西安市主城区土地利用变化及其对地表径流的影响

Land use change and its impact on surface runoff in the main city of Xi′an

为探究西安市城市化引起的土地利用/覆被格局变化对降雨-径流过程产生的影响,借助ARCGIS空间分析工具,采用SCS模型对西安市主城区降雨-径流过程进行模拟,结果表明:CN的高值区在逐步扩大;在相同前期土壤湿润程度状态下,同一时期的径流量随着降雨量的增大而增大;根据1995年、2000年、2006年、2010年四期土地利用数据得到三个时段的土地利用转移矩阵,可知产流能力较强的城镇建设用地面积逐步扩大,产流能力较小的耕地、林地的面积逐步减小。可见,城市化建设的快速发展导致土地利用类型发生变化,使得西安市主城区的径流增大。

The land use change caused by the urbanization in Xi′an will affect the rainfall-runoff.In order to explore the effect,in this paper with the help of ARCGIS spatial analysis tools,SCS model was applied to study the rainfall-runoff process of the main city in Xi′an.The results showed that the high value area in CN value was gradually expanding.At the same antecedent soil moisture degree,runoff increased with increasing rainfall.According to processing of land use data of 1995,2000,2006 and 2010,matrix of land use for the three periods was obtained.It could be concluded that the area of urban construction land which has the strong ability in runoff gradually expanded.In contrast,the area of farmland and woodland gradually decreased.The rapid development of urbanization led to the changes in land use types,which caused runoff increase in the main city of Xi′an.