Application of drastic model and GIS: for assessing vulnerability in hard rock granitic aquifer

Abstract

Geographic information system (GIS) has become one of the leading tools in the field of hydrogeological science that helps in assessing, monitoring, and conserving groundwater resources. Groundwater is a finite resource, which is being overexploited due to increase in demand over the years leading to decrease in its potentiality. In the present study, DRASTIC model has been used to prepare groundwater vulnerable zone in hard rock aquifer of granitic terrain. The main objective is to determine susceptible zone for groundwater pollution by integrating hydrogeological layers in GIS environment. The layers such as depth of aquifer, recharge, aquifer yield, soil type, topography, vadose zone, and transmissivity are incorporated in the DRASTIC model. The final output of the map shows that around 60% of the area falls under low to no risk of pollution zone. The high risk of pollution zones are mostly present towards the margin of southeastern periphery. The lower part of the basin as well as small area on northern side falls under moderate risk of pollution zone. For the assessment of groundwater pollution zone, 24 groundwater samples have been collected from different vulnerable zones. The chemical analysis of sample shows that the southeastern margin of basin has relatively high concentration of nitrate as compared to other parts of the basin. It is present in high pollution zone as well as moderate pollution zone. The present model can be used for assessment and management of groundwater.

Evaluation of local groundwater vulnerability based on DRASTIC index method in Lahore, Pakistan

“…Each hydro-geological parameter is assigned a weighting, from one to ten (Shamsuddin, 2000), according to its ability to affect groundwater. Each of the seven layers possess the ability contribute towards groundwater vulnerability evaluation (Prasad, et al, 2010). The weighting of the parameters ascribe; 1 -lowest pollution potential to 10-highest pollution potential (Table 1).…”

Applying a Modified DRASTIC Model to Assess Groundwater Vulnerability to Pollution: A Case Study in Central Poland

“…Many authors have added new parameters that impact groundwater contamination. Most frequently these were the type of land-use [17][18][19][20], lineament [21], groundwater velocity [22], and soil exchange capacity [23]. Some authors have excluded some parameters from the original DRASTC model, such as a topography and hydraulic conductivity [24], because these parameters are characterized by low spatial variability over the study area or show strong interdependence.…”

Estimation of intrinsic aquifer vulnerability with index-overlay and statistical methods: the case of eastern Kopaida, central Greece

“…Until now, several methods have been proposed for mapping the vulnerability of karstic aquifers; the most well know and frequently used include: EPIK (Dörfliger and Zwahlen 1998), REKS (Malik and Svasta 1999), RISKE (Pételet-Giraud et al 2000) and RISKE 2 (Plagnes et al 2005), PI (Goldscheider 2005), the Slovene approach (Ravbar and Goldscheider 2007), KARSTIC (Davis et al 2002), COP (Vias et al 2002), COP?K method (Andreo et al 2009) and PaPRIKa (Kavouri et al 2011). As a result, several researches worldwide have focused on assessing the vulnerability of diverse aquifer systems and can be found elsewhere (e.g., Prasad et al 2011;Jayasekera et al 2011;Kaliraj et al 2014;Akpan et al 2015;Kumar et al 2015). However, results may differ significantly depending on the method applied and the study area.…”