Determination of Optimal Road Alignment Using GIS Least Cost Path Analysis: A Case Study of Situm - Gagidu Station, Morobe Province-PNG.

Abstract

An access route linking the people of Finschhafen and surrounding villages to Lae City would be life changing. The route would stimulate socio-economic development and help bring in much needed goods and services by road rather than depending on sea and air transportation, which is costly and time consuming. The proposed road seeks the most suitable route, taking into consideration agricultural and environmental factors. Using Geographic Information System (GIS) techniques, the Least Cost Path Analysis method was applied to achieve viable results that were useful in determining a feasible road corridor. The route analysis parameters contained different weighted overlay surfaces; each surface is influenced by various criteria (slope, geology, population, and land use-land cover). The least cost route was then calculated based on the weighted overlay of each criterion. The criterion with the highest influence was used as benchmark for selecting the least cost route. Least cost path analysis (LCPA) has the ability to reduce the overall cost of road construction and minimize the negative impacts of such projects on both the macro and micro environments.