中文摘要：

本文利用普林斯顿大学全球大气强迫场资料，驱动公用陆面过程模式（Community Land Model version 4．0，CLM4．O）模拟了中国区域1961-2010年土壤湿度的时空变化。将模拟结果与观测结果、美国国家环境预报中心再分析数据（Naional Centers for Environmental Prediction Reanalysis，NCEP）和高级微波扫描辐射计（Advanced Microwave Scanning Radiometer-EOS，AMSR-E）反演的土壤湿度进行了对比分析，结果表明CLM4．0模拟结果可以反映出中国区域观测土壤湿度的空间分布和时空变化特征，但东北、江淮和河套三个地区模拟值相对于观测值在各层次均系统性偏大。模拟与NCEP再分析土壤湿度的空间分布基本一致，与AMSR-E的反演值在35°N以北的分布也基本一致；从1961-2010年土壤湿度模拟结果分析得出，各层土壤湿度空间分布从西北向东南增加。低值区主要分布在新疆、青海、甘肃和内蒙古西部地区。东北平原、江淮地区和长江流域为高值区。土壤湿度数值总体上从浅层向深层增加。不同深度土壤湿度变化趋势基本相同。除新疆西部和东北部分地区外，土壤湿度在35°N以北以减少趋势为主，30°N以南的长江流域、华南及西南地区以增加为主。在全球气候变暖的背景下，CLM4．0模拟的夏季土壤湿度在不同程度上响应了降水的变化。中国典型干旱区和半干旱区土壤湿度减小，湿润区增加。其中湿润区土壤湿度对降水的响应最为显著，其次是半干旱区和干旱区。

英文摘要：

The Community Land Model version 4.0 （CLM4.0） driven by the atmospheric forcing data of Princeton University was used to simulate soil moisture （SM） in China from 1961 to 2010. The simulated SM data were compared with observation data, National Centers for Environmental Prediction （NCEP） Reanalysis data, and SM data retrieved from the Advanced Microwave Scanning Radiometer-Earth Observing System （EOS; AMSR-E） data. The results showed that although CLM4.0 simulation is capable of capturing the characteristics of spatial distribution and temporal spatial variation of measured SM, the simulated SM was systematically higher than the observations in every layer in northeast China, the Jianghuai basin, and the Hetao region. The spatial patterns of the simulated SM and the NCEP SM demonstrated reasonable consistencies, and the spatial patterns of simulated SM and AMSR-E retrieved SM showed consistencies in the northern area of 35~N. On the basis on the simulated SM from 1961 to 2010, it can be concluded that the spatial distributions in every layer were characterized by a gradually increasing pattern from the northwest to southeast. Dry regions were located in Xinjiang, Qinghai, Gansu, and western Inner Mongolia, whereas the most humid regions were located in the Northeast China Plain, the Jianghuai region, and the Yangtze River basin. The SM generally increased from surface layer to deeper layers. The variation trends essentially showed consistencies in all layers. The SM mainly decreased in the northern area of 35~N except western Xinjiang and partial regions of Northeast China, and increased mainly in the Yangtze River basin, southern and southwestern China. In the global warming background, the simulated SM of summer demonstrated various responses to the variation in precipitation. SM decreased in typical arid and semiarid regions and increased in humid regions. The humid regions responded significant to precipitation, whereas the semiarid and arid regions were ranked second.