Future river flows and flood extent in the Upper Niger and Inner Niger Delta: GCM-related uncertainty using the CMIP5 ensemble |
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| Authors: | Julian R Thompson Andrew Crawley Daniel G Kingston |
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| Institution: | 1. Wetland Research Unit, UCL Department of Geography, University College London, London, UK;2. Department of Geography, University of Otago, Dunedin, New Zealand |
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| Abstract: | A semi-distributed hydrological model of the Upper Niger and the Inner Niger Delta is used to investigate the RCP 4.5 scenario for 41 CMIP5 GCMs in the 2050s and 2080s. In percentage terms, the range of change in precipitation is around four times as large as for potential evapotranspiration, which increases for most GCMs over most sub-catchments. Almost equal numbers of sub-catchment–GCM combinations experience positive and negative precipitation change. River discharge changes are equally uncertain. Inter-GCM range in mean discharge exceeds that of precipitation by three times in percentage terms. Declining seasonal flooding within the Inner Delta is dominant; 78 and 68% of GCMs project declines in October and November for the 2050s and 2080s, respectively. The 10- and 90-percentile changes in mean annual peak inundation range from ?6136 km2 (?43%) to +987 km2 (+7%) for the 2050s and ?6176 km2 (?43%) to +1165 km2 (+8.2%) for the 2080s. |
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| Keywords: | Inner Niger Delta climate change uncertainty hydrological modelling CMIP5 |
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