| The Columbia and Snake rivers are important components of the economic, social, and environmental fabric of the Pacific Northwest. However with the proposed policy to breach the lower Snake River dams to improve endangered salmon habitat, the very nature of the region may be changed. The impacts of such a policy would be economically, socially, and environmentally far reaching. Interdisciplinary and cooperative research efforts are necessary for impact assessment on this scale. The intent of this dissertation is to propose and develop such interdisciplinary linkages.;System dynamics is conducive to interdisciplinary research by providing a tool for incorporating information across disciplines and methodologies to model complex systems. Such models are valuable for simulating and exploring the potential outcomes of policy alternatives, particularly when they are equipped with a user interface. A system dynamics model of eastern Washington wheat transportation was developed and used to simulate public rail car investment strategies and monitor road damage associated with the policy alternatives. Public rail investment may help maintain competitive and cost effective wheat shipments if barge transportation on the lower Snake River is eliminated with breaching.;The loss of barge transportation may have implications toward energy consumption and emissions output. Freight and agricultural commodities, like wheat and barley, would be transferred on to rail and truck which have different energy and emissions profiles. Historical energy intensity and emissions coefficients from truck, rail, and barge are analyzed for trends and used for predicting future energy coefficients. The predictions show that all three modes continue to make improvements in energy consumption. Change in energy consumption due to wheat and barley transportation after breaching are minor, while some components of emissions increase and others decrease. |
