Recharge processes in karstic systems investigated through the correlation of chemical and isotopic composition of rain and spring-waters

摘要

Four karstic springs in southern France, along with rainwater in the same area, were monitored during two hydrological cycles. Stable isotopic ratios (delta(18)O and delta D) allow the contribution of the rain waters from the previous periods (discretised as winter or summer period) to the spring water to be estimated. These Computations indicate that heavy rainfall events during the autumn season contribute for 56 +/- 7% and 68 +/- 9% of the spring water discharge during the following winter and summer seasons, respectively. During the low flow period, residence time does not exceed 1 hydrological cycle, for a large part of the water.