A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M. Sc.) - Asian Institute of Technology, 1998

Road network system develops with expectation of an assured positive roll in the over all societal, and economical aspects. This understanding is the justification of road planning, funding and developing agencies. Considering road as a basic infrastructure for a countries development, it is neither necessary nor sensible to study the impact of road system development with the attitude of control. Rather, it is necessary to evaluate the impact on the geophysical environment for a guided approach of planning and implementation for a sustainable development. With this point of view, this study attempted to evaluate the relationship of the road system and changes in it geophysical environment. The study investigated the relation between the road network expansion and the deforestation and road network and the flooding condition in the Phetchaburi province of Thailand. The study used the geographic information system and remote sensing technology for it's data extrnction, manipulation, analysis and evaluation, supported by the intensive field visit based knowledge. Topographic ( I :50000) map ( 1972-74) of Royal Thai Survey Department and the recent (1995) digital road data from Ministry of Jnterior is used for road network development analysis. Landsat TM image (January, 1997) and 1987 digital landuse map is used for identify the forest cover changes. A digital elevation model of the study area is generated for topographic analysis. Tambon level distribution of road expansion, deforestation and flood extent is used for the relationshjp analysis. The study findings is that there is a significantly highly relationship between the expansion of roads in the forest area and the rate of deforestation and also the road concentration and flood extent. The study statistically quantifi ed this relationship by correlation and regression analysis. These findings can be an useful input to the road planner, environmentalist and forest department as well as over all national planning.