Vegetation Control for Road Slopes

Needs Address

• Maintenance of basic livelihood and social functions
• Disaster prevention

Adaptation effects

• Enhanced adaptation capacity
• Reduces environmental degradation

Overview and Features

Planting of grasses and enrichment of vegetation to reinforce mountain roads and slopes by slowing migration of water and trapping sediment. This measure is used as part of road slope disaster management approaches. 

Cost

• Costs for seedlings initially
• Maintenance costs

Energy source

construction and maintenance

Ease of maintenance

Must be continuously maintained through pruning and mowing to reduce blocking of other disaster prevention measures such as gabion walls and ensure overgrowth does not impact road vision 

Technology performance

• Aid slope stabilisation and reinforce other road stabilisation measures
• Reduce erosion and therefore landslide risks, saving lives and protecting agricultural lands
• More sustainable and effective than harder technological measures such as stone barriers。E.g. Vetiver grass has been found to decrease water runoff by up to 57% and reduce soil loss by more than 80% compared with stone barriers, other vegetation, and bare ground (Vetiver, n.d.)

Considerations

• Proper assessment regarding road vulnerability and hazard assessments required.
• Must ensure minimal impact on surrounding environment　(including species selection)

Co-benefit, suitability for developing countries

• Carbon sequestration
• Helps to sustain livestock through providing grazing fodder for animals, maximising land use
• Can use naturally occurring vegetation
• Farmers are able to implement the technology independently on their land

Information Resources

Fay, L., Akin, M. and Shi, X. 2012. Cost-Effective and Sustainable Road Slope Stabilization and Erosion Control. National Cooperative Highway Research Program Synthesis 430. Available at: http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_syn_430.pdf [05 January 2015]

GoN, 2003. Guide to Road Slope Protection Works. GESU Publication. Available at: http://www.dor.gov.np/publication/index_publication.php?id=199 [05 January 2015]

Sthapit, K.M. and Tennyson, L.C. n.d. Bio-engineering erosion control in Nepal. FAO. Available at: http://www.fao.org/docrep/u1510e/u1510e04.htm [28 December 2014]

Vetiver, n.d. Slope Stabilisation for Infrastructure – Highways and Construction Sites (Various presentations). Available at: http://www.vetiver.org/g/archives_slopestabilization.htm [05 January 2015]