Water quality assessment has always been a dominant part of environmental quality management. The present study involved the suitability assessment and mapping of groundwater quality for agricultural activities and drinking purposes in Rawalpindi and Islamabad area. A total of 22 samples were collected from borewells and open wells, and these water samples were further analysed for physical and chemical characteristics on the basis of which different indices were developed. Water quality index was calculated for overall water quality quantification from the perspective of human consumption. The results showed that a greater proportion exhibited poor quality for drinking due to over-exploitation of groundwater resource, agricultural impact and direct release of contaminants. Further, evaluation of groundwater for its suitability for irrigation showed that majority of the groundwater was suitable for irrigation purposes.

Use of Geographic Information System and Water Quality Index to Assess Groundwater Quality in Rawalpindi and Islamabad

The area of Thal Doab is located in the Indus Basin and is underlain by a thick alluvial aquifer called the Thal Doab aquifer (TDA). The TDA is undergone intense hydrological stress owing to rapid population growth and excessive groundwater use for livestock and irrigated agricultural land uses. The potential impact of these land uses on groundwater quality was assessed using a DRASTIC model in a Geographic Information System environment. Seven DRASTIC thematic maps were developed at fixed scale and then combined into a groundwater vulnerability map. The resultant vulnerability index values were grouped into four zones as low, moderate, high and very high. The study has established that 76% of the land area that is underlain by the TDA has a high to very high vulnerability to groundwater contamination mainly because of a thin soil profile, a shallow water table and the presence of soils and sediments with high hydraulic conductivity values. In addition, only 2 and 22% of the total area lie in low and moderate vulnerability zones, respectively. The outcomes of this study can be used to improve the sustainability of the groundwater resource through proper land-use management.

Modelling the vulnerability of groundwater to contamination in an unconfined alluvial aquifer in Pakistan

Groundwater vulnerability assessment delineating areas that are susceptible to contamination from future scenarios has aroused worldwide attention. In this study, the authors (1) estimate f...

Combined Impacts of Land Use and Climate Change in the Modeling of Future Groundwater Vulnerability

Our paper presents the possibility of applying the DRASTIC model as a useful tool to support the process of local and regional development planning. The study was carried out in the catchment of Stare Miasto Reservoir in Central Poland. In order to plan the policy to protect the reservoir and groundwater, the assessment of groundwater vulnerability to pollution was made by means of the DRASTIC model. The original model was modified by adding a new parameter called “land use.” The measured nitrate concentrations were used to test the original and modified models. The results of the study revealed that the modified DRASTIC model gave more accurate predictions than the traditional model. The Pearson correlation coefficients characterising the relationship between the vulnerability index and the nitrate concentration was 0.56 before the modification and 0.69 after it. The groundwater vulnerability map is necessary for planning local development and for assessing environmental impact. The DRASTIC model is expected to be a useful tool for designing programs and strategies, e.g., for improving the quality of surface water and groundwater.

http://www.pjoes.com/pdf-84772-34365?filename=Applying a Modified.pdf

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

Effective management of the groundwater resources became an important factor for the growth of urbanized areas, especially for the sector which has considerable agricultural and industrial activities. Along with quantity, assessment of the groundwater quality also plays an important role in its growth. Tandula watershed is one of the populated areas in the Balod district, Chhattisgarh state, which needs an assessment on the groundwater vulnerable zones for its effective management. The vulnerable zones of the study area have been assessed with the help of DRASTIC, DRASTIC–AHP, and modified DRASTIC–AHP methods. The models have been developed with the help of seven parameters which are depth to water, net recharge, aquifer media, soil media, topography, the impact of vadose zone, and hydraulic conductivity. The resulted groundwater pollution vulnerability in the study area has classified into five categories such as very low, low, moderate, high, and very high. Cross-comparison and validation of the model with 77 groundwater samples which contain Nitrate concentration were considered and concluded that the modified DRASTIC–AHP model is most accurate and suitable for the present study area. The study also revealed that groundwater in the study area is contaminated by Nitrate pollution due to excessive application of fertilizers in agricultural activities and improper sewage disposal.

Assessment of groundwater vulnerability to pollution by modified DRASTIC model and analytic hierarchy process

Groundwater has been treated as an important source of water supply due to its relatively low vulnerability to pollution in comparison to surface water, and its huge storage capacity. Because of the known health and economic impacts associated with groundwater contamination, steps to measure the vulnerability of groundwater must be taken for sustainable groundwater protection and management planning. Susceptibility of groundwater refers to the intrinsic characteristics that determine the sensitivity of the water to being adversely affected by an imposed contaminant load. The DRASTIC model is the most extensively used method for identifying the areas where groundwater supplies are most vulnerable to contamination. In this study the DRASTIC model is applied for a part of Kancheepuram district, Tamil Nadu, India, to generate a small-scale map of groundwater vulnerability to contamination. The whole area is classified on a scale of very low, low, moderate and high susceptibility to pollution. The model is considered in relation to groundwater quality data and results have shown a strong relationship between DRASTIC specific vulnerability index and nitrate-as-nitrogen concentrations. A groundwater vulnerability map is developed by using the DRASTIC model in a computer based Geographic Information System. The results show that the central part of the study area is classified as a high vulnerable zone and the south and northeastern parts show medium vulnerable zones, and record higher nitrate values.

D. Thirumalaivasan

Papers

GIS Based Assessment of Groundwater Vulnerability Using Drastic Model