Hydrological features of endorheic areas in southern Italy

This work focuses on hydrogeological behaviour of karst systems in southern Italy (Alburni, Matese, Termino and Cervialto massifs). The karst landform common to all areas analized is endorheic area, which may be considered the preferential vehicle for basal springs and groundwater recharge. A preliminary correlation was found between strata layout and morphometric features of endorheic areas; this relationship helps to better understand the recharge processes of karst systems analyzed, particularly for some karst massifs of southern Apennines, affected by irregular orography and geomorphological features. The first step focused on a detailed analysis of endorheic areas, highlighting the etherogeneous size between the macro depressions of Terminio, Cervialto, Matese (polje) and minor-depressions of Alburni summit plateau typified by high density of sinkholes. The differences among endorheic karst landforms development can't be explained only with various processes of karst rocks dissolution; otherwise the strata dip may be considered the main factor having a strong control on closed depressions evolution. Then Alburno, Matese and Picentini massifs have been split in several blocks homogeneous for strata dip. The analysis highlights that the steep slopes of strata do not allow the formation of the closed areas, whereas gentle dip of strata support endorheic areas development, especially minor-depressions. The closed depressions are especially developed on the summit areas, where most of the surface meteoric water are conveyed underground. Additionally the sinkholes detection allowed to define the kind of statistical distribution which better represent their spatial distribution.