Journal of Geographical Sciences ›› 2016, Vol. 26 ›› Issue (2): 230-242.doi: 10.1007/s11442-016-1265-4

• Orginal Article • Previous Articles     Next Articles

A review on evapotranspiration data assimilation based on hydrological models

Qingqing DONG1(), Chesheng *ZHAN2(), Huixiao WANG1, Feiyu WANG2,3, Mingcheng ZHU1   

  1. 1. College of Water Sciences, Beijing Normal University, Beijing 100875, China
    2. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-06-19 Accepted:2015-07-21 Online:2016-02-25 Published:2016-02-25
  • About author:

    Author: Dong Qingqing (1990-), Master Candidate, specialized in evapotranspiration data assimilation. E-mail: dongqingqing@mail.bnu.edu.cn

    *Corresponding author: Zhan Chesheng (1975-), Associate Professor, E-mail: zhancs@igsnrr.ac.cn

  • Supported by:
    National Key Basic Research Program of China (973 Program), No.2015CB452701;National Natural Science Foundation of China, No.41271003, No.41371043, No.41401042

Abstract:

Accurate estimation of evapotranspiration (ET), especially at the regional scale, is an extensively investigated topic in the field of water science. The ability to obtain a continuous time series of highly precise ET values is necessary for improving our knowledge of fundamental hydrological processes and for addressing various problems regarding the use of water. This objective can be achieved by means of ET data assimilation based on hydrological modeling. In this paper, a comprehensive review of ET data assimilation based on hydrological modeling is provided. The difficulties and bottlenecks of using ET, being a non-state variable, to construct data assimilation relationships are elaborated upon, with a discussion and analysis of the feasibility of assimilating ET into various hydrological models. Based on this, a new easy-to-operate ET assimilation scheme that includes a water circulation physical mechanism is proposed. The scheme was developed with an improved data assimilation system that uses a distributed time-variant gain model (DTVGM), and the ET-soil humidity nonlinear time response relationship of this model. Moreover, the ET mechanism in the DTVGM was improved to perfect the ET data assimilation system. The new scheme may provide the best spatial and temporal characteristics for hydrological states, and may be referenced for accurate estimation of regional evapotranspiration.

Key words: evapotranspiration, data assimilation, hydrological model, non-state variable