Beibei Ding Haipeng Liu Yingxuan Li Xueliang Zhang Puyu Feng De Li Liu Gary W. Marek Srinivasulu Ale David K. Brauer Raghavan Srinivasan Yong Chen
Soil and Water Assessment Tool (SWAT) is widely used for watershed-scale assessment of climate change impacts, but post-processing of model outputs is a tedious job. An R tool was developed in this study for batch processing of SWAT output results. A case study was then performed in the Double Mountain Fork Brazos watershed in the Texas Panhandle using an improved SWAT model with the R tool to evaluate the simulated future changes in water balance components, total nitrogen (TN) load, and crop growth over the watershed. The results showed that the average annual future surface runoff increased by 8.9–17.9 mm and 11.5–22.6 mm in the irrigated and dryland cotton areas, respectively. Similarly, future TN load in irrigated and dryland cotton areas increased by approximately 0.4–0.9 kg ha−1 and 1.9–2.4 kg ha−1. The yields of irrigated and dryland cotton increased by 91.1%–122.1% and 47.5%–84.0% under the future climate scenarios, respectively.
SWAT-MAD; CMIP6; Hydrologic cycle; Total nitrogen load; Cotton; Semi-arid region