Mitigation of Landslides using Nature-Based Solutions (NbS)
Landslides are complex phenomena, and are increasingly visible as human activities trigger them more in Nepal than natural slope adjustment processes. To mitigate the landslide risks it is important to recognize the associated factors (e.g., slope type, cracks, drainage pattern, soil type and its depth, presence of rock and its nature, vegetation cover) that play a pivotal role in determining the likelihood and scale of a landslides.
Each landslide should be assessed and mapped out to design appropriate mitigation strategies. There are many techniques for landslide mitigation and slope stabilization. However, NbS is increasingly accepted and applied in Pratibaddha project municipalities at Bahrabise Municipality, Bhotekoshi Rural Municipality of Sindhupalchok district, Uttargaya and Naukunda Rural Municipality of Rasuwa district. Pratibaddha project is funded by European Union and led by People in Need (PIN) Nepal with its consortium partners, Community Self Reliance Centre (CSRC), Save the Children in Nepal, and SW Nepal Pvt. Ltd.(Scott Wilson Nepal).
Five demonstration events to demonstrate NbS applications using bio-engineering techniques were carried out in above four Municipalities under Pratibaddha Project. The NbS approach adopted by Scott Wilson Nepal for slope stabilization and landslide mitigation in landslide prone communities includes the following steps:
- Assessment and Design of Site: This assessment respects the unique conditions of the site, selecting the right plant species and bio-engineering techniques to maximize effectiveness taking in the account of slope, soil and rock patterns, drainage issues, and vegetation cover.
- Practical Demonstration: Practical demonstration events engaged technical teams, elected representatives, and the vulnerable communities of the municipalities. This hands-on approach allowed the stakeholders to clearly see and engage in the specific bio-engineering techniques used for specific region and how they contribute to slope stabilization and landslide mitigation.
Case Studies: Hands-on application of NbS by vulnerable communities
Case-1: Gautam Buddha School, Naukunda RM, Ward No. 3
Bio-engineering, retaining wall and side drain along the road and tick drain along the slope.
The grass and shrubs are now growing well. The planting of grass and shrubs, combined with improved drainage, has significantly stabilized the slope around Gautam Buddha School.
Case-2: Lamche Dhunga, Category-II Landslide Site, Uttargaya RM, Ward No. 3
Diagonal plantation (Khar and Amlisho), shrub plantation (Nigalo), brush layering (Simali), bamboo plantation.
This diverse approach has successfully stabilized the slope and improved vegetation cover, reducing the likelihood of landslides.
Case-3: Chaku Marming Road, Chainage 0+600 Km, Bhotekoshi RM, Ward No. 5
Diagonal plantation (Amlisho), shrub plantation (Nigalo).
The shrubs are now growing well. The simple intervention of basic bio-engineering techniques is effective in erosion control and slope stabilization.
Case-4: Chaku, Category-II Landslide, Chaku-Bazar, Bhotekoshi, Ward No. 4
Diagonal plantation (Kans and Amlisho), brush layering (Simali), palisade (Kadam), bamboo plantation, stone-paved drain.
The plants are now growing well. Combination of techniques (civil & bio-engineering) is fortifying the area against landslides.
Case-5: Khagdal, Bahrabise M, Ward No. 2
Diagonal plantation (Kans and Amlisho), brush layering (Simali), shrub plantation (Nigalo), bamboo plantation, stone-paved tick drain
This site showcases the ability of NbS in diverse conditions with a variety of techniques employed to mitigate landslide risks.
Local Government and Community Engagement
The plant takes about four years to fully provide engineering functions. As the plants continue to grow, local communities are actively involved in nurturing and protecting the sites.
Local Government of Bhotekoshi allocate funds to implement bio-engineering for landslide mitigation and slope stabilization in local road improvement projects. This commitment demonstrates the long-term viability and sustainability of NbS in Pratibaddha-II municipalities.
Voices of Change: Response from Local Stakeholders
Local communities and elected representatives are the driving force behind the successful implementation of NbS in Pratibaddha-II municipalities. Here are some statements that reflect their commitment and determination:
“We have learnt the methods to stabilize the slope and then reduce the risk of landslide with simple civil engineering structures, locally available materials and plants. We plan to replicate this practice in other sites with technical support from Pratibaddha-II Project” -Ms. Chameli Gurung, Vice-Chairperson, Uttargaya Rural Municipality, Rasuwa
“यो अभ्यासबाट हामीले साधारण सिभिल ईन्जिनियरिङ्ग संरचना, घाँस, बोटबिरुवा तथा स्थानीय सामग्रीको प्रयोग गरी भिर पाखोको सुरक्षा गर्ने र पहिरो जोखिम घटाउने विधि सिकेका छौँ । प्रतिबद्ध परियोजनाको प्राविधिक सहयोगमा यस प्रकारका व्यवहारिक र असल अभ्यास अन्य जोखिमयुक्त ठाउँमा पनि लागू गर्ने योजना गाउँपालिकाको रहेको छ ।” –चमेली गुरुङ्ग, उपाध्यक्ष, उत्तरगया गाउँपालिका
“Our community is working to reduce the risk of landslide with the construction of drainage structures, along with applying bio-engineering techniques by using grass, shrubs and local trees. We shall Protect the plants from cattle until it grows fully into stable form. We shall also try to replicate such plantation works at small slope failure sites at our community’s household areas
.”-Mr. Phunjo Tamang, Community Member and Vice-Chairperson of Chaku Landslide Mitigation Project
“हाम्रो समुदायले पहिरो र भलबाढिको जोखिम कम गर्न नाली निर्माण र बायोईन्जिनियरिङ्ग विधि प्रयोग गरी स्थानीय घाँस, बुट्यान तथा रुख रोप्ने काम गरेका छौं । हामीले रोपेका बोटविरुवालाई गाईबस्तुबाट बचाउन समुदायले नै संरक्षणको कार्य गरिरहेका छौं । यो प्रकारको विधि समुदायका अन्य ठाउँमा प्रयोग गरि भिरालो जमिनलाई स्थिर बनाई पहिरोको जोखिम कम गर्न कोसिस गर्नेछौं ।“-फुञ्जो तामाङ, समुदाय सदस्य तथा चाकु पहिरो न्यूनीकरण योजना, उपाध्यक्ष
And, Finally !!!
The application of NbS with bio-engineering interventions in Pratibaddha-II municipalities is a ray of hope for landslide-prone vulnerable communities. The plant requires approximately four years to become fully operational, encmpassing engineering functions. While the plants continue to mature, the local communities have to play an active role in safeguarding the sites. The success of these small but important projects highlights the potential for communities to mitigate risks with locally available resources in minimal technical support. As local governments and vulnerable communities show increasing interest in these interventions, it becomes evident that NbS is a powerful tool to build disaster resilience, protect the environment, and improve the livelihoods of those living in landslide-prone areas. By harnessing the inherent strength of nature, we can create a safer, more resilient future for the communities.