Contribution to the knowledge of the geohydraulic model of the sulphureous spring of Ponte do Fumo - Tabuaço (Portugal).

The sulphureous spring of Ponte do Fumo is a small natural source of groundwater, whose use for medicinal purposes in rheumatic and dermatological diseases is very old, losing the beginning of its use in time. In the 70's of the last century, it was still used in very vernacular installations, however today it is totally abandoned. Because this type of special water resource, has a long and extensive geohydraulic circuit, that spring today continues to maintain its small flow and its unique chemical characteristics, which are very evident in the place, not only because of its bad smell of eggs rotten, such as by the biojelly (white cream) that develops next to it. On the other hand, this type of resource, if captured at depth, has the potential to obtain adequate flow to build a health unit, of the medical spa type, as well as allowing geothermal uses, as these waters at depth tend to be hot. It is therefore very important that studies are carried out on site, which would make it possible to lead to such a situation. Thus, in this paper, in an initial part, introduction, we present the importance of sulphureous waters for society, the elementary aspects of its chemical composition and of its geohydraulic models, among others, such as previous references about the Ponte do Fumo sulphureous spring. Next, the methodology of the work is presented. Then, as results, the geomorphological, geological and hydrogeological aspects, the conceptual geohydraulic model of sulphureous water and also the order of magnitude of water flow to be explored from a deep well, are presented. Finally, some final remarks are presented with the main conclusions, pointing out the best area for prospecting and research in order to contribute to a future sulphureous groundwater abstraction. [ABSTRACT FROM AUTHOR]