DOI: 10.5194/hess-21-2015-2017
Scopus记录号: 2-s2.0-85017609935
论文题名: The effect of satellite-derived surface soil moisture and leaf area index land data assimilation on streamflow simulations over France
作者: Fairbairn D ; , Lavinia Barbu A ; , Napoly A ; , Albergel C ; , Mahfouf J ; -F ; , Calvet J ; -C
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2017
卷: 21, 期: 4 起始页码: 2015
结束页码: 2033
语种: 英语
Scopus关键词: Aquifers
; Atmospheric radiation
; Efficiency
; Hydrogeology
; Moisture
; Rivers
; Runoff
; Soil moisture
; Soils
; Surface measurement
; Vegetation
; Anthropogenic influence
; Atmospheric reanalysis
; Land data assimilation
; Land surface modeling
; Observation operator
; Physiological process
; Streamflow simulations
; Surface soil moisture
; Random errors
; atmospheric forcing
; correction
; data assimilation
; drainage
; evapotranspiration
; hydrogeology
; hydrological modeling
; land surface
; leaf area index
; river discharge
; runoff
; satellite data
; simulation
; soil moisture
; streamflow
; France
英文摘要: This study evaluates the impact of assimilating surface soil moisture (SSM) and leaf area index (LAI) observations into a land surface model using the SAFRAN-ISBA-MODCOU (SIM) hydrological suite. SIM consists of three stages: (1) an atmospheric reanalysis (SAFRAN) over France, which forces (2) the three-layer ISBA land surface model, which then provides drainage and runoff inputs to (3) the MODCOU hydro-geological model. The drainage and runoff outputs from ISBA are validated by comparing the simulated river discharge from MODCOU with over 500 river-gauge observations over France and with a subset of stations with low-anthropogenic influence, over several years. This study makes use of the A-gs version of ISBA that allows for physiological processes. The atmospheric forcing for the ISBA-A-gs model underestimates direct shortwave and long-wave radiation by approximately 5ĝ€†% averaged over France. The ISBA-A-gs model also substantially underestimates the grassland LAI compared with satellite retrievals during winter dormancy. These differences result in an underestimation (overestimation) of evapotranspiration (drainage and runoff). The excess runoff flowing into the rivers and aquifers contributes to an overestimation of the SIM river discharge. Two experiments attempted to resolve these problems: (i) a correction of the minimum LAI model parameter for grasslands and (ii) a bias-correction of the model radiative forcing. Two data assimilation experiments were also performed, which are designed to correct random errors in the initial conditions: (iii) the assimilation of LAI observations and (iv) the assimilation of SSM and LAI observations. The data assimilation for (iii) and (iv) was done with a simplified extended Kalman filter (SEKF), which uses finite differences in the observation operator Jacobians to relate the observations to the model variables. Experiments (i) and (ii) improved the median SIM Nash scores by about 9ĝ€†% and 18ĝ€†% respectively. Experiment (iii) reduced the LAI phase errors in ISBA-A-gs but had little impact on the discharge Nash efficiency of SIM. In contrast, experiment (iv) resulted in spurious increases in drainage and runoff, which degraded the median discharge Nash efficiency by about 7ĝ€†% . The poor performance of the SEKF originates from the observation operator Jacobians. These Jacobians are dampened when the soil is saturated and when the vegetation is dormant, which leads to positive biases in drainage and/or runoff and to insufficient corrections during winter, respectively. Possible ways to improve the model are discussed, including a new multi-layer diffusion model and a more realistic response of photosynthesis to temperature in mountainous regions. The data assimilation should be advanced by accounting for model and forcing uncertainties. © The Author(s) 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79199
Appears in Collections: 气候变化事实与影响
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作者单位: CNRM, UMR 3589 (Météo-France, CNRS), Toulouse, France
Recommended Citation:
Fairbairn D,, Lavinia Barbu A,, Napoly A,et al. The effect of satellite-derived surface soil moisture and leaf area index land data assimilation on streamflow simulations over France[J]. Hydrology and Earth System Sciences,2017-01-01,21(4)