The use of the DRASTIC-LU/LC model for assessing groundwater vulnerability to Nitrate contamination in Morogoro municipality, Tanzania.
Loading...
Date
2022-11-07
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI Earth
Abstract
Groundwater is a useful source of water for various uses in different places. The major
challenge in the use of this resource is how to manage and protect it from contamination. The current
study was conducted in Morogoro Municipality to identify vulnerable groundwater areas by using
DRASTIC-LU/LC model. The study applied eight input parameters, i.e., depth to water table, net
recharge, aquifer media, soil media, topography, impact of vadose zone, hydraulic conductivity
and land use/land cover patterns, which were overlaid in GIS to generate groundwater vulnerable
map. The model used rating (R = 1–10) and weighting (W = 1–5) techniques to assess the effect of
each parameter on groundwater contamination. The DRASTIC-LU/LC Vulnerability Index map
was classified into low- (area = 29.2 km 2 ), moderate- (area = 120.4 km 2 ) and high-vulnerability zones
(area = 124.4 km 2 ). Nitrate analysis was conducted using the cadmium reduction method (DR 890)
to assess the validity of the model and it was observed that 55%, 15% and 50% of the samples with
unacceptable (>50 mg/L), high (29–50 mg/L) and moderate (14–28 mg/L) nitrate concentrations,
respectively, fall into the high-vulnerability zone. Furthermore, 45%, 70% and 50% of the samples
with unacceptable, high and moderate nitrate concentrations, respectively, fall into the moderate-
vulnerability zone. In the low-vulnerability zone, only 15% of samples were found with a high
nitrate concentration.
Description
Journal Article
Keywords
Groundwater, DRASTIC-LU/LC model, nitrate contamination, vulnerability map