Low cost engineering and vegetative measures for stabilising roadside slopes in Nepal: C. J. Lawrance, in: Vegetation and slopes: stabilisation, protection and ecology. Proc. conference, Oxford, 1994, ed D.H. Barker, (Thomas Telford, for ICE), 1995, pp 142–151

Abstract

In 1984, the Overseas Development Administration set up a major maintenance project on UK-funded roads constructed in Eastern Nepal, under the management of the UK consultants Roughton International. ODA was concerned at the large number of shallow failures affecting slopes above and below its own (and others') roads in Nepal, and commissioned TRL to examine the possibilities for 'low cost' engineering measures for slope protection that could be incorporated into the Nepalese Department of Roads' maintenance routines. TRL's brief turned out to be very wide. From the outset it was evident that vegetation would need to be included in the study, mainly because plants are best suited to the retardation of very shallow failures extending over large areas, of which there are many in Nepal. The approach adopted was to make regular observations of a large number of sites on which a wide range of techniques and species were implemented, on the assumption that the relative success of these would, in time, indicate those that tended to be most positive. The best circumstances in which to make observations is in heavy rain, when a site is put under stress. Visits to Nepal were therefore made annually in the late monsoon, in the years 1987-1992. On several occasions, sites were watched in the process of destruction by a storm. Much was learned about slope processes and the response of stabilisation measures to heavy runoff at these times. The tasks were: (1) to identify 'low cost' engineering techniques suitable for reducing shallow failures on slopes; and (2) to define a role for vegetation in slope protection in Nepal. For the covering abstract see ITRD E116612.