Geographical information systems (GIS) incorporate robust tools that allow
for the incorporation, manipulation and analysis of different types of data, such as
geologic, hydrogeological, meteorological and environmental, and to display large
amounts of geocoded data, useful to map the spatial distribution of natural phenomena.
Groundwater pollution and soil erosion are some of the environmental concerns at
global scale, that require efficient mapping tools. An assessment of the groundwater
vulnerability and soil loss through open source applications, developed for this
purpose, is a valuable contribution to several communities. The applications presented
in this work were developed within the QGIS software, using several open source
libraries. The first application was developed to produce maps to evaluate the
groundwater vulnerability to pollution. The tool integrates the procedures required to
implement the DRASTIC index under a single plugin. The application is easy to use
and provides the possibility of importing the attribute table, and allows for the
possibility of modifying weights, indexes and attributes, in an interactive manner.
Maps can be generated according to the user perception, regarding each aquifer system.
The second application is intended to estimate the expected soil loss by water-caused
erosion, using the Revised Universal Soil Loss Equation (RUSLE) through a web
browser. This application provides the tools to manipulate the input data of the RUSLE
model and to create categorical maps needed to assess the risk of soil loss. This web
application was implemented in order to be used by users without GIS software skills.
In order to test the two applications developed, two study cases were performed: in
River Zêzere Basin Upstream of Manteigas (Serra da Estrela) for DRASTIC index and
Montalegre municipality for RUSLE. The resulting maps met the expectation of soil
scientists for these study areas.
Keywords: DRASTIC, Environment impacts, GIS, Groundwater vulnerability,
Open source, Python, QGIS, RUSLE, Soil erosion, Web.
