Cross-Framework Flood Vulnerability in Oasis Ecosystems: Design of a Recurrence-Rate Metric

Abstract

Although oases and desert regions are generally characterized by arid climates and minimal precipitation, they remain acutely vulnerable to flooding. This paradox constitutes the central focus of the present study, which investigates flood vulnerability in the oases of southern Morocco, with particular attention to the Tata region. The study distinguishes itself by structuring the vulnerability index through five distinct methodological frameworks while introducing a novel metric of vulnerability recurrence. By integrating statistical analyses across the five frameworks, the study delineates the specific strengths and inherent limitations of each, while revealing the complex interactions among geological, socioeconomic, demographic, and topographic determinants that jointly structure spatial vulnerability patterns. The results demonstrate that single-index approaches are inadequate, underscoring the need for multi-dimensional assessment. We therefore propose a dual-layer classification that evaluates vulnerability across five frameworks and ranks municipalities by how often they exceed a high-vulnerability threshold. This frequency—the Vulnerability Recurrence Rate (VRR)—is a novel, robust metric that captures cross-framework consistency of vulnerability, thereby advancing methodological and empirical understanding to support more targeted preparedness strategies. • 1.Oases, despite arid climates, are highly vulnerable to sudden and intense flooding; • 2.The study compares five distinct frameworks, based on exposure, sensitivity and adaptive capacity, to assess flood vulnerability in oases; • 3.Results show the limitations of using a single vulnerability index for flood assessment; • 4.A novel Vulnerability Recurrence Rate (VRR) is introduced to capture repeated high-risk classifications; • 5.Findings support tailored flood mitigation strategies for fragile oasis ecosystems.