Low Casamance inverse estuary : Impacts on water quality and agrosystems in islander area

Autor: THIOR, Mamadou, SY, Amadou Abou, DIEDHIOU, Sécou Omar, CISSE, Idrissa, GOMIS, Joseph Samba, DESCROIX, Luc
Jazyk: francouzština
Rok vydání: 2019
Předmět:
DOI: 10.48421/imist.prsm/ewash-ti-v3i3.17099
Popis: The mouth of the Casamance River, that works as a ria impacts on the estuarine environment of the islands of the lower Casamance. In these islands where the altitude is extremely low (2 to 3 m), silty deposits are almost flush. However, the small tributaries (locally called “bolongs”) that crisscross the islands are connected to the main reach of the Casamance River. They therefore have a salinity increasing upstream except at the end the rainy season when cumulated rainfall is important. Therefore, this contribution aims to be an analysis of the impacts of the inverse functioning of the Casamance estuary on the quality of the water and the agrosystems. To do this, the approach relies on a literature review, the collection of field data (observations, surveys, interviews, etc.) in the islands of Diogue, Carabane and Niomoune, and on GIS analysis. At the same time, surveys of GPS points and the measures in situ of salinity were conducted (wells and sources of water supply, estuary, and mouth). The results showed that the salinity directly affects the wells which here are usually the main sources of water supply. Shallow aquifers are affected by saline intrusion. Besides, the hydrologic conditions of the Casamance River, not allowing an exchange of fresh water permanent, leave a risk of consumption of water from the well which so far is intended for secondary purposes.
Environmental and Water Sciences, public Health and Territorial Intelligence Journal, Vol. 3, No 3 (2019)
Databáze: OpenAIRE