TITLE:
Land-Use Impact and Nitrate Analysis to Validate DRASTIC Vulnerability Maps Using a GIS Platform of Pablillo River Basin, Linares, N.L., Mexico
AUTHORS:
René Alberto Dávila Pórcel, Christoph Schüth, Héctor De León-Gómez, Andreas Hoppe, Rowen Lehné
KEYWORDS:
Vulnerability Maps, DRASTIC, Land Use, Nitrate, GIS
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.12,
November
25,
2014
ABSTRACT: Preventive
management of groundwater resources and their protection against pollution is one
of the major challenges of our society. Groundwater systems are related with the
surficial processes like territorial administration that is one of the most important
tasks into the human development, because it involves serious problems to define
the spatial medium, the industrial site-selection and the land-use allocation. Land-use
and anthropogenic distribution could be the origin of the emission of pollutants
that constitutes a serious health risk in urban areas. Nitrate was used as a pollution
indicator in the Pablillo River Basin (PRB), to know the evolution of groundwater
quality between 1981 and 2009 using GIS platform linked to vulnerability maps of
DRASTIC (Depth to the water table; net
groundwater Recharge; Aquifer type; Soil type; Topography; Impact of the vadose zone and hydraulic Conductivity of the saturated zone). The
study area is centered on the Linares city; changes in aquifer vulnerability were
assessed over time on two stages (2007 and 2001). In both cases, depth from surface
to groundwater plays an important role by being the most dynamic variable over time.
This study shows that the depth of water table is the key factor in the evaluation
of groundwater vulnerability. The significance of land-use impact in contamination
process called Index of Pollution Risk (IPR)
and nitrate distribution process in the aquifer system was used as anthropogenic
indicator together with the IPR in order
to associate the land-use, the aquifer-vulnerability and human-activities. The final
map of IPR allows determining possible
polluted zones verified by high nitrate contents over the aquifer system. Land-use
proved to be an important parameter necessary to correct the vulnerability maps
using the DRASTIC method. This assessment is valid for situations where a specific
time is defined because six of seven parameters change their properties in a very
long term. The IPR-map could be an important key tool to prevent complex scenarios
of groundwater contamination and to improve the aquifer management for decision
makers, governments and private companies.