H24A-01 INVITED
Challenges on Managing California's Water Resources with Changing Climate
California's population is projected to grow to 60 million by year 2050 from the 38 million as of 2007 adding about 500,000 people each year. Meeting the water needs for agricultural production as well as for human and industrial consumption has been and will continue to be a tall challenge for water managers in the state. Winter snow pack in the high Sierra provides about a third of the water supply for the state. Rising temperature due to warming climate will bring more rain than snow; warmer temperature will speed up the melting process of snow pack. Less snow pack (smaller natural storage) and higher early spring runoff (prior to the irrigation season) will pose additional challenge to managing water in an already semi-arid region. Levees located in the Sacramento San Joaquin Delta--the hub of the state's water delivery system—will become more susceptible to flooding because of the rising sea level and because of the changed tidal hydrodynamics in the estuary. Raised temperature in the water column will add further stress to the environmental and fishery resources in the Delta, upstream rivers and tributaries. In this study, historical hydrologic, climatologic, and meteorological records are first examined to detect and quantify the extent of the climate change that has already taken place. Future precipitation, temperature, and other meteorological variables projected by different GCM's, RCM's, and SRES- based emission scenarios are processed to examine the water system performance. Two large public water projects in California—the Central Valley Project and the State Water Project—are examined with the use of simulation models. CalSim is a systems simulation model developed to simulate the operations of the CVP and the SWP. DSM2 is a hydrodynamics and water quality model designed to simulate the stage, velocity, flow, electrical conductivity, and various water quality constituents in the Sacramento-San Joaquin Delta. Both CalSim and DSM2 were extensively used in this study to evaluate the system performance of the major water facilities in the state in light of the projected climate change. http://baydeltaoffice.water.ca.gov/modeling/
H24A-02
Integrated and Adaptive Reservoir Management in the Context of Hydroclimatic Variability: a Case Study of the Gunnison Basin, Colorado
Water resources managers in the West face the challenge of meeting multiple and expanding demands for water in the context of existing and future hydroclimatic variations. This case study of water resources management in the Gunnison Basin of Colorado describes a context similar to many others in the western U.S.: demands match or exceed supply, and yet more demands are being made on the system. As elsewhere, new demands often relate to restoring or maintaining environmental sustainability, in this case the flow requirements to implement the Recovery Program for Endangered Fish of the Colorado River and a water right for the Black Canyon of the Gunnison National Park. Strategies to meet these demands focus on use of stored water in the Aspinall Unit, a system of reservoirs managed by the U.S. Bureau of Reclamation (USBR) in conjunction with a diverse set of stakeholders. In response to increased demands, USBR has implemented strategies to more intensively and efficiently use water. However, as a result, the buffer to shortage or drought is all but exhausted and the system is now more sensitive to shortage. Thus by neglecting the risks of hydroclimatic variations, the implementation of these policies to achieve environmental sustainability could be hindered. On the other hand, by more fully recognizing the risks and uncertainty surrounding these variations, managers might adjust annual to interannual operating plans to mitigate adverse conditions in dry years and take advantage of wet years. The presentation will describe two factors important in the incorporation of hydroclimatic risk into management: 1) the potential to use hydroclimatic climate information in operations and long-range planning, and 2) the institutional capacity to use this information effectively. In contrast to the rigid operating constraints found in other systems, operations here are often adjusted for a variety of reasons, revealing flexibility and adaptability in operations and a collaborative management structure that seeks creative solutions . However, the uncertainty of the inflow forecast is itself a major constraining factor for operations, resulting in conservative operational choices even well into the runoff period. Advance notice about conditions in climate forecast could give more time to negotiate contracts, implement agreements, or develop new ones. The advance notice could also allow managers to plan to take advantage of wet years and maximize benefits of surplus, for example, for peak flows for ecosystems. The incorporation of hydroclimatic risk into longer-range planning, such as building flexibility into reservoir operating policies being negotiated under the EIS for the could avoid problems in implementing these policies later if changes in climate limit the amount of water available in the basin. In particular, the capacity of water management institutions to cope with climate will be described through the responses to past hydroclimatic variations. http://www.cdc.noaa.gov/people/andrea.ray/
H24A-03 INVITED
Decision Making Under Uncertainty and Complexity: A Model-Based Scenario Approach to Supporting Integrated Water Resources Management
Some of the most challenging issues facing contemporary water resources management are those typified by complex coupled human-environmental systems with poorly characterized uncertainties. In other words, major decisions regarding water resources have to be made in the face of substantial uncertainty and complexity. It has been suggested that integrated models can be used to coherently assemble information from a broad set of domains, and can therefore serve as an effective means for tackling the complexity of environmental systems. Further, well-conceived scenarios can effectively inform decision making, particularly when high complexity and poorly characterized uncertainties make the problem intractable via traditional uncertainty analysis methods. This presentation discusses the integrated modeling framework adopted by SAHRA, an NSF Science & Technology Center, to investigate stakeholder-driven water sustainability issues within the semi-arid southwestern US. The multi-disciplinary, multi-resolution modeling framework incorporates a formal scenario approach to analyze the impacts of plausible (albeit uncertain) alternative futures to support adaptive management of water resources systems. Some of the major challenges involved in, and lessons learned from, this effort will be discussed.
H24A-04
End To End Uncertainty Estimation: From Hydrology To Water Resources Management
Taking an integrated approach to assess management options for water-resources systems is necessary to inform the complex decisions facing society today. Improvement of techniques to assist in the sustainable management of water resource systems is a crucial issue since our limited resources are under ever increasing pressure. For reliable and sustainable water resources management and planning, it is essential to account for the various sources of uncertainty impacting our modeling and decision-making process. Many studies have focused on addressing the uncertainties sourcing from climate inputs (e.g. precipitation and temperature) as well as assessment of supply-demand relationship. In the end-to-end projection of hydrological impacts of climate variability, however, hydrological uncertainties have been often ignored or addressed indirectly. We demonstrate the importance of hydrological uncertainties for reliable water resources management. First we assess the hydrological uncertainties associated with hydrological input, parameters and model structural uncertainties using an Integrated Bayesian Uncertainty Estimator (IBUNE) framework. Subsequently these uncertainties are propagated through a hypothetical reservoir system in order to evaluate how various operational rules impact the characteristics of the downstream uncertainties, such as the width of the uncertainty bounds. We examine how hydrological uncertainties impact reliability, resilience and vulnerability of the management system considering different operational rules and why an adaptive operational approach should be considered for a sustainable management of water resources.
H24A-05
Using Climate Forecast Information in Water Resource Planning: Opportunities and Challenges in the Yakima River Basin, Washington, USA
Drought is a costly natural hazard, particularly in the Yakima River basin, whose irrigated crops represent the largest agricultural value in the state of Washington. Like many basins throughout the West, the Yakima has experienced an increasing demand for water for irrigation, environmental flows, and hydropower production. These demands, coupled with shifts in hydrologic timing and variations in water supply, including droughts in 2001 and 2005, have resulted in a narrowing margin within which the Yakima's multi-reservoir system must be managed. Because the region is vulnerable to variations in seasonal water supplies, it has the potential to benefit from information on current and future hydroclimatic conditions, especially information to help prepare for and mitigate drought impacts. To better connect climate forecast information with water management decisions, the University of Washington is working directly with individual stakeholders and public agencies within the Yakima water-user community to understand current and potential uses of medium- and long-lead climate forecast information, and to assess its economic value. Through this case study, we provide concrete examples of the opportunities and challenges in working towards the adoption of decision-focused, understandable forecast information. We emphasize (1) the scope and diversity of decisions water managers make throughout the year, (2) the accuracy and usefulness of forecast products, (3) the limitations of forecast information, (4) the potential for new decision-focused products, and (5) generalizable guidelines on how to effectively communicate and facilitate the adoption of climate forecast information. An ultimate goal is to find ways to develop interactions that provide decision makers with relevant science-based indicators they can use to promote sustainable water resource planning.
H24A-06 INVITED
Bayesian Uncertainty Analysis for Computationally Expensive Hydrologic Simulation Models
This article presents a new computationally efficient method for statistically rigorous assessment of uncertainty in parameters and model output when the model is calibrated to field data. The Bayesian method be general and is here applied to water resource problems The innovative aspect of this procedure is that an optimization method is first used to find the maximum likelihood estimator and then the costly simulation done during the optimization are re used to build a response surface model of the likelihood function. Markov chain Monte Carlo is applied then to the response surface model to obtain the posterior distributions of the model parameters and the appropriate transformations to correct for non normal error. The computational effort to obtain roughly the same accuracy of solution is 150 model simulations for the response surface method versus 10,000 simulations for conventional MCMC analysis, which is a 60 fold reduction in computational effort
H24A-07
Incorporation of Climatic Variability for Management of Water Resources in South Florida
Climate in any region is the result of both short- and long-term phenomena interacting at local, regional and global scales. In South Florida where major changes to the water resources infrastructure are being contemplated for facilitating the restoration of large-scale ecosystems such as the Kissimmee River Basin and the Everglades, consideration of intra-decadal and multi-decadal climate variability is extremely important in both water resources planning and regional operations. Correlations of hydro-climatology of South Florida to such global phenomena as El Nino-Southern Oscillation (ENSO) and Atlantic Multi-Decadal Oscillation (AMO) have been investigated extensively. This paper addresses the considerations of hydroclimatic variability in two areas of water resources management: (a) Operational Planning; and (b) Facility Planning. The South Florida Water Management District, regional agency responsible for management of water resources in South Florida, has effectively employed the seasonal and multi-seasonal outlook for operational planning. Since the agency has embarked on a major infrastructure improvement project to facilitate Everglades Restoration while meeting the meeting the water supplies for agriculture and increasing urban population, the issue of decadal to multi-decadal climate variability in water resources planning has come to the forefront as a major consideration in future investments. This paper provides an application of the research to develop operational rules of Lake Okeechobee as well as the real-time implementation of rules based on climate outlooks. The current research to address the question of decadal to multi-decadal climate variability in facility planning is also discussed. http://www.sfwmd.org
H24A-08
WaterNet: The NASA Water Cycle Solutions Network
Water is essential to life and directly impacts and constrains society's welfare, progress, and sustainable growth, and is continuously being transformed by climate change, erosion, pollution, and engineering practices. The water cycle is a critical resource for industry, agriculture, natural ecosystems, fisheries, aquaculture, hydroelectric power, recreation, and water supply, and is central to drought, flood, transportation-aviation, and disease hazards. It is therefore a national priority to use advancements in scientific observations and knowledge to develop solutions to the water challenges faced by society. NASA's unique role is to use its view from space to improve water and energy cycle monitoring and prediction. NASA has collected substantial water cycle information and knowledge that must be transitioned to develop solutions for all twelve National Priority Application (NPA) areas. NASA cannot achieve this goal alone –it must establish collaborations and interoperability with existing networks and nodes of research organizations, operational agencies, science communities, and private industry. Therefore, WaterNet: The NASA Water Cycle Solutions Network goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national needs. WaterNet is a catalyst for discovery and sharing of creative solutions to water problems. It serves as a creative, discovery process that is the entry-path for a research–to-solutions systems engineering NASA framework, with the end result to ultimately improve decision support. http://www.crew.iges.org/research/waternet