Using a Fuzzy Logic Model in SPANS - GIS to Determine the Vulnerability to Contamination of the Amman-Zarqa Area Aquifer, Jordan.

Abstract:

This study examined the vulnerability of the aquifer in the Amman-Zarqa area to contamination. In order to characterize the type and limits of groundwater contamination, several wells were sampled and analyzed for their chemical and environmental stable and radioactive isotopes.

The most vulnerable locations to contamination from surface sources were delineated using a fuzzy logic model in SPANS GIS. Maps delineating the extent of TDS, NO3- , and tritium were used as major criteria to describe the groundwater contamination and recharge event. Fuzzy membership values were assigned for each class of each map based on their importance. A vulnerability map of groundwater contamination was then created.

Results show that significant variations occur in groundwater chemistry for the TDS and NO3- concentrations. These elevated values are attributed mainly to anthropogenic sources including, Ain Ghazal Waste Water Treatment Plant, septic tanks, and Ruseifa landfill. These contaminants have severely deteriorated the quality of groundwater in the study area.

Also, the presence of radioactive tritium in the groundwater shows that the aquifer in general recharged after 1952. In certain locations the aquifer receives direct recharge from precipitation with a residence time less than one year.

last updated on June 16, 2003