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Luis Ribeiro, Instituto Superior Tecnico (Portugal)
Ana Buxo, Instituto Superior Tecnico (Portugal)
Jorge Quintanilla, Universidad Mayor de San Andres (Bolivia)
Maria Eugenia Garcia, Universidad Mayor de San Andres (Bolivia)
Ricardo Oyarzún , Water Center for Arid and Semi-Arid Zones in Latin America and the Caribbean (Chile)
Nicole Kretschmer , Ceaza (Chile)
Marcela Venegas, Water Management Consultants (Chile)
Percy Jimenez, Universidad Nacional de San Agustin de Arequipa (Peru)
Paul Younger, University of Newcastle (United Kingdom)
Jaime Amezaga, University of Newcastle (United Kingdom)
Tobias Roetting, University of Newcastle (United Kingdom)
Jorge Loredo, Universidad de Oviedo (Spain)
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More than 25% of South America is arid or semi-arid. A general lack of rational water management systems hinders the sustenance / recovery of ecosystems and human communities in these areas. The twin scourges of erosion and salinisation are prone to exacerbation by various human activities. Mining potentially has one of the highest environmental impacts, yet it contributes more to legal export earnings in the region than any other sector. There is clearly a need to rigorously review the effectiveness of existing policies, and to develop new approaches to river-basin management to ensure that such vital economic activities can be carried out in a manner which does not permanently damage fragile ecosystems and water resources upon which human communities depend in arid / semi-arid areas.
CAMINAR (Catchment Management and Mining Impacts in Arid and Semi-Arid South America) project has the general aim of contributing to the establishment of policy options, management strategies and technologies for the sustainable management of ecosystems in river-basins of arid and semi-arid South America where mining operations are present. This aim will be achieved using Peru, Bolivia and Chile as "demonstration" countries, One of the main objectives is to develop a Decision Support System (DSS) tool to support participatory water management planning in the demonstration river-basins.
A water management DSS consists of three main subsystems integrated in an interactive manner: an information management subsystem (i.e., a database integrated in a GIS), a set of models integrated with the database and a user-interface.
Since groundwater plays an important role in those river basins, a set of applications has been carried out in order to evaluate aquifer vulnerability and the risk zones concerning the their probability of contamination.
Most vulnerability methods concentrate on the intrinsic component, assuming that its application is undifferentiated for all potential contaminants. They present an important limitation, since the behaviour of contaminants is extremely variable. To avoid such problems, a new specific vulnerability index named SI (Susceptibility Index), an adaptation of the DRASTIC method, is used here. The main difference is the addition of a parameter defining land cover impact, thus abandoning the concept of a purely intrinsic vulnerability and the reduction of the number of parameters considered to be redundant or inadequate such as the impact of vadose zone (I), soil type (S) and hydraulic conductivity (C) For risk appraisal, the SI constitutes an optimal example of a tool to support decision making. Derived risk indicators can be applied to generate probability maps, clearly indicating the areas of major potential of contamination. The method applies robust non-parametric geostatistical tools, involving variographical analysis and kriging of indicator variables.
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