Inundation prediction in tropical wetlands from JULES-CaMa-Flood global land surface simulations
Open Access
- 21 June 2022
- journal article
- research article
- Published by Copernicus GmbH in Hydrology and Earth System Sciences
- Vol. 26 (12), 3151-3175
- https://doi.org/10.5194/hess-26-3151-2022
Abstract
Wetlands play a key role in hydrological and biogeochemical cycles and provide multiple ecosystem services to society. However, reliable data on the extent of global inundated areas and the magnitude of their contribution to local hydrological dynamics remain surprisingly uncertain. Global hydrological models and land surface models (LSMs) include only the most major inundation sources and mechanisms; therefore, quantifying the uncertainties in available data sources remains a challenge. We address these problems by taking a leading global data product on inundation extents (Global Inundation Extent from Multi-Satellites, GIEMS) and matching against predictions from a global hydrodynamic model (Catchment-based Macro-scale Floodplain – CaMa-Flood) driven by runoff data generated by a land surface model (Joint UK Land and Environment Simulator, JULES). The ability of the model to reproduce patterns and dynamics shown by the observational product is assessed in a number of case studies across the tropics, which show that it performs well in large wetland regions, with a good match between corresponding seasonal cycles. At a finer spatial scale, we found that water inputs (e.g. groundwater inflow to wetland) became underestimated in comparison to water outputs (e.g. infiltration and evaporation from wetland) in some wetlands (e.g. Sudd, Tonlé Sap), and the opposite occurred in others (e.g. Okavango) in our model predictions. We also found evidence for an underestimation of low levels of inundation in our satellite-based inundation data (approx. 10 % of total inundation may not be recorded). Additionally, some wetlands display a clear spatial displacement between observed and simulated inundation as a result of overestimation or underestimation of overbank flooding upstream. This study provides timely information on inherent biases in inundation prediction and observation that can contribute to our current ability to make critical predictions of inundation events at both regional and global levels.Keywords
Funding Information
- Natural Environment Research Council (NE/S017380/1)
This publication has 78 references indexed in Scilit:
- Present state of global wetland extent and wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP)Biogeosciences (online), 2013
- A physically based description of floodplain inundation dynamics in a global river routing modelWater Resources Research, 2011
- A simple inertial formulation of the shallow water equations for efficient two-dimensional flood inundation modellingJournal of Hydrology, 2010
- Feedbacks on convection from an African wetlandGeophysical Research Letters, 2010
- Regional review: the hydrology of the Okavango Delta, Botswana—processes, data and modellingHydrogeology Journal, 2009
- Analysis of self-describing gridded geoscience data with netCDF Operators (NCO)Environmental Modelling & Software, 2008
- Wetland dynamics using a suite of satellite observations: A case study of application and evaluation for the Indian SubcontinentGeophysical Research Letters, 2006
- Development and validation of a global database of lakes, reservoirs and wetlandsJournal of Hydrology, 2004
- The value of wetlands: importance of scale and landscape settingEcological Economics, 2000
- Flood inundation simulation in a river basin using a physically based distributed hydrologic modelHydrological Processes, 2000