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Findings and Recommendations
Our review produced the following findings and recommendations.
FINDINGS
1. The water cycle science plan successfully makes the case that coordination of water cycle research is necessary for making progress in this area of global change science, and the new research resulting from the coordinated program would be greatly beneficial to the nation. The plan recommends developing a coordinated plan around three science questions that we agree are of the utmost importance to USGCRP water cycle research. Thus, the plan offers a useful and challenging science plan to the USGCRP agencies, and we support the new initiative contained in the plan.
2. The USGCRP agencies need to develop as soon as possible implementation plans to address the research proposed in the water cycle science plan. As stated in our review, we are concerned about the prioritization and implementation of the research identified in the plan. One effective approach to enhancing coordination would be for the USGCRP agencies, through their Interagency Working Group on the Global Water Cycle, to organize a “commitments” meeting. The purpose of such a meeting would be for the agencies to discuss overall research priorities and identify the elements of the water cycle science plan for which they will take the lead roles. These commitments for research should take into consideration the recommendations of the water cycle science plan and the comments found in this review.
3. The USGCRP, through its Interagency Working Group on the Global Water Cycle, should develop a mechanism to coordinate the various agency implementation plans and to bring the disparate science and
management communities together. Otherwise, insufficient attention may be given to interagency activities, identification of integration topics across agencies, and general coordination. The water cycle is so pervasive in climate issues that many of the proposed activities are components of research carried out by a number of USGCRP agencies and World Climate Research Program (WCRP) activities. How should the water cycle be integrated into this larger climate science agenda? His-torically, USGCRP agencies have pursued their research activities in a rather independent manner. Coordination of the efforts of separate agencies that are largely either underway or planned under other climate research umbrellas presents a significant challenge to the water cycle initiative.
4. The water cycle science initiative approach to prioritizing the science questions is to identify pillar initiatives. We recognize that the USGCRP agencies must consider which elements they will focus on early in their implementation planning. Establishing priorities and set-ting near-term goals must be a component of the interagency coordination activity recommended above. Nonetheless, we recognize that there are elements that can be effectively addressed during the next few years and those that will require a longer period of a decade or more. The agency implementation plans must be sufficiently coordinated to provide this prioritization and the required resources.
RECOMMENDATIONS
The science questions, goals, and pillar initiatives found in the water cycle science plan presuppose a sound foundation of observations, a thorough understanding of hydrologic processes active on the scale of large river basins and globally, and accurate representation of the water cycle within climate models. The first priority of the USCGRP must be to assure that this foundation is in place. Therefore, we urge the USGCRP agencies in developing their implementation plans to assure that these needs are met first and foremost. Therefore, we believe strongly that implementation of the water cycle initiative by cooperating agencies must give priority to basic work in the following three areas:
1. Clearly define quantitative observational data requirements for regional and global water cycle elements. Pillar Initiative 1 and the first two science questions require as a first step that the climate community be able to assemble observational data that allow the detection of climate signals and close the water balance for large areas and river basins by the
use of observations, including the determination of precipitation and evaporation over the oceans. Reports identifying the need for a climate observing system are available to guide implementation in this area (NRC 1999a, b). Such reports should be the starting point to define the quantitative characteristics of the observing requirements for water cycle variables. Such a set of requirements does not currently exist, and their creation is critical to transition the water cycle science plan into effective agency and interagency implementation plans. The requirements should also include the synergistic use of research-based observations with op-erational-based observations.
2. Validate the water cycle components of climate models. The science questions contained in the water cycle science plan that are related to understanding and predicting variability require an improved understanding of hydrologic processes and their representation in climate models. Therefore, it seems that advances in this area are also fundamental to the water cycle science plan, and the research community is poised to make these advances. Advanced climate change impact assessments are dependent on progress in this area. The path forward in this area requires the identification of the weakest elements in the characterization of the water cycle, and it requires the identification of quantitative improvement goals.
3. Improve the understanding of hydrologic processes that link climate variability to outcomes relevant to the management of water and related natural resources, and hazards. The science requirements of application users need to be brought to the forefront and made important drivers of research related to the water cycle. The agency implementation plans must ensure that research and development thrusts are trace-able to requirements of the science and applications users.
Work in these three areas will help assure that the science questions and pillar initiatives proposed under the water cycle initiative can be successfully addressed and answered.