Sensitivity analysis of transportation corridor location in wetland areas: A multiobjective programming and GIS approach

A multiobjective programming approach for locating transportation corridors through areas containing wetlands is presented. The approach uses a geographic information system in combination with multiple objectives for environment and construction costs, and the North Carolina Coastal Region Evaluation of Wetland Significance (NC-CREWS) program. The multiobjective function is a weighted combination of wetland values and construction cost. The objective minimizes total cost of construction and wetland impacts resulting from a specific transportation corridor. The transportation designer specifies starting and ending points of the desired corridor. The model then finds the best path given the weights placed on each individual objective (i.e. habitat quality, water quality, hydrology, and construction expense). By varying the weight set, several different paths can be found. The approach is tested on a watershed in Carteret County North Carolina using a benchmarking procedure. One benchmark minimizes a combined wetland significance loss (cost). This path avoids crossing wetlands. The other benchmark minimizes construction expense. Varying the weight placed on each of the objective function components generates additional paths. The approach is useful in locating alternative road corridor paths in attempts to satisfy conflicting societal interests.