基于地统计学的作物需水量空间变异性分析

Spatial Variability on Crop Water Requirement Based on Geo-statistics

依据宝鸡峡灌区11个站1981-2008年各月的气象资料,基于ArcGIS9.2平台,运用地统计学分析了灌区三种主要作物多年平均需水量在空间上的变化规律。通过反距离权插法与克里格插值的比较,显示了地统计插值较确定性插值的优越性。分析结果表明:灌区不同作物需水量差异较大,冬小麦多年平均需水量459.5～559.6mm,玉米454.6～528.3mm,棉花609.2～681.3mm。但是,各种作物多年平均需水量的空间分布呈现出类似规律,均在西南-东北方向上变程最大,眉县附近需水量最小,往东北方向逐渐增大。

Based on analyzing climatic material of Baoji gorge irrigation district from 1981 to 2003,the spatial variability and distribution of perennial average value of crop water requirement in the district are researched by using geo-statistical method combined with ARCGIS 9.2.Through the comparison between the Kriging model and the inverse distance weighting,it proved that the method of the geo-statistics is better.The result also shows that the range of perennial average winter-wheat water requirement in the district is 459.5～559.6 mm,the range of maize water requirement is 454.6～528.3 mm,the range of cotton water requirement is 609.2～681.3 mm.The spatial distribution of perennial average crop water requirement for this three kinds of crop has similar regulation.The range from southwest to northeast is the farthest,the water requirement nearby Meixian is the minimum,and it is increased toward northeast.