Nature-based Solutions (NbS) are increasingly promoted as a key strategy for climate adaptation, aiming to improve sponge functioning by intercepting, slowing, storing, and slowly releasing water. By reducing flood peaks, enhancing drought resilience, and delivering ecosystem services such as improved water quality and biodiversity, NbS are central to climate-resilient land and water management. However, implementation at scale remains limited due to insufficient evidence on the (eco-)hydrological impacts of NbS across spatial and temporal scales, and limited translation of this knowledge into decision-making.
Key questions remain regarding how effectiveness evolves over time, how maintenance influences long-term outcomes, how impacts propagate across scales, under which conditions local interventions contribute to landscape-scale resilience, and how scientific evidence can support upscaling.
This session explores the role of quantitative assessment in understanding Nature-based Solutions (NbS) and supporting their upscaling. It examines how evidence from local monitoring and modelling to catchment-scale assessments can guide implementation, inform policy, and strengthen confidence in climate adaptation investments, advancing climate-resilient sponge landscapes. We welcome contributions that:
•Quantify the effectiveness of NbS for multiple objectives, including flood mitigation, drought resilience, and associated co-benefits, trade-offs, and uncertainties to inform design, implementation, prioritization, and upscaling.
•Investigate temporal and spatial scaling, including long-term performance, delayed benefits, degradation processes, maintenance requirements, and cumulative impacts from plot to catchment scales.
•Integrate monitoring, experimental, and modelling approaches to strengthen attribution, process understanding, and impact assessment of NbS, using observed evidence to validate models and evaluate the scaling of flood, drought, and eco-hydrological benefits.
•Highlight the qualitative and quantitative evidence required by local actors, implementers, policy-makers, and investors to support decision-making.
•Develop decision-support tools, indicators, and assessment frameworks that strengthen links between quantification, implementation, governance, financing, and policy.
•Demonstrate how evidence from monitoring and modelling has informed planning, policy development, implementation strategies, investment priorities, and the mainstreaming of NbS.