Assessing the Performance of a Physically-Based Soil Moisture Module Integrated within the Soil and Water Assessment Tool
A Richards equation-based soil moisture module was developed and integrated within the Soil and Water Assessment Tool (SWAT). Four years of daily soil moisture measurements from 10 monitoring stations at three depths (i.e., 5, 10, and 50 cm) in the Choptank River watershed, Maryland, were used to test the module performance. Results show that, as compared with the original SWAT soil moisture module, the Richards-equation-based soil moisture module improved R2 from 0.12 to 0.45 and reduced soil moisture simulation bias from -0.10 to -0.02, averaged across the 10 stations at soil surface layer (i.e., 5 cm depth). Noticeable improvements were also observed for deeper soil layers, and for both dry and wet periods. Notably, the soil moisture coupling strength between different soil layers was substantially improved with the new module. The enhanced SWAT model is expected to better inform soil water and irrigation management.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1495019
- Report Number(s):
- PNNL-SA-134989
- Journal Information:
- Environmental Modelling and Software, Journal Name: Environmental Modelling and Software Journal Issue: C Vol. 109; ISSN 1364-8152
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
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