基于遥感数据的于田绿洲土壤湿度时空变化及其影响因素分析

Effect factors on soil moisture tempo-spatial variability of Yutian Oasis in arid area of China

以典型干旱区新疆于田县绿洲为研究区,利用相关分析和非线性回归分析方法,研究了不同季节和深度的土壤湿度时空变化的影响因素。研究结果表明,对于研究区表层1m深度土壤,各个土层的土壤湿度存在着显著且强烈的相关关系,不同深度土层的土壤湿度空间变异程度不同,表层土壤湿度的空间变异程度较大。地下水位和土壤蒸散发量是研究区土壤湿度时空变化的主要控制因素,不同季节,地下水位和土壤蒸散发量对不同深度土壤湿度空间变化的影响力和影响深度不同,春季和夏季,都是地下水位大于土壤蒸散发量的影响力,土壤蒸散发量的影响深度在春季达到60-80cm,在夏季达到100cm。海拔高度和土壤温度对土壤湿度的空间变异有微弱的影响。在对土壤湿度时空变化具有显著影响的因素中,除土壤温度外,其它因素对土壤湿度时空变化的影响呈非线性关系。

Analysis on effect factors of soil moisture tempo-spatial variation in arid area is very important for the soil moisture forecasting,regulation and understanding of soil moisture spatial variation mechanism. The Yutian oasis was selected as a typical region in arid area,by using correlation and nonlinear regression analysis methods,we analyzed the factors that affect the spatial variation of soil moisture at different depth. The results showed that for the surface soil layer to the depth of 1m,the soil moisture of soil layers at different depth had significant and stronger correlation,spatial variation of soil moisture at different depth was different,the spatial variation degree of soil moisture at depth of 0-10 cm was the strongest. The groundwater level and soil evapotranspiration were the main effect factors on soil spatial variation in the study area; the power of groundwater level and soil evapotranspiration were different to the tempo-spatial variation of soil moisture at different depth,ground water level had a larger effect on soil moisture tempo-spatial variation than soil evapotranspiration in spring and autumn; the soil evapotranspiration had an effect on soil moisture spatial variation at a depth of 60-80 cm in spring,and it was at 100 cm in autumn. Altitude and soil temperature had a significant but weaker influence on soil tempo-moisture spatial variation; the effect factors that had a significant influence on soil tempo-moisture spatial variation had a nonlinear relationship with the tempo-spatial variation of soil moisture,except for soil temperature. This research provided a reference for the study on the mechanism of soil moisture tempo-spatial variation and management of water resource in arid area.