西藏地区降水侵蚀力时空分布研究

Spatiotemporal Distribution of Precipitation Erosivity in Tibet Autonomous Region

以2000—2008年的TRMM3B42数据为基础,在ARC/INFO软件提供的地图代数运算功能支持下,利用日降水量估算降水侵蚀力,对西藏地区降水侵蚀力及其年内分配和年际变化的空间分布特征进行了分析。结果表明,西藏地区降水侵蚀力大体呈由东南向西北递减的趋势,地区差异大。降水侵蚀力年内分配集中度呈由东南向西北增加的趋势,降水侵蚀力越小的地区,年内降水侵蚀力分布越集中。西藏自治区降水侵蚀力在2000—2008年的年际变化同样存在空间分异,整体上呈现降低的趋势。

Based on the map algebra function in ARC/INFO,precipitation erosivity is estimated by the simplified prediction model of daily precipitation using TRMM 3B42 data acquired between 2000 and 2008. The intra-annual and inter-annual spatiotemporal variations of precipitation erosivity are then analyzed. Results show that precipitation erosivity in the Tibet Autonomous Region shows a decreasing trend from the southeast to the northwest with significant spatial variation. The intra-annual concentration degree of precipitation erosivity shows an increasing trend from the southeast to the northwest. The lower precipitation erosivity is,the greater the concentration degree of precipitation erosivity is. The inter-annual variation of precipitation erosivity shows a decreasing trend from 2000 to 2008.