TITLE:
A GIS-Based DRASTIC Model for Assessing Phreatic Aquifere of Bekalta (Tunisian Sahel)
AUTHORS:
Asma El Hanini, Ayed Added, Saâdi Abdeljaoued
KEYWORDS:
Phreatic Aquifer; Vulnerability; Pollution; GIS; Geodatabase; DRASTIC Model
JOURNAL NAME:
Journal of Geographic Information System,
Vol.5 No.3,
June
19,
2013
ABSTRACT: The phreatic aquifer of Bekalta experienced a progressive degradation of
water resources over time: using increasingly important waters for irrigation
and drinking water, nitrate pollution, salinization... This aquifer is of great
economic importance because it is used for irrigation and domestic consumption.
Vulnerability map to nitrate pollution is a necessary tool to developing
management to preserve the quality of groundwater. This study utilized the Geographic Information
System technique and the DRASTIC model to assess the vulnerability of
groundwater resources to contamination. The Geographic Information System (GIS)
technology represents the best method to solve the main problems in the vulnerability
survey. Indeed is allowed for swift organisation, quantification, and
interpretation of large volumes of hydrological data with computer accuracy and
minimal risk of human errors. The Visio model was exported and loaded into an ESRI Geodatabase in
ArcCatalog as defined by the UML model. The purpose of this geodatabase is data
harmonization process within modeling groundwater vulnerability to pollution. The
resulting map shows evidence for three categories of vulnerability (low, middle
and high). The
resultant vulnerability map showed the predominant of moderately vulnerability
class on the most of the Bekalta region which occupying an area of 68%. The low
and high groundwater vulnerability classes occupy respectively an area of 30%
and 2% of the total surface of the study area.