Assessment of specific yield in karstified fractured rock through the water-budget method

Abstract

In this note, the Water Budget Method (WBM) is applied to estimate local values of the specific yield of the deep karst aquifer of Salento peninsula. A selection in a period of two years of relevant short precipitation events has been considered and the related localized recharges have been compared to the water table fluctuations measured at two selected wells. The recharge amounts have been corrected by using data of evapotranspiration and soil water storage available from a micrometeorological base. The results are very similar for both the wells and more consistent when the corrections are applied. A discussion involving frequency and apertures of the fractures in the rock mass of the aquifer suggests the effect of the karst dissolution to be dominant in determining these values of the specific yield.