CAJ | 학술논문

采用集合卡尔曼滤波同化水文模型与遥感模型反演的蒸散发(ET)结果,获得更接近真实情况的 ET,并利用同化后的 ET结果进一步优化水文模型,从而获取连续精度较高的区域 ET.通过对北京市沙河流域1999-2007年的ET过程研究显示,运用本方案可以改善水文模型对 ET的估算精度,模拟出精度较高的流域蒸散发过程.
채용집합잡이만려파동화수문모형여요감모형반연적증산발(ET)결과,획득경접근진실정황적 ET,병이용동화후적 ET결과진일보우화수문모형,종이획취련속정도교고적구역 ET.통과대북경시사하류역1999-2007년적ET과정연구현시,운용본방안가이개선수문모형대 ET적고산정도,모의출정도교고적류역증산발과정.
A new integrated method was used to estimate continuous,high precision regional ET by data assimilation (DA)technology combined with remote sensing and hydrological models.Data from 18 typical TM/ETM+images taken under clear skies from 1999 to 2007 in Shahe river basin(Beijing)were used.Two-layer remote sensing ET was used to calculate regional ETs for 1 8 days;Calculated values were used as observation values for DA.Distributed hydrological model was used to simulate daily ETs for these 8 years as background values. The two data sets were assimilated by ensemble kalman filter (EnKF ) algorithm. Assimilated ETs were used to construct obj ective function to further optimize hydrological model in order to obtain a time-continuous ET process.The model was tested with observed daily ETs from flux observation stations in the study area.Optimization by assimilated ETs reduced average relative ETs error from 1 3.8% to 6.4%.Thus,integrated approach is appropriate for simulating ET process with high precision.