The recharge processes have been evaluated for two karst massifs of southern Italy, the Mt Terminio and Mt Cervialto, characterized by wide endorheic areas. The annual mean recharge has been estimated by Geographic Information System (GIS) tools, from regression of annual mean values of different ground-elevated rain gauges and thermometers. The recharge has been distinguished for endorheic areas and the other areas of spring catchment, and the ratio between the output spring and input rainfall has been also estimated (recharge coefficient). The annual recharge has been used to calibrate a daily scale model, which allows to estimate the amount of effective rainfall, which is retained as soil moisture; the amount reaching the water table (recharge s.s.); and the amount of rainfall, which develops the runoff and leaves the catchment. All these amounts vary through the hydrological year, in function of soil moisture deficit and daily rainfall intensity. The model allows estimating the recharge conditions through the hydrological year, and it is a useful tool for water management.

The upwelling groundwater flux has been investigated by deep piezometers in a spring area characterized by alluvial deposits covering a karst substratum in Southern Italy. The piezometers are of varying depth located in a flat area. They have been monitored for a long period (about 40 years), and when measured, a good relationship between spring discharge and hydraulic head was observed. The local upwelling groundwater flux has been deducted by the increasing of the hydraulic head in depth, which allows the estimation of ascendant hydraulic gradient and groundwater velocity during the dry and wet seasons. A specific analytical solution has been used to estimate the zone involved by the ascendant flow, and could also be used in other spring areas. Some physical and chemical characteristics of spring water have been collected, including the radon (222 Rn) activity, to support the phenomenon of the ascendant flux. The man geological and hydrogeological features leading to ascendant flux in karst environments is also discussed for some areas of Southern Italy, where many springs are affected.

The recharge processes have been evaluated for the Matese massif, a wide karst system of southern Italy, which feeds several major springs. This massif is characterized by wide endorheic areas exploited for hydroelectrical purposes; several hydraulic works have modified the natural recharge processes of the Massif and the regime of karst springs. Recharge on massif is based on the annual means recharge estimation by GIS, using regression of annual mean values of different ground-elevated rain gauges and thermometers. A calibrated daily scale recharge model estimates the amount of effective rainfall that is retained as soil moisture, the amount reaching the water table (recharge s.s.), and the amount of runoff leaving the catchment. All these amounts vary through the hydrological year, as so function of soil moisture deficit and daily rainfall intensity. When soil moisture reaches the field capacity, daily rainfall exceeding 24.3 mm develops runoff; the runoff amount increases during wet year and reduces during dry years, highlighting the important role of the endorheic areas mainly during wet years. The ratio between the total water volume spring outlet and the effective rainfall (effective recharge coefficient) has been estimated for several hydrological years and varies between 0.81 (dry year) and 0.58 (wet year).

The hydraulic phenomenon of upwelling groundwater flow affecting the karst area of the Grassano-Telese springs (southern Italy) has been investigated through piezometric measurements, discharge, and chemical–physical monitoring of springs, radon activity included. Locally, both large karst springs and sulfurous thermal springs are closely located, and raise several questions on their origin. In this study, the phenomenon of the upwelling flow is supported by different types of evidences: Amazing density of sinkholes connected to hypogenic speleogenesis processes, constancy of temperature, and hydraulic conductivity of spring water, change of radon activity during the hydrological year, increasing of the hydraulic head with depth. Numerical code provides an estimation of the upwelling phenomenon in an unconfined aquifer feeding the karst springs, using MODFLOW tools. Based on the results reached, the phenomenon of the upwelling flow is able to explain the hydrological processes observed in the Telese karst area.

On 25 October 1954, a storm hit the area surrounding the villages of Vietri sul Mare and Maiori of the Amalfi Coast (southern Italy) causing more than 300 deaths and severe damage to infrastructures and agriculture. This event has been among the most catastrophic historically documented in Campania Region. On this basis, and considering the lack of an existing complete characterization of the event in terms of triggered slope processes, we used multiple sets of stereoscopic aerial photos and a LiDAR-derived high-resolution topography to produce an event landslide inventory map. Our map provides an overview of the landslide distribution and extent in the area that mainly suffered the effect of the storm and is the basis for a morphometric characterization of landslide source areas that we present in this paper as simplified statistical analysis. In addition, we compared the rainfall distribution with the spatial density of source areas.