不同目标函数对水文模型模拟效果影响研究  

The Influence of Different Objective Functions on Hydrological Model Performance

作　　者：张如强[1] 高红凯[2] 刘俊国[1,3] 田勇 

机构地区：[1]北京林业大学自然保护区学院,北京100083 [2]亚利桑那州立大学,亚利桑那州坦佩az85282 [3]南方科技大学环境科学与工程学院,广东深圳518055

出　　处：《中国农村水利水电》2017年第4期106-111,共6页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(91325302;91425303)

摘　　要：水文模型的模拟效果与目标函数的选取直接相关,最常用的目标函数是纳什系数。纳什系数存在不足之处,因此产生了纳什系数的变形形式,主要包括对数形式、开方形式、绝对值形式和相对值形式。目前,不同目标函数(如纳什系数及其变形形式)对模拟效果影响的研究相对较少。以黑河流域上游为研究区,应用FLEX-Topo水文模型、采用MOSCEM-UA参数优化算法,通过设定不同的目标函数,从纳什系数、相关系数、平均绝对误差和平均值之差4个数值指标评估模拟效果,从而揭示各变形形式对整体模拟效果的影响。结果表明:(1)4种纳什系数变形形式的模拟结果中,开方形式的模拟效果最好;(2)以纳什系数为目标函数的模拟结果会高估洪峰流量,而以变形形式的模拟结果略好,但都会低估基流流量;(3)目标函数分别为纳什系数和开方形式的模拟结果相差不大,但开方形式对洪峰流量的模拟略好,且相关系数更高。黑河流域的水文模拟建议采用开方形式。The selection of the objective function is of great importance for model performance. Nash-Sutcliffe efficiency （E） is the most widespread objective function in hydrological model calibration. Modified forms of E are made due to the inadequacy in NSE, which includes logarithmic transformation （ Et, ）, root squared transformation （ Esqn ）, absolute transformation （ Eabs ） and relative transformation （ Erel ）. However, there are few studies focusing on the influence of different objective functions, such as the modified forms of E, on model perform- ance. We use the FLEX-Topo model, taking the Upper Heihe River basin as the study site, utilize MOSCEM-UA algorithm, to compare the model performance by setting different objective functions from the view point of the dynamic, mean absolute error and water balance. The re- sults show that （1） the simulated flow of taking Esqrt as an objective function is the best among all of modified forms. （2）Simulated flow of tak- ing E as an objective function overestimated the high flow very much while all the five objective functions mentioned above underestimate the low flow. （3）The difference between the simulated flow of E and Esqrt is very small, but the correlation coefficient of Esqrt was a bit higher. In a word, Esqrt is suggested when Nash-Sutcliffe efficiency is selected as the objective function.

关 键 词：纳什系数变形形式 目标函数 模拟效果 黑河上游 

分 类 号：TV1[水利工程]