Spatial Optimization of Land Use Based on Soil Water Distribution in the Hill-gully Areas of the Loess Plateau - A Case Study of the Xingzihe Watershed
基于土壤水分分布的土地利用空间优化方法 --以黄土高原杏子河流域为例

Based on the cumulate soil water replenishment model,soil erosion mode l,and multiple objective nonlinear optimum models,an allocation model for spatia l optimization of land resource was established.The method includes four steps.T he first step,with the objective of making spatial distribution of water resourc e suitable for crop growth in the study area,is to establish the water distribut ion models based on grid data model,SCS discharge model and the principle of wat er content equilibrium.The second step is to establish a soil water prediction model to analyze watershed soil and water loss situation.In this step,Digital El evation Model(DEM),land use map,soil type distribution map,climate,meteorologica l and hydraulic data are required.The third step is to integrate the water conte nt distribution model,soil and water loss model,and a multiple objective model f or land use optimization in order to get the quantitive structure of land use.Th e last step is to allocate the optimized land use structure spatially based upon the current land use patterns and the principles of ecology.To test the model,a typical watershed,Xingzihe watershed,on the Loess Plateau in northern Shaanxi p rovince was selected as the study area.As a result,land resources at the watersh ed were allocated based on the local integrated regulation programming.The ecolo gical and economic benefits of the optimum land use structures were discussed.It is indicated that the eco,environment of the study area would be apparently imp roved after watershed regulation.Moreover,the local farmers' income would be gre atly increased,and the major source of agricultural income would be shifted to w oods and fruits.At the same time,the case study also revealed that both of the e conomic benefit and the ecological benefit will increase until the management de gree reaches 30%.When the degree exceeds 30%, the economic benefit will continue to increase but the ecological benefit will remain almost unchanged.The propose d method can produce better result for local land use structural regulation.