基于EFAST方法的SEBS模型参数全局敏感性分析

应用高效、稳健的EFAST方法,以黑河流域盈科绿洲站为例,从3个方面对SEBS模型的参数敏感性进行了分析:分别以感热通量(H)、潜热通量(λE)、蒸发比(fr)作为SEBS模型的输出结果,分析其对12个输入参数的敏感性;利用气象数据驱动模型,分析H、λE和fr对6个地表特征参数的敏感性;分析了参数取值范围对敏感性分析结果的影响。研究结果表明:H、λE与fr都对参考高度处的气温和风速、地表温度以及植被特征参数的敏感性较高。参数间相互作用对H、λE的间接影响很小,而对fr的影响较大。当气象输入参数确定时,6个地表参数中地表温度对模型输出的直接贡献最大,其主敏感度指数接近0.6。参数采样范围不同时,模型输入参数的敏感性表现不同。

Global Sensitivity Analysis of SEBS Model Parameters based on EFAST Method

The Extend Fourier Amplitude Sensitivity Test (EFAST) was used to analyze the global sensitivity of SEBS model parameters in Yingke oasis station located in Heihe river basin from three points below:(1) the sensitivity of input parameters was analyzed,when sensible heat flux (H),latent heat flux (λE) and evaporation fraction (fr),respectively,are as the output parameter of SEBS model.(2) The sensitivity of surface parameters was analyzed,when the meteorology data was fixed.(3) Impact of parameters ranges on sensitivity index was analyzed by tuning input parameter ranges.The results showed that the model is sensitive to air temperature,wind speed,surface temperature and vegetation parameters.The impact of parameter interactions is slight for H and λE,but great for fr.When the meteorological data is fixed,the output variables are highly sensitive to surface temperature with high main sensitivity index (about 0.6).The sensitivity of input parameters is different using different parameter ranges.