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Now available in PDF format: Abstract Book [7.4 Mb] (posted 10 November 2005)

Abstracts for Posters

Water & Energy (P-WE)

Sub-Theme 2: Science & Information Tools

P-WE2.1

Giovanni – A Vital Tool Enabling Rapid and Accurate Climate Data Analysis
for Evaluation, Assessment, and Research

James G. Acker, NASA GSFC, Goddard Earth Sciences DISC (GES DISC)/Oceans Data Team/SSAI, acker@daac.gsfc.nasa.gov

Stephen Berrick, Goddard Earth Sciences DISC

Gregory Leptoukh, Goddard Earth Sciences DISC

Steven Kempler, Goddard Earth Sciences DISC

Zhong Liu, GES DISC/George Mason University

Hualan Rui, GES DISC/SSAI

William Teng, GES DISC/SSAI

Suhung Shen, GES DISC/George Mason University

Tong Zhu, GES DISC/SSAI

James Johnson, GES DISC/SSAI

The Goddard Earth Sciences Data and Information Services Center (GES DISC) has created the GES DISC Interactive Online Visualization and ANalysis Infrastructure, "Giovanni," to enable Web-based analysis of several NASA remote-sensing climate data sets. Giovanni was conceived as a research tool to increase the "usability" of climate data sets, but it can also be used to evaluate climate data for purposes of overview and site assessment, trend detection, anomaly detection, and identification of significant events and potential hazards. The simplicity of Giovanni allows users unfamiliar with the scientific and technical details of Earth remote sensing to utilize climate data for the purposes of short-term and long-term decision making, and the determination of future research needs.

Giovanni features a simple user interface allowing rapid access to data, establishment of spatial and temporal criteria, and a variety of output options. The data analysis engine provides rapid statistical analyses and generation of area average plots, time plots, Hovmoller latitude vs. time and longitude vs. time plots, vertical profiles, data set intercomparisons, and anomaly analysis. Giovanni has been applied to several different climate data sets, including precipitation, atmospheric chemistry, ocean color, and sea surface temperature.

[Poster PDF]

P-WE2.2

Global Land Data Assimilation System (GLDAS) Products
Available to Support Hydroclimatology and Decision Making

Matthew Rodell, Hydrological Sciences Branch, NASA Goddard Space Flight Center, Matthew.Rodell@nasa.gov

The Global Land Data Assimilation System (GLDAS) ingests satellite- and ground-based observational data products, using advanced land surface modeling and data assimilation techniques, in order to generate optimal fields of hydrological land surface states (e.g., soil moisture and snow) and fluxes (e.g., evaporation). GLDAS drives multiple, offline (not coupled to the atmosphere) numerical models of land surface processes. Through these it integrates a huge quantity of observation based data. It is able to run globally at high resolutions (2.5° to 1 km) and can produce results in near-real time. Observation-based precipitation and downward radiation products, as well as output fields from the best available global coupled atmospheric data assimilation systems, are employed to force the models. The high-quality, global land surface fields provided by GLDAS support several current and proposed investigations of weather, climate, and water resources predictability. GLDAS has been selected as a primary integration tool for scientific products resulting from NASA's Energy- and Water-Cycle Sponsored Research (NEWS) initiative. Twenty-five year simulations with three sophisticated land surface models, parameterized and forced by the best available data, have recently been completed. Preliminary analyses indicate that the resulting fields may be valuable for identifying trends and teleconnections in the global water cycle.

P-WE2.3

Drought Monitoring and Applications of NASA's Hydrosphere States Mission

Christa Peters-Lidard, NASA GSFC, christa.peters@nasa.gov

Peggy O'Neill, NASA GSFC

Dara Entekhabi, MIT

Eni Njoku, NASA JPL

Paul Houser, GMU & CREW

Randy Koster, NASA GSFC

NASA's Hydrosphere States Mission, to be launched in 2010, will provide the first global view of the Earth's changing soil moisture and surface freeze/thaw conditions, enabling new scientific studies of global change and atmospheric predictability, and making new hydrologic applications possible, including drought monitoring. Hydros will make unprecedented measurements of Earth's changing soil moisture and the freeze/thaw status of land surface that, together, define the state of Earth's hydrosphere. This state links the water, energy and carbon cycles over land. Hydros measurements will open new frontiers in our understanding of how these global cycles work together in the Earth system. Numerical models used for day-to-day weather prediction need soil moisture estimates as initial conditions for forecasts. Incorporating real observations into these models will significantly improve forecast accuracy. Soil moisture is among the top terrestrial environment measurement requirements of the Departments of Defense and Transportation because of the impact on land navigation and aviation weather. Contributing partners for the Hydros mission, in addition to NASA, include the Canadian Space Agency and the Department of Defense. The Hydros science team draws from several universities, NASA centers, research and operational branches of federal agencies. The principal investigator is Dr. Dara Entekhabi of the Massachusetts Institute of Technology, Cambridge, Mass.

[Poster PDF]

P-WE2.4

The Hydrologic Ensemble Prediction Experiment (HEPEX) Project

John Schaake, National Weather Service, john.schaake@noaa.gov

The goal of the HEPEX project is to bring the international hydrological and meteorological communities together to demonstrate how to produce reliable hydrological ensemble forecasts that can be used to make decisions that have important consequences for the economy, public health and safety and the environment. The project is overseen by an international User's Forum Council composed of representatives of organizations with a strong interest in using or applying HEPEX results, as well as a Science Steering Group. Nine international test-bed projects are being developed, including projects in Brazil, Canada, Europe and Bangladesh as well as the United States. This presentation will review users' expectations, science issues, project objectives, the status of the test-bed projects and possible relationships between HEPEX and the CCSP.

P-WE2.5

Climate Services for Water Resources Decision Support:
An Overview of the State of the Practice and Some Implications Associated with Global Warming

Alan Hamlet, CSES, University of Washington, hamleaf@u.washington.edu

Edward Miles, CSES, University of Washington

Edward Sarachik, CSES, University of Washington

Climate-related decision support for water resources planning and management involves the production of a number of different kinds of hydrologic forecasting products and related services tailored to the specific needs of the water resources planning and management communities. At shorter time scales (e.g. lead times of a few weeks to 12 months) ensemble streamflow forecasts in specific river basins are useful products for water management. Climate forecasts (e.g. numerical forecasts of ENSO, PDO, PNA indices) can be used directly in hydrologic forecasting systems to create conditional probability distributions of future streamflows as a function of climate forecast information. These kinds of approaches are now fairly well-developed in the academic community, and we discuss the UW West-Wide forecasting system as a case study. Forecasting systems in the operational forecasting community are, in general, less well developed in terms of incorporating climate information and there is an ongoing need to transfer academically developed procedures and tools to the operational communities that directly serve many public sector water managers. Climatic change, although frequently viewed as a separate problem, actually plays a potentially important role in these kinds of forecasts, particularly in temperature sensitive river basins, because the probability distributions of streamflow may systematically change over time. Detrended temperature records for ESP forecasts, or temperature forecasts produced by climate models are two approaches that show some promise in dealing with these issues. Statistically-based streamflow forecasting methods that are trained on a long period of record (the norm in most operational forecasting systems) may contain systematic biases because of regional warming trends. Physically-based hydrologic simulation tools (e.g. the VIC and DHSVM hydrologic models used in the UW experimental forecasting systems) can directly relate altered temperature regimes to changes in snowpack and streamflow timing (or other effects) and may therefore perform more robustly in a rapidly evolving climate system than statistical approaches.

For water planning purposes at longer time scales (i.e. 10-100 years), long range projections of streamflow variability are needed to evaluate alternative water management plans. Using physically-based hydrologic simulation tools, the incorporation of systematic warming simulated by global climate models (GCMs) is relatively straight-forward using scenario based approaches. A number of effective downscaling approaches are available for temperature ranging from simple sensitivity experiments using "delta method" approaches to more sophisticated statistical and dynamical downscaling techniques. The same downscaling approaches have frequently been applied to the task of evaluating potential changes in precipitation, however because of greater underlying uncertainties in GCM precipitation simulations, quantifying precipitation uncertainties remains a significant challenge. The nature of these uncertainties, combined with relatively small GCM sample sizes, suggests that multi-model "super ensemble" or Monte Carlo approaches may be more effective for estimating precipitation uncertainties. Forecasts of energy (supply and demand), water demand, and water quality (particularly temperature) also play an important role in water resources management and planning. Climate is a key variable in such predictions, and as for streamflow, operational forecasts at both short and long time scales using physically-based tools are needed.

P-WE2.6

Assessing the Implications of Climate Variability and Change for Western Water Resources

Andrew W. Wood, University of Washington

Dennis P. Lettenmaier, University of Washington, dennisl@u.washington.edu

Tim P. Barnett, Scripps Institution of Oceanography

The hydrology and water resources, and hence the economy, of the western U.S. is highly sensitive to climate. Over the last 10 years, we have developed an approach that couples macroscale hydrology models to represent the large river basins of the west to climate models for purposes both of forecasting streamflow at seasonal lead times, and for assessing the impacts of climate change at century time scales. In both cases, a key step is removal of bias in climate model predictions using a probability mapping procedure, and downscaling from the spatial scale of GCMs to the hydrology model scale. This step is facilitated by knowledge of the climatology (probability distribution) of the hydrology model forcings from both the climate model and observations. We illustrate applications of this general approach both to the seasonal prediction, and climate assessment problems.

Since 2003, we used have used a variation of the above approach to produce real-time ensemble hydrologic predictions using our Variable Infiltration Capacity (VIC) macroscale hydrology model at lead times of six months to a year. Climate forecast ensembles are downscaled from climate models and the CPC official seasonal outlooks. As a benchmark, we also produce forecasts using the well-known Extended Streamflow Prediction (ESP) method, and the ESP forecasts are further composited to provide ENSO and PDO-conditioned ensembles.

The Accelerated Climate Prediction Initiative assessment of hydrologic and water resources consequences of climate change over the western U.S. used a variation of the same probability mapping method. Multiple ensembles from the NCAR/DOE Parallel Climate Model (PCM) were downscaled and bias adjusted to produce hydrology model forcings for three major western U.S. river basins—the Columbia, the Sacramento-San Joaquin, and the Colorado. The Columbia and Sacramento-San Joaquin basin results are strongly sensitive to the seasonal shifts in streamflow associated with climate change. These hydrologic shifts are reflected in reductions of "firm" hydropower production, and/or reduction in the system's ability to meet minimum spring and summer streamflow targets for fisheries protection and enhancement in the case of the Columbia. For the Sacramento-San Joaquin, the fraction of the time that the system would be in "critically dry" status more than doubles by mid-century. In contrast, the Colorado River reservoir system is almost completely insensitive to seasonal runoff shifts, but is highly sensitive to the approximately 10 percent reduction in annual runoff predicted by mid-century under the PCM scenarios. This change would reduce the system's ability to meet water supply delivery targets, and to meet U.S.-Mexico treaty obligations.

P-WE2.7

Impacts of a Warming Climate on Water Availability in Snow-Dominated Regions

Jennifer Adam, University of Washington, jenny@hydro.washington.edu

Tim Barnett, Scripps Institute of Oceanography

Dennis Lettenmaier, University of Washington

Predictions of future climate conditions in a greenhouse world are sometimes ignored because they are "uncertain." One common trait of all greenhouse predictions to date (warming of the near surface air temperature) has a profound negative impact on regional hydrology, particularly in snowmelt dominated environments: warmer air temperatures cause reductions in maximum snow accumulations, earlier melt, and hence earlier spring runoff. These impacts occur almost independently of changes in future precipitation. (These same simple physics will apply, at least in part, to the world's mountain glaciers and may partially explain why they are in retreat over most of the globe.) The model-predicted changes are already seen in the observed data. If maintained at current levels, these changes will lead to a serious reduction in dry season water availability in many regions of the Earth within the next few decades. The fact that all models predict a warming, and that warming is being observed now, suggests that mitigation strategies can be undertaken now with high confidence.

We present new results from a global land surface hydrology model that identifies the regions of the globe where snowmelt dominates the seasonal patterns of streamflow. In general, we find that snowmelt dominates those parts of the globe that are at latitudes greater than ~45° (North and South), with some exceptions for mountainous regions, regions that are warmed by oceans, and cold dry regions that experience little wintertime precipitation. The disappearance of the glaciers and snow pack reduction affect over one-sixth of the world's population. We also utilized a global data set of major reservoirs to identify regions where reservoir storage is large enough that timing shifts associated with earlier snowmelt are likely to be mitigated by reservoir storage. This is the case, for instance, in the U.S. Colorado River basin, but globally, only a relatively small part of the area identified as being hydrologically dominated by snowmelt would have global warming effects substantially mitigated by reservoirs. In total, we estimate that one-quarter of the global GDP is in areas that are susceptible to change in seasonal patterns of snowmelt.

[Poster PDF]

P-WE2.8

Effects of Water Resources: Monitoring Snowmelt Runoff and Sea Level for Climate Change

Maury Roos, California Department of Water Resources, mroos@water.ca.gov

Substantial changes in mountain snowmelt water supply and sea level are projected to occur as a result of global warming. Water resources managers already collect extensive data to use in forecasting and in operations of water projects. If interested in climate change, they should look carefully at their long-term records of operating projects to see if signs of change are apparent and what the rates of change are. Hydrologic records are inherently highly variable and long stable records and reconstructed natural stream flows are needed to assess systematic changes over time.

The author will present a couple of samples from northern California of the time history of the long term fraction of mountain water year runoff occurring during the April through July period of snowmelt runoff. A second chart will show sea level rise on the California coast. Both parameters show a decrease in the rate of change in the last 15 years. Reconstruction of natural flows will be briefly discussed as well as why change in runoff patterns and in sea level are so important to the large water projects in California.

[Poster PDF]

P-WE2.9

Regional Impacts of Climate Change, Land Use Change, and Human Population Dynamics
on Water Availability and Demand across the Southeastern U.S.

Ge Sun, Research Hydrologist, Southern Global Change Program, USDA Forest Service, Raleigh, NC 27606, Ge_Sun@ncsu.edu

Steven G. McNulty, Research Ecologist and Program Manager, USDA Forest Service, Raleigh, NC 27606, Steve_McNulty@ncsu.edu

Erika Cohen, Resource Information Specialist, USDA Forest Service, Raleigh, NC 27606, Erika_Cohen@ncsu.edu

Jennifer Moore Myers, Resource Information Specialist, Southern Global Change Program, USDA Forest Service, Raleigh, NC 27606, jennifer_mooremyers@ncsu.edu

David Wear, Project Leader, Economics of Forest Management and Protection, USDA Forest Service, RTP, NC 27709, Dwear@fs.fed.us

Projected changes in population, landuse, landcover, and climate could negatively impact the regional water resources in the southeastern U.S. The objective of this study is to develop a method to fully budget annual water availability for water supply [Precipitation - Evapotranspiration (ET) + Groundwater supply + Return Flow] and water use from thermoelectric, irrigation, domestic, industry, livestock, mining, and commercial sectors. We used a generalized annual ET model that estimates water loss as a function of potential ET, annual precipitation, landcover type, and topography. Both the groundwater supply and return flow rates were derived from USGS historical databases. Water use for the domestic, irrigation, and thermoelectric sectors for the future were projected using empirical models derived from historical USGS databases. They were mainly affected by population, irrigation land area, population, and water use efficiency of power generation, respectively. The Water Supply Stress Index (WSSI) as the ratio of water demand and supply was developed to evaluate water stress conditions. The Water Supply Stress Index Ratio (WSSIR) was developed to quantify the average or annual water stress impacts from future changes in climate, landuse, and population individually or in combination. Modeling results from two Global Circulation Models (GCMs) (UK Hadley2CMSul and Canadian CGC1), one landuse change model, and one population change model were integrated to project future water supply and use over the next 50 years. All model runs were performed at the 8-digit USGS Hydrologic Unit Code (HUC) level across 13 southern states. We found that population increase will greatly increase water use in metropolitan areas, but overall its impact on total water use may not be as large as surmised. Predicted future landuse changes (i.e., urbanization) will have little positive effect on water supply-water use relations. In contrast to population and landuse change, climate change and groundwater supply may have serious consequences on regional water supply and demand. In summary, we developed a framework and integrated modeling tool for water resource managers and policy makers to address climate change impact and associated global change issues at the regional to continental scales.

P-WE2.10

Decision Support System (DSS) for the Effects of Climate Change
on Water Supply in San Juan River Basin

Carl W. Chen, Systech Engineering, Inc., carl@systechengineering.com

Laura H.Z. Weintraub, Systech Engineering, Inc.

Limin Chen, Systech Engineering, Inc.

Joel W. Herr, Systech Engineering, Inc.

Paul M. Rich, Los Alamos National Laboratory

R.A. Goldstein, Electric Power Research Institute

We have developed a DSS to analyze and present water supply information at various river segments of the arid San Juan River Basin under various scenarios of climate change and drought. The DSS contains a watershed model (WARMF), which uses the topographic data (DEM) of the river basin (42,000 km²) and is driven by meteorological data (46 stations). A batch scenario tool was developed to construct climate scenarios based on historic data from 1985 to 2004, which contained 4 wet, 4 dry, and 11 normal years. The climate change scenarios assumed temperature increases of 0, 1, and 2°C. Drought sequences of 3 and 5 years were hypothesized by using the batch scenario tool to randomly select meteorological records from the pools of wet, dry and normal year. Fifty selections were made for simulations to provide adequate characterization of uncertainty. The results showed that climate change produced more impact on the hydrology of watersheds at higher elevation. The hydrographs of USGS gauging stations, that receive runoff from high mountain areas, had earlier rises and lower peaks during the snowmelt period. Annual runoff was reduced 8 to 10% by 1 degree warmer temperature. Without climate change, three years' drought dropped the elevation of Navajo Reservoir briefly to 1,822 meters above mean sea level, 3 meters below the minimum required for the siphon pump to divert water to the Navajo Indian Irrigation Project. With one degree warming, the pool elevation was substantially lower for a longer duration. Reservoir releases had to be reduced to maintain the minimum pool elevation. A 35% (8% due to drought and 27% due to warming) reduction of drought year release for two years was required, if it was initiated early in anticipation of the prolong drought. The adjustment increased to 65% for one year, if the action was delayed. The DSS predicted a ripple effect of reduced reservoir releases on downstream water supply. The DSS will be used by stakeholders (local, state, federal governmental agencies, industry, Native American Tribes, and irrigation districts) to understand the scientific facts about the hydrologic system and to evaluate suitable water shortage sharing schemes, that may include using gray water to reduce the diversion for power plant cooling, changing riparian vegetations to reduce evapotranspiration, changing crops to alter the seasonal irrigation demands, reducing diversions equally and/or trading diversions among stakeholders.

The paper is a contribution from the ZeroNet Water-Energy Initiative of Sandia National Laboratory, Los Alamos National Laboratory, Electric Power Research Institute, and Public Service Company of New Mexico.

[Poster PDF]

P-WE2.11

An Assessment of the Effectiveness of Riparian Buffers for Reducing Sediment Loading
to Streams Under Alternative Climate Change Scenarios

T. Johnson, U.S. Environmental Protection Agency, Washington, D.C. 20460, johnson.thomas@epa.gov

M. Huang, ICF Consulting, Inc.

J. Furlow, U.S. Environmental Protection Agency

C. Rogers, U.S. Environmental Protection Agency

R. Freed, ICF Consulting, Inc.

D. Pape, ICF Consulting, Inc.

Sediment loading to streams in agricultural watersheds is a major cause of stream impairment. Factors affecting sediment loading include watershed physiographic characteristics, cropping practices, and climate. During the last century, much of the U.S. has experienced warming temperatures and increased rainfall. Projections of future climate change suggest these trends are likely to continue. Areas experiencing increases in rainfall are thus
vulnerable to increases in sediment related stream impairment. An improved ability of decision makers to predict and respond to these changes is desired.

Riparian buffers are an effective and widely applied management practice for reducing sediment loading from agricultural fields. Buffer effectiveness is strongly influenced by hydrologic processes, however, and could vary in response to changes in precipitation. Buffer width and vegetation type also influence the effectiveness of buffers in retaining sediments.

In this study we assess the influence of changes in precipitation on soil erosion and sediment loading to streams from a 160-meter hillslope consisting of a corn field and riparian buffer. Climate scenarios were generated using the CLIGEN weather generator by modifying historical precipitation probability (i.e. describes the number of events that occur) and event intensity (i.e. describes the intensity of events) parameters by -10, 10, 20, and 30% at two locations, Athens, Georgia, and Salinas, California. Soil erosion from the corn field was simulated using the WEPP model. Sediment was then routed through the REMM model to simulate transport through a riparian buffer and into the stream. Sediment retention by forested and grass buffers ranging in width from 0 to 50 meters were assessed. This approach provides illustrative examples of the nature and magnitude of watershed response to potential changes in precipitation, and is not based on specific climate projections.

Results show that soil erosion is sensitive to changes in precipitation probability and intensity, but is more sensitive to changes in intensity. Increases of 10% in precipitation probability and intensity resulted in increases in erosion of 20 and 35%, respectively. Buffer trapping efficiency (percent of input that is retained) is altered relatively little, but large increases in sediment loading still occur. For example, with a 30-meter buffer, increases of approximately 100% occurred with a 30% increase in precipitation probability or intensity. Decision support tools based on this modeling approach could be used to help watershed managers achieve sediment management goals over a range of time scales.

[Poster PDF]

P-WE2.12

Assessing the Impact of Climate Change on the Hydrology and Water Quality
of the Upper Mississippi River

Eugene Takle, Iowa State University,

Manoj Jha, Iowa State University

Christopher Anderson, NOAA Forecast Systems Laboratory

Phil Gassman, Iowa State University

Recent observations and modeling suggests acceleration of the hydrological cycle at high latitudes in the Northern Hemisphere and that extreme intense precipitation events were more frequent over the last 30 years of the twentieth century. Assessments of local and regional impacts of changes in the hydrological cycle in future climates call for improved capabilities for modeling the hydrological cycle and its individual components at the subwatershed level. We have evaluated the impact of climate change on stream flow in the Upper Mississippi River Basin by use of a regional climate model (RCM) coupled with a hydrologic model - Soil and Water Assessment Tool (SWAT) - and by use of an ensemble of GCMs producing output for the IPCC 4th Assessment Report coupled to SWAT. Both the RCM and the GCM ensemble reproduce quite well the annual flow and interannual variability of observed streamflow of the UMRB for the 20th Century. Individual low-resolution GCMs give poor simulation of annual streamflow, but the one high-resolution GCM tested gave good results.

The RCM driven by a single GCM (HadCM2) results for the decade of the 2040s gave a 21% increase in future precipitation, which resulted in a 51% increase in surface runoff, 43% increase in groundwater recharge, and 50% net increase in total water yield in the UMRB on an annual basis.

Although there is inconsistency among GCMs, the ensemble-mean precipitation increased of 6% due to climate change. ET calculations give positive changes for all models, likely due to warm-season temperature increases. Substantial decreases in snowfall suggest that warming is strong in winter. Runoff decreases substantially for most models, possibly due to enhanced drying of soils between rains. Total water yield varied widely among models, with the ensemble mean showing almost no change from the contemporary climate.

Fugitive nitrates and sediment are carried by overland flow related to runoff. However, the dominant pathway for nitrate loss is through leaching to groundwater and then via baseflow or tile drains. Results show a substantial decrease in runoff in the future climate but increase in baseflow, although with less agreement among models. From this we speculate that both sediment and nitrate loading of streams would decrease due to decreased runoff but that nitrate leaching might increase. Therefore, although water quality might improve due to reduced sediment, the loading due to nitrates is less clear but might increase.

[Poster PDF]