A GIS-based DRASTIC Model for Assessing Aquifer Vulnerability in Kherran Plain, Khuzestan, Iran

Abstract

The Kherran plain is located in the northeast of Ahwaz in Khuzestan Province, Iran. The state of groundwater pollution is a critical issue with increasing population and agricultural development in Iran. For this reason, vulnerability assessment is an important factor in any policy making decision in any part of country. Focusing on this issue, the article attempts to presents a groundwater vulnerability map for the Kherran plain. The map designed to show areas of highest potential for groundwater pollution based on hydro-geological condition and human impacts. Seven major hydro-geological factors (Depth to water table, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone and hydraulic Conductivity) were incorporated into DRASTIC model and geographical information system (GIS) was used to create a groundwater vulnerability map by overlaying the available hydro-geological data. The output map shows that the west and southwest of the aquifer are under medium vulnerability while small areas on northwest and east of the study area have no risk to pollution. Other parts of aquifer have low vulnerability. For testing of the vulnerability assessment, 27 groundwater samples were collected from the different vulnerability zones of the study area. The chemical analysis results show that the southwest and west parts of aquifer (moderate vulnerability zones) have higher nitrate concentration relative to the rest of aquifer, that are located in low vulnerability zone.

Survey and zoning of nitrate-contaminated groundwater in Iran

“…The state of groundwater pollution has become critical as the population and agricultural development have increased in Iran. Pollution assessment is an important factor in policymaking in any country [6]. Pollution assessment is a basis for initiating protective measures for important groundwater resources.…”

Aquifer vulnerability assessment in the Bengal alluvial tract, India, using GIS based DRASTIC model

“…Aquifer media is the characteristics of materials by which the aquifer is made of (Chitsazan and Akhtari 2009). For the understanding of the aquifer media, it is necessary to understand the subsurface lithological condition.…”

“…On the basis of the analysis, the entire region was classified into three zones of vulnerabilities and it was found that important cities with higher to medium groundwater vulnerability were located near groundwater recharge zone. Chitsazan and Akhtari (2009) worked on the similar lines and focused on the GIS based DRASTIC modeling in the Kherran plain of Iran. In association with the conventional modeling, concentration of nitrate in the groundwater was also incorporated and it was observed that southwest and western part of the study area had higher concentration of the elements.…”

Assessment of the Vulnerability Potential for an Unconfined Aquifer in Konya Province, Turkey

“…Geographic Information System (GIS) has been proven as an effective tool for this purpose. As in this research, Chitsazan and Akhtari (2009) and Awawdeh and Jaradat (2009) determined the risk of pollutants to contaminate the groundwater, with the help of GIS. In recent years the increase in the popularity of applying environmental criteria in national planning and management has provided a wide range of scientific approaches to determine the best location of hazardous wastes to be land filled (Abessi and Saeedi 2009).…”