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### 基于数据同化技术的延河流域绿水模拟研究

1. 1.北京市水科学技术研究院,北京 100048
2.北京师范大学地理学与遥感科学学院,北京 100875
• 收稿日期:2016-08-30 修回日期:2016-12-14 出版日期:2017-07-20 发布日期:2017-07-20
• 作者简介:

作者简介: 赵海根（1983-）,男,河北邯郸人,工程师,主要从事生态水文研究。E-mail:zhaohaigen1983@163.com

• 基金资助:
国家重点研发计划（2016YFC0402403）、北京市博士后工作经费资助项目（2016-ZZ-118）、中国博士后工作项目（2016M591093）资助

### The Simulation of Green Water in the Yanhe River Basin Based on Data Assimilation

Haigen Zhao1,2(), Shengtian Yang2, Xu Zhou2

1. 1.Beijing Water Science and Technology Institute, Beijing 100048,China
2. School of Geography, Beijing Normal University, Beijing 100875,China
• Received:2016-08-30 Revised:2016-12-14 Online:2017-07-20 Published:2017-07-20
• Supported by:
National Key Project for R&D(2016YFC0402403), Beijing Postdoctoral Research Foundation(2016-ZZ-118), China Postdoctoral Science(2016M591093)

Abstract:

The accurate green water simulation is very important for the crop growth, agricultural drought monitoring, food security and rational allocation of water resources. Now, there are three methods which can be used to get greenwater: field observation, remote sensing calculation and hydrological model simulation. The field observation can not get the accurate simulation result of catchment green water at large scale because of complicated spatial heterogeneity; the remote sensing calculation method can only get the instantaneous simulation result at a large scale region. Compared to the two methods above, the hydrological model can get the continuous green water simulation results in large scale catchment. But, because hydrological models have different structures and characteristics, different simulation results can be got when inputting the same simulation data in the same region. In order to comprehensively utilize the simulation results of different hydrological models, the data assimilation method is a good choice. In this study, the Distributed Time Variant Gain Model(DTVGM) and Distributed Evapotranspiration Process Model(DEPM) were used to simulate the hydrological process in the catchment controlled by the Yan’an station in the Yanhe River Basin based on their structures and characteristics, and the Extended Kalman Filter(EKF) data assimilation algorithm was used to assimilate the green water (actual evapotranspiration) simulated by the two models to optimize the green water in the study area. The statistical indexes show that the simulation result of DTVGM is applicable to simulate the hydrological processes in this study area, the Nash-Sutcliffe coefficient(NSCE) is 0.83 and the relative water balance is -1.97% in the whole simulation period. The water balance relative index of DEPM is -1.81% in the whole simulation period, which shows that DEPM can model the water balance well at the study area.Besides, the simulation results show that the green water in 2010 simulated by the two models is 378.52 mm and 375.55 mm, respectively. There are not obvious difference for the mean simulation results of two models and the spatial distribution pattern are also similar, but there is more spatial variable information for result simulated by DEPM model than that of DTVGM. Compared to the observed green water, the NSCE of green water simulated by DTVGM and DEPM is respectively 0.76 and 0.59, but the spatial distribution of green water simulated by DEPM has more change information. Then, the green water simulation result of DEPM was used as “observed value” to assimilate the green water simulated by DTVGM based on the EKF data assimilation method in order to optimize the green water simulation result.The average green water simulated by DTVGM after data assimilation is 376.42 mm and the NSCE is 0.78 when comparing to the observed green water. The Standard Deviation(SD) for the green water simulation becomes 40.37 mm after assimilation, which is significantly increased by 7.79 mm than the original modeling results. The green water in spatial distribution shows more spatial change information and is more reasonable in this study area.

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