow upper layer depth hs1 (hs1 = dps1) and the depth hs2 (hs2 = dps2) of only the lower layer are obtained (S25).

  Then, any one of the determination result water depths (surface flow depth hso, intermediate flow upper layer depth hs1 and lower layer depth hs2) is associated with valley number iv and the like, and the slope water amount calculation result storage means 350 is stored as slope flow calculation result data rtSBi for each slope block (see FIG. 17: S26).

  Next, as shown in FIG. 15, the slope flow amount analysis unit 220 a of the generated water amount analysis unit 220 includes a slope portion roughness coefficient ns (S 30), a slope portion intermediate fluidized layer permeability coefficient (S 31), and a slope gradient (S 32). Etc. are read to determine the slope flow rate qws (surface flow rate qws0, upper layer flow rate qws1, lower layer flow rate qws2) (S33).

  The slope flow rate qws is preferably obtained as follows.

(Calculation of slope flow rate)
The slope flow rate is calculated by the following formula based on the water depth generated in each layer.

Where, ns: Manning roughness coefficient on the slope, Is: slope gradient, kps1: hydraulic permeability of the slope intermediate upstream, kps2: hydraulic permeability of the slope intermediate downstream, γ: effective porosity of the soil layer (0.4 )
Next, as shown in FIG. 15, any one of these flow rates is associated with the valley number iv and the slope division block number msi and stored in the slope water amount calculation result storage means 350 as slope block slope calculation result data rtSBi. (S34: See FIG. 17).

  Then, it is determined whether or not the slope division block number msi is the last (msx) (S35). If it is not the last, the slope division block number msi is updated to the next number (msi = msi + 1) and the process is performed as shown in FIG. It returns to step S14b (S36).

  If it is determined in step S35 that the slope division block number msi is the last (msx), the total dragon amount qws of the water in the lowermost slope division block is sent to the valley flow analysis unit (S37). This is also referred to as slope flow calculation result data rtSBxi for each slope block.

  Next, it is determined whether there is another number rpi (tti) of the divided rainfall data (S38).

  If it is determined in step S38 that there is another divided rainfall data number rpi (tti), the number is updated to the next divided rainfall data number, and the process returns to step S16 in FIG. 14 (S40). If it is determined in step S38 that there is no other divided rainfall data rpi, it is determined whether there is another Ri (S41).

  When it is determined in step S41 that there is another Ri, Ri is updated, and the process returns to step S14b in FIG. 14 (S42).

  When it is determined in step S41 that there is no other Ri, it is determined whether there is an opposing slope number Mi (S43).

  If it is determined in step S43 that there is an opposing slope, the slope number is updated and the process returns to step S14a in FIG. 14 (S44).

  Next, when it is determined in step S43 that there is no opposing slope number, it is determined whether or not there is another valley number (S45). Return to S11 (S46).

(Tanibe flowing water analysis unit 220b)
Next, processing of the valley water flow amount analysis unit 220b will be described below with reference to FIGS.

  As shown in FIG. 19, the valley water flow amount analysis unit 220b reads the valley number (iv) of the generated flow rate analysis basic information stored in the basic information database 320 (S51), and is included in the valley slope data. The various parameters for the valley length, valley width, and valley of the valley (the thickness of the valley intermediate upstream layer, the thickness of the valley intermediate downstream layer, the valley gradient, the valley division width (for example, 10 m), etc.) are read (S52), A valley multilayer model is generated (S53; see FIG. 21). In Fig.21 (a), the B arrow view of FIG.21 (b) is shown. As shown in FIG. 21, the valley bottom is the ground surface, and the ground surface is divided into an upper layer and a lower layer and divided at intervals of 10 m (mv1, mv2,... Mvx). This is referred to as a valley division number mvi. The lattice having the valley division number mvi is referred to as a valley multilayer division mesh.

  Next, it is determined whether or not the slope block per-slope flow calculation result data rtSBi in the analysis unit time tti (rpi) is input from the slope part 220a of the generated water amount analysis part 220 (S54).

  If it is determined in step S54 that the slope block calculation result data rtSBi (bottom end) has been input, the valley division number mvi of the slope block slope flow calculation result data rtSBi is set (S55). Initially set to mv1.

  Then, the water depth hs of the set slope block per-slope flow calculation result data rtSBi and the water depth hv of the valley multi-layer divided mesh adjacent to the valley multi-layer divided mesh of this valley division number mvi in the previous step (tti-1). And the total flow rate qwv of water (S56), valley intermediate flow layer thickness (upper layer dpv1, lower layer dpv2: S57), valley roughness coefficient nv (S65), valley intermediate flow layer hydraulic conductivity (upper layer kv1) , Lower layer kv2: S66), valley gradient Iv (S67), etc. are read and the water depth hv (valley water surface) of all layers (surface, upper layer, lower layer) of the valley is obtained as shown in FIG. This is stored in the valley flow amount calculation result storage means 360 as the generated flow amount calculation result data rtVi for each valley (S58: see FIG. 22).

    As shown in FIG. 22, the generated water amount calculation result data rtVi for each valley includes the valley number, the valley division number, the water depth hv of the valley of the valley multi-layer divided mesh of this number, and the total flow of water in the valley. qwv and the like are associated. These are made to correspond to the analysis unit time tti of the rainfall data.

In FIG. 21 (a), the water surface at the valley is defined by the flow rate of water flowing out from the slope to the valley within the time range at the valley division number mvi (msx of the slope). The height from the valley intermediate flow lower layer (the valley lower layer bottom surface) to the water surface is determined as the depth hv of all layers.

  The valley water depth hv is obtained as follows.

(Calculation of valley depth)
The basic equation for calculating the valley water depth is the following equation.

The valley water depth is calculated from the following formula using the Lax-Wendroff method.

Here, hv is the depth of the valley and qvs is the flow rate of the valley. The term of F is calculated as follows.

  Where, Iv: valley gradient, nv: Manning roughness coefficient in the valley, dpv1: thickness of the valley intermediate flow upper layer (m), dpv2: thickness of the valley intermediate flow lower layer (m), kpv1: valley The hydraulic conductivity of the intermediate upper layer, kpv2: the hydraulic conductivity of the valley intermediate lower layer, and γ: the effective porosity of the soil layer (0.4).

hv (m ± 1/2, n-1) is calculated as follows.

Then, when the water depth hv (water surface) of all the layers of the valley is obtained, the valley intermediate flow layer thickness (upper layer dpv1, lower layer dpv2: S57) is read (S59), and it is determined in which layer the flowing water is generated. (S60).

  This determination process is shown in FIG.

FIG. 23 (a) shows a case where running water is generated in the valley middle intermediate flow layer, FIG. 23 (b) shows that flowing water is generated in the upper and lower valley portion intermediate flow, and FIG. 23 (c) is the ground surface. (Valley bottom), it is determined that running water is generated in the valley intermediate flow upper layer and the lower layer.

And in step S60, when it determines with a flowing water only generating in a valley | lower part middle downstream, the depth hv2 of only the intermediate downstream is calculated | required (S61).

In Step S60, when it is determined that flowing water is generated only in the valley intermediate flow upper layer and the lower layer, the depth hv1 (hv1 = h-dpv2) of the valley intermediate flow upper layer and the depth hv2 (hv2 = only in the lower layer). dpv2) is obtained (S62).

Furthermore, in step S60, when it is determined that flowing water is generated only in the surface flow (valley bottom) and the valley intermediate flow upper and lower layers, the depth hvo0 (hv0 = hv-dpv1-) of the surface flow (valley bottom). dpv2), the depth hv1 (hv1 = dpv1) of the valley intermediate flow upper layer, and the depth hv2 (hv2 = dpv2) of only the lower layer are obtained (S63).

  Then, the water depth generated in each valley is related to the valley depth iv, the analysis unit time tti, etc., with the water depth (surface flow depth hv0, intermediate flow upper layer depth hv1 and lower layer depth hv2). It memorize | stores and memorize | stores in the memory | storage means 360 for trough part water quantity calculation results as quantity calculation result data rtVi (refer FIG. 22: S64).

  Next, as shown in FIG. 20, the valley water flow amount analysis unit 220b reads the valley roughness coefficient nv (S77), valley intermediate flow layer hydraulic conductivity (S78), valley gradient Iv (S79), and the like. Then, the trough outflow flow rate qwv is obtained (S70).

  The valley outflow rate qwv is preferably obtained as follows.

(Calculation of trough flow)
The trough flow rate is calculated by the following equation based on the water depth generated in each layer.

Where nv: roughness coefficient of manning on the slope, Iv: slope slope, kpv1: permeability coefficient of the upper slope layer, kpv2: permeability coefficient of the lower slope layer, γ: effective porosity of the soil layer (0.4)
Next, as shown in FIG. 20), the valley water flow analysis unit 220b associates the flow rate (qwv) of these valleys with the valley number, valley division number mvi, analysis unit time tti, etc. The generated flow quantity calculation result data rtVBi is output to the river channel (S71), and the river channel flow is calculated (S80). Then, it is determined whether or not the process is finished. If not finished, the process returns to step 54 in FIG. 19 (S81).

The flow rate of each river channel cross section in the river channel analysis section is the outflow amount of each valley that exists upstream.

  Calculated as the total value of

(Sediment runoff analysis department)
Next, the processing of the sediment runoff analysis unit (sediment runoff calculation model) will be described with reference to the flowchart of FIG.

The slope sediment flow analysis unit 230a of the sediment discharge analysis unit 230 reads the set valley number iv (S92).

Next, the slope division multilayer model of this valley number iv is read (S95).

Next, the initial value VLso of movable earth and sand VLso (S96) and the initial value of particle size distribution fsi (j) and (S94) included in the basic information for generated flow rate analysis in the basic information database 320 are read, and the slope Sediment conditions are set (S97).

  This setting is shown in FIG.

  FIG. 26 (b) shows the setting of the initial value of the particle size distribution of the earth and sand on the slope, and FIG. 26 (c) shows the initial value of the movable earth and sand amount. FIG. 26A shows that these initial values are set for each division width of the surface layer portion of the slope division multilayer model.

  In other words, it indicates that the slope sediment conditions were set in the surface layer of the slope division multilayer model (hereinafter referred to as the slope sediment movement model).

This setting calculates the change in the amount of earth and sand that can be moved according to particle size and the amount of earth and sand movement (the amount of sand flow) in each of the same divisions as the generated water amount analysis unit.

  As shown in FIG. 26, the initial value VLS0 (m) of the movable sediment having the total particle size is given as the initial value, and the initial value fsi (j) of the particle size distribution of the slope is given. Is multiplied by fsi (j) to set the initial value of movable sediment VLS (m, j) for each particle size.

Next, it is determined whether or not the slope flow analysis calculation result data rtSBi for each block under the slope is stored in the memory 350 (S98).

If it is stored, the slope flow calculation result data rtSBi for each block under the slope is set from the top (S99).

Then, the slope surface flow rate qws0 and (S101), the slope surface propulsion hs0 and (S100), the slope roughness coefficient ns and (S103), the slope gradient of the set slope flow calculation result data rtSBi under the slope block. Reading Is and (S102), and reading the amount of slope-movable earth and sand (residual VLs) of the adjacent slope division blocks one step before (tti-1) (S105), this slope division block The amount of sloped sand qLS is calculated (S94).

This calculation is performed as follows.

(Calculation of sloping sand flow)
The amount of sloping sand flow is calculated for each division shown in FIG. In addition, the amount of sloping sand flow is calculated for each particle size.

  The amount of sloping sand flow is calculated based on the swept sand volume formula of Kamata / Takahashi / Mizuyama and the suspended sand quantity formula of Kamata / Michi.

First, the following parameters necessary for calculating the amount of sediment are calculated.

The amount of sloping sand flow is calculated as follows using a function ATM that calculates the amount of scavenging sand and a function AMS that calculates the amount of suspended sand.

  Here, w0: settling velocity, ns: manning roughness coefficient on the slope.

  The contents of the function ATM for calculating the amount of sediment and the function AMS for calculating the amount of suspended sand will be described later.

Then, as shown in FIG. 27, the slope sand flow amount is stored in the slope sediment calculation result storage unit 370 as slope block sediment flow rate calculation result data rtSDi as shown in FIG. 27 in association with the valley number iv, slope division number msi, and analysis unit time tti. (S106).

  Then, it is determined whether or not the slope flow rate existing in the set slope division block number msi moves (S107).

  If it is determined that the amount of slope sediment (qLs: slope movement possible amount) of the calculated slope division block number msi is larger than the amount of slope moveable sediment (residual amount) vLs one step before, the slope can be moved one step before. The amount of sand flow (qLs: the amount of slope movement) of the slope division mesh with the slope division number mi is corrected (updated) to the amount of earth and sand (residual amount) vLs (S108).

In addition, when the amount of slope sediment (qLs: slope movement possible amount) of the slope division block number msi is the same as or less than the amount of slope movable earth and sand (residual amount) vLs one step before, step S110 in FIG. Move processing to. In other words, no correction is made.

Next, in step S110, based on the determination result in step S107, the increase parameter of sediment due to weathering or the like stored in the basic information database 320 is read (S109), and the slope movement of the slope division block number msi is possible. The residual amount of earth and sand (vLs) is calculated (S110).

The above determination is performed as follows.

The amount of sediment is corrected on condition that no more sediment than the amount of movable sediment present in each division flows out.

For each division of the set slope, the amount of remaining movable sediment is calculated based on the amount of sediment flowing out and the amount of sediment flowing out from the upper division.

here,

: The amount of sediment that can move on the slope due to weathering, etc. fsi (j): The initial value of the particle size distribution of the sediment on the slope.

Next, as shown in FIG. 25, it is determined whether there is another slope flow calculation result data rtSBi for each block under the slope (S111). Otherwise, the slope flow calculation result data rtSBi for each block under the slope is updated, and the process returns to step S99 in FIG. 24 (S112).

  If it is determined in step S111 that there is no other slope flow calculation result data rtSBi for each block under the slope, qLs at the lower end of the slope is passed to the valley analysis unit (S113). Then, it is determined whether there is an opposing slope (S114). If there is an opposing slope, the slope number Mi is updated, and the process returns to step S94 in FIG. 24 (S115).

If it is determined that there is no opposing slope, it is determined whether the valley number is the last (S116), and if it is not the last, the valley number is updated and the process proceeds to step S92 of FIG. 24 (S117).

The amount of sediment flowing into the valley is the amount of sediment at the lower end of the slope (point at m = msx).

Shall flow out.

  Next, valley part earth and sand movement is demonstrated below using the flowchart of FIG.

  The valley sediment flow analysis unit 230b of the sediment discharge analysis unit 230 reads the valley number iv of the valley model storage means 340 (S120), and reads this valley division multilayer model (S121).

And the movable sediment amount initial value vLv0 and the particle size distribution initial value fvi (i), which are parameters for analyzing the debris flow included in the various valley parameters of the basic information for analyzing the generated flow rate of the valley number (S122) Is read and the valley sediment conditions are set for each division width (S123).

  The generation of the valley sediment transport model is shown in FIG.

  FIG. 30 (b) shows a setting table of the roughness distribution initial value of the sediment in the valley, and FIG. 30 (c) shows the initial value of the particle size distribution. FIG. 30A shows the initial values set in the valley division multilayer model.

In the sediment movement model of the valley, the change in the amount of earth and sand that can be moved according to the particle size and the amount of sediment movement (the amount of sediment flow) are calculated in each of the same divisions as the valley.

    As the initial value, as shown in FIG. 30 (a), the initial value VLS0 (m) of the movable earth and sand with the total particle size is given, and the initial value fsi (j) of the grain size distribution of the slope is given. Multiply VLS0 (m) by fsi (j) to set the initial value of movable sediment VLS (m, j) for each particle size.

  Next, as shown in FIG. 28, it is determined whether or not the slope block-by-slope block sediment flow rate calculation result data rtSDi is input at the analysis unit time tti (rpi) (S124).

  When it is determined in step S124 that the slope block-by-slope block sediment flow rate calculation result data rtSDi is input, the record number of the slope block-by-slope block sediment flow rate calculation result data rtSDi is set (S125).

Then, the adhesive force of the slope is read (S126), and the water depth hs0 of the valley surface flow based on the set slope block sediment flow rate calculation result data rtSDi (S129), the valley slope and (S131) are read. The occurrence of debris flow is determined (S128).

This determination is made under the following conditions.

(Judgment of debris flow occurrence)
Debris flow generation is determined by the following equation based on the surface water depth hv0 of the valley.

Where, Iv: valley slope, C *: sediment density, σ: gravel density, ρ: water density, hv0: surface flow depth in the valley, dm: average grain size in the valley, φ: internal friction Corner

And when the determination result of step S128 determines that no debris flow occurs, the water depth hv0 (S129) of the valley surface flow based on the slope block sediment flow rate calculation result data rtSDi, and the flow rate qwv0 of the valley surface flow (S130), valley gradient Iv and (S131), valley portion probability coefficient nv and (S132) are read, and the amount of sediment movable sediment (residual amount) one step before (tti-1) is read (S136), the amount of valley sediment flow when debris flow does not occur is calculated (S133).

When the debris flow does not occur,
The amount of trough sediment is calculated for each division. In addition, the amount of sediment flowing in the valley is calculated for each particle size.

  If no debris flow occurs, the amount of sediment flowing in the valley is calculated based on the sand flow equation of Kamata / Takahashi / Mizuyama and the floating sand equation of Kamata / Michi.

First, the following parameters necessary for calculating the amount of sediment are calculated.

When the debris flow does not occur, the valley sediment flow rate is calculated as follows using the function ATM for calculating the amount of scavenging sand and the function AMS for calculating the amount of suspended sand.

  Here, qLv: valley sediment flow rate, w0: sedimentation velocity, nv: roughness coefficient of Manning in the valley.

  The contents of the function AMB for calculating the amount of sediment and the function AMS for calculating the amount of suspended sand will be described later.

If the determination result in step S128 indicates that debris flow has occurred, the valley slope (S131), the valley surface flow qwv0 and (S130) are read, and the valley one step before (tti-1) The upper and lower valley moveable sediment volume (residual amount) adjacent to the division number mvi is read (S136), the valley flow rate in the case of debris flow generation is calculated (S134), and this result is calculated for each valley sediment flow rate. The result data rtVDi is stored in the valley section sediment flow calculation result storage means 380 (S135: see FIG. 31).

Calculation of the trough flow rate in the case of this debris flow generation is performed as follows.

  The amount of trough sediment is calculated for each division. In addition, the amount of sediment flowing in the valley is calculated for each particle size.

  The amount of sediment flowing in the valley when debris flow occurs is calculated using the debris flow sediment concentration formula of Takahashi.

First, the following parameters necessary for calculating the amount of sediment are calculated.

  Here, σ: density of soil particles, ρ: density of water, φ: internal friction angle.

Then, as shown in FIG. 29, the amount of discharged sediment is determined (S141; it is determined whether or not the slope flow rate existing in the valley division number moves).

  If the trough flowing sand amount (qLv: trough movable amount) of the trough divided multilayer mesh of the trough division number mvi calculated in step S141 is larger than the trough movable soil amount (residual amount) vLv one step before If determined, the trough moving sand amount (qLv: trough movable amount) of the trough division number mvi is corrected (updated) to the trough movable soil amount (residual amount) vLv one step before. (S142). In addition, the trough flowing sand amount (qLv: trough moveable amount) of the trough division mesh of the calculated trough division number mvi is equal to or less than the trough movable soil amount (residual portion) vLv one step before. If not, do not make corrections.

Next, based on the determination result of step S141, a residual amount of the slope movable soil amount (vLs) of the slope division number mi is calculated (S143).

The above-described determination of the amount of discharged sediment is performed as follows.

The amount of sediment is corrected on condition that no more sediment than the amount of movable sediment present in each division flows out.

  The residual amount is calculated as follows.

(Calculation of trough residual sediment)
For each division of the set valley, the amount of movable sediment that remains is calculated based on the amount of sediment that flows out and the amount of sediment that flows out from the upper division.

This calculation is based on the sediment runoff from the valley to the river channel. The runoff to the river is the sediment flow at the bottom of the valley (m = mvx).

Shall flow out (see FIG. 32).

Next, this is output as the sediment discharge amount qsv from the valley to the river channel in the analysis unit time tti (S145).

Next, it is determined whether or not there is another sediment flow rate calculation result data rtSDi for each slope block (S146). If there is, the slope block sediment flow rate calculation result data rtSDi is updated, and the process returns to step S125 of FIG. (S147). If not, it is determined whether the valley number is the last (S149). If not, the valley number is updated and the process returns to step S121 in FIG. 28 (S150). The slope block-by-slope sediment flow rate calculation result data rtSDi (bottom end) is assigned in correspondence with the valley number.

That is, according to the configuration of the above embodiment, when it rains in a predetermined area, in a designated time range (for example, from 1 pm on June 1, 24 to 5 pm on June 1, 24), Each unit time (for example, 5 minutes) is further divided into fine time tti, and the total water flow (surface layer, upper layer, lower layer) and generation of soil on the slope for each divided rainfall of this tti. The total amount is sent to the valley, and the flow (water, earth and sand) summed up in the valley is flowing into the river channel.

Therefore, it is possible to accurately calculate the amount of sediment and water generated in the river channel.

  Therefore, it can be predicted to be described below.

  When there is one sabo dam (FIG. 33 (a)), it becomes full of earth and sand after A year), but when there is no sabo dam, the thickness of A in FIG. .

  Further, although three sabo dams are full after B years (FIG. 33B), when there are no three sabo dams, the thickness becomes B in FIG. 34 after B years downstream.

If there are five sabo dams, five sabo dams will be full after C years (FIG. 33 (c)), but after C years, the downstream area will have the thickness C in FIG. For this reason, when there is no dam upstream in the downstream area, as shown in FIG. 34, it can be seen how much sediment is accumulated in the downstream area.

Here, each function will be described.

<< Function to calculate the amount of sand flow >>
The function for calculating the amount of scavenging sand is expressed as follows, with the friction velocity u *, the target particle size d, the target particle size content f, and the average particle size dm as arguments.

  First, the following parameters necessary for calculating the amount of sand flow are calculated.

Limiting tractive force against average particle size: τ * cm
The critical scavenging force with respect to the average particle diameter is calculated as follows based on the Iwagaki equation.

(Sediment amount function)

  Here, s: specific gravity of soil particles in water, g: gravitational acceleration.

Limit tractive force for target particle size: τ * cm
The critical scavenging force for the target particle size is calculated by the following modified Egiazaroff equation.

(Function that calculates the amount of suspended sand)
The function to calculate the amount of suspended sand has friction velocity u *, flow rate q, water depth h, target particle size content f, target particle size settling velocity w0, and Manning roughness coefficient n as arguments. It is expressed as follows.

  Here, κ: Kalman constant, g: gravitational acceleration.

CB is the bottom surface concentration and is calculated by the following formula.

210 Analysis Data Generation Unit 220 Generated Water Volume Analysis Unit 230 Sediment Runoff Analysis Unit 240 River Channel Fluctuation Analysis Unit 220a Slope Flow Rate Analysis Unit 220b Valley Flow Rate Analysis Unit 230a Slope Sediment Flow Rate Analysis Unit 230b Valley Sediment Flow Rate Analysis Unit

Claims (14)

It is obtained by dividing the intermediate flow layer that flows through the ground on the slopes on the left and right of the valley when rain falls in a predetermined area including the valley connected to the river channel into a slope intermediate upstream layer and a slope intermediate downstream layer. The generated outflow prediction simulation method for predicting the flow rate generated in the valley by outputting the calculated result to the valley analysis unit,
A rainfall data storage means for storing a divided rainfall obtained by dividing the rainfall data per unit time in the predetermined area by a finer analysis unit time;
Based on the generated flow analysis basic information including the slope length of the left and right slopes, the valley length of the valley, the thickness of the right and left slope middle upstream layer, the thickness of the right and left slope middle downstream layer, and the slope slope of the left and right A slope model storage means in which left and right slope multilayer models sandwiching a valley are stored in association with the valley number (iv);
Slope parameter storage means in which various parameters for slopes on the left and right slopes for analyzing the amount of water flowing on the slope and the sediment flow are stored in association with the valley number (iv),
Slope flow calculation result storage means for storing calculation result data for each of the left and right slope division blocks in association with the valley number (iv);
With
Computer
(A1). Converting the left and right slope multilayer model into a slope split multilayer model having a slope split block that is split from the surface to the bottom surface of the intermediate flow layer with a constant split width;
(A2). Defining the divided rainfall for each analysis unit time in each slope division block of the slope division multilayer model;
(A3). Means for setting the left or right slope of the slope division multilayer model, and for each setting, sequentially setting the slope division block from the upper side toward the edge of the valley;
(A4). Each time the slope division block is set, the step of designating adjacent slope division blocks on both sides;
(A5) For each of the designated slope division blocks, the divided rainfall of the slope division block is read, and the both sides of the both sides obtained by the division rainfall of the analysis unit time immediately before the analysis unit time are obtained. The water depth (hs) accumulated from the bottom surface of the slope intermediate flow layer in the slope division block set using the water depth of each slope division block, the total flow rate of each water, the slope gradient, and various parameters for the slope. The desired process;
(A6). Each time the water depth (hs) in the designated slope dividing block is obtained, the flow rate of water flowing on the surface of the slope in the slope dividing block based on the water depth (hs), the various parameters of the slope, and the slope gradient. (Qws0), a step of obtaining a total flow rate (qws2) of the slope divided block as a total flow rate (qws2) of water flowing through the slope intermediate upstream layer (qws1) and a flow rate of water flowing through the slope intermediate downstream layer (qws2);
(A7). The slope flow calculation result storage unit stores the slope (hs), the total water flow rate (qws), and the analysis unit time in association with the designated slope division block as slope calculation result data for each slope block. Memorizing process;
(A8). Outputting the total water flow rate (qws) of the slope calculation result data for each slope block at the lowest end in the analysis unit time from the slope flow calculation result storage means to the valley analysis unit as the calculation result; A simulation method for predicting a generated outflow amount, which is performed. Computer
(A9). Defining a parameter for analyzing debris flow included in the various parameters for the slope for each of the slope division blocks;
(A10). Parameters for analyzing the water depth (hs), total water flow rate (qws), and debris flow in the slope divided block, and the both sides obtained by the divided rainfall of the analysis unit time one time before the analysis unit time Calculating the amount of slope sediment (qLs) on the basis of the amount of slope-movable earth and sand (VLs), and storing this in association with the slope calculation result data for each slope block of the slope division block;
(A11). The step of outputting the slope sand flow amount (qLs) of the slope calculation result data for each slope block at the lowest end from the slope flow calculation result storage means to the valley analysis unit as the calculation result is performed. Item 3. The generated outflow prediction simulation method according to Item 1. Computer
(B1). Analyzing whether the water surface at the depth (hs) obtained in the step (A5) is present in any one of the surface layer, the intermediate upper layer, or the intermediate lower layer;
(B2). The method according to claim 1 or 2, wherein the step of associating the analysis result with the calculation result data for each slope is performed. Based on the basic information for flow rate analysis including the valley length of the valley, the width of the valley, the thickness of the intermediate flow flowing through the valley bottom, the thickness of the valley intermediate flow upper layer, the thickness of the valley intermediate flow lower layer, and the valley gradient A trough model storage unit that stores a trough multilayer model associated with the trough number as a trough sandwiching the left and right slope multilayer models;
Various parameters for valleys for analyzing the amount of water flowing through the valleys and the sediment flow, parameter storage means for valleys stored in association with valley numbers,
Storage means for trough calculation results in which trough calculation result data is stored;
With
Computer
(C1). A valley division multilayer model having a valley multilayer division mesh divided to the bottom surface of the valley intermediate flow layer at the slope division width; and
(C2). Setting the valley multi-layer divided mesh in order from the most upstream side of the valley division multi-layer model,
(C3). For each of the set valley multi-layer divided mesh, assigning the various parameters for the valley,
(C4). Assigning the total water flow rate (qws) of the slope division block at the lowest end in the output analysis unit time to each of the valley multilayer division meshes instead of the division rain amount;
(C5). For each of the valley division meshes, the both sides of the both sides determined by the total water flow rate (qws) of the water and the total water flow rate (qws) of the lowest end of the analysis unit time one time before the analysis unit time. The total water flow rate of the valley divided mesh, the valley gradient, and the various parameters for the valley are used to determine the water depth (hv) accumulated from the bottom surface of the valley intermediate flow layer in the valley multi-layer divided mesh that has been set. Process,
(C6). Each time the water depth (hv) is obtained, the flow rate (qwv0) of water flowing on the surface of the valley portion in the valley multi-layer divided mesh is read by reading the various parameters of the valley portion and the valley gradient, The total flow rate (qwv) of the water flowing through the set valley multi-layer divided mesh is obtained as the total of the flow rate (qwv1) of the water flowing through the upper part of the middle intermediate flow and the flow rate (qwv2) of the water flowing through the middle intermediate downstream layer. Process,
(C7). The step of storing the water depth (hv) per the valley multi-layer divided mesh, the total flow rate (qwv) of the water, and the analysis unit time in the valley calculation result storage unit as the calculation result data for each valley When,
(C8). And a step of outputting the total flow rate (qwv) of the water of the lowest-valley multi-layer divided mesh in the analysis unit time of the valley calculation result storage means to the river channel analysis unit. The generated outflow amount prediction simulation method according to claim 1, 2 or 3. Computer
(C9). Defining a parameter for analyzing the debris flow included in the various parameters for the valley for each of the valley multi-layer divided mesh;
(C10). The water depth (hv), the total flow rate (qwv) of water and the parameters for analyzing the debris flow in the valley multi-layer divided mesh, and the divided rainfall of the analysis unit time one time before the analysis unit time A step of obtaining a valley portion sand flow amount (qLv) based on the amount of sediment movable sediment (VLv) on both sides, and storing this in association with the calculation result data for each valley portion of the valley multi-layer divided mesh;
(C11). 5. The step of outputting the valley sediment flow rate (qLv) of the calculation result data for each valley at the lowest end from the valley calculation result storage means to the river channel analysis unit is performed. The generated outflow prediction simulation method according to any one of the above. Computer
(D1). A step of analyzing whether the water surface of the water depth (hv) obtained in the step (C5) is present in any one of a surface layer of a valley, an intermediate upstream layer of a valley, or an intermediate downstream layer of a valley;
(D2). The generated outflow prediction simulation method according to any one of claims 1 to 5, wherein a step of associating the analysis result with the calculation result data for each valley is performed. Each time the calculation result data is input from the valley analysis unit, the river channel analysis unit accumulates the valley flow rate (qLv) and the total water flow (qwv) of the valley. And a means for displaying on the screen as a flow rate accumulated in a river channel. It is obtained by dividing the intermediate flow layer that flows through the ground on the slopes on the left and right of the valley when rain falls in a predetermined area including the valley connected to the river channel into a slope intermediate upstream layer and a slope intermediate downstream layer. Output calculation result to the trough analysis unit to predict the flow rate generated in the trough, the generated outflow prediction simulation program,
A rainfall data storage means for storing a divided rainfall obtained by dividing the rainfall data per unit time in the predetermined area by a finer analysis unit time;
Based on the generated flow analysis basic information including the slope length of the left and right slopes, the valley length of the valley, the thickness of the right and left slope middle upstream layer, the thickness of the right and left slope middle downstream layer, and the slope slope of the left and right A slope model storage means in which left and right slope multilayer models sandwiching a valley are stored in association with the valley number (iv);
Slope parameter storage means in which various parameters for slopes on the left and right slopes for analyzing the amount of water flowing on the slope and the sediment flow are stored in association with the valley number (iv),
Slope flow calculation result storage means for storing calculation result data for each of the left and right slope division blocks in association with the valley number (iv);
With
On the computer,
(A1). Means for converting the left and right slope multilayer model into a slope division multilayer model having slope division blocks divided from the surface to the bottom surface of the intermediate flow layer with a constant division width;
(A2). Means for defining the divided rainfall in each slope division block of the slope division multilayer model for each analysis unit time;
(A3). Means for setting the left or right slope of the slope division multilayer model, and for each setting, sequentially setting the slope division block from the upper side toward the edge of the valley;
(A4). Each time the slope division block is set, means for designating adjacent slope division blocks on both sides,
(A5) For each of the designated slope division blocks, the divided rainfall of the slope division block is read, and the both sides of the both sides obtained by the division rainfall of the analysis unit time immediately before the analysis unit time are obtained. The water depth (hs) accumulated from the bottom surface of the slope intermediate flow layer in the slope division block set using the water depth of each slope division block, the total flow rate of each water, the slope gradient, and various parameters for the slope. Means to seek,
(A6). Each time the water depth (hs) in the designated slope dividing block is obtained, the flow rate of water flowing on the surface of the slope in the slope dividing block based on the water depth (hs), the various parameters of the slope, and the slope gradient. (Qws0), means for determining the total flow rate (qws) of the water in the slope dividing block, the sum of the flow rate (qws1) of the water flowing through the slope intermediate upstream layer and the flow rate of the water flowing through the slope intermediate downstream layer (qws2),
(A7). The slope flow calculation result storage unit stores the slope (hs), the total water flow rate (qws), and the analysis unit time in association with the designated slope division block as slope calculation result data for each slope block. Means for storing,
(A8). As means for outputting the total flow rate (qws) of the slope calculation result data for each slope block at the lowest end in the analysis unit time from the slope flow calculation result storage means to the valley analysis unit as the calculation result A simulation program for predicting the amount of generated runoff to execute the function. On the computer,
(A9). Means for defining parameters for analyzing debris flow included in the various parameters for the slope for each slope division block,
(A10). Parameters for analyzing the water depth (hs), total water flow rate (qws), and debris flow in the slope divided block, and the both sides obtained by the divided rainfall of the analysis unit time one time before the analysis unit time Means for determining the amount of sludge flowing sand (qLs) based on the amount of landslide movable sediment (VLs), and storing this in association with the slope calculation result data for each slope block of the slope division block;
(A11). Claim for executing a function as means for outputting the slope sand flow amount (qLs) of the slope calculation result data for each slope block at the lowest end from the slope flow calculation result storage means as the calculation result to the valley analysis unit. Item 9. The generated outflow prediction simulation program according to Item 8. On the computer,
(B1). Means for analyzing whether the water surface at the water depth (hs) obtained by the means (A5) is present in any one of the surface layer, the intermediate upstream layer or the intermediate downstream layer;
(B2). 10. The generated outflow prediction simulation program according to claim 8 or 9 for executing a function as means for associating the analysis result with the calculation result data for each slope. Based on the basic information for flow rate analysis including the valley length of the valley, the width of the valley, the thickness of the intermediate flow flowing through the valley bottom, the thickness of the valley intermediate flow upper layer, the thickness of the valley intermediate flow lower layer, and the valley gradient A trough model storage unit that stores a trough multilayer model associated with the trough number as a trough sandwiching the left and right slope multilayer models;
Various parameters for valleys for analyzing the amount of water flowing through the valleys and the sediment flow, parameter storage means for valleys stored in association with valley numbers,
Storage means for trough calculation results in which trough calculation result data is stored;
With
On the computer,
(C1). Means for forming a valley divided multilayer model having a valley multilayer divided mesh divided to the bottom surface of the valley intermediate flow layer at the slope division width;
(C2). Means for sequentially setting the valley multi-layer divided mesh from the most upstream side of the valley division multi-layer model,
(C3). Means for assigning the various parameters for the valleys for each of the set valley multi-layer divided mesh,
(C4). Means for allocating the total water flow rate (qws) of the slope division block at the lowest end in the outputted analysis unit time to each of the valley multi-layer division meshes instead of the division rainfall amount,
(C5). For each of the valley division meshes, the both sides of the both sides determined by the total water flow rate (qws) of the water and the total water flow rate (qws) of the lowest end of the analysis unit time one time before the analysis unit time. The total water flow rate of the valley divided mesh, the valley gradient, and the various parameters for the valley are used to determine the water depth (hv) accumulated from the bottom surface of the valley intermediate flow layer in the valley multi-layer divided mesh that has been set. means,
(C6). Each time the water depth (hv) is obtained, the flow rate (qwv0) of water flowing on the surface of the valley portion in the valley multi-layer divided mesh is read by reading the various parameters of the valley portion and the valley gradient, The total flow rate (qwv) of the water flowing through the set valley multi-layer divided mesh is obtained as the total of the flow rate (qwv1) of the water flowing through the upper part of the middle intermediate flow and the flow rate (qwv2) of the water flowing through the middle intermediate downstream layer. means,
(C7). Means for associating the water depth (hv) per the valley multi-layer divided mesh with the total water flow rate (qwv) and the analysis unit time and storing them in the valley calculation result storage means as the calculation results data for each valley. ,
(C8). For executing the function as means for outputting the total flow rate (qwv) of the water of the bottommost multi-layer divided mesh at the analysis unit time of the valley calculation result storage means to the river channel analysis unit. A program for predicting a generated outflow amount according to any one of claims 8, 9 and 10. On the computer,
(C9). Means for defining parameters for analyzing debris flow included in the various parameters for the valley for each of the valley multi-layer divided mesh,
(C10). The water depth (hv), the total flow rate (qwv) of water and the parameters for analyzing the debris flow in the valley multi-layer divided mesh, and the divided rainfall of the analysis unit time one time before the analysis unit time Means for determining a valley sediment load (qLv) based on the amount of sediment movable sediment (VLv) on both sides, and storing this in association with the calculation result data for each valley of the valley multi-layer divided mesh,
(C11). The function according to claim 8 to 11 for executing a function as means for outputting the valley sediment flow rate (qLv) of the calculation result data for each valley at the lowest end from the valley calculation result storage means to the river channel analysis unit. One of the generated outflow prediction simulation programs. On the computer,
(D1). Means for analyzing whether the water surface of the water depth (hv) obtained by the means (C5) is present in any one of a surface layer of a valley, an intermediate upstream layer of a valley, or an intermediate downstream layer of a valley;
(D2). 13. The generated outflow prediction simulation program according to claim 8, wherein means for associating the analysis result with the calculation result data for each valley is performed. On the computer,
Each time the calculation result data is input from the valley analysis unit, the sum of the accumulated valley flow rate (qLv) and the total water flow rate (qwv) of the valley is defined as the flow rate accumulated in the river channel. The generated outflow prediction simulation program according to any one of claims 8 to 13, for executing a function as means for displaying on a screen.

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