Water balance within soil water reservoir in the loess tableland by means of combination of SWAT model and remote sensing: A case study in the Dongzhi Loess Tableland of eastern Gansu
In this study, the hydrologic model of SWAT and the remote sensing methods were combined to illustrate the dynamics of the soil water reservoir in the loess tableland. The Dongzhi Loess Tableland was selected as a study area to comprehensively and quantitatively determine the water balance of the soil water reservoir. It is found that a distinct monthly variation of water in the soil water reservoir and a soil water deficit takes place frequently in May and June, which restricts land surface ecology. Irrigation regulation ought to be especially considered in the two months. During the period from 1981 to 2010, increase of air temperature and decrease of precipitation had led to more evaporative and less recharge to the soil water reservoir, respectively. Both result in more negative water balance of the soil water reservoir in the area. It is verified that under the background of climate change, an overall plan for external water transfer into the area must be considered and implemented as soon as possible to deal with the water shortage problem.