Contribution of Geographic Information Systems in Protection Zones Delineation around a Surface Water Resource in Adzope Region (Southeast of Côte d’Ivoire)

Abstract

Adzope's Municipal Artificial Lake which serves as a drinking water supply to the population is prone to pollution due to human activities and increasing urbanization. Thus, it is essential to protect this surface water supply for sustainable use. The objective of this study is to determine the protection zones around this water reservoir in order to preserve the stored water quality. To achieve this, a methodological approach based on a Geographic Information System (GIS) was adopted. This methodological approach first consisted to assess the water reservoir vulnerability to pollution according to certain hydrological parameters (slope, land use, soil type, runoff, and drainage network density) and then to determine the protection zones according to the different vulnerability classes. After the scoring of different parameters, a weight was assigned to each, from the multi-criteria method (AHP). The combination of the weighted parameters in the GIS enabled to establish the water reservoir vulnerability indexes map. The vulnerability map established subsequently presents five (5) vulnerability classes in the watershed: very low (12%) and low (23%) in the North and South of the study area, moderate (32%) disseminated throughout the study area, high (20%) and very high (13%) particularly in the West and North of the water reservoir and in the East of study area. This water reservoir vulnerability map is potentially influenced by the land use parameter according to the sensitivity analysis test. The different vulnerability classes then allowed the delimitation of three protection zones (Zone 1, Zone 2 and Zone 3) around the water reservoir. The immediate protection zone (Zone 1) has a width between 100 and 450 m around the water reservoir with *Geographic Information System for protection zones delineation around a surface water resource.

Contribution of Geomatics to the Delimitation of Protection Perimeters: Case of Agbo River in Agboville (South-East of Côte d’Ivoire)

“…Each of the required factors is then prioritized and weighted according to the importance of its role in the process of delineating protection perimeters. This methodological approach has been used by several authors in Côte d'Ivoire, namely Eba et al [2] in Gagnoa; Anoh [14] in Taabo; Deh et al [15] in Adzope; Ake et al [16] in Aboisso and in other countries, namely Garouani et Abdelaziz [1] in Morocco (Hachef dam).…”

“…This supervised classification made it possible to discriminate between five land use classes (Figure 7): water, degraded forest, industrial crops, habitats and bare soil, and crop and fallow mosaic, which were validated by a field mission (8 and 9 October 2019). The method of Saaty [19], used by Eba et al [2] Deh et al [15] Ake et al [16] El Morjani [20] has been exploited. It is a pairwise comparison method using the Analytical Hierarchy Process (AHP).…”

Assessment of Ground Water Vulnerability to Pollution in the City of Bafoussam, Western Region-Cameroon

“…This vulnerability is much more pronounced in urban areas, according to the analyzes carried out in these various observation wells, it results that certain groundwater in the heart of urban and peri-urban centers is already contaminated by faecal matter. After carrying out several studies on aquifers in the city of Dschang [7,8,15] in Bafoussam come to a conclusion that the poor management of faecal effluents are potentially at the origin groundwater pollution, especially in a context of precarious urban development. These comments can be verified for faecal pollution with 51.78 % of the study area presenting an average specific vulnerability to faecal pollution that is 8,387.25 ha.…”

“…These aquifer vulnerability studies are becoming more and more urgent with the pressure exerted by the waste or effluent generated by various activities of anthropogenic origin [5,6]. This is potentially the cause of the chemical and bacteriological pollution already observed in certain underground resources throughout the world [7].…”

Utilizing Hydrodynamic Modeling and GIS for Surface Water Intake Vulnerability Analysis

“…Accidental pollution incidents have caused a major threat to water safety of drinking water sources, so Tian et al studied the vulnerability of risk receptors such as drinking water intakes, and the environmental risk of different sub-regions were evaluated by model [20].Wang et al developed a water source risk assessment method based on GIS in Shenzhen [21].The Municipal Artificial Lake is protected by three protection zones that have been constructed using Geographic Information Systems (GIS) techniques [22]. The objectives of this study are to develop a GIS application for the river surface municipal intakes data and apply the Delft3D model to simulate the river flow for different flow conditions.…”