The characteristics of soil water cycle and water balance on steep grassland under natural and simulated rainfall conditions in the Loess Plateau of China
The characteristics of soil water cycle and water balance on steep grassland under natural and simulated rainfall conditions in the Loess Plateau of China
复制标题
黄土高原自然和模拟降雨条件下陡峭草地土壤水循环与水平衡特征
DOI：
10.1016/j.jhydrol.2008.07.037
复制
发表时间：
2008-10-15
影响因子：
6.4
通讯作者：
Li, Yuyuan
中科院分区：
文献类型：
--
作者：
Chen, Hongsong;Shao, Mingan;Li, Yuyuan
大规模的植被恢复很有帮助。但也加剧了水资源短缺，导致中国黄土高原200 cm以下的土壤干燥化。研究黄土高原土壤干燥化形成的动力学机制对黄土高原农业的可持续发展具有重要意义。2002年6 ~ 11月，在陕西省黄土高原长武县草地陡坡地，利用自然降雨和人工模拟降雨，对0-400 cm土层土壤水分循环和水分平衡特征进行了研究。干旱年，年降雨量为460毫米。在模拟降雨下，该年同样被视为多雨年，年降雨量为850毫米条件结果表明，随着降雨量的增加，0-200 cm土层土壤含水量的时间变异性减小。干旱年降雨入渗深度为0-200 cm，多雨年为0-300 cm。在自然条件下的耗水过程中，2002年7月21日受蒸散影响的最深土层迅速达到200 cm，整个0-200 cm土层土壤贮水量减少48 mm。而在同一调查期内，模拟降雨条件下，0-400 cm土层的土壤储水量仅增加了71 mm，而对应的降雨量约为640 mm; 5月29日~ 8月10日的458 mm超模拟降雨并未导致200-400 cm土层土壤干化现象的消失。大部分入渗的雨水滞留在0-200 cm土层中，随后在雨季被ET耗尽。由于200 cm以下土层水分运移量很小，干旱和正常降雨年份深层土壤都出现了干化现象。(C)2008 Elsevier B. V.保留所有权利。
Large-scale vegetation restoration has been helpful. to prevent serious soil erosion, but also has aggravated water scarcity and resulted in soil desiccation below a depth of 200 cm in the Loess Plateau of China. To understand the dynamic mechanism of soil desiccation formation is very important for sustainable development of agriculture in the Loess Plateau. Based on natural and simulated rainfall, the characteristics of soil water cycle and water balance in the 0-400 cm soil Layer on a steep grassland hillslope in Changwu County of Shaanxi Loess Plateau were investigated from June to November in 2002, a drought year with annual rainfall of 460 mm. It was similarly considered to represent a rainy year with annual rainfall of 850 mm under simulated rainfall conditions. The results showed that the temporal variability of water contents would decrease in the upper 0-200 cm soil layer with the increase in rainfall. The depth of soil affected by rainfall infiltration was 0-200 cm in the drought year and 0-300 cm in the rainy year. During the period of water consumption under natural conditions, the deepest layer of soil influenced by evapotranspiration (ET) rapidly reached a depth of 200 cm on July 21, 2002, and soil water storage decreased by 48 mm from the whole 0-200 cm soil Layer. However, during the same investigation period under simulated rainfall conditions, soil water storage in the 0-400 cm soil layer increased by only 71 mm, although the corresponding rainfall was about 640 mm. The extra-simulated rainfall of 458 mm from May 29 to August 10 did not result in the disappearance of soil desiccation in the 200-400 cm deep soil layer. Most infiltrated rainwater retained in the top 0-200 cm soil layer, and it was subsequently depleted by ET in the rainy season. Because very little water moved below the 200 cm depth, there was desiccation in the deep soil Layer in drought and normal rainfall years. (C) 2008 Elsevier B.V. ALL rights reserved.