Soil water is the main form of water in desert areas, and its primary source is precipitation, which has a vital impact on the changes in soil moisture and plays an important role in deep soil water recharge(DSWR) in ...Soil water is the main form of water in desert areas, and its primary source is precipitation, which has a vital impact on the changes in soil moisture and plays an important role in deep soil water recharge(DSWR) in sandy areas. This study investigated the soil water response of mobile sand dunes to precipitation in a semi-arid sandy area of China. Precipitation and soil moisture sensors were used to simultaneously monitor the precipitation and the soil water content(SWC) dynamics of the upper 200-cm soil layer of mobile sand dunes located at the northeastern edge of the Mu Us Sandy Land of China in 2013. The data were used to analyze the characteristics of SWC, infiltration, and eventually DSWR. The results show that the accumulated precipitation(494 mm) from April 1 to November 1 of 2013 significantly influenced SWC at soil depths of 0-200 cm. When SWC in the upper 200-cm soil layer was relatively low(6.49%), the wetting front associated with53.8 mm of accumulated precipitation could reach the 200-cm deep soil layer. When the SWC of the upper 200-cm soil layer was relatively high(10.22%), the wetting front associated with the 24.2 mm of accumulated precipitation could reach the upper 200-cm deep soil layer. Of the accumulated 494-mm precipitation in 2013, 103.2 mm of precipitation eventually became DSWR, accounting for 20.9% of the precipitation of that year. The annual soil moisture increase was 54.26 mm in 2013. Accurate calculation of DSWR will have important theoretical and practical significance for desert water resources assessment and ecological construction.展开更多
利用东北地区地面102站56a（1951～2006年）逐日气象观测资料，驱动NCAR陆面模式CLM3．5，模拟东北地区生长季地表水分盈余量（Surface Water Surplus，SWS），探讨和分析了东北地区生长季1951～2006年地表干湿状况的时空变化规律。结...利用东北地区地面102站56a（1951～2006年）逐日气象观测资料，驱动NCAR陆面模式CLM3．5，模拟东北地区生长季地表水分盈余量（Surface Water Surplus，SWS），探讨和分析了东北地区生长季1951～2006年地表干湿状况的时空变化规律。结果表明：1971～2000年平均东北地区生长季SWS反映的地表干湿状况具有较大的地域差异，全区SWS为100～800mm；中、西部为SWS低值区，属半干旱、半湿润区；东、南、北部为相对高值区，属湿润、半湿润区。生长季地表干湿状况存在显著的年际、年代际变化；56a来，东北地区生长季SWS呈线性减少趋势，即地表变干，SWS空间分布的年代际变化，同样表现为变干趋势，尤其2000～2006年是地表变干最为显著的时期，表明在全球变暖背景下东北地区地表干旱化趋势增强。分析表明地表干湿状况是下垫面与气候变化共同作用的结果，研究地表干湿状况需要综合考虑水分收支项。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41661006)the Fundamental Research Funds for the Central Non-Profit Research Institution of Chinese Academy of Forestry(Grant No.CAFYBB2014QB046)Chinese Scholarship Council
文摘Soil water is the main form of water in desert areas, and its primary source is precipitation, which has a vital impact on the changes in soil moisture and plays an important role in deep soil water recharge(DSWR) in sandy areas. This study investigated the soil water response of mobile sand dunes to precipitation in a semi-arid sandy area of China. Precipitation and soil moisture sensors were used to simultaneously monitor the precipitation and the soil water content(SWC) dynamics of the upper 200-cm soil layer of mobile sand dunes located at the northeastern edge of the Mu Us Sandy Land of China in 2013. The data were used to analyze the characteristics of SWC, infiltration, and eventually DSWR. The results show that the accumulated precipitation(494 mm) from April 1 to November 1 of 2013 significantly influenced SWC at soil depths of 0-200 cm. When SWC in the upper 200-cm soil layer was relatively low(6.49%), the wetting front associated with53.8 mm of accumulated precipitation could reach the 200-cm deep soil layer. When the SWC of the upper 200-cm soil layer was relatively high(10.22%), the wetting front associated with the 24.2 mm of accumulated precipitation could reach the upper 200-cm deep soil layer. Of the accumulated 494-mm precipitation in 2013, 103.2 mm of precipitation eventually became DSWR, accounting for 20.9% of the precipitation of that year. The annual soil moisture increase was 54.26 mm in 2013. Accurate calculation of DSWR will have important theoretical and practical significance for desert water resources assessment and ecological construction.
文摘利用东北地区地面102站56a（1951～2006年）逐日气象观测资料，驱动NCAR陆面模式CLM3．5，模拟东北地区生长季地表水分盈余量（Surface Water Surplus，SWS），探讨和分析了东北地区生长季1951～2006年地表干湿状况的时空变化规律。结果表明：1971～2000年平均东北地区生长季SWS反映的地表干湿状况具有较大的地域差异，全区SWS为100～800mm；中、西部为SWS低值区，属半干旱、半湿润区；东、南、北部为相对高值区，属湿润、半湿润区。生长季地表干湿状况存在显著的年际、年代际变化；56a来，东北地区生长季SWS呈线性减少趋势，即地表变干，SWS空间分布的年代际变化，同样表现为变干趋势，尤其2000～2006年是地表变干最为显著的时期，表明在全球变暖背景下东北地区地表干旱化趋势增强。分析表明地表干湿状况是下垫面与气候变化共同作用的结果，研究地表干湿状况需要综合考虑水分收支项。
