宁南山区典型流域土壤水分动态变化规律研究

采用定位观测、谐波分析以及灰色关联度等方法对典型流域所选的６个断面共５６个水分观测点的实测数据进行了分析，研究流域土壤水分动态变化规律．结果表明，土壤含水量年内变化主要受降雨和蒸发散的年内变化影响，明显分为干湿两季；土壤水分年内变化可划分为四个时期：春季土壤水分缓慢蒸发期、旱季土壤水分严重亏缺期、雨季土壤水分补偿期、冬春土壤水分相对稳定期．研究中利用标准差和变异系数对土壤水分垂直变化进行了分层，并用灰色关联度方法分析了各层次间土壤水分及其与期间降雨量的关系，得出土壤水分剖面分布可分为速变层、活跃层和次活跃层，林地水分活跃层较深，草、农、裸地水分活跃层偏上的土壤水分垂直分布规律

Study on Soil Moisture Dynamic Variation Law of Typical Watershed in the Southern Mountainous Area of Ningxia Hui Autonomous Region

The observed data in the 56 selected observation spots with six sections in the watershed are analysed by means of location observation,harmonic analysis and grey correlativity.The soil moisture dynamic variation law in the watershed is also studied. The results show that the yearly variation of soil moisture content affected by the yearly variation of rainfall and evaportranspiration is remarkably divided into the arid and humid seasons,and then the soil moisture is divided into four periods,which are the slow soil moisture evaporation period in spring,the serious soil moisture deficiency period in arid season,the soil moisture supplement period,the relative stable soil moisture period in the winter and spring.The two indexes of standard deviation and variation coefficient are used to separate the layer of the soil vertical moisture variation,and the method of grey correlativity is applied to analyse the relation of soil moisture among different layers and the relation of the soil moisture and the precipitation in the same period. The results show that the soil moisture vertical layer is divided into the rapid change layer, the active layer and the second active layer. The active layer of soil moisture is relatively deep in woodland and it is relatively shallow in grassland, farmland and bare land.