多年平均降水资源空间变化模拟方法的研究

区域多年平均降水量的研究是集水农业工程规划的基础，也是有限的降水资源合理利用和配置的依据。研究利用ＡＲＣ／ＩＮＦＯ地理信息系统，建立了研究区的栅格数字高程模型（ＤＥＭ）及近３０年的年均降水量空间数据库；采用９种算法（距离权重法、趋势面法、样条函数法、普通Ｋｒｉｇｉｎｇ法、通用Ｋｒｉｇｉｎｇ方法１、通用Ｋｒｉｇｉｎｇ方法２、泰森多边形法、多元回归法和综合方法），计算并比较分析了研究区多年平均降水量的

Simulating methods of average annual rainfall on spatial changes

Study on the spatial changes of Average Annual Rainfall (AAR) is not only a basis of the engineering planning for rain harvesting agriculture,but also an important index for the reasonable utilization of limited rainfall water resources.Using ARC/INFO GIS technology,the raster Digital Elevation Model (DEM) and the average annual rainfall databases for nearly 30 years in the study areas were established.By means of 9 methods (Inverse distance weighted,trend,spline,ordinary Kriging,Universal Kriging 1,Universal Kriging 2,multivariable regression,and comprehensive approach),the spatial and temporal changes of AAR were calculated and comparatively analyzed.Results indicated that simulating precision of the comprehensive method is the best one in the 9 approaches,and its maximum relative error is 6.395%,the next is ordinary Kriging method with exponential model to simulate semivariogram,and its maximum relative error reaches to 6.756%.As far as the seven kinds of interpolation approaches are concerned,the precision of ordinary Kriging method is the best one,and the error of statistical model is relatively high,of which the relative error reaches to 9.041%.The AAR information system,established by raster rainfall spatial databases using optimized methods,can quickly and timely calculate the total quantity and its spatial changes on any scales in the study areas,which has an important role in runoff simulating,engineering planning,strategy developing,and decision making as well as management for rainfall harvesting agriculture.