تحقیقات جنگل و صنوبر ایران (Sep 2006)
Determining proper method of preliminary forecasting of mountain and forest roads using GIS
Abstract
using GIS capability and information-simultaneous management. This study accomplished to determine proper method for forecasting traces of mountain, forest, recreational regions and forest remains roads, in Sorkhab watershed, Khorram Abad. Concerning to environmental principals and network topology of forest roads, affecting factors in road tracing were studied after gathering of data and necessary maps. The interested maps including slope, landslide hazard, future land use, distance to village regions, recreational, and holly places were prepared as raster format using GIS. With concerning of importance of their categories, the maps were classified with range of 1 to 9. Using Analytical Hierarchy Process (AHP) method, the maps were weighted with regard to mentioned affecting factors. By overlaying of the weighted maps using GIS, the suitable regions map was prepared for tracing. The forest routes were automatically projected using PEGGER program implemented with ARCVIEW software. The TIN Digital Elevation Model was generated using 1:25000 digitized maps. The new 20 meters intervals contours were again produced from digital elevation model. Necessary layers including route location suitable regions map, streams, village regions, recreational and future land use imported to determine the routes. Regarding to kinds of roads the desired grades were inserted in PEGGER program. The various traces between two points were rapidly predicted and suitable routes were selected after valuation. Besides of road tracing in regions with low expenses for road making, results showed that using this method could prepare the feasible road network for interested area and important land uses such as forest and tourism areas. In the other hand, with consideration of present data in current condition such as digitized maps in this study, introduced method is an appropriate method for forecasting of preliminary route of mountain and forest roads in extensive scale so that this method can be replaced with the traditional methods in Iran.
