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.

The lake system of Taabo watershed contributes at 35% in the country electrification. Besides this use, water is also used in agriculture, fishing and for drinking water. The increasing human activities in its basin led to siltation of Kossou's Lake and eutrophication of 26% of Taabo's Lake total area. However, no study has yet been performed to protect or prevent this resource against pollution. This study is the first in Ivory Coast intending to delineate three protection areas around the watershed lakes. It tries firstly to define all parameters involved in the surface water intrinsic vulnerability. Their integration in multicriteria analysis coupled to use of Geographic Information System (GIS) has then used to delineate protection area around the basin lakes. Three zones were proposed: (1) the immediate protection zone, with a radius of 2000 m around the lake including water, its islands and coastal strip; (2) the near protection perimeter, limited to intense vulnerability zones in the immediate sub-basins of lake; (3) the distance protection perimeter has been estimated to the whole catchment in order to take into account diffuse pollution. As conclusion of protection perimeters elaboration, assistance must be provided for restoring quality and quantity of basin water.

The lagoon that is the subject of this study, was chosen as drinking water alternative source of supply for the city of Abidjan. However, this language is shown in a very favorable area of forest to agriculture. We observe large rubber plantations, food and oil palm crops spread throughout the lagoon basin. Also, fertilizers injected into these plantations, as well as releases from industries and homes they are potential sources of pollution of the lagoon. According Humbert (2012), this pollution is reflected in particular by widespread concentration of nitrates and pesticides. Given these observed problems related to the quality of this resource, this study was initiated. Its objective is to develop a methodology based on the functionality of a Geographic Information System (GIS) to assess the degree of threat to what the Aghein lagoon faces through the completion of a vulnerability map at pollution. The method used here is a spatial analysis model incorporating several parameters including the slope, land cover, soil type, runoff and drainage density. These parameters have been previously defined, prioritized and weighted, and then integrated into a GIS. The resulting map shows five classes of vulnerability indices to pollution of the lagoon Aghein. They are: very small classes, low, medium, high and very high. These indices highlight the areas from which the lagoon is threatened.

The present study aims to delimit protection perimeters around the "Agbo" river in Agboville in order to reduce the risks of pollution of this water resource. The methodological approach consisted first all in assessing the vulnerability of the resource and then in determining the protection perimeters based on the vulnerability map and previous studies. Five parameters (slope, land use, soil type, annual runoff and drainage density) were used. These parameters were then weighted using the Saaty multicriteria analysis method. The vulnerability map reveals four classes (very low, low, medium and high) with a dominance of the low class (41.35% of the area). Three protection perimeters were delineated (immediate, close and remote). The immediate protection perimeter is delimited at a distance of 200 m around the SODECI water intake on the "Agbo" river and covers the areas with a strong influence on the vulnerability to pollution of the river. The closer protection perimeter at a distance of 1000 m, is represented by the zones with strong influence on the vulnerability of the resource and the direction of water flow in the watershed. Finally, the remote protection perimeter covers a large part of the catchment area with a surface area of 510.36 km 2 and takes into account the zones that have an influence on the vulnerability to pollution of the resource. These delimited protection perimeters can serve as a guide for the management and protection of the water intake in Agboville as well as for land use planning in this area.