ments. In doing so CCSP should identify decision-making processes of high priority or broad application that address key regional or sectoral vulner-abilities, and then evaluate the decision-support needs in those applications. New analytical and predictive tools can then be devised that have direct benefits in specific assessment applications.
Adaptive approaches are needed to continually integrate advances in knowledge into the policy context. Although it would be ideal to address impacts and responses for each sector at local, regional, and national scales, it is unlikely that sufficient resources will ever be available to do this comprehensively on an ongoing basis. One way to address this issue is to construct a broad conceptual framework or matrix linked to smaller-scale illustrative examples. For example, an assessment could be conducted at a national level, accompanied by selected localized case studies of impacts on specific sectors or implications for specific local decision making. The work on broad themes and trends can be an ongoing effort, while individual, integrated local, or sectoral assessments can be strategically nested in the broader research agenda. This will help develop an ongoing assessments program that has more coherence over time.
An example of the application of the nested matrix approach is using global climate models to identify likely future changes in temperature and precipitation at the national and regional level that may result from climate change. By connecting such outputs to hydrologic models, it is possible to identify a range of likely impacts on runoff for specific watersheds and evaluate potential vulnerabilities for regions and sectors. Based on that information, specific local or regional areas or sectors that are areas of high vulnerability can be selected for a more focused integrated assessment that includes the demographic and institutional context as well as physical parameters. At a regional scale, the vast amount of place-based information, including the additional drivers (e.g., land-use change), can be incorporated into the analysis to provide a more comprehensive treatment of potential changes in water quality and quantity.
Recommendation: CCSP should consider implementing this nested matrix concept in developing subsequent assessments.