Evaluation of the Scenic Beauty of the Existing Landscape of Southern Expressway and Suggestions to Improve the Landscape Using GIS and Remote Sensing

Abstract

The occurrence of landslides, frequent accidents and negative impacts on environmentally sensitive areas are some of the issues associated with the Southern Expressway in Sri Lanka. Most of these issues could be resolved through proper landscape designing along the highway. This study was intended to assess the existing landscape and land cover/use types of the Southern Expressway using GIS and remote sensing. Study area boundary of 1 km buffer zone along the expressway was demarcated and existing land cover/ use types and environmental sensitive areas were identified. Using “Landsat 8 imageries”, a map was developed based on Normal Difference Vegetative Index (NDVI) values within the buffer zone. Landscape models were developed and a visual preference survey was conducted using a focus group of 30 people. Results revealed that the expressway is surrounded by environmentally sensitive areas, archaeological reserves, protected ancient monuments, landslide prone areas, hydrological areas, forest and wild life reserves. The greenness varied throughout the buffer zone. The visual preference survey revealed that the respondents preferred more natural landscape designs which fully or partially cover the residential areas and natural designs that fully screen the religious areas along the highway. Respondents mostly preferred to have landscape designs which express the importance of the area with clear interpretative labelling. Visual preference survey suggests that there is a need of area-specific landscape designs for the Southern Expressway and the importance of human perception-based methods in designing landscape.