Dynamic assessment of compound flooding through a risk index approach
摘要
Assessing flood risk in estuarine and coastal zones is challenging when river discharge, tidal peaks, and weather-driven forces coincide. Traditional models–based on fixed dependency patterns or isolated extreme events–tend to overlook the rapidly evolving, non-linear interactions among these drivers over short time scales, leading to systematic underestimation of compound flooding severity. The Compound Dynamic Risk Index overcomes these limitations by integrating daily-resolution probabilistic dependence modeling (via copula-derived joint exceedance probabilities of river discharge and storm surge) with a curvature-based diagnostic that captures second-order temporal dynamics. Unlike conventional indicators activated only upon threshold exceedance, the curvature component enables early detection of shifts in hazard trajectory, providing an anticipatory signal of risk escalation before peak intensity is reached. CDRI values are classified into four categories: Low (CDRI