Public water supply system analysis in the region of Castelo Branco (Portugal) : geostatistical methodologies to the groundwater productivity estimation

Abstract

The present work concerns to the study of the public water supply system, actual situation in Castelo Branco, Portugal. The Castelo Branco geographical area is about 1439.94 Km2 with a 500000 people population being an inner region of the country with big problems of water supply during the summer months. The purpose of this work is to develop a methodological procedure as a working tool to the management optimisation of the water supply system taking in consideration: the groundwater supply; the system management and the captured water volumes control. The definition of a groundwater hydraulic potential in a major fractured hydrogeology field, in which the water is conditioned by the presence of extended altered formations and it’s mobility conditioned by the intense fracture density is the goal of the propose work. The working data is available in a few Portuguese water institutions, and summarizes to 2002, the groundwater volumetric supplies, hydrological basin type, planning regions, geology, litology and served population. To the groundwater productivity estimated cartography was adopted a set of statistics and geostatistics methodologies like Ordinary Kriging, using a preliminary variographic data analysis that allowed the inference of the preferential underground flow.