中文摘要：

玷污水力的参数 _s ,， n ， K _s , L 和 _{货车 Genuchten-Mualem 模型的 r} 在中国为上面的长江的最大的主要支流集水( Jialing 河)的表面土壤基于土壤性质用三 pedotransfer 功能( PTF )被估计。土壤数据库从中国与的第二国家土壤调查一空间 30 X 30 弧秒分辨率。根据为学习集水的水力的参数和为一个特定的质地类的引用值在特定的 PTF 的开发数据库提供了的土壤的 continuous-PTFs-estimated 值之间的差别的统计分析，最好的评价用 W 被获得 ? 小型机关枪的一种 PTF。Rawls 与 Brakenssiek PTF 是为参数 _{被 W 作为零假定的 r} ? 小型机关枪的一种 PTF。确定的更高的 _r (0.08%)和更低的 K _s ( 20 cm/d )和 _{在相对集水的另外的区域的中间下游的区域的 s} (0.43%)能导致大量表面流量并且因而提供更高的精力侵蚀土壤。因此，这些因素为发生在这个区域的以前报导的严重土壤侵蚀提供支持的解释。为估计的水力的参数的空间异质分析以 semivariogram 证明空间关联距离在 50-80 km 的范围并且空间可变性(基石) 不除了参数 K _s 和 L。与在零距离(金块) 的指数的模型一起的半变化是基石的 30%-50% 。这研究为估计从在一个大分水岭的土壤调查数据的水力的性质放大的土壤提供了一条实际 PTF 途径。评价结果能提供更好的卓见进表面流量和土壤侵蚀的机制，它是重要的更好在集水理解并且设法侵蚀。

英文摘要：

Soil hydraulic parameters θs,α,n,Ks,L and θr of the van Genuchten-Mualem model were estimated using three pedotransfer functions（PTFs） based on soil properties for surface soils of the largest main tributary catchment（the Jialing River） of the upper Yangtze River in China.The soil database was from the second national soil survey of China with a spatial 30 × 30 arc-second resolution.According to the statistical analysis of the differences between the continuous-PTFs-estimated values of soil hydraulic parameters for the study catchment and the reference values for a specific texture class provided in the development database of a specific PTF,best estimations were obtained using the W？sten PTF.The Rawls ＆ Brakenssiek PTF was good estimation for parameter θr that was assumed as zero by W？sten PTF.The established higher θr（0.08%） and lower Ks（20 cm/d） and θs（0.43%） in the mid-downstream area relative to the other areas of the catchment could lead to larger amounts of surface runoff andconsequently provide higher energy to erode soil.Thus,these factors provide a supporting explanation for previously reported severe soil erosion occurring in this area.Spatial heterogeneity analysis for estimated hydraulic parameters in terms of semivariogram showed that the spatial correlation distance was in the range of 50-80 km and that the spatial variability（sill） was not large except for parameters Ks and L.The semi-variance with the exponential model at the zero distance（nugget） was 30%-50% of the sill.This study provided a practical PTF approach for estimating soil hydraulic properties from soil survey data at a large watershed scale.The estimation results could provide better insight into the mechanism of surface runoff and soil erosion,which is important to better understand and manage erosion in the catchment.