The Yaqui Valley of Sonora, Mexico is a region of rapid demographic, economic, and ecological change. Population growth, urbanization, agricultural intensification, land-use change, altered water allocations, intensified ground-water pumping, coastal modifications, and wetland conversions are only some of the major physical developments that are on-going in the region.

Partly as cause, and partly as effect, these physical changes are intimately bound up with successive waves of liberization and privatization that are sweeping across large parts of Mexico. Many markets, e.g., land, fertilizer, irrigation water, and agricultural marketing, that had been under public ownership or national control have been moved to community control or to private ownership. Reforms in the financial and foreign-exchange sectors have magnified these effects and have further opened the region to new forms of competition and institutional arrangements.

The Yaqui Valley is, in short, a region in transition similar to other transformations that are underway all over the world. Understanding these transitions, which affect human welfare, economic growth, environmental quality, and resource sustainability, requires the integration of information from numerous scientific fields of study. Managing these transitions for maximum current and future welfare also requires policy analysis to develop relevant sets of policy and management alternatives that are based on good science. This project brings together the specialists needed to both develop fundamental understanding and explore managment and policy alternatives that could increase human welfare and minimize resource and environmental risks in the Yaqui Basin.

We believe that the proposed project is unique, but not without some risk. It requires a research setting in which scholars can easily cross disciplinary boundaries; a genuine enthusiasm among those scholars for interdisciplinary work; a location that is large enough to be interesting, but small enough to be manageable; ingenuity in modeling the various biological, engineering, social, and economic dimensions of a region in ways meaningful for the development of policy alternatives; and "consumers" for the analyses who want to understand the findings, and, where appropriate, to implement policy changes. We believe that we have found the relevant site, researchers, and consumers.

Our inability to cite similar efforts at other universities is both daunting and exhilarating. We realize that integrative work of this kind is enormously challenging, and that assembling and integrating all of the pieces sufficiently well to satisfy our objectives to far from a sure thing. On the other hand, we believe that the project breaks new ground in interdisciplinary work, and that it therefore has the potential to demonstrate critical new ways of doing research, as well as to make real contributions to the communities of the Yaqui region.