Using GIS-based multicriteria decision support system for planning road networks with visual quality constraints: a case study of protected areas in Ankara, Turkey

Protected areas are important zones due to their natural and cultural assets and their biodiversity preservation functions. Ecotourism activities in these areas have gained great importance for visitors in recent decades. Road networks established in protected areas have ecotourism-related functions, such as providing visitors with continuous access to/within these areas and offering visual richness to visitors while cruising on the roads. Road network planning that prioritizes visual quality is one of the scientific issues discussed today regarding the sustainable management of protected areas. This study focuses on planning new road networks that prioritize visual quality in protected areas and determining the optimum route that maximizes the visual quality experience of visitors. The study area was selected from the protected areas between the Kızılcahamam and Çamlıdere Districts of Ankara, Turkey, and their surroundings. In the model application, a road network was planned using the multicriteria decision support system (MDSS) method by considering visual quality parameters. In this stage, the road network that prioritized visual quality during spring and autumn seasons was investigated. Hence, weighted linear combination (WLC) was used as a geographic information system (GIS)-based MDSS method. Then, the GIS-based network analysis method was used to determine the optimum route that provided access to the scenic viewpoints (existing and proposed viewpoints) in the study area and maximized the visual quality during both seasons. In the new road network planned by considering the visual quality parameters, the total road length was calculated as 121.21 km for the spring and 129.47 km for the autumn. The lengths of the optimum routes that allowed visitors to reach the scenic viewpoints and ensured the maximum visual quality were 30.91 km and 30.70 km on the new road network for the spring and autumn seasons, respectively. This study introduced a new methodology that utilized GIS-based decision support systems to plan a road network that prioritized visual quality and determined the optimum route with the maximum visual quality. It is anticipated that this methodology can be used for sustainable management and effective planning of protected areas to reach and protect resources with high visual quality.