柴达木盆地地表湿润特征及气候因子影响分析

基于Penman-Monteith模型计算出的潜在蒸散量得出柴达木盆地各站点的湿润指数，运用Sen趋势，Mann-Kendall检验，EOF模型分析了34 a湿润指数的时空变化趋势，运用偏相关分析方法讨论了影响地表湿润程度变化的气候因子。结果表明:从时间变化来看，34 a间柴达木盆地地表湿润指数表现为增加趋势，倾向率为0.00097 a^-1，并在1987年前后发生突变。从空间变化来看，主要表现为由东向西逐渐递减。异常空间分布模态主要分为“东西空间差异”和“南北反向差异”两个类型，且这两种分布型呈上升趋势。湿润指数与降水量、相对湿度、日照时数呈正偏相关，与平均气温、平均风速呈显著负偏相关。降水量和相对湿度是影响湿润指数上升最显著的因素。

Analysis on Surface Humidity Index and Climatic Impacting Factors in Qaidam Basin

In this paper, potential evaporation was calculated by using Penman-Monteith model, which generates the surface humidity index for the Qaidam Basin of each station.The characteristics of spatiotemporal variations of the humidity index were analyzed by using the Sen’s method, the Mann-Kendall test, Empirical Orthogonal Function (EOF) in Qaidam Basin during 34 years.Based on these, the climatic factors impacting the level of surface humidity were investigated by partial correlation methods.The results showed as follows: During the period of 34 years, the humidity index in Qaidam Basin presented an increasing trend with an interannual decrease rate of 0.000 97 a^-1, and the abrupt change happened in 1987.The spatial distribution showed a decreasing trend from east to west.The abnormal spatial pattern resides in two aspects: the difference of spatial in the east to the west, and the opposite changes in the south and the north, and the tendency of these two kinds of distribution presented an increasing trend.The humidity index had positive partial correlations with precipitation, relative humidity and sunshine duration, but negative partial correlations with average temperature and average wind speed.Precipitation and relative humidity were the main factors affecting the humidity index.