Spatial multi-criteria decision process to define maintenance priorities of forest road network: an application in the Italian Alpine region

The combination of GIS tools and Analytic Hierarchy Process (AHP) techniques is used to develop a Decision Support System to rank the maintenance priorities of a forest road network according to the actual conditions and needs. The decision-making process is divided into 4 stages. The first stage fixes the objectives of the analysis as the minimization of the sediment production from road surface and the maximization of the social value of the road. The second stage defines the hierarchical structure of the decision problem. At this stage the set of factors (criteria) to maximize each objective and the evaluation methods are defined. At the third stage AHP analysis is applied using a specific application running on ArcGIS, to calculate the evaluation layer that represents the importance of each road according to the set objectives. The values of the evaluation layer are used at the fourth stage to rank the maintenance interventions according to the given benefit. The methodology has been tested in a forest road network with an extension of 107.8 km including in the analysis the real budget constraints and maintenance costs. The results show that the integrated use of GIS and AHP analysis represents a valuable tool to rate the importance of the forest road network for the management of a mountain territory and to define priorities among maintenance operations of the road network, in order to maximize the overall benefit with limited economic resources