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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #316374
Title: Erosion and runoff evaluation using the SWAT-T model

Author
item THONGPUSSAWAL, SITARRINE - University Of Missouri
item GANTZER, CLARK - University Of Missouri
item Baffaut, Claire
item SHAO, HUI - University Of Guelph

Submitted to: Annual International SWAT Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2015
Publication Date: 6/24/2015
Citation: Thongpussawal, S., Gantzer, C.J., Baffaut, C., Shao, H. 2015. Erosion and runoff evaluation using the SWAT-T model. Annual International SWAT Conference [abstract]. Session G1.

Interpretive Summary:

Technical Abstract: Agricultural terraces are an effective conservation practice to reduce concentrated flow erosion. Researchers have simulated terrace effects using the Soil and Water Assessment Tool (SWAT) by adjusting the slope length and the USLE Practice P-factor. An algorithm was incorporated into SWAT (SWAT-Terrace; or SWAT-T), to better account of terrace benefits by simulating the effects of temporary storage of water. The objective of this work is to evaluate and validate SWAT-T by simulating the impacts of terraces on erosion and runoff for the 72 km2 Goodwater Creek Experimental Watershed (GCEW) at watershed and Hydrologic Response Unit (HRU) scales. The GCEW is located in Boone and Audrain counties of north-central Missouri. The GCEW consists of mainly claypan soils, which have high erodibility and runoff that contribute to high sediment transport. Between 1990 and 2006, about 13% of GCEW was terraced, with most of these terraces being located in one 19 km2 sub-basin. Discharge and sediment data that were collected at the watershed outlet from 1993 2010 were used to calibrate and validate the model. Results from SWAT-T with terraces will be compared to simulated results obtained with SWAT-T without terraces, and also to measured data. Preliminary results at the HRU level show significant sediment reductions, with smaller significant runoff reductions. However, in some years, annual sediment transport increased during heavy rainfall periods when terraces might have been overtopped. Sediment and runoff results will be analyzed to identify terrace benefits as part of the validation work of the terrace model. The SWAT-T improvements will be useful for soil and water conservationists to better quantify terrace benefits.