Application of SWAT in Hydrologic and Nutrient Transport Modelling of the Lake Winnipeg Watershed

Rajesh Shrestha, Yonas Dibike, Terry Prowse ENVIRONMENT CANADA

August 7, 2009

W-CIRC WATER AND CLIMATE IMPACTS RESEARCH CENTRE

Outline

Project background

Study area

Selection of representative sub-basins

SWAT model set up and calibration

Preliminary results

Summary and future work

Background

Lake Winnipeg is Canada’s sixth- largest freshwater lake P and N loading to Lake Winnipeg has increased by 13% and 10%,

respectively, over last 30 years (Jones and Armstrong, 2001). Stainton et al. (2003) suggested that Lake Winnipeg is becoming

increasing Eutrophic.

Project overview

Environment Canada’s action plan on clean water - Lake Winnipeg basin initiatives (LWBI)

Water & Climate Impacts Research Centre (W-CIRC) project -Climate Impacts on the Landscape Hydrology/Nutrient Transport of the Lake Winnipeg Watershed.

Project components

1. Analysis of current and future precipitation regimes in the watershed

2. Selection of GCM/RCMs that best replicates the current climate of this region

3. Selection of representative sub-catchments in the LWW

4. Set up and calibration of a hydrologic/nutrient transport model for application in representative sub-catchments

5. Ensemble prediction of future climate scenarios by coupling GCM/RCM outputs with hydrologic/nutrient transport model

Lake Winnipeg Watershed

N

Red River

Assiniboine River

Winnipeg River

Lake Winnipeg

Lake Manitoba

SASKATCHEWANMANITOBA

ONTARIO

ALBERTA

MONTANA

NORTH DAKOTA

MINNESOTA

0 100 Km

Saskatchewan River

Q = 28%

Q = 11%

Q = 44%

Data source: Discharge (McCullough & Barber, 2008)Nutrients (Bourne et al., 2002)

TN = 9%TP = 4%

TN = 44%TP = 63%

TN = 19%TP = 11%

N

0 50 km0 50 km

Upper Assiniboine CatchmentMorris Catchment

Assiniboine River

Morris River

Selection of representative basins

Area=13500 km2Landuse=55% Agri.

Area=4300 km2Landuse=80% Agri.

Topography: Flat – low risk of water erosion

Precipitation: ≈ 400 mm/year

Temperature: Avg. temperature -30 to 30° C

Hydrologic regime: ≈ 80 runoff from snowmelt: from accumulated snow cover and frozen soil

Catchment Hydrologic Characteristics

Photo: Flaten (2009)

Hydrologic/Nutrients characteristics

0

10

20

30

40

50

60

17/03/1992 06/04/1992 26/04/1992 16/05/1992 05/06/1992 25/06/1992

Dis

char

ge [m

3/s]

-40

-30

-20

-10

0

10

20

Tem

pera

ture

[oC

]

DishargeTemperature C

Hydrologic/Nutrients characteristics

0

10

20

30

40

50

60

17/03/1992 06/04/1992 26/04/1992 16/05/1992 05/06/1992 25/06/1992

Disc

harg

e [m

3/s]

0

0.5

1

1.5

2

2.5

Tota

l Nitr

ogen

[mg/

l]

Discharge [m3/s]Nitrogen_total

Hydrologic/Nutrients characteristics

0

10

20

30

40

50

60

17/03/1992 06/04/1992 26/04/1992 16/05/1992 05/06/1992 25/06/1992

Dis

char

ge [m

3/s]

0

0.1

0.2

0.3

0.4

0.5

0.6

Tota

l P [m

g/l]

Discharge [m3/s]Phosphorus_total

Topography

Soil

Land cover

Meteorological input

Model Output(runoff, nutrient

loads)

Hydrologic cycle

Crop/Vegetation growth

Nutrient leaching & transport

SWAT

Hydrologic/nutrient transport modelling

Soil Water Assessment Tool (SWAT)

SWAT snow accumulation and melt routines

Temperature indexed approach for simulating snow regime (Fontaine et al., 2002)

Snowpack calculation using mass balance

where SNO = water content at day, Ps = snow precipitation amount, Esub = sublimation & SNOmlt = snowmelt on day

Snowmelt using temperature index approach

where SNOmlt = snowmelt amount, bmlt = melt factor, SNOcov = the fraction of HRU covered by snow, Tsnow = snowpack temperature (°C), Tmx =daily max. air temperature (°C) & Tmlt = base temperature for snowmelt (°C).

SNOi+1 = SNOi + Ps− Esub − SNOmlt

SNOmlt = bmltSNOcov [(Tsnow+ Tmx)/2 − Tmlt]

Model setup: Upper Assiniboine catchment

N

Whitesand river (Springside)

Assiniboine river (Kamsack)

Spatial data DEM: 90 m DEM (CGIAR-CSI; Jarvis et

al., 2008) Land cover: 1 km (Land Cover of

Canada; Cihlar and Beaubien, 1998) Soil : 1:1 mil. (Soil Landscapes of

Canada; SLC Working Group, 2007)

Model setup: Morris catchment

Spatial data DEM: 90 m DEM (CGIAR-CSI; Jarvis

et al., 2008) Land cover: 1 km (Land Cover of

Canada; Cihlar and Beaubien, 1998) Soil : 1:1 mil. (Soil Landscapes of

Canada; SLC Working Group, 2007)

Sub-catchment delineation Burning with existing river network

data to adequately represent the sub-catchments

Morris Catchment

Morris River

Morris Catchment

Morris River

Carmen

Rosenport

Precipitation, max./min. air temperature, solar radiation, wind speed and relative humidity of 45 km spatial resolution from North America Regional Reanalysis (NARR).

Additional model calibration with precipitation data of 10 km spatial resolution from Gridded Climate Dataset for Canada (GCDC).

Meteorological Inputs

Spatial domain of NARR inputs

Uses long-term consistent climate datasets for North American domain

Uses Global Reanalysis (GR) to drive Regional Reanalysis (RR) system

Output at 3-hr interval Horizontal resolution: 45 km RR time period: 1979-2006

North America Regional Reanalysis (NARR) Data

Calibration parameters selection

Abbaspour et al. (2007). Modelling hydrology and water quality in the pre-alpine/alpine

Thur watershed using SWAT. Journal of Hydrology, 333(2-4): 413-430.

Ahl, R.S., Woods, S.W. and Zuuring, H.R. (2008). Hydrologic Calibration and Validation

of SWAT in a Snow-Dominated Rocky Mountain Watershed, Montana, USA. Journal

of the American Water Resources Association, 44(6): 1411-1430.

Levesque, E., Anctil, F., van Griensven, A. and Beauchamp, N., (2008). Evaluation of

streamflow simulation by SWAT model for two small watersheds under snowmelt

and rainfall. Hydrological Sciences Journal, 53(5): 961-976.

Selection of parameters for calibration based on previous studies in cold

climate conditions

SWAT model parametersParameter Description Default value Min. Max

CN2 SCS runoff curve number Soil data -35% 35%

SURLAG Surface runoff lag coefficient 4 0.01 10

TIMP Snowpack temperature lag factor 1 0.01 1

SMTMP Snowmelt base temperature 0.5°C -3 3

SMFMX Maximum melt factor 4.5 mm °C-1 d-1 0 10

SMFMN Minimum melt factor 4.5 mm °C-1 d-1 0 10

SNO50COV Areal snow coverage threshold at 50% 0.5 0.01 1

SNOCOVMX Areal snow coverage threshold at 100% 1 mm 0 400

SFTMP Snowfall temperature threshold 1°C -3 3

ALPHA_BF Baseflow factor for bank storage 0.048 d 0.01 0.5

GW_DELAY Groundwater delay time 31 d 10 100

CH_N Manning n for the main channel 0.014 0.01 0.2

CH_K2 Effective hydraulic conductivity in main channel 0 mm/h 2 20

Model calibration

Parameter Solutions (ParaSol) (van Griensven and Meixner, 2003) Aggregates objective functions (OF’s) into a global optimization criterion

(GOC) minimizes a GOC using the SCE-UA algorithm

Calibration strategy Simultaneous calibration of the two gauging station by combining into single

objective function. Calibration: 1986-1995 Validation: 1996-2003 Warm up period: 1 year

Model performance with different precipitation

Input Precipitation Catchment Calibration Validation (Station) R2 NSCE R2 NSCE

GCDC (10 km) Assiniboine (Kamsack) 0.86 0.79 0.79 0.73

NARR (45 km) Assiniboine (Kamsack) 0.84 0.75 0.69 0.10

GCDC (10 km) Morris (Rosenport)

0.70 0.70 0.56 0.56

NARR (45 km) Moris (Rosenport)

0.67 0.66 0.58 0.49

Model Results: Upper Assiniboine catchment (Kamsack)

01/01/1986 01/01/1988 01/01/1990 01/01/1992 01/01/1994 01/01/1996 01/01/1998 01/01/2000 01/01/2002 01/01/20040

50

100

150

200

250

300

350

400

450

500

Dis

char

ge [m

3/s]

ObservedSimulated

Calibration Validation

Model Results: Morris catchment (Rosenport)

01/01/1986 01/01/1988 01/01/1990 01/01/1992 01/01/1994 01/01/1996 01/01/1998 01/01/2000 01/01/2002 01/01/20040

50

100

150

Dis

char

ge [m

3/s]

ObservedSimulated

ValidationCalibration

Summary

SWAT is able to reproduce reasonable match with observedrunoff.

SWAT is able approximate the processes in flat cold and dryregions of the Lake Winnipeg watershed.

Gridded precipitation data of 10 km resolution led to a betterperformance compared to the NARR inputs of 45 km resolution.

Future works

Comparison of SWAT results with land surface schemes (VIC,MESH) with frozen ground routines.

Set up and calibration of nutrient (nitrogen and phosphorus)transport models in the catchments using SWAT.

Prediction of impacts of future climate scenarios by combiningGCM/RCM outputs with SWAT.

Acknowledgements

Barry Bonsal & Charles Cuell, National Hydrology ResearchCentre, Environment Canada

Xiaoyuan Geng, Canadian Soil Information System (CanSIS)Agriculture and Agri-Food Canada

Manitoba water stewardship for water quality data Developers of SWAT model & calibration routines for providing us

this wonderful tool!

Thanks!!

Rajesh Shrestha, Yonas Dibike, Terry Prowse

rajesh.shrestha@ec.gc.ca

Application of SWAT in Hydrologic and Nutrient Transport Modelling of the Lake Winnipeg WatershedOutline Background Project overview Project componentsLake Winnipeg WatershedSelection of representative basinsCatchment Hydrologic CharacteristicsHydrologic/Nutrients characteristicsHydrologic/Nutrients characteristicsHydrologic/Nutrients characteristicsSlide Number 12Slide Number 13Model setup: Upper Assiniboine catchmentModel setup: Morris catchmentMeteorological Inputs North America Regional Reanalysis (NARR) Data�Calibration parameters selectionSWAT model parametersModel calibrationModel performance with different precipitationModel Results: Upper Assiniboine catchment (Kamsack)Model Results: Morris catchment (Rosenport)SummaryFuture worksAcknowledgementsThanks!!