中国东北地区地表干湿状况的变化及趋势分析

利用1961~2000年中国东北地区80个测站的月降水和平均气温资料，通过计算地表最大潜在蒸发、地表干燥度指数和地表水分盈亏量，分析了东北地区及其7个不同气候区域地表干湿状况的时空分布规律及其变化趋势，并探讨了它与降水和气温的关系。结果表明，东北地区及其不同区域的地表干湿状况不仅具有较大的地域差别和年际及年代际变率，而且存在着明显的阶段性和低频变化特征，特别是20世纪90年代中期以来，东北地区呈现出较强的变干倾向，并且由于气温升高所导致的潜在蒸发的加大与降水一样对这一变干倾向也有十分重要的影响。

A Study of the Variation and Tendency of Surface Dry-and-wet State of Northeast Area in China

Based on the 80 observation station's data of monthly precipitation and mean monthly temperature over the northeast area in China from 1961 to 2000, the maximum potential evaporation, the aridity index and the water budget in the surface are computed. The spatial and temporal distribution and the variation and tendency of the surface dry and wet status over the northeast China are analyzed, and the relationship between the dry wet status and precipitation and temperature is examined. The results show that not only the surface aridity index have a large interannual and decadal variation, but also have an obvious phasic change and low frequency variation characteristics. Since the mid of the 1990s, the northeast area in China shows the arid tendency obviously, and it is mainly controlled by the higher temperature which caused the potential evaporation increasing greatly.