Apport des SIG dans l’élaboration d’un plan d’aménagement anti-érosif : Cas du sous bassin de Bouguedfine (Zahrez Chlef, Algérie)

L’érosion des sols par la pluie et le ruissellement est un grave processus de dégradation du capital sol, entraînant un décapage de l’horizon superficiel, une baisse de son degré de fertilité et la détérioration des conditions de vie des paysans. L’aménagement des bassins versants est sans doute le moyen le plus efficace pour lutter contre ce phénomène. Le présent travail vise à démontrer l’intérêt que peut apporter un outil tel que le Système d’information Géographique (SIG) pour l’aménagement des bassins versants et à mettre en valeur les informations à caractère géographique déjà existantes, par la réalisation d’une carte globale de vulnérabilité du sous bassin versant de l’oued Bouguedfine au phénomène érosif en tenant compte les facteurs physico climatiques, responsables de l’érosion hydrique, tels que la pente, la pluviométrie, la lithologie, l’exposition des versants, l’occupation du sol ainsi que sa nature, en se basant sur l’analyse détaillée de la zone d’étude pour l’élaboration de la base de données. Les sites sensibles sont classés en 05 catégories, de la plus à la moins sensible, une stratégie d’intervention dans le sous bassin versant de l’oued Bouguedfine est contribuée (aménagement des cours d’eau et conservation des terrains en pente), en proposant un ensemble de techniques de protection. Mots-clés : Plan d’Aménagement de Protection,  SIG, érosion hydrique, Sous bassin de l’oued Bouguedfine, Algérie

Performance indicators of water supply network of Goma Township in the Democratic Republic of Congo: a tripartite assessment

peer reviewedIn Goma Township, the water supply system has become ineffective and insufficient against the background of an increasing population with high water demand. A study was therefore carried out to assess the water supply network of Goma Township using three performances indicators with a view to proposing possible solutions to the existing water supply challenges. The methodology involved the assessment and evaluation of the water production, the physical characteristics, and the hydraulic characteristics of the current water supply network. The research utilized secondary data comprising technical reports from review of the literature, GIS data sets, and a database of the existing network converted into an EPANET model to assess its performances. The results generally showed a low performance of the current water supply system (production capacity: 11%, hydraulic characteristic: 33%, physical characteristic: 71%) mainly related to the water demand which has outpaced the water supply capacity and several design issues. The methodology used in this study and the results obtained can be used not only for Goma Township but also by other Sub-Saharan African cities in order to solve the urban water supply crisis

Water assessment in transboundary river basins : the case of the Medjerda River Basin

Water resources in the Middle East and North Africa (MENA region) face over-exploitation and over-pollution due to population growth, climate change and the lack of advanced water governance approaches. These challenges become more serious in transboundary river basins and may lead to conflict between riparian countries. The main objective of this paper is to assess water resources and needs at the Medjerda River Basin (MRB), shared by Tunisia and Algeria using the Water Evaluation and Planning (WEAP) system between 2020 and 2050. Four scenarios were built to assess the current and future status of the water supply and demands in both countries. The results show that water demands, and shortages are increasing, and some demand sites will face real water scarcity in the future due to climate change and development practices. Therefore, new allocation and management plans should be examined at the regional level based on real collaboration among all stakeholders

Multi-Hazard Risk Assessment and Landslide Susceptibility Mapping: A Case Study from Bensekrane in Algeria

Landslides and their disastrous consequences on the environment and human life have emphasized the need for a better understanding of the dangers associated with slope movement. The objective of this research was to assess and utilize mapping methods for predicting the hazards of landslides and thus to limit the damage of these phenomena more effectively. In the current investigation, multi-hazard mapping was employed in evaluating the risk of slope movements for the municipality of Bensekrane in Tlemcen in Algeria. There has been no hazard assessment made for the study area although it has factors responsible for triggering landslides. The standard Farès method (arithmetic and probabilistic) was employed, and the results were compared with those obtained from the modified Farès technique (arithmetic and probabilistic), which was developed based on a synthesis or combination of previous approaches. In the modified Farès technique, dynamic factors were also included, such as seismic activity, vegetation cover and groundwater level, and, thus, it was considered more reliable. However, the choice of method depended mainly on the availability of data from the study area. The maps obtained showed that the study area is susceptible to slope movements and will be employed for land use planning. The maps obtained by the arithmetic modified Farès method were different from those obtained by the arithmetic Farès method. The former presented a large part of the surface (88%) with an average hazard, unlike the latter, which presented the largest surface (66%) and a low hazard. The maps generated by the probabilistic modified Farès method showed a surface with a high hazard, unlike that obtained by the probabilistic Farès method, where a high hazard did not exist. These differences between the maps were due to the addition of dynamic factors. It is better to choose the modified Farès method, which takes into account all the factors that exist in reality. In this study, enhanced spatial, natural hazard maps were created using the modified Farès method to better aid decision makers and builders in making correct choices for increased safety and town planning. It is crucial to be able to utilize reliable maps based on multi-hazard risk assessment for land development purposes to lessen the possibility of destructive landslides. The modified Farès method can be applied to any other comparable areas around the world

Strategic Decision-Making in Sustainable Water Management Using Demand Analysis and the Water Evaluation and Planning Model

Water infrastructure management relies on information, communication strategies, and affordable technologies. This paper used demand analysis and modeling to guide strategic decision-making in sustainable water management for the urban cluster in Tlemcen, Algeria. To achieve this, the water supply and demand of the study area were assessed over the past three decades. The Water Evaluation and Planning (WEAP) system was employed considering different future scenarios to help decision-makers consider the best choices for sustainable urban water resources management. The results showed that the average water production and distribution efficiency was only 46% due to the high network loss. Therefore, urgent action should be considered to increase the efficiency of the distribution network. Moreover, the outcome showed severe unmet demand in 2050, which can be managed by improving the water networks, increasing conventional water production, and reducing personal water consumption. In cooperation with key stakeholders, new scenarios can be analyzed to develop efficient water management policies and to implement sustainable water allocation approaches