【摘要】 为分析桉树林土壤含水量时间稳定性特征,选取桉树林典型坡面,测量坡面9个样点5年土壤含水量,基于所测数据采用相对差分法和Spearman秩相关系数法分析土壤含水率的时空变异性和时间稳定性。结果表明,研究区坡面5年的表层平均土壤含水率为21.81%,在空间上表现为较弱的变异性,在时间上具有中等程度变异性。各年平均土壤含水率相关系数偏低,土壤含水率的空间模式在观测时间上的相似性较弱,其平均相对差分变化范围为-7.08%～5.03%,相对差分标准差和时间稳定性指数的平均值分别为5.73%和6.58%,说明不同坡度条件下土壤水分具有较好的时间稳定性。测点2,3,6,7,8水分含量较平均值高,测点1,4,9,5水分含量相对较低,湿润点的标准差和时间稳定性指数都相对小且稳定,即土壤湿润状态的水分稳定性比干燥状态的好。回归分析得到测点5的土壤含水量和整个坡面水分均值具有较高相关性,R2值为0.879,MBE值为0.141,RMSE值为99.4%,即测点5可作为代表性测点估计整个研究区浅层平均土壤含水率。更多还原

【Abstract】 In order to analyze the temporal stability characteristics of soil moisture content in Eucalyptus forests,nine sample points on a typical eucalyptus forest slope were selected to measure the soil moisture content for five years.Based on the measured data,the temporal and spatial variability and temporal stability of soil water content were analyzed by relative difference method and Spearman rank correlation coefficient method.The results illustrated that the average surface soil moisture content of five years of the study slope area was 21.81%,which showed weak variability in space and moderate variability in time.The correlation coefficient of average soil moisture content was low in each year,and the spatial pattern of soil water content had weak similarity in observation time,and the variation range of the average relative difference was-7.08%to 5.03%,and the average values of relative difference standard deviation and time stability index were 5.73% and 6.58%,respectively,indicating that the soil moisture had better time stability under different slope conditions.The moisture content of measuring points 2,3,6,7 and 8 were higher than the average value,while the moisture content of measuring points 1,4,9,and 5 were relatively low.The standard deviation and time stability index of the wetting point were relatively small and stable,indicating that the moisture stability of soil in the wet state was better than that in the dry state.According to the regression analysis,there was a high correlation between the soil moisture content of point 5 and the mean water content of the whole slope,with the R2 value of 0.879,the MBE value of 0.141 and the RMSE value of99.4%.In other words,point 5 could be used as a representative measurement point to estimate the average soil moisture content in the shallow layer of the whole research area.更多还原