Appraising groundwater potential zones using geospatial and multi-criteria decision analysis (MCDA) techniques in Andasa-Tul watershed, Upper Blue Nile basin, Ethiopia

Abstract

Ever increase in population growth and drastic climatic changes augment the demand and exploration of groundwater from time to time. An integrated approach of remote sensing (RS), geographic information system (GIS) and multicriteria decision analysis (MCDA) of analytical hierarchical process (AHP) were applied to delineate groundwater potential (GWP) zones in Andasa-Tul watershed, Upper Blue Nile Basin, Ethiopia. For this purpose, nine GWP influencing thematic layers comprising lithology, lineament density, geomorphology, slope, soil, drainage density, land use/land cover, rainfall and depth to groundwater level were used. The thematic layers and classes within them were given scale values based on literature and experts' decision and calculated using Satty's AHP. The thematic layers have been integrated via their weights/rates using weighted overlay spatial function tool of ArcGIS to provide GWP map. The result shows that GWP map comprises very good (13.4%), good (7%), moderate (23.6 %), poor (35.4%) and very poor (20.5%) zones. Validation of the GWP map with existing water point yields shows 84.21 % agreement indicating good accuracy of the method. The map removal sensitivity analysis result reveals that GWP is more sensitive to lithology (mean variation index, 1.92 %) and less sensitive to geomorphology (mean variation index, 0.59 %). Similarly, from the single layer sensitivity analysis, lithology and slope are found to be more effective parameters, whereas rainfall and depth to groundwater level are less effective variables.

Integrated Geospatial and Geophysical Approaches for Mapping Groundwater Potential in the Semi-Arid Bukombe District, Tanzania

“…At this stage, each thematic layer was compared to other layers one at a time to choose which of the two is more important than the other with regard to groundwater potentiality. The choices made assigned ranks to themes and their classes from 1 (equally important) to 9 (extremely important) depending on how important a factor is over the others, as per Saaty's (1980) classification [10,36] as Table 1 elaborates. Of equal importance, the consistency ratio was monitored at all times, making sure it was an acceptable value of at most ten percent (see Appendix A) [12].…”

“…Demographic data show that about 11% of the world's population, particularly in Sub-Saharan Africa and Oceania, do not have access to clean and safe water [9]. The majority have aligned themselves to an alternative and cost-effective source, which is groundwater [10]. The lack of adequate hydrogeological and updated geospatial data in place to identify groundwater potential areas has led to the drilling of boreholes and the digging of wells in areas where groundwater potentiality is suboptimal [11][12][13].…”

Delineating Groundwater Potential Zones in Hyper-Arid Regions Using the Applications of Remote Sensing and GIS Modeling in the Eastern Desert, Egypt

“…The thematic layer of lithology is essential in groundwater potential mapping because the porosity and permeability of the surface layer mainly control the infiltration of the precipitated water into the shallow groundwater aquifers [56,57]. The interpretation of the false color composite (FCC) of the Landsat 8 band ratios (3/5, 1/4, and 1/6) associated with a published geological map [62] were used in the lithological discrimination of various rock units (Figure 10a,b).…”

Spatial analysis of groundwater potential using remote sensing and GIS-based multi-criteria decision analysis method in Fetam-Yisir catchment, Blue Nile Basin, Ethiopia

“…They are the principal tools in the area of subsurface water research as they help in evaluating, monitoring, and preserving groundwater resources (Srinivasa Rao and Jugran 2003). These days several researchers (Machiwal et al 2011;Aykut 2021;Fenta et al 2015;Hussein et al 2017;Pinto et al 2017;Thapa et al 2018;Ahmad et al 2020;Andualem and Demeke 2019;Kindie et al 2019;Anteneh et al 2022) apply RS and GIS-based analytical hierarchy process (AHP) for the assessment of GWP.…”