Assessment of sustainability of groundwater in urban areas (Porto, NW Portugal): a GIS mapping approach to evaluate vulnerability, infiltration and recharge

The urban water cycle concept demonstrates the connectivity and interdependence of urban water resources and human activities, and the need for integrated sustainable management studies and approaches. The role of climate, geology, geomorphology, land-use/cover, hydrogeochemistry, hydraulics, human activities among other features is significant in urban areas. In addition, land-use development has a stronger influence on terrestrial hydrology than climate variability. The need for provision of safe water, sanitation and drainage systems is key elements to consider for the groundwater resources in complex urban environments. In recent years, a new focus has emerged, addressing issues on integrated GIS mapping studies on urban water supply systems, particularly in historical cities. To illustrate that approach the Porto urban area (NW Portugal) was selected. This work presents a comprehensive study to demonstrate the key importance of urban groundwater studies, as well as the evaluation of the Urban Infiltration Potential Index and the potential groundwater yields that might be available for non-potable uses, such as irrigation of parks and lawns, street cleaning and firefighting. This strategy is useful for the planning and management of urban groundwater abstraction in an equitable and sustainable manner.