Sustainable Slope Stabilization Post-Cyclone Gabrielle

The purpose of this abstract is to outline the innovative and sustainable approaches employed in revegetating slips and slopes following the devastation caused by Cyclone Gabrielle. It aims to highlight the effectiveness of bioengineering techniques and the integration of sustainable revegetation in stabilizing slopes and reopening critical highway infrastructure. By showcasing these methodologies, the abstract seeks to demonstrate the potential for combining modern technology with traditional practices to address complex environmental challenges in post-disaster scenarios. The devastation caused by Cyclone Gabrielle necessitated a rapid and innovative approach to revegetating slips and slopes to reopen critical highway infrastructure. This abstract explores the methodologies employed in the restoration efforts, emphasizing the use of unique techniques and sustainable practices to ensure long-term stability and resilience against future climatic events.
Cyclone Gabrielle's unprecedented rainfall triggered widespread landslides and slope failures, obstructing major highways and disrupting transportation networks. Traditional methods of slope stabilization, such as rock bolting and concrete retaining walls, were deemed insufficient due to their environmental impact and the scale of the destruction. Instead, a combination of bioengineering techniques, geosynthetics, and revegetation was employed to rehabilitate the affected areas.
Bioengineering played a crucial role in stabilizing the slopes. Techniques such as hydroseeding, which involves spraying a slurry of seed, mulch, and nutrients onto the soil, facilitated rapid vegetation growth. This approach was supplemented with the planting of fast establishing grasses such a perennial ryegrass (Lolium perenne) and native species known for their soil-binding properties, such as mānuka (Leptospermum scoparium), Stewarts Slender Poa (Poa imbecilla) and kānuka (Kunzea ericoides). These plants not only stabilized the soil but also restored the biodiversity lost in the cyclone. Additionally, the use of mycorrhizal fungi inoculants enhanced plant root systems, improving nutrient uptake and soil structure.
The combination of these innovative approaches resulted in a successful and sustainable revegetation of slips and slopes, facilitating the reopening of highways while enhancing the resilience of the landscape. The methodologies employed not only addressed the immediate need for infrastructure restoration but also contributed to long-term environmental sustainability. This case study highlights the potential for integrating traditional knowledge with modern technology to address complex environmental challenges in a post-disaster context.