RZDD: Risk Zone-Diversified Network Design for Disaster Resilience

With the growing need for a robust network backbone to ensure uninterrupted connectivity in the face of large-scale natural disasters, we introduce the Risk Zone-Diversified Network Design (RZDD) problem. This problem requires diverse paths between source-destination pairs to be risk zone-disjoint, preventing any single disaster from disrupting overall network connectivity. Unlike previous research, we propose an innovative cost framework that considers geographically overlapping links and long-term maintenance costs, providing a comprehensive approach to cost analysis. We prove the intractability of the RZDD problem and present the Risk Zone-Diversified Network Design Algorithm (RZDD-Algorithm). In small-scale networks with a single source-destination pair, our algorithm achieves optimal outcomes. Comparative analysis shows that our method reduces costs by an average of 24% compared to an SRLG algorithm that does not consider the preference of geographically overlapping links. For multiple pairs, our approach maintains a gap ratio within 4% and 7% of optimal solutions. Furthermore, experimental evaluations on large networks demonstrate reductions of 26% and 31% compared to the SRLG baseline for single pairs. We also showcase the efficiency of our method in designing large-scale networks with multiple pairs.