孙家岔流域坡面不同土地利用的土壤水分变化分析

以甘肃省兰州市孙家岔流域为研究对象,采用1982—1983年和2011年土壤水分实测资料,分析该流域坡面防护区不同土地利用土壤水分的年内、年际变化特征。结果表明,在黄土丘陵区小流域内,农坡和荒坡土壤水分的年内动态变化具有相同的规律,但农坡年内平均含水量要高于荒地。流域内降雨量的多少以及时空分配是土壤水分变化趋势的主要影响因子。土壤水分的变异程度随降雨量和土层深度的增加而减小,土壤深度在1.20~1.40 m内含水量受季节气候动态变化影响显著,土壤深度超过1.60 m内含水量在相同年度具有一定的时间稳定性。土质较好的荒地,选择适宜的农作物(如洋芋),可提高缓坡区(5°~15°)降水资源的有效利用率。

Study on soil moisture content under different land use types in Sunjiacha basin

The characteristics of annual and seasonal changes of soil moisture in Sunjiacha basin from 1982—1983 and in 2011 were measured and analyzed.The results show that in the small watershed of loess hilly region, the change trend of soil moisture in a year is basically the same in farmland and wasteland.The soil moisture is strongly influenced by rainfall and its spatial and temporal distribution.The variability of soil moisture decreases with the increase in soil depth and rainfall.The dynamic changes of soil moisture in 1.20～1.40 m layer are significantly affected by seasonal climate,while soil moisture has temporal stability in the same year when soil depth is more than 1.60 m.Growing suitable crops(such as potato) in wasteland with good soil can improve water use efficiency in the gentle slope area(5°～15°).