The aim of this paper is to present a study on DRASTIC groundwater pollutionvulnerability assessment.
Aquifer vulnerability mapping is the acquisitionand accumulation of aquifer attribute spatial data, placing the spatial datainto a database, and using the database in a Geographic Information System (GIS)to show where an aquifer is at risk to pollution.
GIS is the dynamic toolfor study hydrologic setting and various parameters, which influence the groundwater vulnerability i.e., drastic parameters.
The study area is located inHaridwar district,Uttaranchal,India.
DRASTIC is a methodology foridentifying vulnerability to groundwater pollution.
It uses seven parameters,which are a combination of geologic, hydrologic, geomorphologic andmeteorological factors, to relate an aquifer to the sources of its water and theconstituents within that water.
The parameters (Depth to water, annual Recharge,Aquifer media, Soil media, Topography, vadose zone Impact, and hydraulic Conductivity) are weighted according to their relative importance in determining the abilityof a pollutant to reach an aquifer.
The parameters are used to produceDRASTIC index numbers from which maps are constructed.
The relative rankingscheme uses a combination of weights and rating to produce a numeric valuecalled he DRASTIC index, which helps to prioritize areas with respect topollution potential.
GIS, due to its capabilities in terms of management, analysis, and manipulation of spatial data can be efficiently be used forgeneration of vulnerability maps for the study area.
The vulnerability mapof study area indicates that different parts of the area are susceptible to ground water pollution to different degrees i.e. highly susceptible and leastsusceptible.
The pollution risk to the study area drinking water systemwill increase as a result of urban sprawl.
Thus, it is prudent to protectthe drinking water system by determining aquifer pollution risk throughmapping aquifer vulnerability prior to urban sprawl.
The Drastic rankingscheme can then be applied enlightened layman for valid comparative evaluationwith acceptable results. |
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