Groundwater Potential zones

Le Liban est un pays méditerranéen avec une superficie de 10 452 km2, dont 65 % sont karstiques, il est considéré riche en eaux superficielles et souterraines, mais en dépit de cette richesse, le Liban montre une pénurie en eau à cause de la mauvaise gestion des ressources hydriques et de la variation interannuelle des pluies (6 à 7 mois de sécheresse). Cette situation hydrique nécessite le lancement des recherches ayant pour objectif la résolution du problème du manque en eau.
Ce travail a pour objective de déterminer les zones favorables à la recharge du bassin versant Abou Ali (Liban Nord) en se basant sur une approche cartographique, utilisant ainsi le système d’information géographique (SIG). La détection de ces zones potentielles de recharge de la nappe nécessite un croisement des informations spatiales relatives aux différents paramètres (lithologie, sol, densité de fracture, densité de drainage, pente et l’occupation du sol) influençant la recharge cartographiée. Une reclassification suivie d’une pondération de ces paramètres a été effectuée selon leur degré d’influence dans le processus de recharge et suivant une analyse de l’index de score cumulatif CSI. Ces paramètres analysés sont par la suite intégrés dans un SIG afin d’établir la carte des zones potentielles de recharge de la nappe souterraine. L’application du modèle de potentialité hydrique montre que 13 % de la superficie du bassin présente une potentialité hydrique très forte surtout au sud-est, 39 % montre une potentialité moyenne dans les zones ayant une lithologie marno-sableuse et calcaire-marneuses, et 20 % dénotent une potentialité faible surtout à l’ouest et au centre du bassin.

The objective of this paper is to exploit the potential application of weighted index overlay analysis for assessing groundwater potential mapping at Dhungeta-Ramis sub-basin, Wabi Shebele basin, Ethiopia using remote sensing and geographic information system (GIS) technique. For this purpose, seven groundwater occurrences and movement controlling factors, including, lithology, slope, land use land cover (LULC), rainfall, lineaments, soil, and drainage density were mapped. Then, weight was assigned to thematic maps, and the groundwater prospective of the sub-basin is qualitatively classified into five classes, namely, very good, good, moderate, poor, and very poor which account for 2.22%, 26.93%, 56.74%, 13.84%, and 0.26% landscape, respectively. The cross-validation of the resultant model was carefully carried out using spring, hand-dug, and deep well data. The result reveals that 89% of springs were overlaying good and/or very good groundwater potential zones and 58% of deep well shows the same scenario, whereas 42% of deep well overlays moderate zone. As a result, the map generated using this platform could be used as a preliminary reference in selecting suitable sites for groundwater resource exploitation. ARTICLE HISTORY

This study was conducted in Tikamgarh district of Bundelkhand, Madhya Pradesh, India to spatially delineate the groundwater potential zones using the integrated RS-GIS and MIF techniques. To do so, eight major biophysical and environmental factors like drainage density, geomorphology, geology, lineament density, land use/land cover, rainfall, slope and soil were considered. All the factors and their features have been assigned weights according to their relative importance and their normalized weights were calculated using the multi influence factor technique. Groundwater potential zoning map has been prepared through weighted overlay model in GIS environment after integrating all the thematic layers. The entire district has been classified into five different groundwater potential zones-Very Good, Good, Moderate, Poor and Very Poor depending on the likelihood of availability of ground water. Greater portion of the study area (40.60%) fall within the poor potentiality zone. About 3.10% and 11.54% of the total area fall under the very good and good potential zone respectively. 38.60% of the total area comes under the moderately potentiality zone. Only 6.16% of the total area fall under the very low potential zone. It shows that the applied technique produces considerably reliable results for this study which may facilitate the decision makers to formulate an effective plan for the study area. Highlights m This study conducted in Tikamgarh district of Bundelkhand, Madhya Pradesh, India to spatially delineate the groundwater prospect zones through RS-GIS approach. m Tikamgarh district is under comes drought prone zone of Bundelkhand region, so need have explore the ground water status. m In this study, we employed maximum eight groundwater influence factor for developing the ground water potential zones.

Groundwater resources can be expected to be increasingly relied upon shortly due to rapidly growing population and global environmental and climatic changes. Groundwater is a vital resource contributing significantly in the annual supply of water for domestic, industrial, and irrigation sectors. This paper aims to groundwater prospect zones and their spatial distribution and couples this information with pollution parameters for groundwater prioritization. The study is carried out in the Bangalore region of Karnataka state, which is geographically located between 12.40° N to 13.20° N latitudes and 77.30° E to 78.00° E longitudes and covers an area of 1617.12 sq. km. Groundwater prioritization is one of the most important aspects of watershed management. Groundwater potential zones are optimized in the study by using the GIS based Analytical Hierarchy Process (AHP). Five groundwater prospect zones have been identified in the present study, ranging from a very good prospect zone to a very low prospect zone. The study area has only 7% of very good zones, about 19% of good prospect zones, and 36% moderate zones. This cautions the decision-makers and concerned departments to promote the scientific and sustainable use of groundwater for future needs and initiate the appropriate measures to develop groundwater resources.