This book is a result of the NATO-SPS (NFA) Workshop held in Istanbul, Turkey, in October 2007. The main goal of the Workshop was to provide knowledge and build the skills of scientists, engineers, and decision- and policy-makers for the effective management of watersheds and prevention of or coping with catastrophic events. The aim of this effort was to transfer the multidisciplinary approach, information, and knowledge gained by the LEMSM group (NATO CCMS Pilot Study Group on Ecosystem Modeling of Coastal Lagoons for Sustainable Management) during their 12 years of collaboration on the Pilot Study to international scientists and decision-makers.

The Workshop provided participants with an excellent opportunity to develop understanding and skills in scenario-based decision-making management of watersheds. Participants from 21 countries exchanged knowledge on how to use advanced tools for assessment and decision-making that provide the ability to manage watersheds. Participants benefited from applying the sustainable use and development models to minimize and mitigate effects on the natural capital of water resources, watersheds, and thus socioeconomic systems. This led to recommendations based on a oeecosystem approacha for decision-making for protection of human security and peace. Further, group sessions resulted in the identification of Terms and Principles as well as the recommendations for application and implementation of sustainable use and development practices in developing countries. The program of the Workshop was challenging by embracing a a oehands ona learning experience.

The book specifically reframes the need for decision support tools and scientific knowledgein watershed management in the context of a multidisciplinary, integrated approach.

John Wesley Powell, U.S. scientist and geographer, put it best when he said that a watershed is: ...that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community. Watersheds come in all shapes and sizes. They cross sectorial boundaries (e.g. county, state/province, and country). No matter where you are, you are in a watershed! World-wide, watersheds supply drinking water, provide r- reation and respite, and sustain life. Watersheds are rich in natural capital, producing goods (agriculture and fisheries products) and services (industry and technology) for broad geographic areas. In many countries, at the base of watersheds where tributaries empty into large water-bodies (e.g. estuaries, seas, oceans) are centers of society and are typically densely populated areas. These areas serve as concentrated centers of the socio-economic system. They also are centers of domestic and international trade, tourism, and c- merce as well as the center of governments (capitals) where local, regional and national legislatures are located. As we all live in a watershed, our individual actions can directly affect it. The cumulative effects of all the individual actions of everyone within a watershed may be, and often are devastating to the quality of water resources and affect the health of living things including humans. Therefore, watershed systems are highly subject to threat to human security and peace.