为了明确陕北黄土区草地土壤水分特征及其对季节的响应,选取吴起县金佛坪流域草地为研究对象,通过采用定位监测法,分析研究区草地土壤水分特征,结果表明:1)不同季节草地土壤含水量存在显著差异(P<0.05),总体表现出春季>秋季>夏季;不同坡向、坡位土壤含水量也均存在差异。2)草地土壤含水量随季节变化有明显的波动性,其中,在0~100 cm土层受季节变化表现最为明显;100 cm土层以下变化较小,相对稳定。不同季节草地土壤干燥强度均属于轻度干燥化,干燥化指数介于0.21%~1.03%之间。3)秋季储水亏缺度总体呈现出先增加后减少的趋势,且随土层深度的增加,亏缺度逐渐降低;春季土壤水分亏缺度总体呈现出波动降低的趋势,且随着土层深度的增加趋于稳定。4)降水对100 cm以下草地土壤水分有所补充,且不同坡向、坡位表现各不相同。

In order to clarify the soil moisture characteristics of grassland in the loess region of northern Shaanxi and its response to seasons,this paper selected the grassland of Jinfoping Watershed in Wuqi County as the research object,and analyzed the soil moisture characteristics of grassland in the research area by using positioning monitoring method. The results showed that:1) there were significant differences in soil moisture content in different seasons (P<0.05),and the general pattern was spring>autumn >summer. 2) The soil water content of grassland had obvious fluctuation with the seasons,especially in the 0~100cm soil layer,and the change was small and relatively stable below 100cm soil layer. The drying intensity of grassland soil in different seasons was light drying,and the drying index ranged from 0.21% to 1.03%. 3) The deficit degree of water storage in autumn showed a trend of first increasing and then decreasing,and gradually decreased with the increase of soil depth,while the deficit degree of soil water in spring showed a trend of fluctuation decreasing and tended to be stable with the increase of soil depth. 4) The precipitation supplemented the soil moisture of the grassland below 100cm,and the performance of different slope direction and slope position was different.