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| Titel |
Vulnerability of agricultural production in the Inner Niger Delta to water resources management under climate variability and change |
| VerfasserIn |
Stefan Liersch, Hagen Koch, Fred F. Hattermann |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052407
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| Zusammenfassung |
| A key pattern in most tropical and sub-tropical river basins is the strong seasonality of
the flow regime. Especially in densely populated lowland areas the flow regime
governs the water availability for human use. During the rainy season large lowland
areas are inundated and the additional water surfaces of these wetlands increase
evapotranspiration and groundwater recharge. However, these conditions change
totally during the dry season. The study area, the Inner Niger Delta (IND), situated
in an arid region in West Africa, is an example of such a wetland. The IND is a
network of tributaries, channels, swamps, and lakes providing vital habitats supporting
livelihoods in fishing, farming, and stock farming. These floodplains support the highest
livestock density in Africa, and are increasingly threatened by a variety of external
and internal pressures, such as climate variability as well as unsustainable uses.
Food production in the IND is closely related to wetland inundation and of outmost
importance for the livelihood of approximately one million people inhabiting the wetland
region. The extent of the temporary inundated area ranges between 10,000 and
30,000 km2 and is one important indicator for food security. It highly depends
on rainfall volumes and intensities of the monsoon in the mountainous headwater
region.
Assessing the vulnerability of the socio-ecological system of the IND to climate
variability, droughts, water and land management is subject of this study. This requires
adequate representation of natural processes, particularly the processes of wetland inundation
and release. Process-based modeling of wetlands in catchments, especially in large-scale river
basins, is still a challenge, and integration of riparian zones in catchment modeling is even
more challenging because of the complex interactions and feedbacks between hydrology,
vegetation and soils in wetlands.
For this purpose an inundation module was implemented in a semi-distributed
eco-hydrological model. Moreover, a reservoir module was developed and integrated into the
hydrological model in order to account for the impacts of different reservoir management
strategies in the upstream catchment. On the one hand the integrated model is used to
investigate the impacts of climate variability and change on inflow patterns and inundation
processes in the wetland, and on the other hand it is used to study possible adaptation and
mitigation strategies in terms of reservoir management. The results show that beside
climate change the reservoir management of existing and planned reservoirs has
an important effect on the inflow to the IND and therefore on food production. |
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