寒冷干旱区土壤水力特性参数的模拟估算

Simulation and Prediction of Hydraulic Characteristics in the Cold-Arid Zone

测量非饱和带水力特性参数 ,诸如 :饱和含水率、田间持水率等系数 ,即耗时、费力又难以保证试验精度。但利用实测的土壤基本物化特征参数 ,颗粒级配、土壤容重等 ,通过土壤传递函数 (PTFs)可以较准确地内插估算出土壤水力特性参数。本研究利用国家自然基金重点项目区———内蒙古太仆寺旗试验断面的实测资料 ,引入对数平均粒径和对数标准偏差 ,通过人工神经网络方法建立了太仆寺旗研究区的BP -PTFs函数模型和BP -PTFs-log函数模型 ,用误差分析理论分析评价了两函数模型的有效性、适用性和精度 ,并通过两种函数模型的外推预测结果的分析检验比较 ,结果表明 ,所建立的BP -PTFs-log函数模型要优于BP

Measuring unsaturated hydraulic characteristics, such as saturated soil moisture, field moisture etc., is not only costly,time consuming, but also not accurate. The soil hydraulic characteristics can be estimated accurately using the Pedo-transfer functions (PTFs) depending on soil fundamental parameters which are easy to get such as size-grade distribution of soil and bulk density,etc. PTFs (BP-PTFs, BP-PTFs-log) were developed with using neural network with the equilibratous gradus diameter of logarithm and normative windage of logarithm of data measured in Taipusi Banner, Inner Mongolia. The two PTFs were analyzed with error theory and accuracy of BP-PTFs and BP-PTFs-log. The evaluating results indicatd that BP-PTFs-log model is better than BP-PTFs model.