Integrated forecasting approaches for optimizing alluvial-coastal drainage systems

Alluvial-coastal plains and shallow-marine areas are facing increasing hydrological pressure from rising sea levels, changing precipitation patterns, and more frequent extreme events that alter their water balance. Prolonged droughts and unsustainable freshwater withdrawals further exacerbate the problem, causing saline intrusion into already vulnerable aquifers. In this context, adjusting drainage channel levels has become a key climate adaptation strategy. Our work combines long-term forecasting of aquifer dynamics using hydro-climatic data, including meteorological forecasts, with near-real-time forecasting to optimize the operation of high-capacity pumping stations that safeguard the drainage network of San Rossore Migliarino Massaciuccoli Regional Park (Pisa, Italy). The study addresses two complementary forecasting approaches: 1. Extended-range forecasting of aquifer levels through the integration of historical groundwater measurements and meteorological forecasts, with particular emphasis on precipitation and temperature projections over a two-week period. This approach provides weekly predictive outputs essential for determining optimal operational thresholds for pump activation, accurately tailored to varying seasonal and meteorological conditions throughout the year. 2. An operational, near-real-time forecasting framework designed to support daily management decisions. This system incorporates real-time data on meteorological conditions, groundwater levels, channel hydrometric levels, and drainage system activity to serve as an early warning mechanism during exceptional events requiring prompt intervention. Overall, preliminary results unequivocally highlight how integrated long-term and near-real-time operational forecasting systems are now indispensable for sustainable and resilient water resource management. Such systems allow for proactive anticipation of critical conditions, optimized drainage system use, reduced energy consumption, and preservation of the hydro-saline equilibrium in coastal aquifers. This emphasizes the necessity for continuous monitoring and technologically advanced solutions in fragile alluvial-coastal plains facing intensifying climatic and anthropogenic pressures.