Spatio-Temporal Groundwater Vulnerability Assessment - A Coupled Remote Sensing and GIS Approach for Historical Land Cover Reconstruction

This paper presents a spatial-temporal groundwater vulnerability assessment, based on a coupled remote sensing and GIS approach for historical land cover reconstruction. This flexible methodological tool can be used for spatiotemporal vulnerability assessment in fresh water systems. The transboundary watershed of the Águeda River was used as an experimental case study where the DRASTIC and DRASTIC pesticide indices and the Susceptibility Index (SI) were used for vulnerability assessment. Land-use temporal evolution was mapped using remote sensing, taking into account the aerial frames of the historical American Flight of 1956/59, the IGN’s 1984 Flight and CORINE Land Cover (1990, 2000 and 2006) as spatial information. Four new land-use layers were considered in the SI’s temporal evolution assessment, namely for 1959, 1990, 2000 and 2006, respectively. In the last 50 years, the highest vulnerable areas to groundwater contamination have been concentrated mainly in the central zone of the watershed where the tertiary aquifer and the largest urban area are located. Future research will involve feasibility studies of different treatment schemes and the development of specific monitoring activities.