基于图形特征的Green-Ampt入渗模型关键参数S_f和K_s的简化求解  

A SIMPLIFIED SOLUTION TO KEY PARAMETERS S_f AND K_s IN GRAPHICS-BASED GREEN-AMPT INFILTRATION MODEL

作　　者：张振华[1] 谢恒星[1] 刘继龙[1] 蔡焕杰[2] 

机构地区：[1]烟台师范学院地理与资源管理学院,山东烟台264025 [2]西北农林科技大学旱区农业水土工程教育部重点实验室,陕西杨凌712100

出　　处：《土壤学报》2006年第2期203-208,共6页Acta Pedologica Sinica

基　　金：国家自然科学基金重点项目(50339030);国家自然科学基金项目(50479051);烟台师范学院校基金(000444;043201)资助

摘　　要：Green—Ampt入渗模型应用广泛，是模拟坡面降雨入渗、产流过程常用的手段，湿润锋平均基质吸力S和表征导水率K是模型中的关键参数。对地表积水入渗过程中湿润区内平均含水率增量△θ（t）进行了定义，对烟台棕壤土积水入渗试验分析表明，在入渗过程中△θ（t）为一常量0．34。根据水量平衡原理得到了Greer-Ampt入渗模型中概化湿润锋磊和实际湿润锋Z^αf的定量关系，并通过对Green．Ampt入渗模型的分析，提出了利用i（t）～I（t）或i（t）-Z^αf之间图形特征关系来确定湿润锋平均基质吸力Sf，和表征导水率Ks的方法。同实测资料相比，利用基于i（t）-I（t）和i（t）-Z^αf图形关系所获Sf和Ks预测的累计入渗量和湿润锋精度较高，整体相对误差小于6％。The Green-Ampt infiltration model is extensively applied in many aspects, and a common means used for simulation of rainfall infiltration and stream production on slope. Average potential suction Sf and general saturation water conductivity Ks are key parameters of this model. In this paper the mean water content increment △θ（t） in wetted zone during ponded infiltration was defined. A ponded infiltration experiment was carried out on brown earth in Yantai, indicating △θ（t） was a constant of 0.34. The relation between general wetting front and actual wetting front was quantified based on the water balance principle, and methods of determining Sf and Ks were put forward on the basis of the relationships of infiltration rate i （t） with cumulation infiltration I（t） or with actual wetting front Z^αf in graphic characteristics. Compared with the field data, the calculation of infiltration rate and accumulation infiltration based on graphic characterization of i（t） - I（t） and i（t） - Z^αf was relatively high in accuracy with overall relative error being less than 6 %.

关 键 词：GREEN-AMPT入渗模型 平均含水率增量 图形法 Sf KS 

分 类 号：S275.6[农业科学—农业水土工程]