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土壤水分是干旱生态系统的重要制约因素,一直是干旱区研究和生态建设的热点和难点问题,对降雨的深层土壤渗漏水量仍缺少定量观测研究.本文采用作者自主研发的YWB-01型土壤深层水分渗漏计量仪对毛乌素沙地等4大沙漠(地)的流动沙地测试记录了降雨入渗到150 cm以下深层土壤的渗漏水量,连续2年的资料表明:(1)降雨的深层渗漏水量自东向西由半干旱区向干旱区递减,其中:乌审旗流动沙地渗漏水总量高达508.4 mm,占同期降雨量58.4%,磴口的渗漏水量为23.8 mm,占降雨量13.9%,而阿拉善左旗和右旗未测试到渗漏水量,但≥25 mm的强降水对干旱和半干旱区流沙地深层土壤水分的渗漏补给具有重要作用;(2)渗漏水量的季节变化与降水的变化趋于一致,但有一定滞后,在降雨量较大地区,二者变化的相似性更强;(3)单次较强降雨在降雨开始的40~55 h后出现一个渗漏水量峰值,渗漏速率增加较快但其减少相对缓慢,持续渗漏过程长达150 h左右,降雨量越大,渗漏水量峰值就越高,渗漏水量所占降雨量的比例也越高;受降雨强度、雨量和历时的共同作用,就低强度、长历时和单次降雨量大的降雨事件更有利于降雨对沙地深层土壤的渗漏补给;(4)受土壤冻融作用的影响,在快速消融期3月份出现一个小的渗漏补给峰值.研究结果对我国干旱和半干旱区沙地水资源的准确评估和合理利用及生态建设具有现实指导意义.
Soil moisture is an important restricting factor of arid ecosystems and has been a hot and difficult issue in the research and ecological construction of arid areas all the time. There is still a lack of quantitative observational study on the amount of soil water leakage in rainy days.In this paper, YWB-01 soil Deep Moisture Leakage Meter The mobile sand test in 4 deserts (ground), such as Mu Us Sandy Land, recorded the amount of seepage water infiltration into deeper soil below 150 cm. The data for 2 consecutive years showed that: (1) The amount of deep seepage water decreased from arid area to arid area from east to west, of which, the total amount of seepage water in the flowing sandy land of Wushen Banner was as high as 508.4 mm, accounting for 58.4% of the total rainfall in the littoral area and 23.8 mm , Accounting for 13.9% of the rainfall, while the Alashan Zuoqi and Right Banner did not detect the amount of water leakage, but heavy rainfall ≥ 25 mm played an important role in the leakage of deep soil moisture in quicksand and sandstorm in arid and semi-arid regions; ) The seasonal variation of leakage water tends to be consistent with the change of precipitation, but there is a certain lag. In the areas with large rainfall, the similarities between the two changes are stronger. (3) Single strong rainfall is 40 ~ After 55 h, a leakage of water peak, leakage rate But the decrease is relatively slow. The continuous leaking process lasts up to about 150 h. The larger the rainfall is, the higher the peak value of seepage water quantity is, and the higher the proportion of the amount of water leakage is. The higher the rainfall intensity, And diachronic events, rainfall events with low intensity, long duration and single heavy rains are more conducive to the supply of rainfall to the deep soil in sandy land. (4) Under the influence of soil freeze-thaw, A small leakage recharge peak appears in March. The research results have realistic guiding significance for the accurate assessment and rational utilization of water resources and ecological construction of sandy land in arid and semi-arid regions in China.