【摘要】 研究了黄土丘陵小流域土壤水分空间异质性的剖面及时间变化规律 ,从土壤水分与环境因子的关系分析入手 ,探讨了景观尺度上土壤水分空间异质性的影响因子 .结果表明 ,黄土丘陵小流域土壤水分的平均值与空间异质性均呈现出明显的剖面变化与季节变化规律 .土壤平均含水量从表土层开始 ,随着土层深度的增加而增高 ;空间异质性 (变异系数 )从亚表层开始增加 .土壤含水量在降雨后立即升高随后逐渐降低 ;空间异质性却正好相反 .方差分析与相关分析表明 ,土壤水分的空间异质性是立地尺度 (坡度 )、坡面尺度 (坡位与相对高度 )和流域尺度 (土地利用与降雨 )等多重尺度上的环境因子共同作用的结果 .这些不同尺度的环境因子对土壤水分空间异质性的影响表现出明显的剖面变化规律与季节变化规律 .更多还原

【Abstract】 The degree of spatial heterogeneity of soil moisture and the ability of environm ental attributes to predict that heterogeneity were studied at 81 locations in D anangou catchment (3.5km 2) in the semi arid Loess area of China. Soil moistu re measurements were performed biweekly at five depths in soil profile (0～5,10～1 5,20～25, 40～45 and 70～75cm) from May to September 1999 using time domain refl ectometry (TDRabstract It was observed that the mean and the spatial heterogeneity of soil moisture exhibit significant profile patterns. As the increasing of soil de pth, the mean soil moisture content increases significantly beginning at 0～5cm and the spatial heterogeneity also exhibits an increasing trend but beginning at 10～15cm. The temporal changes in the mean and the heterogeneity are also obvio us. During the measured periods, the mean moisture increases after precipitation events and is followed by a decline as the soil dries down, whilst the heteroge neity exhibits an opposite pattern. The spatial heterogeneity of both the time averaged soil moisture and the layer averaged soil moisture are influenced by t he environmental attributes at site scale (slope angle), hillslope scale (hillsl op e position and relative elevation) and watershed scale (precipitation and land u seabstract However, the relative roles of environmental attributes vary with soil dept hs and with seasonal evolution.更多还原