1961-2010年中国降水时空变化特征及对地表干湿状况影响

开展气候变化背景下中国降水时空变化特征及对地表干湿状况影响研究,对揭示陆地表层系统对气候变化的动态响应与变化规律以及防灾减灾具有重要意义。基于1961-2010年地面气象观测资料,分析我国降水与地表干湿状况时空格局;在此基础上,采用敏感性与贡献度分析,定量评估降水变化对干湿状况的影响。结果表明：过去50年间我国年降水量呈轻微增加趋势,其中,青藏高原（高原亚寒带、高原温带）、西北（中温带西部、暖温带西部）和南方地区（亚热带、热带）呈增加趋势,东北（寒温带、中温带东部）和华北地区（中温带中东部、暖温带东部）呈减少趋势。就地表干湿状况而言,华北和东北地区以干旱化趋势为主,西北、青藏高原及南方地区主要呈湿润化趋势。地表干湿状况对降水变化响应较为敏感（全国多年平均敏感系数：-1.13）,干湿指数和降水呈负相关。内陆干旱地区降水对干湿状况变化的贡献高于湿润地区,局部地区降水贡献度超过60%。

Spatiotemporal variation of precipitation in China and its impact on surface dry-wet conditions during 1961-2010

Studying the spatiotemporal variation of precipitation in China under the backgr-ound of climate change and its impact on surface dry-wet conditions is of great significance in revealing the dynamic responses and changes of land surface systems to climate change and disaster prevention and mitigation. Based on measured meteorological data from 1961 to 2010, the spatiotemporal variations of precipitation and surface dry-wet conditions were analyzed. Furthermore, sensitivity and contribution analysis were used to quantify the impact of precipitation on dry-wet conditions. Results showed that the annual precipitation in national scale showed a slight increasing trend over the past 50 years, but the variations of annual precipitation in different temperature zones were significant, the Qinghai-Tibet Plateau (Plateau sub-cold zone and Plateau temperate zone), the northwestern (the west of both Medium temperate zone and Warm temperate zone) and southern regions of China (Subtropical zone and Tropical zone) showed an increasing trend, while the northeastern (Cold temperate zone and the east of Medium temperate zone) and northern regions of China (middle and east of Medium temperate zone and east of Warm temperate zone) showed a decreasing trend. In terms of dry-wet conditions, it varied greatly in different regions, the northern and northeastern regions of China got dried while the Qinghai-Tibet Plateau, the northwestern and the southern regions got wet. The dry-wet conditions were sensitive to the change of precipitation (mean annual sensitivity coefficient: -1.13). The dry-wet index was negatively correlated with precipitation. In the inland arid regions, precipitation contributed more to the change of dry and wet conditions than that in humid regions, and some of the regions exceeded 60%.