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Assimilation of Backscatter Observations into a Hydrological Model: A Case Study in Belgium Using ASCAT Data

Authors :
Pierre Baguis
Alberto Carrassi
Emmanuel Roulin
Stéphane Vannitsem
Sara Modanesi
Hans Lievens
Michel Bechtold
Gabrielle De Lannoy
Source :
Remote Sensing, Vol 14, Iss 22, p 5740 (2022)
Publication Year :
2022
Publisher :
MDPI AG, 2022.

Abstract

We investigated the possibilities of improving hydrological simulations by assimilating radar backscatter observations from the advanced scatterometer (ASCAT) in the hydrological model SCHEME using a calibrated water cloud model (WCM) as an observation operator. The WCM simulates backscatter based on soil moisture and vegetation data and can therefore be used to generate observation predictions for data assimilation. The study was conducted over two Belgian catchments with different hydrological regimes: the Demer and the Ourthe catchment. The main differences between the two catchments can be summarized in precipitation and streamflow levels, which are higher in the Ourthe. The data assimilation method adopted here was the ensemble Kalman filter (EnKF), whereby the uncertainty of the state estimate was described via the ensemble statistics. The focus was on the optimization of the EnKF, and possible solutions to address biases introduced by ensemble perturbations were investigated. The latter issue contributes to the fact that backscatter data assimilation only marginally improves the overall scores of the discharge simulations over the deterministic reference run, and only for the Ourthe catchment. These performances, however, considerably depend on the period considered within the 5 years of analysis. Future lines of research on bias correction, the data assimilation of soil moisture and backscatter data are also outlined.

Details

Language :
English
ISSN :
20724292
Volume :
14
Issue :
22
Database :
Directory of Open Access Journals
Journal :
Remote Sensing
Publication Type :
Academic Journal
Accession number :
edsdoj.b696e2720ec407fb56df2021dfc2c43
Document Type :
article
Full Text :
https://doi.org/10.3390/rs14225740