非参数化蒸散发估算方法在黑河流域的适用性分析  

Applicability Analysis of Nonparametric Evapotranspiration Approach over Heihe River Basin

作　　者：王宁[1,2] 贾立[1] 李占胜[1,2] 李娜娜[1,2] 胡光成[1] 

机构地区：[1]中国科学院遥感与数字地球研究所遥感科学国家重点实验室,北京100101 [2]中国科学院大学,北京100049

出　　处：《高原气象》2016年第1期118-128,共11页Plateau Meteorology

基　　金：国家863计划课题基金(2012AA12A304);中国科学院;国家外国专家局创新团队国际合作伙伴计划(KZZD-EW-TZ-09);国家自然科学青年基金项目(41101326)

摘　　要：陆面蒸散发是水循环过程中的重要组成部分,直接关系到地表的能量和水量平衡。基于哈密顿原理的非参数化蒸散发估算方法能够避免复杂的参数化过程,降低计算过程的不确定性。首先,利用非参数化方法估算了黑河流域不同下垫面的蒸散发,并利用地面观测数据进行了验证,分析了非参数化方法在不同下垫面和不同季节的适用性。对不同下垫面的验证结果表明,在湿润下垫面该方法会低估实际蒸散发,在干旱下垫面会高估实际蒸散发;对不同季节的验证结果表明,夏季蒸散发估算精度明显优于冬季。其次,进一步对非参数化方法进行了敏感性分析:在湿润下垫面,地表净辐射通量对估算结果影响较大;在干旱下垫面,地表净辐射通量和地表温度对非参数化估算方法结果影响较大。最后,利用非参数化方法结合遥感数据和大气驱动数据估算了黑河流域中上游的区域蒸散发,并利用地面观测数据结合足迹模型进行了验证,分析了非参数化方法估算区域蒸散发的适用性,估算结果能够反映该区域地表通量的分布特征,但是与地面观测数据相比存在一定的误差,不同下垫面的均方根误差在50~100W·m^(-2)之间。Terrestrial evapotranspiration（ET） is essential to the global hydrological cycle and climate systems.A nonparametric evapotranspiration approach based on Hamilton principle was verified in Heihe river basin.This approach can estimate ET without parameterization of the surface transfer coefficients,and need not to go into detailed micro-processes for complex ET.Furthermore,all the associated variables are measurable,so this approach can avoid the complicated parametric process of other models,and reduce the uncertainty in the process of calculation.At present,nonparametric ET approach was verified only in a few sites.There is no sufficient research on the applicability of this approach in other ecosystems and the regional scale.The applicability of the nonparametric approach in different underlying surface and different seasons were analyzed.The results show that the nonparametric approach will underestimate the ET in humid area and overestimate ET in arid area.Sensitivity analysis show that net radiation has the great impact on the result of the nonparametric approachin humid areas,but in arid area,land surface temperature is also a significantly sensitive parameter.The regional ET over the Heihe river basin was calculated using nonparametric approach combined with remote sensing data and atmospheric driven data,and validated the results against ground based flux measurements.And then the applicability of the nonparametric approach in regional ET was analyzed.The nonparametric approach results can reflect the surface flux distribution characteristics of this region,but there were some errors compared with the ground based flux measurements.The root mean square errors were range 50 to 100 W ？ m^2 over different land cover types.

关 键 词：非参数化方法 黑河流域 蒸散发 

分 类 号：P426.2[天文地球—大气科学及气象学]