土壤湿度方程求解方法的比较  

A comparative study of the difference algorithms for solving the soil moisture equation

作　　者：张述文[1] 李得勤[1] 刘彦华[1] 邱崇践[1] 

机构地区：[1]兰州大学大气科学学院甘肃省干旱气候变化与减灾重点实验室,兰州730000

出　　处：《兰州大学学报（自然科学版）》2010年第4期46-52,57,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(40775065,40475012);科技部公益性行业(气象)科研专项基金项目(GYHY200806029)

摘　　要：为了定量评估不同差分方案以及这些近似对模拟土壤湿度的影响,以三类代表性陆面模式中Richards方程离散化方法为例,针对四类均匀和非均匀土壤,在三种不同上边界条件下分别比较不同方法在模拟土壤湿度方面的差异,同时与满足土壤水分守恒并具有高精度的迭代方案结果作对比.结果显示:对于均匀土壤,各种离散化方法模拟的土壤湿度廓线基本一致;但对非均匀土壤,除一种方法外,其他两类方法的结果均与迭代差分方案存在差别.In order to quantitatively evaluate the impact of the discretization schemes and approximations on the modeling of soil moisture, three difference methods from the three land surface models were investigated. Under three different upper boundary conditions combined with four types of homogeneous and heterogeneous soils, the results from the three methods were compared with each other and furthermore with the general mass-conservation iteration numerical solutions. The conclusions are that, for the homogeneous soil, almost no difference is found among the results from the four schemes; however, for the heterogeneous soil, except for the results from one difference method, the soil moisture profiles simulated by the other two difference methods are completely different from those by the iteration difference scheme.

关 键 词：RICHARDS方程 数值模拟 土壤湿度 差分格式 

分 类 号：P456.7[天文地球—大气科学及气象学] O241.82[理学—计算数学]