ROLE OF BIOENGINEERING IN MOUNTAIN ROAD MAINTENANCE:OBSERVATIONS FROM NEPAL

摘要

Nepalese road network expanded rapidly in the last two decades and is increasing everyday. Different types of instabilities are caused in mountain road slopes depending upon thetype of material and the environment. Alignment selection, spoil management, drainagesystems, and the type of protection measures considered during construction stage playvital role in maintenance stage of the roads. The environment friendly road constructionwas introduced during 1980s on rural roads and gradually adapted on strategic roads. Theconcept is labour based construction, reduced geometry and balanced cut and fill.Similarly, suitable bio-engineering techniques in conjunction with small scale civilengineering structures are used to stabilize road side slopes. This concept emphasizes onpreventive measures and begins from the planning stage of the road promotingsustainable maintenance. The most significant aspect in mountain road maintenance liesin the use of scale of vegetation cover. The roadside bio-engineering is not just used forslope protection but also incorporates productive plants to become a part of theneighbouring agricultural system. This paper examines how to cope with roadside erosionand landslides through the use of bio-engineering which ultimately contributes to thesustainability of mountain roads.