The Urban Hydrologics Strategic Adaptation Framework for Tropical Watersheds offers an innovative approach to addressing the complex challenges of water management in urban environments. This framework is particularly relevant for tropical islands like Puerto Rico and Singapore, where the interplay between inland and coastal ecosystems is crucial for achieving island-wide climate resilience. Given their exposure to tropical weather extremes and the need for meticulous resource management, this strategic framework ensures a comprehensive, integrated approach to managing water resources, ecosystem services, and socio-economic co-benefits effectively.

Blue-Green Policy Overlay
The first component of the framework is the blue-green policy overlay, which mandates the integration of vegetation into urban development and retrofitting projects. This policy facilitates the creation of an interconnected network of blue-green infrastructure that spans public and private lands, ensuring seamless stormwater management. Incentives and financial mechanisms support this integration, prioritizing areas prone to flooding and those contributing to downstream peak flows. The policy overlay sets new standards for developments, retrofitting efforts, and property owners, aiming to create a resilient urban environment.

Holistic Coastal and Inland Resilience
The second component addresses the interconnected challenges of coastal and inland resilience. Traditionally treated separately, these areas are integrated within the Urban Hydrologics framework to achieve comprehensive resilience across the watershed. This approach emphasizes the need for coordinated investments in blue-green infrastructure and nature-based solutions from coastal areas to upstream river systems. By considering the entire watershed as a cohesive unit, the framework ensures that interventions are effective in mitigating risks and enhancing ecological connectivity.

Strategic Network Levels
The third component involves three strategic network levels: primary, secondary, and tertiary. Primary networks include major waterways and coastlines, where nature-based solutions enhance resilience to sea level rise and storm flows. Secondary networks consist of parks, open spaces, and urban corridors, focusing on habitat connectivity and stormwater management. Tertiary networks encompass private properties and urban surfaces, integrating stormwater management tools to reduce peak flows and restore pre-development hydrological conditions. This multi-scalar approach ensures that blue-green infrastructure is effectively implemented across various urban and ecological contexts.

Four Key Variables
The fourth component revolves around four key variables: water quantity, water quality, community, and ecology. Strategies and measures are disseminated across the primary, secondary, and tertiary networks to address issues related to these variables. Areas where these issues overlap become focal points for intervention, ensuring that blue-green infrastructure investments are targeted and effective. This comprehensive evaluation ensures that the framework addresses the most critical vulnerabilities and maximizes the benefits of nature-based solutions.

In summary, the Urban Hydrologics Strategic Adaptation Framework for Tropical Watersheds is a pioneering approach developed from ongoing research and practical experience in Singapore. This framework provides a robust foundation for climate adaptation and resilience in tropical cities, and coastal watersheds and serves as a model for tropical islands globally. By leveraging transdisciplinary expertise and innovative strategies, the framework aims to create resilient, sustainable urban environments that can effectively manage stormwater, enhance ecological health, and improve community well being.