GROUNDWATER FOOΤPRINT: A TOOL FOR ECOLOGICAL-BASED GROUNDWATER RESOURCES
MANAGEMENT ASSESSMENT
Abstract
Over-pumping and extended drought events have raised awareness on
groundwater resources management within the Mediterranean Basin. As
groundwater often has an important role in sustaining certain types of
aquatic, terrestrial and coastal ecosystems, water policy makers should
pay special concern to maintain groundwater contribution to the
environmental flow. To this aim, the present study focuses on the
assessment of a newly introduced groundwater management tool, the
Groundwater Footprint (GWF) (Gleeson et al., 2012). GWF represents a
water balance between aquifer inflows and outflows, focusing on
environmental flow requirements and expresses the area required to
sustain groundwater use and groundwater dependent ecosystem services.
GWF is applied to a pilot aquifer in the Mediterranean Basin, crossed by
an intermittent river. Total abstraction, natural and artificial
recharge, groundwater contribution to environmental stream flow are the
critical parameters related to GWF estimation. In order to estimate
groundwater contribution to the environmental stream flow, the
assumption that groundwater contributes to the environmental flow to the
same percentage as baseflow contributes to the natural flow has been
made. However, the main constraint met in GWF estimation has been the
estimation of the environmental flow in non-perennial river, as the
quantification of the environmental flow requirements has been mainly
studied for perennial rivers. For this reason, the available to the
literature studies referring to environmental flow requirements have
been assessed and the most appropriate method for the specific pilot
area has been applied. The ratio GWF to the actual area of the aquifer
(A) can be used to assess groundwater management, as
GWF/A>1 indicates unsustainable groundwater consumption.
Consequently, GWF/A may consist a comprehensible to the general public
groundwater stress indicator and can be used to raise awareness.