Evaluation of Physical Environment of Kakarbhitta-Pathlaiya Road Segment of East-West Highway of Nepal

The Government of Nepal (GoN) is planning to upgrade the two-lane East-West Highway to four-lane standard in phase wise basis, in response to the increased number of vehicles and frequency of travel associated with the increased population growth. In the first phase, the GoN is planning to upgrade the Kakarbhitta-Pathlaiya corridor of the highway. Since the road construction may lead to multi-dimensional environmental degradation, it is crucial to investigate the physical environment of the influence area of the road for the sustainable design of the structures associated with it. Therefore, the overarching goal of this paper is to explore the existing physical environment conditions in the project influence area of the Kakarbhitta-Pathlaiya corridor. Field observation and a walk-through survey were conducted to gather information related to the physical environment. Our analysis indicates that the slope stability along the road alignment is found to be good to the extent that further realignment of any of the subsection is not essential. Because the existing river networks of the project influence area may cause drainage problems associated with water-logging along the highway, the sediment and streamflow capacity of the rivers must be enhanced near the hydraulic structures including bridges and dams, especially during monsoon season. The groundwater is contaminated with the toxic minerals including arsenic in several locations near the road corridor. In addition, dust pollution along the road section is highly noticeable especially during the dry season. Similarly, the noise pollution due to the vehicles running on the highway is significant both for the human and wildlife. However, there are barren lands that can be utilized for quarries, stockpiling, camping, and for other technical purpose during road construction. The study results are expected to provide planners and designers with information related to the valued environmental components in the project area.