黄土高原近52年降水时空动态特征

Spatial-temporal Dynamic Characteristics of Precipitation in the Loess Plateau, China for Recent 52 Years

本文利用1960-2011年黄土高原及其周边77个气象台站逐日降水资料,采用SPSS、GIS空间分析和转移矩阵,分析黄土高原地区年均降水量变异特征,多年及各年代平均降水量时空分布特征。结果表明：黄土高原地区年降水量空间变异性和时间变异性较大。区域内多年及各年代平均降水量呈现从东南向西北减少的空间趋势。区域内年降水量整体呈减少趋势,但在2000年之后略有回升。在1960~2011年间平均降水量〈200 mm/a和200-400 mm/a的区域面积扩大,平均降水量在400-800 mm/a和〉800 mm/a的区域面积缩小。平均降水量〈200 mm/a的区域在西北地区有扩张趋势,平均降水量200-400 mm/a的区域在区域中部扩张,平均降水量在400-800mm/a和〉800 mm/a的区域在区域南部呈缩减趋势。

This paper used daily precipitation data of 77 stations in Loess Plateau and its neighbors from 1960 to 2011. This study analyzed variation characteristics of annual precipitation, spatial distribution of average precipitation and spatial-temporal characteristics of each decade＇s precipitation in Loess Plateau through SPSS19, GIS spatial interpolation and transition matrix. Results showed that temporal and spatial variability of annual precipitation was obvious. The average precipitation of whole period and four decades showed a tendency that precipitation decreased from southeast to northwest.Annual precipitation showed a decreasing trend from 1960-2011, but it became to increase since 2000. The area of annual precipitation that less than 200 mm/a and between 200 and 400 mm/a had increased, and the area that larger than 400 mm/a had reduced. The area of precipitation that less than 200 mm/a extended in the northwest; the area of precipitation that between 200 and 400 mm/a extended in the central; the area of precipitation that larger than 400 mm/a narrowed in the south.