Nature-based solutions potential for flood risk reduction under extreme rainfall events

Area of Science:

• Environmental Science
• Urban Planning
• Climate Adaptation

Background:

• Climate change exacerbates extreme rainfall events, particularly in tropical regions.
• Increased flood risks in urban areas necessitate effective climate adaptation strategies.
• Nature-based solutions are increasingly recognized for their potential in urban resilience.

Purpose of the Study:

• To evaluate the effectiveness of nature-based solutions for mitigating flood risks.
• To assess the cost-effectiveness of different land recovery scenarios in an urban setting.
• To analyze the co-benefits associated with nature-based flood risk reduction strategies.

Main Methods:

• Ecosystem service modeling approach to assess flood risk.
• Evaluation of four land recovery scenarios with varying reforestation proportions.
• Cost-effectiveness analysis of implemented scenarios and their co-benefits.

Main Results:

• All evaluated land recovery scenarios demonstrated increased flood risk reduction and co-benefits with greater land recovery.
• An intermediate land recovery scenario, specifically 30% reforestation, was identified as the most cost-effective.
• The study highlights a clear gradient of increasing benefits with increased land recovery proportions.

Conclusions:

• Nature-based solutions provide significant benefits for urban flood risk reduction.
• A 30% reforestation strategy offers an optimal balance between cost-effectiveness and flood mitigation.
• Implementing nature-based solutions requires consideration of landscape scale and stakeholder needs for successful urban adaptation.