Vulnerability Assessment of Groundwater to NO3 Contamination Using GIS, DRASTIC Model and Geostatistical Analysis

• Main Author: Adu Agyemang, Adela Beauty
• Format: Others
• Language: English
• Published: Digital Commons @ East Tennessee State University 2017
• Subjects: GIS-based DRASTIC Model; Kriging; Cokriging; NO3; Groundwater; Spatial Statistics; Earth Sciences; Environmental Sciences; Hydrology; Water Resource Management
• Online Access: https://dc.etsu.edu/etd/3264; https://dc.etsu.edu/cgi/viewcontent.cgi?article=4695&context=etd

The study employed Geographical Information System (GIS) technology to investigate the vulnerability of groundwater to NO3 content in Buncombe County, North Carolina in two different approaches. In the first study, the spatial distribution of NO3 contamination was analyzed in a GIS environment using Kriging Interpolation. Cokriging interpolation was used to establish how NO3 relates to land cover types and depth to water table of wells in the county. The second study used DRASTIC model to assess the vulnerability of groundwater in Buncombe County to NO3 contamination. To get an accurate vulnerability index, the DRASTIC parameters were modified to fit the hydrogeological settings of the county. A final vulnerability map was created using regression based DRASTIC, a statistic method to measure how NO3 relates to each of the DRASTIC variables. Although the NO3 concentration in the county didn’t exceed the USEPA standard limit (10mg/L), some areas had NO3 as high as 8.5mg/L.