Riflusso

Riflusso is a hydrological term used to describe backflow within a groundwater system, typically the reversal of hydraulic gradients that drives water from discharge zones back into an aquifer or toward a water body. The term derives from Italian riflusso, meaning backflow or reflux, and is used in hydrogeology, especially in Italian-language sources.

Backflow can arise when hydraulic pressure in a water-bearing formation temporarily exceeds surrounding pressures, due to pumping, changes in recharge, seasonal fluctuations, or artesian conditions. It is more likely in layered or fractured aquifers, karst systems, and near recharge zones where gradients are dynamic. Natural riflusso may occur after heavy rainfall or rapid drawdown in confined aquifers, while anthropogenic riflusso can result from excessive pumping, reduced recharge, or improper well construction.

Implications include alteration of groundwater flow directions, contamination risk, and challenges in estimating aquifer recharge and discharge. Riflusso can complicate the interpretation of tracer tests and groundwater models, requiring careful monitoring of water levels, quality, and flow directions in a network of observation wells.

Mitigation and management strategies focus on controlling pumping rates, protecting recharge areas, and installing backflow-prevention measures in wells and distribution systems where applicable. In environmental assessment, recognizing riflusso effects improves understanding of pollutant transport and aquifer resilience.