Application of remote sensing and geographic information system in infrastructure development

Road transportation network development is a vital component of infrastructure development. Absence of database on roads of Trivandrum district was felt as a major hindrance in prioritizing improvement/development/repair of the roads for better traffic efficacy. High resolution PAN imagery (IRS-IC, September-December 1999, 1:25,000 scale) was visually interpreted to decipher road net work for preparing an elaborate database for Kerala Highway. The data were incorporated on 1:25,000 scale SOI base maps. Field verification was carried out to identify and categorize the PWD roads as per their administrative sections. Final maps were digitized in ARC/INFO environment. Information about terrain conditions was also generated using satellite remote sensing images and aerial photographs. Incorporating the height source and elevation data in the value field and taking mass points as input, a TIN (Triangulated Irregular Network) model of a sample area near Vellanad, 22 km east of Trivandrum city was created to analyse the terrain-road network interrelationship. Our case study involving draping of road network on TIN model as well as on geomorphology map established that this methodology could be used to define alternative and efficient route corridors, with particular emphasis on selection of the least-cost route and prioritization of repair.