A methodology of hydrogeological mapping for Northern Apennines. Experiences from Upper Montone and Upper Secchia Watersheds.

The paper deals with defining a methodology to map the combination of groundwater resources allocation key factors in such a way to define the areas where there is the maximum likehood to locate groundwater discharge phenomena, either by point springs or creeks base flow discharge. To get such a tool, however, it\u2019s important to manage geological and hydrogeological data according to a GIS based approach and, also, to link morphological and geological spatially discretized data to groundwater and creeks base flow data (hydrological data); moreover the results must be validated against some watershed with a detailed geological survey already performed and where location and hydrology of all existing springs and creeks are well known. The chosen pilot catchments for the research are the upper watershed of the Montone river, in Romagna Apennines across boundary between Tuscany and Emilia-Romagna, and the upper Secchia watershed, in the Reggio Emilia Apennines; the first one is entirely located in the outcropping area of Marnoso Arenacea formation, whereas the second presents a widespread variety of units: flysch units, argillitic chaotic units, evaporites, moraines. Concerning the base geological features (lithostratigraphic units otucrops, tectonic lineaments, quaternary deposits and strata setting) they were derived from the geological maps available in the Geological, Seismic and Soil service of Emilia-Romagna region, because of its participation in the CARG project. The objective of the study is to propose a hydrogeological map legenda useful for the estimation of renewable and exploitable underground water volumes, so becoming a tool for technicians committed with the management of prescribed permissions for water abstraction according to the Emilia-Romagna regulations. Data on spring discharge and their chemical characteristics, creek base flows inferred by using NaCl tracer, spring and creek hydrographs reconstruction and runoff partitioning based on continuous monitoring, GIS based data elaboration, are among the research tool utilized