Comparison of multiple point and single point calibration

performance for the Saginaw River Watershed

Fariborz Daneshvar, A1. Pouyan Nejadhashemi1, Matthew R. Herman1

1Department of Biosystems and Agricultural Engineering, Michigan State University

2015 SWAT Conference at Purdue

October 14-16th

SWAT Model Calibration-Validation

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SWAT uses a large number of default input parameters for model development

Subbasin level parameters (e.g. ground water, soil, routing …)

Basin level parameters (e.g. surface runoff lag coefficient)

Calibration-Validation process is required to verify the accuracy of the model for the simulated

condition

Single point calibration is the common approach for water quantity and water quality calibration

Challenges

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Single point calibration will not account for spatial variation of hydrological processes.

Multiple point calibration was introduced to tackle this issue

Multiple point calibration software (e.g. SWAT-CUP) still uses unique basin level parameters for the

whole watershed.

Time consuming process!

Solution

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Introduce a new multiple point calibration process which is:

Faster

Can use multiple values for basin level parameters.

Study Area

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Figure 1- Study area

Saginaw River Watershed

Largest HUC-6 (040802) in Michigan

Total drainage area 16,120 km2

Drains to the Lake Huron

Defined as an area of concern by EPA

Mostly agricultural and forest lands (74%)

SWAT ProjectSWAT 2012 (rev-622)

Watershed Delineation

Predefined reaches and Subbasins by Michigan Institute of Fisheries

Research (IFR), based on National Hydrology Dataset Plus (NHDPlus)

Land-use

Cropland Data Layer 2013

Soil

SSURGO soil

Slope

5 slopes (1-2,2-4,4-7,7-10,>10)

Climate Data

NCDC data for 1990-2010 period

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Figure 2- SWAT overlapping layers

Calibration Criteria

Criteria Very Good Good Satisfactory Unsatisfactory

NSE 0.75 – 1.0 0.65 – 0.75 0.5 – 0.65 < 0.5

PBIAS (%) < ±10 ±10 - ±15 ±15 - ±25 > ±25

RSR 0.0 - 0.5 0.5 – 0.6 0.6 – 0.7 > 0.7

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Table 1- Flow calibration criteria1

1 Moriasi D.N., Arnold J.G., Van Liew M.W., Bingner R.L., Harmel R.D., Veith T. L., 2007, Model evaluation guidelines for systematic quantification of accuracy

in watershed simulations. Trans. ASABE. vol. 50(3), pp. 885-900.

Nash-Sutcliffe Efficiency (NSE)

Percent Bias (PBIAS)

RMSE-observations Standard-Deviation Ratio (RSR)

Single Point Calibration

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Saginaw River (USGS 04157000) station is used for flow calibration

13242 out of 13831 reaches (~96% of watershed) drain to this river

All reaches/Subbasins parameters (e.g. ground water, soil,

management, etc.) are assumed to be the same.

Monthly flow calibration:

Calibration: 2002-2003

Validation: 2004-2005

Calibration Validation

NSE PBIAS (%) RSR NSE PBIAS(%) RSR

0.72 6.02 0.53 0.85 -1.74 0.39

Figure 3- Single point Calibration

Single Point Calibration

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No spatial variation is considered

Each year of SWAT run ~ 5 min.

Cons.:

Figure 3- Single point Calibration

Multiple Points Calibration

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Using 9 USGS stations for calibration

USGS 04144500

(1053 reaches)

USGS 04155500

(553 reaches)

USGS 04154000

(627 reaches)

USGS 04151500

(2140 reaches)

USGS 04148140

(773 reaches)

USGS 04147500

(1311 reaches)

USGS 04156000

(2682 reaches)

USGS 04148500

(1048 reaches)

USGS 04157000

(3055 reaches)

Figure 4- Multiple point Calibration

Multiple Points Calibration

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Daily Flow Calibration

Calibration: 2001-2005

Validation: 2006-2010

Calibration Validation

USGS Station NSE PBIAS (%) RSR NSE PBIAS(%) RSR

04144500 0.64 20.88 0.6 0.62 9.12 0.62

04147500 0.61 9.43 0.62 0.65 -10.04 0.59

04148140 0.54 9.69 0.68 0.53 -24.98 0.68

04151500 0.59 15.14 0.64 0.68 12.62 0.57

04154000 0.54 5.51 0.68 0.54 13.24 0.68

04155500 0.63 20.1 0.61 0.59 1.29 0.64

04148500

04156000

04157000

Calibration Validation

USGS Station NSE PBIAS (%) RSR NSE PBIAS(%) RSR

04144500 0.64 20.88 0.6 0.62 9.12 0.62

04147500 0.61 9.43 0.62 0.65 -10.04 0.59

04148140 0.54 9.69 0.68 0.53 -24.98 0.68

04151500 0.59 15.14 0.64 0.68 12.62 0.57

04154000 0.54 5.51 0.68 0.54 13.24 0.68

04155500 0.63 20.1 0.61 0.59 1.29 0.64

04148500 0.65 26.3 0.59 0.76 8.08 0.49

04156000 0.73 3.27 0.52 0.74 8.98 0.51

04157000

Calibration Validation

USGS Station NSE PBIAS (%) RSR NSE PBIAS(%) RSR

04144500 0.64 20.88 0.6 0.62 9.12 0.62

04147500 0.61 9.43 0.62 0.65 -10.04 0.59

04148140 0.54 9.69 0.68 0.53 -24.98 0.68

04151500 0.59 15.14 0.64 0.68 12.62 0.57

04154000 0.54 5.51 0.68 0.54 13.24 0.68

04155500 0.63 20.1 0.61 0.59 1.29 0.64

04148500 0.65 26.3 0.59 0.76 8.08 0.49

04156000 0.73 3.27 0.52 0.74 8.98 0.51

04157000 0.79 11.66 0.46 0.8 10.3 0.44

Figure 4- Multiple point Calibration

Multiple Points Calibration

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0

200

400

600

800

1000

1200

1/1/2001 1/1/2002 1/1/2003 1/1/2004 1/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010

Series1 Series2Obs. Sim.

Figure 5- observed flow vs. simulated flow for USGS 04157000 station

Conclusion

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Longer calibration period can be achieved.

Multiple point calibration will speed up the process.

SWAT parameters can be changed locally, which is more realistic compared to

previous approaches.

Acknowledgement

We would like to thank the Environmental Science and Policy Program (ESPP) at Michigan State University for funding this project

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Thank You

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