Nature-Based Solutions for Geohazard Mitigation on Slopes

Nature-Based Solutions (NBS) leverage natural materials and mimic biological processes to mitigate geohazards such as slope instability and erosion, which are increasingly exacerbated by climate change and extreme weather events. Vetiver grass (Vetiveria zizanioides), known for its extensive root network and resilience, has emerged as a key component in bioengineering strategies aimed at improving soil stability, reducing erosion, and maintaining ecosystem services. Vetiver-based bioengineering integrates ecological approaches with engineering principles, offering scalable, cost-effective, and sustainable solutions for geotechnical challenges. The application of vetiver grass spans diverse contexts, including stabilizing road embankments, construction sites, and hill slopes, as well as mitigating erosion in riverbanks, canal banks, and coastal zones. It is particularly effective in areas prone to landslides, floods, and salinity intrusion, demonstrating its adaptability to varied climatic and geographic conditions. The efficacy of vetiver-based solutions has been validated through a range of studies, including laboratory experiments, field pilots, and large-scale implementations. Laboratory tests have shown that vetiver roots significantly enhance soil cohesion and internal friction angles, improving slope stability. Finite element modeling corroborates these findings, indicating increased factors of safety and reduced displacement in reinforced soils. Field pilots conducted across diverse soil types including saline soils, silty clays, and sandy soils reveal the adaptability of vetiver roots, which penetrate up to 2 meters, strengthening soil structures and mitigating erosion. Large-scale applications on coastal embankments have proven effective in resisting cyclone-induced erosion and lowering maintenance costs compared to traditional hard engineering solutions. Similarly, applications on pond and canal banks have reduced sedimentation and improved water quality, while slope stabilization in landslide-prone regions has minimized slope movement and rain-induced erosion. The implementation of vetiver systems is frequently community-driven, promoting local engagement and capacity building. Community acceptance has been high due to the simplicity, low cost, and multifaceted benefits of the approach. Beyond geohazard mitigation, vetiver-based solutions enhance biodiversity and provide habitats for local ecosystems. Additionally, the extensive root biomass contributes to carbon sequestration, supporting climate change mitigation efforts. By integrating ecological and engineering principles, vetiver systems offer a practical approach to slope protection and stabilization, while delivering co-benefits such as enhanced ecosystem services and community resilience. These solutions exemplify the potential of NBS in advancing global strategies for geohazard mitigation and sustainable development, bridging the gap between research and real-world applications.