Evaluation of the quality index of the riparian strip of three tributaries of the Ayamé 1 hydroelectric dam lake, subject to agricultural pressure (South-Comoé Region, Côte d’Ivoire)

In Côte d’Ivoire, the progressive degradation of the riparian vegetation of the tributaries of the artificial lake of Ayamé 1 represents the source of the deterioration of water quality. Thus, the general objective of this study is to acquire a better understanding of the quality of the banks of the lake's tributaries in order to identify priority areas for intervention in the event of revegetation. To do this, the protocol for evaluating the riparian strip quality index consisted of delimiting segments 200 m long and 10 m wide, along the riparian vegetation of three streams that communicate directly with Lake Ayamé 1. Within these sampling areas, an inventory was conducted to assign a coverage percentage to the different components of the riparian strip, allowing for the calculation of the riparian quality index. Data analysis revealed low floristic richness with 36 plant species, distributed into 15 species of herbs, 8 species of lianas, 7 species of shrubs, 5 species of trees and 1 species of small shrub. Almost all riparian zone segments of the three streams have IQBR values classified as low and very low. This is due to the destruction of riverbanks for the benefit of crops and pastures. The results of this study could represent an awareness-raising tool for local residents and public authorities to plan revegetation actions in order to restore all the ecosystem services related to this important water resource.