Assessment of groundwater vulnerability in the coastal region of Oman using DRASTIC index method in GIS environment

Abstract

A study was carried out to develop a vulnerability map for Barka region in the North Batina of Oman using DRASTIC vulnerability index method in GIS environment. DRASTIC layers were created using data from published reports and the seven DRASTIC layers were processed by the ArcGIS geographic information system. Finally, DRASTIC maps were created for 1995 and 2004 to understand the long-term changes in the vulnerability index. DRASTIC vulnerability maps were evaluated using groundwater quality data such as chemical and biological parameters. DRASTIC vulnerability maps of 1995 and 2004 indicate that the northern part of Barka is more vulnerable to pollution than southern part and the central part of Barka also shows high relative vulnerability which is mostly related to the high conductivity values. Moreover, the changes in water level due to high abstraction rate of groundwater reflect in the vulnerability maps and low vulnerability area is increased in the southern part during 2004 compared to 1995. Moreover, regional distribution maps of nitrate, chloride and total and fecal coliforms are well correlated with DRASTIC vulnerability maps. In contrast to this, even though DRASTIC method predicted the central part of the study region is highly vulnerable, both chemical and biological parameters show lower concentrations in this region compared to coastal belt, which is mainly due to agricultural and urban development. In Barka, urban development and agricultural activities are very high in coastal region compared to southern and central part of the study area. Hence, this study concluded that DRASTIC method is also applicable in coastal region having ubiquitous contamination sources.

Geochemical process regulating groundwater quality in a coastal region with complex contamination sources: Barka, Sultanate of Oman

“…9d). This argument is well supported by distribution of fecal and total coliforms in Barka region (Jamrah et al 2008).…”

“…In Barka, nitrogen fertilizers and farm manures, which are normally used for paddy and other crops, are the major ammonium sources in agricultural areas, whereas in In Barka open dumping site, liquid waste, collected from septic tank and poultry farms, was disposed directly into the land and collected as lagoons during this study. Further, distribution of fecal and total coliforms, reported by Jamrah et al (2008), in Barka region firmly suggests the infiltration of effluents from septic tank and open dumping site. Even though ammonium is not found in groundwater; bacterial population strongly suggests the source of ammonium from surface contamination sources.…”

Groundwater stress and vulnerability in rural coastal aquifers under competing demands: a case study from Sri Lanka

“…The DRASTIC method has also been applied in humid climates (Babiker et al 2005) and semi-arid to arid climates (Werz and Hötzl 2007). A study by Jamrah et al (2008) concluded that the DRASTIC method is also applicable in coastal regions having ubiquitous contamination sources. A vulnerability assessment provides the intrinsic vulnerability of a given region to potential contamination using hydrologic and recharge properties independent of a contaminant.…”

Assessment of groundwater vulnerability using modified DRASTIC model in Kharun Basin, Chhattisgarh, India

“…Groundwater is one of the most important water resources on earth (Villeneuve et al 1990), particularly for those in arid and semi-arid areas due to its relatively low susceptibility to pollution in comparison to surface water (Jamrah et al 2008). The quality of groundwater plays an important role in its suitability for various uses.…”