Spatial-temporal pattern study on water conservation function using the SWAT model

Abstract

The performance of the water conservation function (WCF) affects the water supply and flood control capabilities of an ecosystem. In this study, we combined the water balance method with the Soil and Water Assessment Tool (SWAT) model to calculate the water conservation amount (WCA) upstream of the Xiong'an New Area (Zijingguan (ZJG), Zhongtangmei (ZJG) and Fuping (FP) basins) at annual and monthly scales from 2007 to 2017, and used multiple linear regression and geographic detector models to analyze the factors affecting the temporal changes and spatial pattern of the WCA. Our results reveal that the annual WCAs of the ZTM basin are all positive, while the WCAs of the ZJG and FP basins have negative values in drought years. The annual WCAs in the upstream of each basin have changed between positive and negative values. On the monthly scale, all areas of the ZJG, ZTM, and FP basins have positive and negative value changes of WCA between the rainy and non-rainy seasons. Precipitation, evapotranspiration, and their combined effects are the main factors leading to the temporal changes and spatial patterns of WCA in the study area. The above results can provide reference cases for other regions to carry out relevant research work. HIGHLIGHTS The combination of the SWAT model and water balance method can quantitatively calculate the water conservation amount (WCA) on multi-temporal scales.; The WCA has a positive-negative change between the rainy season and non-rainy season.; Precipitation, evapotranspiration, and their combined effects are the main factors leading to the temporal changes and spatial pattern of WCA.;

Keywords

• geographic detector
• multi-temporal scale
• swat
• water conservation function