Sea level rise and climate change hazards: an integrated and multidisciplinary NBS approach to the hydrological impacts of erosion and land degradation

Introduction

Soil erosion, sediment loss, and catchment degradation are typical of the combined effects of sea level rise and climate change at the coastline and further inland. We describe an integrated, multidisciplinary, nature-based solutions (NBSs) approach to resolving some of the most pressing issues facing coastal communities affected by hydrological impacts due to increasing water levels and saline intrusion. Our blue and green infrastructure solutions are developed for coastal Africa and are equally applicable and scalable to coastlines and hydrological systems around the world where sediment starvation, changing rainfall patterns, and saline intrusion of the coastal aquifer are causing major changes to natural ecosystems, human habitats, and agriculture.

Methods

We use a systems approach that combines modeling and data collection to examine the complete system, from upstream riverine inputs and reservoirs to coastal wetlands, the littoral system, and the coastal aquifer. We emphasize the requirement to understand the interactions between existing natural and artificial assets as a precursor to recommending any management changes to the natural or anthropogenic infrastructure systems in place. A combination of NBSs and novel management techniques are proposed to restore natural sediment and freshwater supplies to coastal communities. We introduce two new green infrastructure types, which have been extensively tested and have the potential to significantly reduce erosion while simultaneously providing desalinated water (and electricity) to nearby coastal communities. We hypothesize that it is possible to reduce the extent of land degradation caused by saline intrusion through better management of water abstraction in the coastal aquifer.

   

Results

We expect our approach to deliver significant environmental and socio-economic co-benefits to coastal and inland communities and ecosystems, many of which are already suffering from the effects of land degradation and a lack of investment. When our NBSs are combined, their synergy greatly increases benefits on a regional scale.