3.3. Proposed Eco-Safe Rural Road Assessment Framework
Based on the case study and review of the available research materials, the “eco-safe rural road assessment framework” was contextualized. The framework outlines the issues to be addressed through appropriate techniques with the pre-defined objectives, and provides guidance for understanding, designing, developing, implementing and assessing eco-engineering as one type of NbS for the roadside slope protection measures. The proposed framework consists of seven steps. All the steps (shown below) need to be implemented together with the relevant stakeholders, ensuring full gender-balanced community participation from the very beginning through to the final monitoring and evaluation.
Define the problems to be addressed (baseline);
Establish the eco-safe road objectives;
Identify suitable NbS measures and alternatives for eco-safe rural roads;
Implement the eco-safe rural road plan;
Establish an awareness and communication plan;
Mobilize the community for implementation and upscaling;
Establish monitoring and evaluation plan and follow-up.
The framework also discussed a number of issues to be addressed at different stages of the eco-engineering implementation process in the Panchase region, which may be suitable for other similar geographical areas of Nepal.
Step 1: Define the Problems to be Addressed (Baseline)
The problems to be addressed by NbS are multi-dimensional and complex; however, participatory and solution-led assessments can support a holistic mapping of the problem and explore the possible feedback loops [42
]. Having identified the problem areas, criteria need to be established for assessing the relationships between the problem dimensions and the potential opportunities.
The starting point for a better assessment of “eco-safe rural roads” adopting eco-engineering involves using the NbS technique to describe and analyze the unsatisfactory situations all along the rural roads to be addressed. This step implies establishing the boundaries and structure of the system of interest, by accurately describing the present situation of climate, socio-economy, ecology, governance, and geographical scale [35
]. The aim at this stage is to define the issue of roadside slope failures (i.e., problems in the ground), conceptualize the societal challenges, and create a baseline for the implementation of the “eco-safe rural road” strategy. In order to address and understand the slope failure problems and to establish the baseline of roads in Panchase geographic region, secondary data such as DEM and RS data and other soil physical and climate variables are important. It is important to include climate variables, especially the intense rainfall and soil properties of the study area to model and visualize unstable slopes in preparing the baseline. A list of important data and variables to be assessed while defining the problem is shown below.
Identify and evaluate available (digital) data (e.g., DEM, RS images);
Assess rural road alignment:
Map the unstable and shallow landslides failure;
Assess the drainage patterns;
Identify and evaluate the soil physical properties and soil depth to bed rock;
Evaluate the rainfall intensity through the regional IDF model and assess the soil moisture considering the antecedent rainfall and rainy days;
Implement the infinite-slope stability model considering the rainfall-induced saturation depth to better understand the most unstable locations and the road alignment passing through.
For example, the Panchase region is known to be the zone with the highest rainfall in the country [54
]. Studies showed that the rainfall intensity in the region increased due to the climate change impacts [65
]. The increased rainfall intensity is the triggering factor for many shallow landslides. In addition to the rainfall, anthropogenic activities such as construction of unplanned rural roads magnified the catastrophic landslides in the region [62
shows that the representative shallow slope failure, turning into debris flows, damaged the rural road and agricultural lands, and threatened livelihoods in the hilly terrain of Nepal.
Step 2: Establish the Eco-safe Rural Road Objective(s)
The objectives describe the desired situation and, therefore, the concrete goals that an action or set of actions aims to attain [35
]. However, the solution put in place to solve or reduce the problem could positively or negatively affect other system components [35
]. Calliari et al. (2019) [35
] suggested identifying a number of sub-objectives, such as mitigating roadside slope failures, while concurrently providing economic opportunities.
The main objective to be established is to detect solutions for the above-identified problems of rural roadside slope failure through various types of eco-engineering techniques (Figure 7
). In addition, it is important to consider any possible negative impacts that the eco-engineering solution may have, especially if it is located in a sensitive area along a rural road passing through cultivated land, settlement, and natural forest. Moreover, additional benefits also need to be considered, such as economic benefits from the use of certain species such as Amriso (T. maxima
) which communities can harvest and sell on the market. This was the case in Gharelu village, where community members earned up to 500 dollars over three years, which enabled them to expand the bioengineering works there.
Step 3: Identify suitable NbS Measures and Alternatives for Eco-safe Rural Roads
After identifying key issues (step 1) and setting up the main objective and any possible negative or positive impacts (step 2), the next important step (step 3) is to identify the types of NbS measures that are appropriate [42
]. Various types of green or grey/hybrid measures may provide multiple benefits that need to be identified and compared with the benefits from alternative solutions. In order to better understand the optimum benefit of selected solutions (i.e., green, gray, or hybrid), cost–benefit analysis (CBA) should be performed. In some cases, however, the CBA analysis alone may not adequately address the multiple benefits of NbS. For this reason, Raymond et al. [42
] suggested participatory assessment, group modeling, and sustainability assessment. The mapping of multiple benefits and how they change over time is also required to be assessed [66
] while selecting the NbS for eco-safe rural roads.
The research conducted in the Panchase geographic region explored the usefulness of perennial local and non-local grass species, among which Amriso (T. maxima), Urlo-Khar (C. microtheca), Napier (P. purpurreum), Salim-Khar (C. gryllus), Kans (S. spontaneum), Kush (C. indica), and Babiyo (E. binate) were local, and Vetiver (C. zizanioides) was the only non-local grass species used in the research. The usefulness of the plant species, in terms of their KPIs for soil slope reinforcement and co-benefits (e.g., economic and livelihood values), was assessed through the test plots (i.e., demonstration sites and rhizotrons) and through community consultations.
The research successfully identified hybrid-type eco-engineering measures suitable for roadside slope protection (Figure 8
and Figure 9
). Hybrid eco-engineering is one type of NbS that includes the construction of roadside and cross drainage, shallow stone walls/retaining walls, stone rip-rap surface drainage, and the plantation of species such as Broom grass (T. maxima)
and Vetiver (C. zizanioides
) on the roadside slopes, as these species were observed to be useful in terms of root depth, root strength, and above- and below-ground biomass, thereby leading to better root cohesion. Yet, in Nepal, more research needs to be conducted to better understand the KPIs of other grass, shrub, and tree species available in the region and their mechanical and hydrological contributions to slope stability.
Step 4: Implement the Eco-Safe Rural Road Plan
The implementation of “eco-safe rural roads plan” requires the integration of different types of knowledge such as civil engineering, geotechnics, hydro-meteorology, biology, environment, and, importantly, the local knowledge about plant species and climate [39
]. In addition, the implementation process needs to support openness, transparency in governance processes, and legitimacy of knowledge from citizens, practitioners, and policy stakeholders [39
The demonstration sites established for conducting this research in Panchase region indicated that the selected eco-engineering measures can be implemented successfully utilizing local knowledge provided by community members and by ensuring a close dialogue with the local government and other stakeholders. Community members have expert knowledge about their land, climate, and plant species. The RUG, which was described in Section 2
, was critical for establishing ownership of the demonstration sites, and the local government demonstrated interest in expanding the eco-engineering measures for extended the length of the rural road in the Panchase region.
Step 5: Establish Awareness and Communication Plan
Once the eco-safe road implementation plan is agreed upon by engaging the multi-disciplinary teams, the next step is to prepare for the action plans. Implementation should consider the relative costs and benefits of a given action, as well as managing the difficulties relating to uncertainty [42
]. There are several stakeholder perceptions and challenges that need to be managed during the implementation of the plan, for which community awareness and communication with the concerned stakeholder is important. This means communicating the co-benefits to different levels of decision-makers and community members throughout the entire lifespan of the project [42
]. Proper communication among different interest groups, stakeholders, policy- and decision-makers, and the local population is important and effective when realized through a series of parallel and overlapping top-down and bottom-up approaches that help anticipate and correct any negative impacts that may result from the eco-safe road implementation [36
For example, while exploring the opportunity of implementing the “eco-safe” roadside demonstration activities in the Panchase region, at first, several community members were not convinced. They were more in favor of larger gray measures, such as gabion walls. However, during discussions and meetings through clear and transparent communication the concept and co-benefits for livelihoods were better understood. This helped community members to understand the importance of “NbS and eco-safe roads” and NbS in the region and increase their interest and participation. Community members actively participated in every step of the research work. In addition, as a part of capacity development, soil bioengineering training was provided to the RUG members, and a community-based soil bioengineering manual (e.g., Devkota et al. (2014) [57
]) for the “eco-safe road” was prepared and translated into Nepali language. The manual was distributed to the RUG members and other interest groups.
Step 6: Mobilize the Community for Implementation and Upscaling
Communities are critical for sustainable implementation of an eco-safe road strategy at the community level. After the dialogue process created awareness about the benefits of the NbS measures, the communities mobilized members to participate in the field activities. Community members with specific skills were assigned various responsibilities, such as collection of suitable plant species, land development, and construction of simple civil engineering measures (e.g., roadside drainage, toe wall construction, etc.). The engagement of the community members in establishing the demonstration sites was voluntary, inter-disciplinary, and participatory, without any discrimination on the basis of ethnicity or gender.
After the successful establishment of the three demonstration sites in collaboration with the local community and the government in the Panchase region, different interest groups (e.g., NGOs) and the local government demonstrated their interest in expanding and upscaling the “eco-safe roads” approach in their communities. Community members and RUGs started reporting rural roadside slope failures to the local government and insisted on their support in implementing and expanding eco-engineering measures.
Step 7: Establish Monitoring and Evaluation Plan and Follow-Up
Monitoring of NbS activities for “eco-safe roads” observes the system characteristics after the implementation and collects evidence on the way eco-engineering measures perform in practice [35
]. The difference between expected and actual outcomes sheds light on the system’s response. The interventions should be reviewed and adjusted to respond to challenges or to potential new needs, while the evaluation phase can also lead to corrective action to safeguard the long-term effectiveness of the measure [35
]. Long-term monitoring should lead to new insights into eco-engineering functioning and active learning—even from failure—which can help improve future “eco-safe road” implementation plans [69
]. Evaluation relates to the numerous ways of assessing the direct and co-benefits (and costs) of “eco-safe road” within and across challenge areas (i.e., rural roadside slope failure) and within different stages of implementation [42
Indicators of the performance of “eco-safe roads” cover a range of aspects such as integrated environmental performance, participation of RUGs in the maintenance, effectiveness of the measures in stabilizing the roadside slopes, and transferability of “eco-safe road” actions. Indicators may also relate to the administrative budget and staff allocated for the “eco-safe road” monitoring and implementation of the projects [42
]. Indicators that quantify the cost–benefit in addition to the involvement of stakeholders can enable a cost-added value quantification, as demonstrated by Connop et al. (2016) [69
In the case of the “eco-safe rural road” demonstration research project in the Panchase region, the performance of the chosen NbS (i.e., eco-engineering) was assessed scientifically and through public consultation, using FGDs and KIIs at the local level. The performance of the plant species was evaluated and quantified scientifically. The variables were used to establish a multi-criterion-based PCA model, and co-benefits were evaluated qualitatively (e.g., high, medium, and low). While performing the FGDs and KIIs at the end of the project (i.e., fifth year of the project), the response was encouragingly high to medium as demonstrated by the strong performance of plant species used in eco-engineering demonstration plots. In addition, the communities accepted the technique because of very tangible co-benefits, especially after the roads became practicable year-round and they were able to utilize the grasses for economic purposes. The local government stakeholders, on the other hand, were inspired by the eco-engineering measures as being cost-effective and effective for rural roadside slope protection.
In addition, the demonstration sites were visited by national and international experts, policy-makers, and the media [70
] at different stages of the research project, and positive responses were received about the adopted methodology and performance of the selected eco-engineering techniques. Finally, the research project was evaluated by an international expert [71
], who reported that the community-based “eco-safe road” initiatives were highly successful in terms of addressing the challenges and expectations.