Identification of Artificial Recharge Sites for Nand Samand Catchment

Security of groundwater is widely regarded as a serious impediment to India's economic and social progress. According to the Central Ground Water Board's (CGWB) assessment, India's groundwater tables are plummeting at an alarming rate, with reserves in some regions reaching critical levels. Unregulated groundwater use in southern peninsular India has also resulted in excessive extraction, lowering the 'critical' threshold. With over 30 million groundwater structures in use, India is on the verge of a disaster of over-extraction that will leave 60% of all aquifers in critical condition within the next two decades. To resolve the issue, a variety of renewable groundwater solutions must be implemented. Artificial recharge is a procedure that augments groundwater at a pace that is significantly greater than the rate of replenishment under natural conditions, which may give a solution. The current study is for the Nand Samand catchment in the district of Rajasthan. The investigation of artificial groundwater recharge sites is being conducted using an integrated Remote Sensing and Geographic Information System (GIS) approach. Thematic maps such as topographic elevation, post-mosoon groundwater level, recharge, slope, transmissivity and soils map are created, and weighted overlay analysis is used to identify areas suitable for artificial recharge. Keywords: Nand Samand catchment, artificial recharge zone, thematic map, remote sensing, GIS

Identifying potential sites for artificial groundwater recharge using GIS and AHP techniques: A case study of Erbil basin, Iraq

Excessive extraction, uncontrolled withdrawal of groundwater, and unregulated practices have caused severe depletion of groundwater resources in the Erbil basin, Iraq. This situation has had a number of negative consequences on human settlement, agricultural activities, clean water supply, and the environment. Runoff harvesting and artificial groundwater recharge play a significant role in the sustainable management of water resources, particularly in arid and semi-arid regions. This study aims to: (1) delineate groundwater recharge zones using multiple thematic layers that control the groundwater recharge process, and (2) identify prospective sites and structures to perform artificial groundwater recharge. In order to generate a potential map for groundwater recharge zones, seven thematic layers are considered in this study, namely, topographic position index, geomorphology, lithology, land cover, slope, drainage-length density, and lineament-length density. After that, the analytic hierarchy process was applied to weight, rank, and reclassify these seven thematic layers. All maps are then integrated within the ArcGIS environment for delineating groundwater recharge zones. Accordingly, the resulting map categorizes the study area into five zones: extremely high, high, moderate, low, and extremely low potential for groundwater recharge. As expected, areas along the Greater Zab river show the highest possibility for groundwater recharge. Likewise, rugged eastern hills demonstrate an encouraging capacity for artificial aquifer recharge, whereas the least effective area is represented by built-up land. Based on the generated map, two dams are proposed as promising artificial recharge structures for harvesting runoff water east of Erbil city. Lastly, the resulting map of the potential groundwater recharge zones is verified using static water level data, where the coefficient of determination (R2) achieved a satisfactory result (0.73). These findings provide crucial evidence for implementing a sustainable management plan of surface and groundwater resources. The applied method is eventually valid for regions where appropriate and adequate field data availability is a serious issue.

Source water quality requirements for artificial groundwater recharge

This study was an investigation of the need for pre-treatment of a new raw water source for artificial groundwater recharge. The study was done through a column test, well sampling and survey data relating to 11 artificial recharge plants in Sweden. The column test showed that only 30% of the natural organic matter (NOM) was removed from the new raw water source during infiltration. The survey revealed that the new water source's quality was within the range requiring pre-treatment prior to infiltration. The well sampling results showed a significant correlation between the NOM-content in the raw and treated waters for WTPs without pre-treatment (r = 0.78 and ρ = 0.04), indicating one of the short-term limitations of artificial recharge. The study results indicate that the new raw water source is unsuitable for direct use in artificial recharge and that treatment is required prior to infiltration.

Site Suitability analysis for artificial groundwater recharge potential zone using a GIS approach in Basaltic terrain, Buldhana District, Maharashtra, India

We have selected the site suitability for artificial groundwater recharge in basaltic terrain in India. The overarching aim of this research is to identify appropriate locations for artificial groundwater recharge in the Godavari river basin in the semi-arid zone of Buldhana district, Maharashtra, India. The research involves the selection of an appropriate location with an artificial recharge, the use of weighted values in a (GIS) environment, and the development of thematic layers. The precise type of artificial recharge system, such as a check dam, nullah bund, drainage ditch trying to plug, or percolation ponds, is chosen. Water harvesting considers the availability of land, conventionally, while on the local conditions depends the suitability of a particular artificial recharge technique and the area which is to get benefited. As a result, decisions on the site for water conservation and structure construction could only be undertaken after detailed field research. In stipulated time, the GIS modelling approach provides an excellent tool for the identification of recharge zones with suitable structures. The integrated study helps in designing a suitable groundwater management plan for the areas such as the basaltic terrain.