典型草原禁牧条件下土壤水分对降雨模式的响应  

Response of Soil Moisture Content to Rainfall Patterns in Typical Steppe under Grazing Prohibition

作　　者：徐冉[1] 张圣微[1,2,3] 朱仲元 张鹏[1] 高露 XU Ran;ZHANG Sheng-wei;ZHU Zhong-yuan;ZHANG Peng;GAO Lu(College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,Inner Mongolia,China;Key Laboratory of Protection and Utilization of Water Resources of Inner Mongolia Autonomous Region,Hohhot 010018,inzier Mongolia,China;Inner Mongolia Autonomous Region Key Laboratory of Big Data Research and Application of Agriculture and Animal Husbandry,Hohhot 010018,inner Mongolia,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018 [2]内蒙古自治区水资源保护与利用重点实验室,内蒙古呼和浩特010018 [3]内蒙古自治区农牧业大数据研究与应用重点实验室,内蒙古呼和浩特010018

出　　处：《干旱区研究》2019年第6期1359-1367,共9页Arid Zone Research

基　　金：国家自然科学基金项目(51779116,51669018);内蒙古自治区杰出青年培育基金项目(2019JQ06)资助

摘　　要：通过在锡林郭勒草原设置禁牧和放牧试验点,对气象、植被、土壤要素和5cm、10cm、15cm、30cm层土壤水分进行监测分析,揭示典型草原禁牧条件下降雨和土壤水分的变化及转化规律,结果表明:禁牧3a后土壤垂向异质性增强,降雨过程中各土层土壤含水量差异显著,放牧区则相反;土壤水分对降雨响应的滞后时间随土层深度增加而增加,相对于禁牧区,放牧区浅层土壤(5cm、10cm)持水性能较弱,入渗完成用时较短;5mm以下的降雨对禁牧和放牧区土壤水分均无明显补给作用,当降雨连续均匀且强度不超过5 mm·h^-1时最有利于入渗,放牧区入渗深度达到15cm和30cm层分别需要7.9mm和大于25 mm的降雨,而禁牧区大于5 mm的降雨就可以入渗到30cm土层;强度5~6 mm·h^-1的独立降雨只能入渗到表层土壤中(5cm),强度大于15 mm·h^-1的降雨在禁牧区能通过大孔隙快速入渗到30cm及更深层土壤,放牧区则表层入渗较快(0~5cm),深层入渗较慢,会形成地表径流甚至洪水灾害。该研究的结果可以为草地生态水文过程研究和制定合理的放牧政策提供参考。The meteorological,vegetation and soil factors as well as the soil moisture content in depths of 5-,10-,15-and 30-cm layers were monitored and analyzed.The purposes were to analyze and reveal the change of rainfall patterns and soil moisture content under grazing prohibition in the Xilin Gol typical steppe in Inner Mongolia.The results showed that the vertical heterogeneity of soil moisture content was increased after implementing the grazing prohibition for 3 years,the difference of soil moisture content in each soil layer was significant during rainfall process in the grazing prohibition sites,while the situation was opposite in the grazing areas.The lag time of soil moisture response to rainfall increased with the increase of soil depth.Compared with the grazing prohibition sites,the water holding capacity of shallow soil(5cm and 10cm in depth)in the grazing areas was weaker,and the infiltration time was shorter.There was no obvious replenishment effect of rainfall on soil moisture when the rainfall was less than 5 mm in both the grazing areas and grazing prohibition sites,and it was the most advantageous for the rainwater infiltration when rained continuously and uniformly and the rainfall intensity did not exceed 5 mm·h-1.Rainwater could infiltrate into 15-and 30-cm soil layers when rainfall was 7.9 mm and more than 25 mm respectively in the grazing areas,but it could infiltrate into 30-cm soil layer when rainfall was more than 5mm in the grazing prohibition sites.Rainwater could infiltrate into topsoil(5cm)only when the intensity of an independent rainfall was 5-6 mm·h^-1,and it could infiltrate rapidly into 30-cm soil layer or deeper through the macropores when the rainfall intensity was higher than 15 mm·h^-1 in the grazing prohibition sites.In the grazing areas,rainwater could infiltrate rapidly into topsoil(0-5cm)but slowly into deep soil to form surface runoff and even flood disasters.The study results could be referred in researching the grassland ecohydrological process and formulating a rational

关 键 词：锡林郭勒草原 降雨模式 土壤含水量 降雨入渗 内蒙古 

分 类 号：S81[农业科学—畜牧学]