中国不同气候区模拟土壤含水量的时空特征分析

基于水文模型（VIC）模拟的1951~2010年逐日土壤含水量数据，分析了全国土壤含水量的空间分布特征及不同气候区土壤含水量年内变化规律、持续性特征和年际变化趋势。结果表明：1）空间分布上，全国土壤含水量由西北向东南递增，与降水分布较一致；2）年内变化上，湿润区季节变化最大，半干旱区次之，干旱区不明显；3）持续性上，干旱区最强，半干旱区次之，湿润区最弱，且各气候区深层土壤含水量持续性比浅层强；4）年际变化趋势上，干旱区呈增加趋势，半干旱区呈先增后减趋势，而湿润区变化不显著。不同气候区土壤含水量的时空特征对干旱指标选取和干旱特征分析有十分重要的意义。

Spatial and Temporal Characteristics of Soil Moisture in Different Climatic

The spatial characteristic of soil moisture from 1951 to 2010 simulated by the Variable Infiltration Capacity (VIC) hydrology model was studied, and the annual variability, durative and tendency of soil moisture in different climatic regions was also analyzed. The results show that, 1) soil moisture all over China increases from northwest to southeast, whose spatial distribution is similar to that of precipitation, 2) the seasonal variability of soil moisture is the most obvious in humid region, while the least obvious in arid region, 3) the durative of soil moisture is the strongest in arid region, while the weakest in humid region, 4) soil moisture shows an increasing trend in arid region, an first increasing and then decreasing trend in semi-arid region, while no significant trend in humid region. The spatial and temporal characteristic of soil moisture in different climatic regions plays a vital role in choosing drought index and analyzing drought characteristic.