Transportation network optimization for the movement of indigenous goods in Amazonian Ecuador

摘要

This paper presents an unusual case study and a new network optimization model for transportation of agricultural products in a largely roadless region of Amazonian Ecuador. One proposed sustainable economic development strategy to help protect the biodiversity and indigenous cultures of this region is to grow and transport locally produced organic crops to markets outside the region. Transportation options include for-hire modes such as small planes that can land at grass airstrips and truck transport available from only one node. Other options include self-owned modes such as motorized canoes, which can be purchased and based at certain villages for use on a few navigable rivers. To analyze this unique logistics problem, this paper develops a hybrid mixed-integer linear programming model combining elements from cost-minimizing multimodal network flow models and location-routing models with vehicle-capacity constraints. Because of the small volumes shipped, the keys to minimizing transport costs for both for-hire and self-owned modes are the economies of scale of larger vehicles as well as high utilization of the capacity of those vehicles. The model solves for optimal modes, sizes, routes, bases, stops, and volumes, as well as location of storage and transshipment facilities. The five different scenarios demonstrate the substantial cost savings achievable with network optimization as opposed to direct routing from each community. This type of model could be adapted to help address logistics problems facing other inaccessible regions in mountainous, polar, or rainforest ecosystems.