KR20040104007A - Method for Hydrological Modeling Based with GIS - Google Patents

Abstract

PURPOSE: A GIS(Geographic Information System) based floodgate modeling method for managing basin is provided to contribute water resource management and water quality management related to the basin, and offer a more simple and systematic basin management method for a process to execute a model and confirm a modeling result. CONSTITUTION: A project file is generated by databasing entire basin data, small basin data, weather data, input water data, an input water distribution rate, and an actual outflow data needed for a basin water balance analysis(201). A daily or annual basin water balance of each small basin is performed in an operation module by receiving the data included in the project file(202). A daily inflow, a daily irrigation requirement, and a daily basin water balance result file are generated. The results are output by using the GIS(203).

Description

Hydrologic Modeling Based on GIS {Method for Hydrological Modeling Based with GIS}

The present invention relates to a hydrological modeling method, and more specifically, based on the Geographic Information System (GIS), it is simple and systematic in not only watershed management and water quality preservation, but also the process for model execution and the results of model execution. A method of providing watershed management methods.

In Korea, as the existing hydrological modeling method for watershed management, linkage of hydrological models using GIS has recently been attempted, and the BASINS / HSPF model for Kajiyama runoff or the recent point and nonpoint source management has been used.

In Korea, the Agricultural Water Quality Information Management System of the Korea Agricultural Infrastructure Corporation conducts water quality surveys and repair surveys for efficient and systematic water quality management of agricultural waters, and implements a hydrologic model based on the Kajiyama spill formula. Doing.

The comprehensive agricultural water quality information management system can link the pollutant source database with the hydrologic model and water quality model based on the Kajiyama runoff formula, and can support decision making such as a pollutant treatment alternative system suitable for the watershed characteristics. To this end, overall reduction scenarios such as water quality modeling and treatment alternative selection are supported in search, correction and search of pollutant databases.

The BASINS / HSPF model was developed by the US Environmental Protection Agency (EPA) in 1999 to combine the GIS software AreView with the water quality model to manage both point and nonpoint sources in water units. The watershed balance analysis through the program is evaluated by the PWATER model, and the water quality of rivers or lakes by nonpoint sources from the watershed is evaluated using the QUAL2E and NPSM models.

However, in the case of hydrologic models using the comprehensive agricultural water quality management system, watershed characteristics data and rainfall data are inputted into empirical equations to perform watershed analysis, which is insufficient to reflect the complex water supply system in the watershed. However, there are difficulties in elastic application due to the change of water balance element at any point. In addition, the BASINS / HSPF hydrological model is developed for all regions of the United States and is used to analyze hydrologic data in the watershed, but it is designed to be suitable for large watersheds. Somewhat inadequate For this reason, when the above models are applied to the domestic watershed environment, it is difficult to systematically manage the watershed by analyzing the accurate watershed balance.

The present invention has been made to solve the problems of the prior art, the purpose of which contributes to watershed management and water quality conservation through GIS-based hydrological modeling for watershed management, and also processes and models for model execution It provides a simpler and more systematic watershed management method for identifying the results of implementation.

Another object of the present invention is to provide a computer-readable recording medium recording means for implementing the GIS-based hydrological modeling method.

1 is a river network model that is one of the basic components of the hydrological model constituting the present invention (a: upstream point without reservoir, b: upstream point with reservoir, c: upstream point without reservoir, d: midstream point with reservoir )

2 is a flow chart of a watershed balance model that forms an embodiment of the invention.

3 is a flow chart of the basin water balance system

4 is an implementation example of a path setting window displaying a file setting process of model input data according to the present invention;

5 is an embodiment of the module for editing input data according to the present invention

Figure 6 is an output screen showing the hydrological modeling analysis results according to the present invention

In order to achieve the above object, the present invention provides a hydrological model method,

A preprocessing step of generating a project file by databaseting the total watershed data, subwatershed data, meteorological data, tap water inflow data, tap water inflow rate distribution, and measured outflow data required for watershed balance analysis; Receiving the data included in the project file and performing a daily or annual watershed balance for each subwatershed by a predetermined calculation module; And generating a daily inflow, a daily required amount of water, and a daily basin water balance result file obtained as a result of the watershed balance calculation, so that the results can be output using a geographic information system (GIS). Provides a hydrological model method.

In another aspect, the present invention is a pre-processing step of generating a project file by the database of the total watershed data, subwatershed data, meteorological data, distilled water inflow data, distilled water flow rate distribution and actual runoff data required for basin water balance analysis; Receiving the data included in the project file and performing a daily or annual watershed balance for each subwatershed by a predetermined calculation module; And generating a daily inflow, a daily required amount of water, and a daily basin water balance result file obtained as a result of the watershed balance calculation, so that the results can be output using a geographic information system (GIS). To provide a computer-readable recording medium for recording the program.

Figure 1 is a river network model which is one of the basic components of the hydrological model constituting the present invention is classified by the type of water balance element. 2 is a flow chart of a watershed balance model constituting an embodiment of the present invention. 3 is a flow chart of the basin water balance system. Figure 4 is an embodiment included in the pre-processing step for implementing the GIS-based hydrological model method of the present invention, an embodiment of the path setting window for displaying the file setting process of the model input data. 5 is an embodiment included in the preprocessing step for implementing the GIS-based hydrological model method of the present invention, an embodiment of a module for editing each input data. Figure 6 is an embodiment showing the hydrological modeling analysis results according to the present invention, an output screen performed in the GIS-based output form.

Hereinafter, the present invention will be described in detail with reference to the drawings, the basic components for the hydrological model, and the implementation of the hydrologic modeling system for performing the watershed resin using these components.

Basic composition of hydrologic model

Water balance elements at any point in the stream are largely divided into inflow, outflow, and storage elements. In order to have a watershed balance in a river basin, each of these factors must be accurately estimated. Therefore, the basin water balance model is a hydrological model that can estimate the inflow and outflow at any point in the river, and a hydraulic model that can estimate the change of the reservoir by water balance of these results and the water balance over the entire basin. It should be composed of river network model that can be executed sequentially. The details of these water balance elements are as follows.

(1) Inflow component calculation and hydrologic model

The inflow component of the river section consists of the inflow from the upstream basin, the transverse inflow from its own basin, and the return flow of various types of water. The calculation method and their calculation model for each inflow factor are as follows.

end. Upstream Inflow

The inflow from the upstream basin is zero at the top of the stream section, while in other basins it is the overflow or control point outflow calculated from the upstream basin water balance.

I. Self-watershed transverse flow

The transverse flows from the self-water basin are the flows from the tributary stream and from the back basin, which are estimated from the DIROM model developed for the planning, design and management of irrigation reservoirs.

All. Return flow

Various water is required to generate a regression amount, and the regression amount may show a difference in time depending on the water use method. Therefore, in this model, the delay time is considered and the regression rate is calculated as follows.

Where R _i = regression quantity, Fj = regression rate by water purpose, D _i = water intake by purpose, j = subscript representing water purpose.

(2) Estimation of Supply Quantity and Hydrologic Model

Supply factors can be classified into agricultural water, domestic water, industrial water, livestock water, and environmental water. Environmental water is a stream maintenance index concept, which is to discharge shortages in reservoirs when the flow rate of rivers is less than natural water flow due to the installation of reservoirs, etc., within the river sections.

end. Agricultural water

Agricultural water refers to irrigation water that artificially supplies the arable land for the purpose of producing crops. Accurate estimation of the required time and quantity is very important in the development of water development and management plan. The required quantity of water (REQP _(t) ) can be expressed by the following equation.

here,ET _p = tPotential evaporation of work (mm), K _c = Crop factor of rice,I= Osmolality (mm / day),R _e = Effective rainfall (mm)

I. Living water

Household water is usually estimated by the daily consumption and the number of people to be watered. It is a common phenomenon to increase with the improvement of living standards. In addition, the amount of water for daily use changes seasonally, but the change in the amount of water for each time zone is adjusted in the water tank.

Where REQR = required water for living water (㎥ / day), ARQR = average water supply per person (ℓ / 인 · 일), N _p = number of people subject to water supply (person).

All. Industrial water

Industrial water is water needed for the production of the product and the operation of its auxiliary facilities. The calculation of the required quantity is based on the unit-by-unit estimation method per ton of product, the number of employees or the plant site area. Estimation of water volume per product weight takes into account changes in industrial activities over time, but estimates based on plant area by industry are generally used due to uncertainties about changes. Determination of the required quantity of industrial water is as follows.

Here, REQI = required amount of industrial water (m 3 / day), A = plant area by industry (1000 m 2), ARQI = required amount of daily unit per unit (m 3/1000 m 2 / day).

la. Livestock Water

Livestock water differs depending on the type of livestock, the number of heads of cattle, livestock facilities and management methods. In the water balance model according to the present invention, the value determined by multiplying the number of heads by the daily standard quantity for each type of livestock was inputted quantitatively, and the quality of the reduced water was not considered. In other words, the required quantity of livestock water for each livestock is determined as follows.

Where REQL = required quantity per animal (㎥ / day), ARQ = consumption per head (ℓ / day / head), N = number of cattle.

(3) storage calculation model

The amount of storage in rivers can be classified into the amount of storage in dams and reservoirs, the amount of storage in beams, and the amount of storage in rivers. However, reservoirs at beams and underpasses are negligible because daily changes are not so large. Therefore, the storage of the river section is to consider the change of the storage of the reservoir, etc., and if the storage in the Bona sewer is large, it is assumed that the reservoir can be treated. The change of daily storage by the water balance of the reservoir can be obtained by the following equation.

Where Δ S = change in reservoir, Qin = reservoir inflow, R = rainfall in reservoir area, OVF = discharge from sediment or hydrology of reservoir, DV = intake or clearance discharge, LSS = amount of water evaporation, infiltration as loss Etc.

(4) river network model

The shape of the water balance element for any point of the river can be divided into four types: upstream without reservoir, upstream with reservoir, upstream without reservoir, and upstream with reservoir. The water balance element at the upstream point without reservoir consists of the inflow and outflow of the self-watershed by rainfall, the supply or return of various waters, the inflow and outflow and other losses (see Fig. 1A). The water balance element upstream of the reservoir is added to the water balance element upstream without the reservoir and the amount of evaporation, generation discharge, and penetration of the reservoir (FIG. 1b). The water balance element of the upstream point without the reservoir is the same as the upstream water balance element without the reservoir, with the inflow from the upstream point added (FIG. 1C). The water balance element of the reservoir upstream is composed of upstream inflow, self-discharge, regression, evaporation, tap water outflow, etc. in the form of a mixture of upstream with reservoir and upstream with no reservoir (FIG. 1D).

Implementation of Hydrologic Modeling System

(1) basic algorithm

Referring to Figure 2, the execution of the watershed balance model can be achieved by inputting data (step 201), calculating the inflow and outflow for each subwatershed (step 202), and outputting the water balance and the result (step 203). .

The design of the input and output constituting the basic algorithm and the implementation of the system will be described in more detail below through separate items.

(2) I / O design

end. Input design

The input data for the watershed balance are largely classified into six categories: total watershed data, subwatershed data, meteorological data, distillate inflow data, distillate inflow distribution, and measured runoff data. Total watershed data includes items commonly applied to each subwatershed, control of simulation, output control, etc. (Table 1 below illustrates a database for total watershed data).

TABLE 1

Field name Data type Digit Contents PRO_NAME text 10 PROJECT people LOCATE text 10 location PERIOD text 12 Between calculators SEG_WATER essence 3 Number of subwatersheds OBSERV essence 3 Number of jurisdictions INPUT_NUM essence 3 Frequency inflow data VAPOR_NUM mistake 15,1 Basin Evaporation Factor YOUNGSU mistake 15,1 Yiang water MAX_DEEP mistake 15,1 Maximum allowable freshwater depth MIN_DEEP mistake 15,1 Minimum allowable freshwater depth MIN_BANG mistake 15,1 Discharge VAPOR_CO mistake 15,1 Pan evaporation coefficient MONVAPOR_C mistake 15,1 Monthly Evaporation Factor JACK_DAY text 10 Cultivation JACK_CO1 mistake 15,1 Crop coefficients (early) ACK_CO2 mistake 15,1 Crop Factor (Mid) JACK_CO3 mistake 15,1 Crop Factor (Late) DAY_SIMU essence 2 Daily Inflow Simulation RESULT_OUT essence 2 Inflow Result Output INPUT_UNIT essence 2 Daily Inflow Unit NEED_SIMU essence 2 Irrigation Water Required Simulation NEED_OUPUT essence 2 Output required amount of irrigation water DAYWAT_SIM essence 2 Daily Water Balance Simulation DAYWAT_OUT essence 2 Daily water balance output CON_WATHEI mistake 15,1 Confirmed water level in frequency analysis OUTPUT_STA essence 5 Water balance result print start year OUTPUT_END essence 5 Water balance result output end year

Subwatershed data includes data identifying watershed characteristics of subwatersheds (Table 2 below illustrates a database for subwatershed data).

TABLE 2

Field name Data type Digit Contents CP_NAME text 20 Subwater number and branch name LOWER_NUM text 10 Number of downstream basins IN_LOCATE essence 3 Location in the watershed SHED_OUT essence 3 Output of subwatershed LIM_HEG mistake 10,1 Current limit of the reservoir LINK_NUM essence 5 Subwatershed Number of the Reservoir SUP_HEG mistake 10,1 Supply level difference TOT_AREA mistake 20,1 Subwatershed area NON_AREA mistake 20,1 Paddy area BAT_AREA mistake 20,1 Field area FOR_AREA mistake 20,1 Forest area DELAY_TIME mistake 10,1 Delay WATLINE_LO mistake 20,1 Channel loss ETC_LOSS mistake 20,1 Other loss NEED_WAT mistake 20,1 Quantity required RECUR_WAT mistake 20,1 Regression Quantity RECUR_RATE mistake 20,1 Monthly regression rate MONAVG_INP mistake 20,1 Monthly average frequency inflow INDIR_CONT essence 3 Breakdown of indirect watershed RESERVOIR text 20 Reservoir name HEIGHT_CON essence 5 Shiitake TOT_VOLUM mistake 10,1 Total water MAX_HEIGH mistake 10,1 Water level EFF_VOLUM mistake 10,1 Effective storage MIN_HEIGH mistake 10,1 Shooter MIN_VOLUM mistake 10,1 Quantity of shooter SUPPLY_CON mistake 10,1 Irrigation Water Conditions at Low Yields SUP_RATE mistake 10,1 Irrigation Water Supply Rate HEIGHT mistake 20,1 Elevation AREA mistake 20,2 area TOT_INVOL essence 20,2 Luke Content

Meteorological data includes data required for the calculation of inflows and outflows in subwatersheds (Table 3 below illustrates a database for meteorological data).

TABLE 3

Field name Data type Digit Contents STAT_NAME text 20 Posterior side calling N_STAT essence 10 Rear and rear minor number AL_AT mistake 10,1 Latitude ELEVAT mistake 10,1 Height above sea level HE_WIND mistake 10,1 Anemometer height ST_CODE text 20 Weather data code YEAR text 10 year DAY_1 mistake 10,1 Daily weather data1 DAY_2 mistake 10,1 Daily weather data2 DAY_3 mistake 10,1 Daily weather data3 DAY_4 mistake 10,1 Daily weather data4 DAY_5 mistake 10,1 Daily weather data5 DAY_6 mistake 10,1 Daily weather data6 DAY_7 mistake 10,1 Daily weather data7 DAY_8 mistake 10,1 Daily weather data8 DAY_9 mistake 10,1 Daily weather data9 DAY_10 mistake 10,1 Daily weather data10 DAY_11 mistake 10,1 Daily Weather 11

The frequency inflow data includes data for inputting inflows for each subwatershed from another basin (Table 4 below illustrates a database for frequency inflow data).

TABLE 4

Field name Data type Digit Contents DIN_NUM essence 10 Number of inflow data RE_FAL mistake 10,1 Limited rainfall DV_NAME text 20 Supply facility name YEAR text 10 year D_IM1 mistake 10,1 Monthly Average Frequency Inflows by Year1 D_IM2 mistake 10,1 Monthly average frequency inflow by year2 D_IM3 mistake 10,1 Monthly Average Frequency Inflows by Year3 D_IM4 mistake 10,1 Average Monthly Inflows by Year4 D_IM5 mistake 10,1 Monthly average frequency inflow by year5 D_IM6 mistake 10,1 Average Monthly Inflows by Year6 D_IM7 mistake 10,1 Average Monthly Inflows by Year7 D_IM8 mistake 10,1 Average Monthly Inflows by Year8 D_IM9 mistake 10,1 Average Monthly Inflows by Year9 D_IM10 mistake 10,1 Monthly Average Frequency Inflows by Year10 D_IM11 mistake 10,1 Monthly Average Frequency Inflows by Year11 D_IM12 mistake 10,1 Monthly Average Frequency Inflows by Year12

The frequency inflow data includes data for entering the frequency of water inflow by subwatershed to be distributed (Table 5 below illustrates a database for frequency inflow data).

TABLE 5

Field name Data type Digit Contents SYD text 10 Start year EYD text 10 End year W_CP essence 5 Number of subwatersheds to distribute D_NAME text 20 Supply facility name IN_NUM essence 5 Incoming subwatershed number IN_NAME text 10 Influent Subwater Name M_RATE1 mistake 10,1 Monthly Distribution Rate1 M_RATE2 mistake 10,1 Monthly Distribution Rate2 M_RATE3 mistake 10,1 Monthly Distribution Rate3 M_RATE4 mistake 10,1 Monthly Distribution Rate4 M_RATE5 mistake 10,1 Monthly Distribution Rate5 M_RATE6 mistake 10,1 Monthly Distribution Rate6 M_RATE7 mistake 10,1 Monthly Distribution Rate7 M_RATE8 mistake 10,1 Monthly Distribution Rate8 M_RATE9 mistake 10,1 Monthly Distribution Rate9 M_RATE10 mistake 10,1 Monthly Distribution Rate10 M_RATE11 mistake 10,1 Monthly Distribution Rate11 M_RATE12 mistake 10,1 Monthly Distribution Rate12

Measured runoff data includes data input for model calibration and testing (Table 6 below illustrates a database for frequency inflow data).

TABLE 6

Field name Data type Digit Contents OB_CPNUM essence 5 Subwatershed Number of Actual Data SYD text 10 Start year EYD text 10 End year CP_NAME text 10 Subwatershed OB_RESOR mistake 10,1 Actual water storage OB_OUTFLOW mistake 10,1 Actual flow rate

I. Output design

The watershed balance model outputs inflows, outflows, and water balance results by subwatershed; these results are output daily, monthly, and yearly by subwatershed, and, if necessary, summarize water balance results. The output design for the watershed balance analysis results is illustrated in Table 7 below.

TABLE 7

division The details Required irrigation quantity (Penman type) ◎ Input data of the whole watershed ◎ Input data by subwatershed ◎ Output year, unit ◎ Consumption quantity, rainfall, effective rainfall, net quantity, quiet quantity, irrigation quantity Daily Basin Water Balance ◎ Input data of total watershed ◎ Input data by subwatershed ◎ Monthly average frequency inflow data by year ◎ Monthly distribution rate of frequency inflow of subwatershed ◎ Output year, unit <summary> , Low yield <All output items> ◎ Rainfall ◎ Inflow: Upstream inflow, self inflow, tap water inflow, agricultural return, fresh water return, other inflows ◎ Supply: tap water flow, agricultural water, evaporation, fresh water and other runoff ◎ WATER-BALANCE, CP outflow, consolidation supply ◎ Required water level, water level, low yield, low water <Frequency analysis> ◎ Subwatershed name, jurisdiction ◎ Required water level, required water level and 10% SEDIMENT water level: GUMBEL, GUMBEL CHOW, NORMAL DISTRIBUTION Daily runoff (DIROM) ◎ PROJECT name, location ◎ Number of subwatershed, subwatershed name, jurisdiction ◎ Basin area, rice field ratio, field ratio, mountain ratio, delay time ◎ Parameters of one, two, three steps TANK ◎ Output year, unit ◎ , Monthly runoff ◎ Area of CP site, accumulated annual rainfall and runoff

(3) system implementation

end. Specific flow chart of the system

Referring to FIG. 3, the system flow of the watershed balance model calculates daily inflows and outflows and watershed balances by subwatershed by step 302, which is a daily routine from the input of total watershed and subwatershed data (see process group 301). When the one-year calculation is completed by performing 303, which is a monthly routine, a water balance result is output (304) according to whether the output is performed for each point. In this order, the routine routine 305 repeats the entire calculator on an annual basis, and when the calculation of the entire period is completed (determined in step 306), frequency analysis is performed and the process ends (step 307).

At this time, the runoff of the own watershed due to rainfall by subwatershed is preferably using the DIROM model, and the required amount of the relationship is estimated using the Penman equation.

I. Execution of the program

The specific execution step of the hydrological modeling system as described above may include an input data preprocessing step of processing data into a form suitable for processing by a predetermined program based on a GIS, and a predetermined program targeting an input file that has undergone the preprocessing step. A model execution step of performing a water balance by the calculation process using a, and a post-processing step of processing the results obtained by the model execution as GIS-based output data.

This hydrologic modeling system can remove the complexity of the existing DOS-based modeling, so that the systematic water resources can be secured and managed in the watershed, which can bring about an improved effect on water quality management of the watershed.

① Pretreatment Step

The input file generation process required for the watershed balance modeling is automated by software means, and provides a more convenient environment when the user performs modeling. The input data required for the water balance is not particularly limited, but, for example, a project file superfile may be used to provide convenience in executing the model.

Referring to FIG. 4, a file setting process of the model input data is shown. As an example, a project named SEMAN.WPR is included in the data folder included in the watershed model, which is a subfolder in the Saemangeum folder, from the input data path window 40. The input data list window 41 shows that the file is included. The project file includes the WATSH.DBF data file including the entire watershed data, the SUBWAT.DBF data file including the subwatershed data, and the SJJ.DBF, SGS.DBF, SJE.DBF, SBA.DBF data file including the weather data. , SJMON1.DBF data file containing frequency flow rate data and RATE.DBF containing frequency flow rate distribution data. (However, the specific name of the file is arbitrarily selected for convenience of understanding. It is not implied by any one of ordinary skill in the art as a name or initials representing the characteristics of the material.)

The creation and editing of hydrologic model inputs takes into account the user interface and allows the module to more easily process the elements necessary for model execution. An example of the execution of such an input data editing module is shown in FIG.

② Modeling Execution Stage

The modeling control elements (data) inputted in the step of executing the actual model perform the daily or annual watershed balance for each subwatershed and output the corresponding water balance results. Factors controlling the execution of the modeling are: between the calculator, whether the daily runoff is simulated, output and unit, whether the required amount of simulation and output, the fixed water level during frequency analysis, whether the simulation and output of the daily basin water balance, the output of the results Includes start and end year, etc. Specifically, a modeling execution process uses a predetermined program executable by a computer, and specific examples of algorithms performed by the program include the process of FIG. 3 described above.

③ Post-processing step

After modeling, the result file may be implemented as, for example, a file such as TANK.TXT, IRREQ.TXT, WBAL.TXT. The TANK.TXT file records the daily inflow results calculated by the TANK model, and the IRREQ.TXT file records the daily relationship required quantity results calculated by the Penman equation. The WBAL.TXT file records the daily results for the watershed balance. (The specific name of the above file is also arbitrarily written for convenience of understanding.)

In the present invention, a GUI-based analysis system is used to more conveniently utilize the result file for analysis. In order to check the watershed balance results intuitively for each subwatershed, the present invention is fully integrated with the GIS and plotted as graphs and attribute data. Figure 6 shows the figure data, modeling result graph, modeling result attribute data of the watershed for which the model was executed.

Specific embodiments of the present invention can be written as a program executable in a computer system. In addition, the program can be read from a computer readable recording medium having recorded such a program and executed in a general-purpose digital computer system. Such recording media include magnetic storage media (e.g., ROM, floppy disk, hard disk, etc.), optical reading media (e.g., CD-ROM, DVD, etc.) and carrier waves (e.g., transmission over the Internet). Media is included.

So far, the present invention has been described with reference to the preferred embodiment (s). Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

According to the present invention, GIS-based hydrologic modeling for watershed management contributes to watershed-related water resource management and water quality preservation, and provides a simpler and more systematic watershed management method in the process of model execution and the results of model execution. can do.

Claims (4)

In hydrological modeling method, A preprocessing step of generating a project file by databaseting the total watershed data, subwatershed data, meteorological data, tap water inflow data, tap water inflow rate distribution, and measured outflow data required for watershed balance analysis; Receiving the data included in the project file and performing a daily or annual watershed balance for each subwatershed by a predetermined calculation module; And generating a daily inflow, a daily required amount of water, and a daily basin water balance result file obtained as a result of the watershed balance calculation, so that the results can be output using a geographic information system (GIS). How to model a hydrology The hydrological model method according to claim 1, wherein the daily inflow is calculated by a tank model. The method of claim 1, wherein the daily necessary quantity is calculated by Penman's equation. In a computer-readable recording medium recording a program for performing hydrological modeling, A preprocessing step of generating a project file by databaseting the total watershed data, subwatershed data, meteorological data, tap water inflow data, tap water inflow rate distribution, and measured outflow data required for watershed balance analysis; Receiving the data included in the project file and performing a daily or annual watershed balance for each subwatershed by a predetermined calculation module; And generating a daily inflow, a daily required amount of water, and a daily basin water balance result file obtained as a result of the watershed balance calculation, so that the results can be output using a geographic information system (GIS). Computer-readable recording media having recorded programs