Il monitoraggio in continuo delle portate in torrenti e sorgenti alpini per la valutazione del Deflusso Minimo Vitale

Water diversion for irrigation and power supply induces an effective decreasing of environmental flows in alpine area, with negative effects on the river ecosystem. As a consequence it’s worthwhile to assess environmental flow for the proper management of water diversion. This type of assessment is generally performed by hydrologic methods taking into account duration curves or morphological features of the watersheds or by naturalistic parameters. Another method is to directly measure creeks and springs water discharge in order to construct a continuous watershed outflow hydrogram. The study area is located in the Belluno Dolomites National Park (Veneto Region, Northern Italy). Three watersheds (streams) and two main springs are taken into account; all streams are affected by hydraulic diversion for hydroelectric power. The upper reach of each watershed is fully located inside a protected area.; from an hydrogeologic stand-point dominant groundwater flow is of a karst type with few important springs contributing to the major percentage of creeks base flow. The monitoring system installed on later 2006 is based upon a total amount of 11 continuous stream gauging stations (2 of these are located in the main springs). The paper deals with the description of the installed gauging stations