中文摘要：

为掌握黄土高原区域尺度土壤水分的时空分异特征及其影响因素,在黄土高原布设一条南北方向样带（N=86）,动态监测0~5 m剖面土壤含水率。采用经典统计学方法分析了土壤蓄水量的分布规律、变异特征及影响因素。结果表明：不同土层土壤水分均呈中等程度变异,并由南向北递减,样带0~5 m剖面平均土壤蓄水量为735mm;随着土层深度的增加,土壤水分在空间上的变异增强,而在时间上的变异减弱,表明深层土壤水分具有较强的时间稳定性特征。干燥度、黏粒、归一化植被指数和坡度是影响区域土壤水分空间分布的主要因素,可作为一定置信水平上预测区域土壤水分空间分布状况的预测变量。

英文摘要：

Soil moisture is one of the key factors for vegetation restoration and ecological reconstruction on the Chinese Loess Plateau（ CLP）. To understand the regional spatio-temporal variations of profile soil water content and its potential influencing factors,a south-north transect with 86 observational sites were determined on the CLP. Soil water content was measured using a neutron probe to depth of 5 m from June to November 2013. The distribution and variation characteristics of soil water storage（ SWS） were evaluated and simulated using classical statistics. The results showed that SWS within different soil layers exhibited moderate variation and generally decreased from the south to the north of the CLP. The mean SWS within the 0—5 m profile for the transect was 735 mm. Spatial variation in SWS increased with increasing soil depth,while the temporal variation had a decreasing trend,suggesting that soil water content tend to be more temporally stable in deeper layers. Soil moisture was primarily influenced by the aridity,the content of clay,normalized difference vegetation index,and slope gradient on the regional scale. These parameters,therefore,could be used to predict spatial distribution of soil water content at a regional scale in a certain confidence level.