【摘要】 选取长江源北麓河地区受冻融作用影响而严重退化的高寒草甸典型区域进行取样,通过实验和模拟等方法,对该区域内不同深度土层的土壤特征曲线、土壤饱和导水率、土壤粒径、容重和总孔隙度进行了研究和分析.结果表明:土壤的水分特征曲线由Gardner等与van Genuchten提出的幂函数方程拟合效果良好,0.1MPa为土壤水分特征曲线的临界值.0～5cm表层土壤的持水能力最小,20～30cm土壤的持水能力最大.0～5cm表层土壤供水能力最小,15～30cm土层的供水性能最好,适合植被根系的生长.土壤的饱和导水率随着深度的增加而减小.更多还原

【Abstract】 The research is carried out in Beiluhe River basin on the Tibetan Plateau,which is in the source regions of the Yangtze River,where degrading meadows are severely affected by the freezing and thawing,with the methods of choosing typical areas and quadrats to do experiment and simulation,and then studying the soil water characteristics,soil saturated hydraulic conductivities,soil particle size fractionation,soil bulk density and other soil porosities at different depths.The results show that the power function equation proposed by Gardner et al.and van Genuchten has a good simulation function to the soil moisture characteristics;there is a critical value of the soil moisture,0.1MPa.It is found that the water-retention capacity of the soil at the depth of 0～5cm is the minimum,and that at the depth of 20～30cm is the maximum.It is indicated that the soil at the depth of 0～5cm has the poorest capacity of water supplying.The soil at the depth of 15～30cm shows the greatest water supplying capacity,which is the optimum soil layer for the growth and development of plant roots.It is also found that the soil saturated hydraulic conductivity decreases with depth.更多还原