长江中上游区基于GIS的不同时间尺度降水插值方法探讨

The Successive Interpolation Approach of Precipitation Space in the Mid-and Upper-Reaches of the Yangtze River under Different Time Scales Based on GIS

为了获取长江中上游地区高分辨率的降水情况,本文以长江中上游及其周围地区共613个气象站点的降水资料为基本数据,利用分辨率为4 km的DEM(Digital elevation model),采用了较适合地理信息系统(GIS)的插值方法,分别对该区域1992—2001年间年、月及日平均等不同时间尺度降水量进行了分析。结果表明:逐步插值法得到的高分辨率降水空间分析效果较好,计算的精度较高。该方法提高了计算的准确性,体现了降水随地形的变化以及在空间分布上的不连续性,有效地解决了复杂地形条件下降水空间插值精度不高的问题,对于不同的时间尺度都有较好的适用性。

Abstract： In order to obtain the precipitation instance of high resolution in the mid-and upper- reaches of Yangtze River, this paper analyses the annual, montlly and daily precipitation with an interpolation method which adapts to the geographic information system （GIS） by the precipitation data of 613 meteorological stations from 1992 to 2001. The result shows that the effect of the SIA based on the DEM of 4 km resolutions is good, the precision is satisfactory. This method improves the computing veracity, embodies the precipitation changes followed by the topographty and the distributing incontinuity, resolves the problem of precision under complicated topographty availably. It shows preferable adaptability to different time scale.