基于DEM的地理要素PRISM空间内插研究

Interpolation of Meteorological Data Based on DEM Using PRISM Model

利用PRISM模型基于DEM、站点数据和其它空间数据图层内插了气象要素,以便准确表达其空间分布特征。为了比较PRISM空间内插结果,采用GIS常用的Kriging内插、Spline内插等方法分别对降水和气温站点数据进行空间插补,并对内插结果进行精度分析、DEM空间分辨率的影响分析和各个权重因子的影响分析。分析表明,PRISM方法比其它内插方法能够更加精确地表达气象要素的空间分布,更适合于在地形复杂地区地表参数的空间内插。由于气象要素空间分布的复杂性,PRISM内插方法不能完全表达地表参数空间异质性。以后研究中,应在更小的站点影响单元内考虑更多因子利用PRISM方法进行气象要素的空间内插。

On the basis of brief review of several common approaches on spatial data interpolation in GIS, an independent approach based on PRISM concepts for accurately interpolating meteorological parameters, such as temperature and precipitation, were developed and compared with those commonly used. The test and comparison for the proposed PRISM approach was carried out on the Heihe River Basin, Northwest China, by means of DEM, spatially distributed station data and other control factors. The results show the best performance of the PRISM approach compared with other methods discussed in the context, such as Kriging and Spline method, over Qilian Mountain region and the further improvements of the approach are discussed briefly.