Drought Mitigation Through Nature-based Solutions for Climate Adaptation in Headwater Catchments

: Best Practices Compared with Scientific Knowledge

Abstract

Drought is a topical issue, give extreme drought records in the Netherlands over the past five years and the IPCC’s 2021 pronouncements on drought. Drought is a consequence of disruptions in the hydrological cycle in response to climate change and can have social-economic impacts as a climate effect. To reduce vulnerability to climate effects, Nature-based Solutions (NbS) are being designed and implemented in co-creation with society. In this study, we look at whether NbS designed for flood mitigation in headwater catchments are also effective against the impacts of drought. This research is conducted within eight catchments involved in the European project Co-Adapt. We conducted a document analysis, a Concensus Decision Process (CDP) with 40 water professionals and an SLR to collect data. NbS were analyzed on involved processes and parameters using the definition from Keesstra et al. (2018). Based on the concept of evidence-based practice (EBP), we combined field expertise with scientific knowledge to arrive at best practices of NbS with a mitigating effect on drought. This is tested in one of the involved catchments. The results showed that drought was a primary or secondary motive for designing NbS. According to EBP, water sinks, runoff pathways and soil processes are the most effective parameters to influence for mitigation of drought. Therewith we predicted that drought will be mitigated in the sample catchment area by enhancing water sinks. We conclude that if the underlying processes (geomorphological, soil, surface and chemical) are included in the design of flood measures, it is expected that after implementation of NbS in headwater catchments, water storage capacity will increase and ecological and socio-economic drought will decrease.

Date of Award	24 Mar 2023
Original language	English
Supervisor	Angelique Lansu (Supervisor), Frank van Lamoen (Co-assessor) & Wilfried Ivens (Co-assessor)