ANTHROPOGENIC PRESSURE IN RURAL AREAS: DIAGNOSIS AND MAPPING OF POTENTIAL POLLUTION SOURCES AFFECTING WATER RESOURCESIN THE WATERSHED HEADS OF THE OUEME AND PENDJARI RIVERS IN THE COMMUNE OF COPARGO (NORTH-WEST BENIN)

Abstract

Critical in assessing the quality and quantity of watercourses, headwaters of watersheds have been under anthropogenic pressure for several years, which has had negative impacts on water resources and soils. This study aims to assess the state of anthropogenic activities within the headwaters of the Copargo watersheds, followed by identifying and mapping potential sources of pollution to the water resources of the Oueme and Pendjari river headwaters in the Copargo municipality. To achieve this, data were collected through surveys, interviews, direct field observations, and remote sensing using Google Earth Engine. The results indicate that agriculture is the main activity, practiced by 90.84% of the population. Livestock farming (8.9%) and wood exploitation (7.2%) follow. The surveys reveal that the land is rarely left fallow, indicating overexploitation. The average duration of land cultivation during an agricultural season is 7.77 months. The agricultural inputs used include chemical fertilizers (NPK fertilizers and urea) and pesticides (herbicides and insecticides). On average, 120.5 kg of NPK fertilizer, 63 kg of urea, and 6.99 liters of pesticides are used per season per farmer. 2% of the producers attribute soil depletion to the use of agricultural inputs. The results of this study show that the potential sources of pollution in the study area remain anthropogenic activities, particularly agriculture, through the increased use of chemical fertilizers and pesticides (herbicides, insecticides). The absence of industrial units in the study area eliminates any risk of pollution from factories. Given the activities carried out in the area, this study will be followed by a physicochemical characterization of water resources and soils to evaluate their physicochemical and chemical quality.