黑河上游土壤含水量的空间分布与环境因子的关系

Analysis of the relationships between the spatial variations of soil moisture and the environmental factors in the upstream of the Heihe River watershed

通过原位观测及大范围多尺度采集位于青藏高原北缘的祁连山地黑河上游土壤含水量数据,得到土壤含水量的空间分布,并运用旋转主成分分析法分析影响黑河上游土壤含水量的主要环境因子.结果表明:在黑河上游,影响土壤含水量的主要因子是地形因子,土壤物理属性与土壤含水量之间的相关关系不显著;地形因子中坡度和坡向与土壤含水量呈显著负相关,土壤含水量在坡向作用下呈现北坡高于南坡的趋势,海拔与土壤含水量呈现显著的正相关关系.

The relationships were analyzed between the spatial distribution of soil moisture and the environ-mental factors in the upstream of the Heihe River watershed in Northwest China. Both in-situ and random soil samples were collected across the entire study area to determine the soil texture and moisture content in August 2012. Satellite images, DEM, land cover, and soil databases were used to derive the normalized differ-ential vegetation index （NDVI）, slope, aspect, and vegetation covers, etc. using geographic information systems （GIS）. Geostatistical analysis and rotated principal component analysis （RPCA） were conducted to derive the relationships between the soil moisture content and related environmental variables. The results showed that topography was the main factor affecting the spatial variations of soil moisture in the study area, the slope gradient and aspect were negatively correlated to the soil moisture content and the soil water content was higher in the north-faced slope than in the south-faced slope in the upstream of the Heihe River watershed.