A modeling tool to support decision making in future hydropower development in Chile

Modeling tools support planning by providing transparent means to assess the outcome of natural resources management alternatives within technical frameworks in the presence of conflicting objectives. Such tools, when employed to model different scenarios, complement discussion in a policy-making context. Examples of practical use of this type of tool exist, such as the Canadian public forest management, but are not common, especially in the context of developing countries. We present a tool to support the selection from a portfolio of potential future hydropower projects in Chile. This tool, developed by a large team of researchers under the guidance of the Chilean Energy Ministry, is especially relevant in the context of evident regionalism, skepticism and change in societal values in a country that has achieved a sustained growth alongside increased demands from society. The tool operates at a scale of a river reach, between 1-5 km long, on a domain that can be defined according to the scale needs of the related discussion, and its application can vary from river basins to regions or other spatial configurations that may be of interest. The tool addresses both available hydropower potential and the existence (inferred or observed) of other ecological, social, cultural and productive characteristics of the territory which are valuable to society, and provides a means to evaluate their interaction. The occurrence of each of these other valuable characteristics in the territory is measured by generating a presence-density score for each. Considering the level of constraint each characteristic imposes on hydropower development, they are weighted against each other and an aggregate score is computed. With this information, optimal trade-offs are computed between additional hydropower capacity and valuable local characteristics over the entire domain, using the classical knapsack 0-1 optimization algorithm. Various scenarios of different weightings and hydropower development targets are tested and compared. The results illustrate the capabilities of the tool to identify promising hydropower development strategies and to aid public policy discussions aimed at establishing incentives and regulations, and therefore provide decision makers with supporting material allowing a more informed discussion.