Studio geo-idrologico della Sardegna settentrionale: memoria 6.: il bacino idrografico del Fiume Temo

This comment consists essentially of three well defined partes: the is first physical geography, the second hydrogeology and the last is hydrogeochemistry. The AA., after a preliminary and organic geological investigation which permitted the preparation of the map (Fig. 3) in which the various geolithologic units are corelated, then made a particular study of the principal geomorphologic structures present in the entire basin. The multiple presence of such structure is justified in the geological difference of the formations present. Among the typical structures of the basic vulcanites was the evidence of cushion lava, block lava and tabularcolumn lava; among the typical acid vulcanites are the stratoid lava and the cave like structures. Also the evidence were the pointed tabular structures, the concave tabular structures and the dip-shop, tabular structures present in the series of lava flows, and of porous stone deposits and sea deposits in alternate stratus. The part relative to the hydrogeology was preceded by an examination of the climatology and the hydrometry of the basinc. Five meteorological rain measuring stations and two thermometeorological rain measuring stations were used for this study and the following information were gathered: - the maximum precipitations were concentrated in the late autumn period, in winter and in the early spring; the maximum aridity was during the summer months; there is a great irregularity in the intensity of the precipitations; within the area of the basin proportional differences of values of precipitation due to altitudes do not exist. The hydrometric characteristics of the basin have been brought to light using the information of hydrometric data given by the station at Reinamare. From an hydrological point of view, by suddividing the general area into thre larges complexes based on their permeability, the most important hydrogeological series and water structures of the basin have been located. As well as this, 60 perpetual water springs have been registered, and for the most part they have been actually identified and their waters have been analized and studied. These analysis have proved the waters as belonging to three families: magnesium-chloride water, sodium-bicarbonate water and sodium-sulphate water. This latter water family which includes the majority of the springs, whose sources are diffused almost all over the enti re area of the basin, presents a fairly similar chemical characteristic as we have found by using linear co-relations with pairs of geochemical «parameters».