Integrated approaches to map groundwater potential zones using AHP, GIS, and remote sensing in semi-arid region of Morocco: Case study from Khouribga area

Geospatial technology has wide applications within the groundwater resource assessment studies. Satellite images are increasingly being used in groundwater exploration due to their utility in distinguishing numerous geo-system options. The present study has been disbursed in and around Gondar, Ethiopia. The groundwater potential zones were depicted from the six geo-system parameters like lithology, lineament density, geomorphology, slope, land use/land cover, and drainage density using weighted overlay analysis methodology. Integration of the above mentioned geo-systems has been performed in GIS platform using weighted overlay analysis. Totally different categories of thematic maps are assigned weights supported influence on groundwater hydrology (through intensive literature review), and eventually, factor ranks area were assigned. The ultimate map indicates the potentiality values of groundwater prevalence within the study area, that was classified into 3 categories—high, moderate and low. a total of 24% of the study area fall in low groundwater potential zone, 42%in moderate potential zones and 34%of the realm in the high potential zone. Keywords : Groundwater potential zones, remote sensing, GIS, Gondar, Ethiopia.

A case study was conducted to find out the groundwater potential zones in Kattakulathur block, Tamil Nadu, India with an aerial extent of 360.60 km2. The thematic maps such as geology, geomorphology, soil hydrological group, land use / land cover and drainage map were prepared for the study area. The Digital Elevation Model (DEM) has been generated from the 10 m interval contour lines (which is derived from SOI, Toposheet 1:25000 scale) and obtained the slope (%) of the study area. The groundwater potential zones were obtained by overlaying all the thematic maps in terms of weighted overlay methods using the spatial analysis tool in ArcGIS 9.2. During weighted overlay analysis, the ranking has been given for each individual parameter of each thematic map and weights were assigned according to the influence such as soil −25%, geomorphology − 25%, land use/land cover −25%, slope − 15%, lineament − 5% and drainage / streams − 5% and find out the potential zones in terms of good, moderate and poor zones with the area of 49.70 km2, 261.61 km2 and 46.04 km2 respectively. The potential zone wise study area was overlaid with village boundary map and the village wise groundwater potential zones with three categories such as good, moderate and poor zones were obtained. This GIS based output result was validated by conducting field survey by randomly selecting wells in different villages using GPS instruments. The coordinates of each well location were obtained by GPS and plotted in the GIS platform and it was clearly shown that the well coordinates were exactly seated with the classified zones.

Over-exploitation of groundwater and marked changes in climate over the years have imposed immense pressure on the global groundwater resources. As demand of potable water increases across the globe for human consumption, agriculture and industrial uses, the need to evaluate the groundwater potential and productivity of aquifers also increases. In the recent years, geographic information system based studies have gained much prominence in groundwater exploration because it is rapid and will provide first - hand information on the resource for further developments. Therefore, the present study has been undertaken with an objective to delineate the groundwater potential of a small tropical river basin located in the western side of the Western Ghats in India as an example. A combination of geographical information system and analytical hierarchical process techniques (AHP) was used in the present study. A total of 12 thematic layers such as Geology, Geomorphology, Land Use/Land Cover, Lineament density, Drainage density, Rainfall, Soil, Slope, Roughness, Topographic Wetness Index, Topographic Position Index and Curvature were prepared and studied for groundwater potential zone demarcation. Weights assigned to each class in all the thematic maps are based on their characteristics and water potential capacity through AHP method. The accuracy of the output was cross-validated with information on groundwater prospects of the area and the overall accuracy of the method comes to around 85%. The groundwater potential zone map thus obtained was categorized into five classes-very high, high, moderate, low and very low. The study reveals that about 59% of the river basin is covered under moderate groundwater potential zone. The low and high groundwater potential zones are observed in 29% and 11% respectively. Area under very high and very low potential zones are recorded only in very limited areas in the basin.

In India, groundwater is the major source for fulfilling domestic and commercial water requirements. Since groundwater levels in various regions have been decreasing at a much faster rate in the last few decades, it has become important to delineate potential new zones of groundwater to meet future requirements. The intermontane basins in the Outer Himalaya have the potential to hold significant amount of subsurface water in a region that is currently water deficient. The present study discusses groundwater prospect zonation in the Soan Basin of the Outer Himalaya in Una District of Himachal Pradesh in India. ASTER DEM, LANDSAT 8 satellite data and existing geological mapping of the Himalayan foothills were used to prepare a groundwater prospect map of the Soan Basin. Various thematic maps including maps of geomorphology, drainage and land use map were prepared using LANDSAT 8 Satellite data and a geological map of Himalayan foothills using ARC GIS 10.0. Watershed and slope maps were extracted from ASTER DEM with 30 m resolution. A groundwater prospect map was prepared by overlaying the various thematic maps and was subdivided into five potential zones on the basis of potential discharge conditions. These are: regions bearing very low [ 800 LPM) potential zones of groundwater. The high and very high potential zones are located in the central synclinal valley along the fluvial terraces, alluvial fans and piedmont deposits. The low and very low potential zones lie in the hilly areas with high slopes and rugged topography causing rapid downslope movement of water, which results in less infiltration and consequently deeper groundwater levels with a low groundwater potential.

This article deals with the remote sensing and geographic information system techniques in assessing groundwater potential zones by the manipulation and analysis of the individual layer of spatial controlling data in a part of Deccan Volcanic Province, Maharashtra. Available geology, geomorphology, and soil maps were collected. Land use and land cover (LULC) and Lineament maps had been prepared using the LANDSAT-8 (TM and OLI) Satellite Image (November 2015). The SRTM DEM (resolution: 30 m) data had been employed for the preparation of slope and drainage maps. These maps were converted into the raster format. Analytic hierarchy process was applied to weight, ranking, and reclassify these maps in the ArcGIS version 10.4. Then, groundwater prospect map had been prepared by overlaying the maps. The results show that five groundwater potential zones such as very poor (11.77%), poor (21.73%), moderate (30.13%), good (25.34%), and very good (11.02%) exit. Sensitivity analysis reveals that the lineament density, LULC, and slope increase the area slightly only in the very poor to poor potential zones. Besides, the well yields, groundwater level fluctuation corresponding rainfall data had been utilized to validate. The yield values vary from 5.94 to 14.88 l/s in the good to very good potential zones, whereas 0.38 to 1.37 l/s within the poor to very poor potential zones. In addition, cross-correlation coefficients among groundwater level and rainfall is well-related to the groundwater potential index (R2 = 0.84), which will help to construct artificial recharge structures and the planning of sustainable groundwater management.

Water is one of the primary requisites for the existence of life. Overutilization of this critical wealth is threatening our ecosystems as well as the life of future generations. To change pressure on this natural resource, there is a need to find out potential sites of groundwater using modern techniques. The aim of this study is to determine groundwater potential zones using consolidation of Remote Sensing and GIS technique. The data used for this study includes 30 meter resolution ASTER GDEM, Landsat 8 imagery and existing Geological and Soil maps. Using these data, different thematic layers were developed i.e. slope, drainage density, lineaments density, geological, soil and land cover maps. Lineaments were carried out by visual interpretation of different band combinations. Weightage are assigned based on their capability to store groundwater. These were then integrated with weighted overlay in ArcGIS to get potential zones of ground water. The groundwater potential zones were then classified into five categories like excellent, good, moderate, poor and very poor. Produced ground water potential zone map were compared and validated by existing hand pumps and well data obtained from different localities of the project area. This study specifically show that Geo-spatial techniques with compounding of field data could be used for the determination of ground water potential zones. It can be considered as a time and cost-efficient practice for depiction and designation of high potential ground water target areas.

GIS-based multi-criteria analysis for identification of potential groundwater recharge zones - a case study from Ponnaniyaru watershed, Tamil Nadu, India

Groundwater is the most crucial resource for human beings and plays an important role in combating climate change and is substantial to human existence on the globe. Overall increased demand for water in different sectors, population growth, and unreliable rainfall necessitates the planning and management of groundwater. In this study, groundwater potential zones are delineated by combining remote sensing and geographical information system techniques in the Guder watersheds of the Upper Blue Nile Basin. Groundwater potential zones are prepared by using various multi-influencing factors like geomorphology, land use/cover, lithology, soil type, soil texture, drainage density, slope, lineament, rainfall, and elevation. These influencing factors’ features were given appropriate weightage according to Saaty’s AHP method, expert judgment, and their relative significance for groundwater occurrence. The groundwater potential zone was classified into different categories as very poor, poor, moderate, good, and very good according to quantile classification. This study reveals that about 33.6% of the Guder River Basin represents a good andvery good GWPZ category with an equal value of 16.8%,; while values 23.3%, 20.2%, and 22.9% were denoted by very poor, poor, and moderate groundwater potential zone, respectively. GWPZ was validated by field-collected data such as well discharge and soil depth. An accepted similarity was observed between delineated GWPZ and the basin’s soil depth graphically. The results of this study were also verified by correlation and kappa statistics values of 0.73and 77%, respectively. The study is certain with a sensible dimension of consistency in pairwise comparison between influencing and the overall weightage. The very high GWPZs are found in the northern part starting from the center longitude of the study area, more along with the northwestern, southern, and southwestern of the Guder subbasin. Low to very low groundwater potentiality has been seen at different distances from the center due to the presence of escapements, hills and steep side slopes, slopes, and rock surfaces. The study also revealed that the zone of high groundwater potential has high soil depth, and the zone of low groundwater showed low soil depth as the capacity of the aquifer to store water may depend on the depth of soil profile. This study attests to the GIS and remote sensing techniques as an effective model for delineation of GWPZs and can be applied at other basins of Ethiopia.

In the present study, remote sensing techniques, GIS models and field measurements are integrated to identify and map groundwater potential zones at Wadi Yalamlam (Sa’diyah) basin, Makkah Province, Western Saudi Arabia. The study area is located in the Arabian Shield heterogeneous basement terrain. It is characterized by insignificant primary porosity and permeability and is mainly covered by massive and altered gneissose granites, diorite, and gabbro and metamorphosed basalts. Lithology, rainfall, lineament density, drainage density, slope steepness and landuse/landcover are the main hydrogeological parameters defined to be related to the groundwater storage in the study area. They are prepared using the processed satellite data and integrated using weights of evidence and index overlay GIS models to generate groundwater potential zones map. Within the GIS model, those parameters are assigned values of 30, 20, 15, 15, 10 and 10, respectively, as score values. The resulting groundwater potential zone map for Wadi Yalamlam basin is categorized into three main classes (high, moderate and low groundwater potential zones) based on pixel values. The results of this study indicate that the lower parts of the Wadi Yalamlam basin is the most promising area for groundwater occurrences and contains both high and moderate potential zones. High groundwater potential zones are located to the north of the main dyke area around Abu Helal farm. They are characterized by loose wadi deposits, flat areas, gentle slope (ranges between 0 and 5 degrees), low drainage density (<100 D/30 km2) and shallow water table (water table is 7 m from the ground surface). The present study proved: (1) the usefulness of the processed remote sensing satellite imageries for generating several indirect groundwater parameters; (2) the usefulness of weights of evidence and index overlay GIS models for the integration process and the production of groundwater potential zone map along the study area.

Effective groundwater management is crucial under the current climatic conditions, addressing both qualitative and quantitative aspects. An important step in delineating groundwater potential zones involves remote sensing (RS) data and geographic information systems (GISs), facilitating resource assessment, and the implementation of suitable field data management. This study introduces the delineation of potential groundwater zones using seven layers and the Multi-Criteria Decision Analysis (MCDA) method. Satty’s Analytic Hierarchy Process (AHP) was employed to rank the seven selected parameters, contributing to the advancement of groundwater research and resource assessment. All seven thematic layers (Rainfall, Geology, Land Use/Land Cover, Drainage Density, Elevation, Slope, and Soil) were prepared and analyzed to delineate groundwater potential zones. The resulting groundwater potential zone map was categorized into four classes, Very Good, Good, Moderate, and Poor, covering areas of 81.53 km2 (45.1%), 56.36 km2 (31.2%), 19.54 km2 (10.8%), and 23.17 km2 (12.8%) of the total area, respectively. The accuracy of the output was validated by comparing it with information on groundwater prospects in the area, and the overall accuracy of the method was approximately 72%. High-yield boreholes were drilled and concentrated in the Very Good groundwater potential zones, while low-yield ones were developed in the Poor areas.

This study incorporates the Groundwater Quality Index (GQI) to alter the conventional groundwater potential zoning to quantity-quality potential zoning in the Chennai coastal region, which is experiencing groundwater decline and quality deterioration. Using Analytical Hierarchy Process (AHP), weights for twelve thematic layers were assigned and are superimposed with a weighted overlay technique. Pre- and post-monsoon groundwater quantity-quality potential zone (GQQPZ) are classified into poor, moderate, good, and very good zone using pre-and post-monsoon GQI, respectively. Furthermore, the study revealed that seasonal changes also influence the quantity-quality potential zone of the study area. According to the study, the poor zone areas changed from 3.58% to 0.94% due to reduced concentration of pollutants and increased quantity of groundwater during monsoon rain. The validation is carried out with pre and post-monsoon Electrical Conductivity (EC) for pre and post-GQQPZ and resulted in an accuracy of 88.5% and 89.3%, respectively.

Delineation of groundwater potential zones using the integration of geospatial and MIF techniques: A case study on Rarh region of West Bengal, India

The present study has been carried out in Gangajalghati Block, Bankura district which is located on the eastern slope of Chotanagpur Plateau. IRS—LISS-III data along with other data sets, e.g. existing toposheets and field observation data have been utilized to extract information on the hydrogeomorphic features which include valley fills (VF), buried pediment moderate, buried pediment shallow and structural hills, lineament density contour and slope map of this area. All the information layers have been integrated through geographical information systems analysis and the groundwater potential zones have been delineated. Weighted overlay modelling technique was used to develop a groundwater potential model with three weighted and scored parameters. Although the area is characterized by hard rock, it has groundwater prospective zones due to fracturing, weathering the presence of VF overlying a planation surface. The area has been categorized into four distinct zones—excellent, good, fair and poor. Excellent groundwater potential zones constitute 10–15 % of the total block area, good groundwater potential zones occupy majority of the block, covering approximately 30–35 % and the fair potential zones occupy about 50–55 % of the total block. Poor potential zones occupy very insignificant portion (less than 1 %).

Chapter 25 - Delineation of Groundwater Potential Zones in Hard Rock Terrain Using Integrated Remote Sensing, GIS and MCDM Techniques: A Case Study From Vamanapuram River Basin, Kerala, India

Combined use of groundwater modeling and potential zone analysis for management of groundwater