This work aims to evaluate the impact of climate change on the quantitative availability of the Aghien lagoon located in the north of the Abidjan district in Côte d’Ivoire. In the first step, the semi-distri...This work aims to evaluate the impact of climate change on the quantitative availability of the Aghien lagoon located in the north of the Abidjan district in Côte d’Ivoire. In the first step, the semi-distributed SWAT (Soil and Water Assessment Tools) based physical model (Arnold et al., 1998) was calibrated and validated at the monthly time step over the period 1960-1981, in the Me watershed for which data from flow rates are available. SWAT was then applied on the watershed of the lagoon of Aghien which is ungauged but for which the challenges are considerable for the drinking water supply of the Abidjanese population. In the second step, the gross outputs (precipitation, temperatures) of six climate models of the CORDEX-Africa project under the “Representative Concentration Pathways” (RCP 4.5 and RCP 8.5) scenarios were corrected using the delta method. These corrected outputs were used at the SWAT model input to project the impact of climate change on the flow of the Aghien lagoon to horizons 2040 (2035-2056), 2060 (2057-2078) and 2080 (2079-2100). The projections made on these different horizons were compared with the simulated flow over the period 1960-1981. The results show a sensible decrease in the annual flow of the Aghien lagoon compared to the reference period (1960-1981). Under the medium assumption (RCP 4.5), the models predict a decrease in the annual discharge almost 10% on average. Under the pessimistic hypothesis (RCP 8.5), the average annual discharge should decrease by more than 17%. On a monthly basis, flows in August and September would increase by more than 80% and those in October and November would increase by more than 20% in both RCP scenarios.展开更多
This study aims to identify human uses and activities in the watershed Aghien lagoon in nine rural communities located downstream, near the lagoon in rural area, and upstream of the lagoon in the urban area. A sample ...This study aims to identify human uses and activities in the watershed Aghien lagoon in nine rural communities located downstream, near the lagoon in rural area, and upstream of the lagoon in the urban area. A sample of two thousand two hundred fifty eight (2258) households is selected by the cluster sampling technique to three degrees. To these persons, a survey was administered. An interview guide was submitted to the various economic operators of these areas. The results show that the lagoon is used by localities near the lagoon for the dishes, laundry, bathing and swimming for more than 80% of households. This resource is also used for fishing, transport, irrigation, consumption and defecation but at low levels and as a receptacle for garbage. In the villages bordering the lagoon, the main economic activity is agriculture, unlike trade in upstream urban areas.展开更多
The operating capacity of the Abidjan’s groundwater became insufficient. The deficit in drinking water resources in the District of Abidjan remains the major concern of the decision maker. The Aghien lagoon stands as...The operating capacity of the Abidjan’s groundwater became insufficient. The deficit in drinking water resources in the District of Abidjan remains the major concern of the decision maker. The Aghien lagoon stands as one of the most interesting alternatives. However, studies show the levels of pollutions of this resource without lighting out on the causes and sources of these pollutions. The present study extends over the entire catchment of the Aghien lagoon which reveals the presence of urban areas and agricultural activity areas. This raises real concerns for the Ivorian authorities. This study suggests making cartography of the risk levels of pollution on the Aghien lagoon by the surface runoff on the watershed to enlighten the decision-makers on the possible measures to be taken for the protection of this resource. It emerges from it that the risk of contamination of the lagoon is very likely. Agricultural and domestic best practices inside the pouring pond are compulsory to fight against the pollutions of this resource.展开更多
基金This reflection received financial support from the ERASMUS MUNDUS program through the KITE(Knowledge Integration and Transparency in Education)mobility project.
文摘This work aims to evaluate the impact of climate change on the quantitative availability of the Aghien lagoon located in the north of the Abidjan district in Côte d’Ivoire. In the first step, the semi-distributed SWAT (Soil and Water Assessment Tools) based physical model (Arnold et al., 1998) was calibrated and validated at the monthly time step over the period 1960-1981, in the Me watershed for which data from flow rates are available. SWAT was then applied on the watershed of the lagoon of Aghien which is ungauged but for which the challenges are considerable for the drinking water supply of the Abidjanese population. In the second step, the gross outputs (precipitation, temperatures) of six climate models of the CORDEX-Africa project under the “Representative Concentration Pathways” (RCP 4.5 and RCP 8.5) scenarios were corrected using the delta method. These corrected outputs were used at the SWAT model input to project the impact of climate change on the flow of the Aghien lagoon to horizons 2040 (2035-2056), 2060 (2057-2078) and 2080 (2079-2100). The projections made on these different horizons were compared with the simulated flow over the period 1960-1981. The results show a sensible decrease in the annual flow of the Aghien lagoon compared to the reference period (1960-1981). Under the medium assumption (RCP 4.5), the models predict a decrease in the annual discharge almost 10% on average. Under the pessimistic hypothesis (RCP 8.5), the average annual discharge should decrease by more than 17%. On a monthly basis, flows in August and September would increase by more than 80% and those in October and November would increase by more than 20% in both RCP scenarios.
基金funded by the AMRUGE-C2D 2015-2017 program,the Ivorian Ministry of Scientific Research and Higher Education and the French Research Institute for Development(IRD).
文摘This study aims to identify human uses and activities in the watershed Aghien lagoon in nine rural communities located downstream, near the lagoon in rural area, and upstream of the lagoon in the urban area. A sample of two thousand two hundred fifty eight (2258) households is selected by the cluster sampling technique to three degrees. To these persons, a survey was administered. An interview guide was submitted to the various economic operators of these areas. The results show that the lagoon is used by localities near the lagoon for the dishes, laundry, bathing and swimming for more than 80% of households. This resource is also used for fishing, transport, irrigation, consumption and defecation but at low levels and as a receptacle for garbage. In the villages bordering the lagoon, the main economic activity is agriculture, unlike trade in upstream urban areas.
文摘The operating capacity of the Abidjan’s groundwater became insufficient. The deficit in drinking water resources in the District of Abidjan remains the major concern of the decision maker. The Aghien lagoon stands as one of the most interesting alternatives. However, studies show the levels of pollutions of this resource without lighting out on the causes and sources of these pollutions. The present study extends over the entire catchment of the Aghien lagoon which reveals the presence of urban areas and agricultural activity areas. This raises real concerns for the Ivorian authorities. This study suggests making cartography of the risk levels of pollution on the Aghien lagoon by the surface runoff on the watershed to enlighten the decision-makers on the possible measures to be taken for the protection of this resource. It emerges from it that the risk of contamination of the lagoon is very likely. Agricultural and domestic best practices inside the pouring pond are compulsory to fight against the pollutions of this resource.
