Ecosystem services approach to natural flood management in the Derwent and Cocker catchments of the Lake District National Park

Abstract

In light of increasing pressures on rural land use as a result of farming, tourism, industry, population growth, and climate change, the incorporation of sustainable land management practices is becoming increasingly important. Ecosystem services account for the benefits that the natural world provides, and can be used to inform sustainable land use change. The Derwent and Cocker catchments in the Lake District National Park are home to the aforementioned pressures, resulting in issues such as flooding, water quality, and balancing cultural heritage with environmental protection. Natural flood management (NFM) is an example of a measure that works with natural processes to reduce flood risk, while providing multiple ecosystem services benefits.

In this study, the Sustainable Land Management (SLM) GIS model is used to constrain existing open source Working With Natural Processes (WWNP) NFM opportunity maps, using ecosystem services and land cover change transition matrices. NFM opportunities are constrained for wider catchment woodland, floodplain woodland, riparian woodland, and floodplain reconnection, and are constrained by 54%, 66%, 31% and 75% respectively (by area). An example scenario is explored to identify NFM opportunities upstream of a known flood event area when combined with additional sub catchment and flood data.

Ecosystem services vary by NFM measure, but include the following opportunities: water cycling – purification, water cycling – nutrients, erosion regulation, woodland connectivity, and productivity – woodland.

Stakeholder engagement constrains the land cover transitions to those that are realistic in the Lake District. The results show that acid grassland is a priority land cover for NFM opportunities due to its upper catchment location, widespread area, and low economic value. It is found that constraining NFM opportunities using the methodology in this study is effective, but that more ecosystem service opportunity maps, together with hydrological modelling and additional stakeholder engagement are required to better target areas.