Mapping favorable groundwater potential recharge zones using a GIS-based analytical hierarchical process and probability frequency ratio model: A case study from an agro-urban region of Pakistan

• Published in: Di xue qian yuan. 2020-09, Vol.11 (5), p.1805-1819
• Main Authors: Arshad, Arfan, Zhang, Zhijie, Zhang, Wanchang, Dilawar, Adil
• Format: Article
• Language: English
• Subjects: Agricultural land; Analytic hierarchy process; Analytical hierarchical process (AHP) analysis; Area under curve (AUC); Evaluation; Frequency ratio (FR); Groundwater; Groundwater recharge; Groundwater recharge zones; Hydraulic structures; Land use; Literature reviews; Sustainable development; Vulnerability; Water table; Weightage overlay
• ISSN: 1674-9871; 2588-9192
• DOI: 10.1016/j.gsf.2019.12.013

In Punjab (Pakistan), the increasing population and expansion of land use for agriculture have severely exploited the regional groundwater resources. Intensive pumping has resulted in a rapid decline in the level of the water table as well as its quality. Better management practices and artificial recharge are needed for the development of sustainable groundwater resources. This study proposes a methodology to delineate favorable groundwater potential recharge zones (FPRI) by integrating maps of groundwater potential recharge index (PRI) with the DRASTIC-based groundwater vulnerability index (VI). In order to evaluate both indexes, different thematic layers corresponding to each index were overlaid in ArcGIS. In the overlay analysis, the weights (for various thematic layers) and rating values (for sub-classes) were allocated based on a review of published literature. Both were then normalized and modified using the analytical hierarchical process (AHP) and a frequency ratio model respectively. After evaluating PRI and FPRI, these maps were validated using the area under the curve (AUC) method. The PRI map indicates that 53% of the area assessed exists in very low to low recharge zones, 22% in moderate, and 25% in high to excellent potential recharge zones. The VI map indicates that 38% of the area assessed exists in very low to low vulnerability, 33% in moderate, and 29% in high to very high vulnerability zones. The FPRI map shows that the central region of Punjab is moderately-to-highly favorable for recharge due to its low vulnerability and high recharge potential. During the validation process, it was found that the AUC estimated with modified weights and rating values was 79% and 67%, for PRI and VI indexes, respectively. The AUC was less when evaluated using original weights and rating values taken from published literature. Maps of favorable groundwater potential recharge zones are helpful for planning and implementation of wells and hydraulic structures in this region. [Display omitted] •Remotely derived maps and conventional data are helpful in mapping recharge zones.•Probability frequency ratio is preferred to allocate highly validated rating values.•Analytical hierarchical process is multi-criterion approach for weightage allocation.•Recharge potential and vulnerability help evaluate favorable recharge zones.•The area under the curve approach can be used to validate maps.