Hydrogeological Vulnerability Assessment in Urban Systems, Spain G. Sanz 1 , M. T. D. Albuquerque 2 , R. Martínez-Alegría 3 , I. M. H. R. Antunes 2 and J. Taboada 4 1 University of Goiania, Brazil 2 Polytechnic Institute of Castelo Branco, CERENA, FEUP, Portugal 3 European University of Miguel Cervantes, Spain; 4 University of Vigo, Spain Abstract. The main objective of this research is the study of vulnerability to pollution in an unconfined karstic aquifer system. Aquifer vulnerability assessment to define critical zones of contamination is a core issue an effective monitoring network for groundwater management. Vulnerability integration is addressed for risk valuation and risk–benefit considerations, focusing the requirements of the European Community’s Water and Groundwater Directives. The development of an integrated vulnerability assessment methodology can be useful for the effective management and protection of this valuable freshwater source. The research insights suggest that an effective governance is mandatory as the future highway, the prison and the airport are overlaying the aquifer’s most vulnerable areas. Keywords: Groundwater management, vulnerability, geostatistics, environmental risk. 1. Introduction Cleaning and restoring contaminated groundwater has been often technically difficult and a considerable financial burden. Otherwise, searching for alternative sources for water supply is not always feasible. Therefore, the most efficient and realistic result is to prevent groundwater from pollution. A comprehensive regional approach, identifying vulnerability patterns of groundwater to contamination can be a utilitarian instrument to make out this valuable resource. Vulnerability can be somehow an ambiguous concept. Several sources provide a sound overview of different definitions for vulnerability assessment [1]-[5]). Vulnerability, as a relative aquifer’s characteristic, is a non-measurable and dimensionless property and should be used as an indicator for risk assessment. The identification of “cold” and “hot” vulnerable spots, and the subsequent overlapping of impacting activities provides policy makers guidance in overcoming urban water governance challenges. In this paper, was used the DRASTIC method [6], a non-parametric method widely used [7]-[10]. In the herein work, the results of the vulnerability mapping using DRASTIC are used as an attribute for the sustainability study of the unconfined limestone aquifer of Montes Torozos, Duero river watershed. Torozos area (total area= 10000 km2), is situated in the central northwest of the Iberian Peninsula, extending between the Spanish provinces of Valladolid and Palencia (Fig. 1), encompassing 57 municipalities and parishes [11] with a population around 47000 inhabitants [12]. The main human activities are agriculture and livestock. The anthropogenic impact has grown exponentially in the last fifty years, primarily due to alterations in consumer habits which induced environmental changes and deferred direct effects on the endangered population.  Corresponding author. E-mail address: teresal@ipcb.pt. 2015 5th International Conference on Environment Science and Engineering Volume 83 of IPCBEE (2015) DOI: 10.7763/IPCBEE. 2015. V83. 28 157