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WATERSHED-SCALE HYDROLOGIC AND NONPOINT-SOURCE POLLUTION MODELS: REVIEW OF MATHEMATICAL BASES

D. K. Borah, M. Bera

授課老師：林俐玲博士　鄭皆達博士　　　　　陳鴻烈博士　林德貴博士學生姓名：王浩中 89742001

98年度第 1 學期‧博士班專題討論

Report Outlines

INTRODUCTION WATERSHED-SCALE MODEL

DESCRIPTIONS FLOW-GOVERNING EQUATIONS MATHEMATICAL BASES OF THE

WATERSHED MODELS SUMMARY AND CONCLUSIONS

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The Illinois State Water Survey (ISWS) The Illinois State Water Survey (ISWS) is a Division

of the Institute of Natural Resource Sustainability (INRS) of the University of Illinois at Urbana-Champaign (UIUC).

The Water Survey was founded in 1895 as a unit of the University of Illinois Department of Chemistry.

The Water Survey has addressed societal problems concerning air pollution, contaminated drinking water, disintegrating wetlands, and water shortages.

INTRODUCTION

flooding

upland soil and

streambank erosion

contamination

of water

sedimentation

Impaired by sediment and chemicals→Drinking water supplies The drinking water standard of 10 mg/L of

nitrate-nitrogen (nitrate - N) →set to prevent incidence of methemoglobinemia (blue baby syndrome)

The 3 μg/L maximum concentration level (MCL) for atrazine, acommonly used herbicide→require expensive water treatments

Lake Springfield

Lake Decatur

Impaired by sediment and chemicals

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Lake Springfield, and Peoria Lake in Illinois are examples of serious lake sedimentation reducing water supply capacity of the former two, filling the navigation channel of the latter, and adversely affecting recreational opportunities in all.

The Efficacy of Models

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WATERSHED-SCALE MODEL DESCRIPTIONS

AGNPS AnnAGNPS ANSWERS ANSWERS-Continuous CASC2D DWSM

HSPF KINEROS MIKE SHE PRMS SWAT

AGNPS (Young et al., 1987, 1989)Agricultural NonPoint Source pollution model Developed at the USDA-ARS North Central Soil

Conservation Research Laboratory in Morris, Minnesota.

It is an event-based model simulating runoff, sediment, and transport of nitrogen (N), phosphorous (P), and chemical oxygen demand (COD) resulting from single rainfall events.

Version 4.03 of the model (Young et al., 1994) was widely distributed.

AnnAGNPS (Bingner and Theurer, 2001)

(Annualized AGNPS) AnnAGNPS is extensive revisions of AGNPS and upgrading at the USDA-ARS National Sedimentation Laboratory (NSL) in Oxford, Mississippi.

The AnnAGNPS model for continuous simulations of hydrology, soil erosion, and transport of sediment, nutrients, and pesticides.

It is designed to analyze the impact on the environment of nonpoint-source pollutants from predominantly agricultural watersheds.

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ANSWERS (Beasley et al., 1980) Areal Nonpoint Source Watershed Environment Response Simulation Developed at Purdue University in

West Lafayette, Indiana. Uses a distributed parameter concept

to model the spatially varying processes of runoff, infiltration, subsurface drainage, and erosion for single-event storms.

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ANSWERS (Beasley et al., 1980) Areal Nonpoint Source Watershed Environment Response Simulation

The model has two major components: hydrology and upland erosion responses.

The conceptual basis for the hydrologic model was taken from Huggins and Monke (1966) and for the erosion simulation from Foster and Meyer (1972).

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ANSWERS-Continuous (Bouraoui and Dillaha, 1996; Bouraoui et al., 2002) Emerged from ANSWERS as a continuous

model at the Virginia Polytechnic Institute and State University in Blacksburg, Virginia.

The model was expanded with upland nutrient transport and losses based on GLEAMS (Groundwater Loading Effects of

Agricultural Management Systems) (Leonard et al., 1987), EPIC (The Erosion-Productivity Impact

Calculator) (Williams et al.,1984), and others.

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Initially developed at Colorado State University in Fort Collins, Colorado and further modified at the University of Connecticut in Storrs, Connecticut (Ogden, 1998; Ogden and Julien, 2002)

It is a physically based model. It simulates water and sediment in two-dimensional overland grids and one-dimensional channels and has both single-event and long-term continuous simulation capabilities.

CASC2D (Julien and Saghafian, 1991;

Julien et al., 1995) CASCade of planes in 2-Dimensions

MIKE SHE (Refsgaard and Storm, 1995)(Based on European Hydrological System ) Developed by a European consortium of

three organizations: the U.K. Institute of Hydrology, the French consulting firm SOGREAH, and the Danish Hydraulic Institute.

It’s a comprehensive, distributed, and physically based model simulating water, sediment, and water quality parameters in two-dimensional overland grids, one-dimensional channels, and one-dimensional unsaturated and three-dimensional saturated flow layers.

It also has both continuous long-term and single-event simulation capabilities.

DWSM (Borah et al., 2002b) Dynamic Watershed Simulation Model DWSM was put together at the Illinois State

Water Survey (ISWS) in Champaign, Illinois. DWSM simulates distributed surface and

subsurface storm water runoff, propagation of flood waves, upland soil and streambed erosion, sediment transport, and agrochemical transport in agricultural and rural watersheds during single rainfall events.

KINEROS (Woolhiser et al., 1990;Smith et al., 1995)

KINematic runoff and EROSion model Which evolved during the 1960s to the

1980s at the USDA-ARS in Fort Collins, Colorado

KINEROS is an event oriented, physically based model describing the processes of interception, infiltration, surface runoff and erosion from small agricultural and urban watersheds.

It is a distributed rainfall-runoff and soil erosion-sediment transport model for single rainfall events.

HSPF (Johanson et al., 1980) Hydrological Simulation Program – Fortran First publicly released in 1980, was put

together by a group of consultants under contract with the U.S. Environmental Protection Agency (USEPA).

It is a continuous watershed simulation model that produces a time history of water quantity and quality at any point in a watershed.

HSPF is an extension of several previously developed models.

PRMS (Leavesley et al., 1983, Leavesley and Stannard, 1995)

Precipitation-Runoff Modeling System Developed at the USGS in Lakewood,

Colorado. A modular design, distributed-parameter,

physical-process watershed model. PRMS was developed to evaluate the

effects of various combinations of precipitation, climate, and land use on watershed response.

PRMS (Leavesley et al., 1983, Leavesley and Stannard, 1995)

Precipitation-Runoff Modeling System Watershed response to normal and

extreme rainfall and snowmelt can be simulated to evaluate changes in water-balance relations, flow regimes, flood peaks and volumes, soil-water relations, sediment yields,and groundwater recharge.

PRMS has both long-term and single-storm modes.

20Rosita, Colorado, USGS Photo, 1880-1890

SWAT (Arnold et al., 1998; Neitsch et al.,

2002), Soil and Water Assessment Tool Developed at the USDA-ARS Grassland,

Soil, and Water Research Laboratory inTemple, Texas.

Assist water resources managers in predicting and assessing the impact of management on water, sediment, and agricultural chemical yields in large ungauged watersheds or river basins.

SWAT (Arnold et al., 1998; Neitsch et al.,

2002), Soil and Water Assessment Tool The model is intended for long-term yield

prediction sand is not capable of detailed single-event flood routing.

It is an operational or conceptual model that operates on a daily time step.

The model has eight major components: hydrology, weather, sedimentation, soil temperature, crop growth, nutrients, pesticides, and agricultural management.

FLOW-GOVERNING EQUATIONS

DYNAMIC WAVE EQUATIONS

DIFFUSIVE WAVE EQUATIONS

FLOW-GOVERNING EQUATIONS

MANNING’S FORMULA KINEMATIC WAVE EQUATIONS

FLOW-GOVERNING EQUATIONS

STORAGE-BASED OR NONLINEAR RESERVOIR EQUATIONS

CURVE NUMBER AND EMPIRICAL EQUATIONS

LONG-TERM CONTINUOUS AND SHORT-TERM STORM EVENT MODELS

Useful for analyzing long-term effects of hydrological changes and watershed management practices, especially agricultural practices.

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SWATSWAT

LONG-TERM CONTINUOUS AND SHORT-TERM STORM EVENT MODELS

land usessimulate single-event storms

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Due to its use of daily time steps

LONG-TERM CONTINUOUS AND SHORT-TERM STORM EVENT MODELS

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Not adequately formulated to simulate intense single -event storms

AGNPS, ANSWERS,DWSM, KINEROS, and PRMS Storm Mode

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CASC2D and MIKE SHE

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MODEL ALGORITHMS AND EFFICIENCIES

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CASC2D and MIKE SHE would be suitable for …

MODEL ALGORITHMS AND EFFICIENCIES

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ANSWERS, KINEROS, and PRMS Storm Mode models would be suitable for …

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MODEL ALGORITHMS AND EFFICIENCIES

Due to its robust closed-form solutions and algorithms, DWSM could potentially be used for large watersheds.

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AnnAGNPS, ANSWERS-

Continuous, HSPF, MIKE SHE, and SWAT

FULLY DEVELOPED CONTINUOUS MODELS

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FULLY DEVELOPED CONTINUOUS MODELS (land use)

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FULLY DEVELOPED CONTINUOUS MODELS ANSWERS-Continuous does not have channel

erosion and sediment transport routines, and therefore the sediment and chemical components are not applicable to watersheds.

Due to the computationally intensive numerical schemes, MIKE SHE may become prohibitive for long-term continuous simulations in medium to large-sized watersheds.

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AGNPS, DWSM, and MIKE SHE

FULLY DEVELOPED STORM EVENT MODELS

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FULLY DEVELOPED STORM EVENT MODELS … DWSM

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FULLY DEVELOPED STORM EVENT MODELS

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SUMMARY AND CONCLUSIONS

AnnAGNPS, ANSWERS-Continuous, HSPF, and SWAT → continuous simulation models →especially agricultural practices.

AGNPS, ANSWERS, DWSM, and KINEROS → single rainfall event models →useful for analyzing severe actual or design single-event storms and evaluating watershed management practices, especially structural practices.

SUMMARY AND CONCLUSIONS

CASC2D, MIKE SHE, and PRMS have both long-term and single-event simulation capabilities.

AGNPS, AnnAGNPS, DWSM, HSPF, MIKE SHE, and SWAT were found to have all the three major components (hydrology, sediment, and chemical) applicable to watershed-scale catchments.

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SUMMARY AND CONCLUSIONS SWAT is a promising model for continuous

simulations in predominantly agricultural watersheds.

HSPF is promising for mixed agricultural and urban watersheds.

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REFERENCES

D. K. Borah, M. Bera. 2003. Watershed-scale hydrologic and nonpoint-source pollution models: Review of mathematical bases. Transactions of the ASAE (American Society of Agricultural Engineers) : Vol. 46(6): 1553-1566.

Thanks for your attention !

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