wAbstract
@Intensive use of land resources in arid and semi-arid regions
exert serious pressures on groundwater resources and jeopardize
further socio-economical developments. The Amman-Zarqa Basin (AZB),
the most vital basin in Jordan, is facing recent groundwater deterioration
due to a very large increase in what demands for domestic, agricultural,
and industrial uses. The objectives of this paper were to quantify
the degree of contamination in the basin by evaluating the characteristics,
distribution and seasonal variations of two pollution indicators
(nitrate concentration and salinity) and to determine the impacts
of human activities (land use) on groundwater quality. Based upon
long-term data (1970-2005) of groundwater samples collected from
538 wells across the AZB, spatial analyses indicated that both
indicators have a strong spatial dependence and are anisotropically
distributed. Prediction maps of Ordinary Kriging and Indicator
Kriging provided detailed indications of the major and minor sources
of pollution in the basin. Inefficient wastewater treatment plants,
industrial activities and agricultural practices were responsible
for 91, 85, and 25 salinization of nearby wells, respectively.
Nitrate pollution had reached 73 above threshold (50 mg/L) in
some cases. The temporal analyses estimated the salinity buildup
rate to be around 8~10-2 ΚS/cm per day, while nitrate
buildup rate was estimated to be around 6~10-2 mg/L
per day. Remote sensing and spatial analyses helped greatly in
groundwater quality assessment not only in providing the environmental
status of the AZB but also in delineating the potential of contamination
risk zones and their correlation to human activities. Furthermore,
the paper suggests some environmental protection strategies that
should be adopted to protect the vital groundwater resources of
the basin from further deterioration.
Keywords: Salinity; Nitrate; Ordinary kriging; Indicator kriging;
Probability kriging; Risk assessmentx
Introduction
Characteristics of the study area
@Geology and hydrogeology
@Water chemistry
@Spatial analyses
@Temporal analyses
Results and discussion
@Spatial analyses
@Nitrate pollution and salinization relationships to land use
@Temporal analyses
Conclusions
Acknowledgments
References