A multi-model simulation framework for the 'Sponge Park' concept: achieving urban water-energy nexus sustainability in hyper-arid climates

Urban areas in hyper-arid regions face a dual threat of water scarcity and urban heat islands, exacerbated by conventional infrastructure. This study introduces and evaluates the "Sponge Park" concept—a decentralized, nature-based system of permeable surfaces and subsurface storage—as a replicable model for integrated water management and climate adaptation in arid cities. A novel multi-model computational framework was developed, coupling Computational Fluid Dynamics (CFD) for process-level subsurface hydrology and heat transfer, the EPA HELP model for long-term water balance, and TR-55/HydroCAD for extreme storm event routing. The system, designed for a 13-ha site in Abu Dhabi, integrates high-infiltration silica-sand pavers and breathable aquicludes (APAC). A comprehensive Monte Carlo analysis (n=1,000) quantified uncertainties in key parameters. Simulations under local climatic inputs (80 mm/yr rainfall) project exceptional performance: >93.6 ± 3.8% annual rainfall infiltration,