Regional Climate and Hydrologic Change:
Internally Consistent Future Climate Projections for Resource Management


Project description


Climate information is a key component of prioritizing adaptation actions and conducting vulnerability assessments. However, despite the increasing availability of climate information in the Western United States, a consistent set of hydro-climatic projections does not exist for the region at large. Furthermore, managers require information on the uncertainty in climate projections, in particular for changes in climatic extremes, which affect aquatic and terrestrial ecosystem vulnerability. The goal of this project is to address these needs.

This project is an update to a previous "quasi west-wide" climate change dataset, with the addition of the follwing:

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WUS CSC domain

Figure 1 The study domain and five major basins in the Western US.

Methods and Products


We analyzed global climate models (GCMs) available from the IPCC AR4 assessment to better understand the projected future climate by region and individual model sensitivities within regions. We then developed an ensemble of climate models that have the best capability in the 6 major river basins (Columbia, Upper Missouri, Upper Colorado, Lower Colorado, Great Basin, and California) and projected downscaled climate and hydrology based on an ensemble delta method and four bracketing scenarios. Bracketing scenarios were chosen to span the range from cooler/drier (less winter flooding) to warmer/wetter (more winter flooding) and from cooler/wetter (less summer drought) to warmer/drier (more summer drought) -- i.e., spanning the four "corners" of changes in temperature and precipitation. Figure 2 shows the projected changes for all IPCC AR4 models, and highlights the changes for the 10 models included in the ensemble, as well as the 4 bracketing models.

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IPCC AR4 model projections

Figure 2 Precipitation (Oct-Mar) and temperature (Annual average) projections for all IPCC AR4 models, for A1b 2040s. Models included in the ensemble are highlighted in blue and green, those that are not included in the ensemble are shown in gray. The ensemble average projection is denoted by the plus ("+") symbol, and the four bracketing models are highlighted in green.

Applying the downscaled climate data to the historical (1916-2006) and two future timeframes (2030-2059 / "2040s"; 2070-2099 / "2080s") at 1/16th degree (~6km), we estimated hydrologic output tailored for impacts assessments (e.g., snow water equivalent, soil moisture, potential evapotranspiration, actual evapotranspiration, and runoff). The result is a consistent set of downscaled climate and hydrologic projections at ~6km for the entire Columbia, upper Missouri, California, and upper and lower Colorado basins and 1/8th degree (~12km) for the Great basin. The data are summarized at monthly time scales for Bailey's Ecosections (Figure 3), Omernik Level III Ecoregions (Figure 4), and 8-digit Hydrologic Unit Code (HUC 4) basins. Raw data are also available in raw form on a grid-cell basis at daily time steps and in ascii grid (ArcGIS) format for historical and future climatologies.

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bailey regions

Figure 2 Bailey ecosections in the project domain. The green polygons beneath the Bailey ecosections represent USFS lands.

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omernik regions

Figure 3 Omernik ecoregions in the project domain. The green polygons beneath the Omernik ecoregions represent USFS lands.

Available Data


The CIG maintains a database of products from this project that are available at the following links. We would appreciate it if you could send a brief note describing how you plan to use the data (contact information below).

Summary Products:

Primary Data:

Model setup:


Funding


This research was funded through a grant from the US Department of Interior Northwest Climate Science Center.


Publications


Littell, J.S., M.M. Elsner, G. Mauger, E. Lutz, A.F. Hamlet,, and E. Salathé. 2011. Regional Climate and Hydrologic Change in the Northern US Rockies and Pacific Northwest: Internally Consistent Projections of Future Climate for Resource Management. DRAFT report available online here.

Littell, J.S., D. McKenzie, B. K. Kerns, S. Cushman, and C. G. Shaw. 2011. Managing uncertainty in climate-driven ecological models to inform adaptation to climate change. Ecosphere 2:102. Available here.

McKelvey, K.S., J. P. Copeland, M. K. Schwartz, J. S. Littell, K. B. Aubry, J. R. Squires, S. A. Parks, M.M. Elsner, G.S. Mauger. 2011. Climate change predicted to shift wolverine distributions, connectivity, and dispersal corridors. Ecological Applications. Pre-print available here.

McWethy D. B., S. T. Gray, P. E. Higuera, J. S. Littell, G. T. Pederson, A.J. Ray, and C. Whitlock. 2010. Climate and terrestrial ecosystem change in the U.S. Rocky Mountains and Upper Columbia Basin: Historical and future perspectives for natural resource management. Natural Resource Report NPS/GRYN/NRR—2010/260. National Park Service, Fort Collins, Colorado.

McKelvey, K.S., J. P. Copeland, M. K. Schwartz, J. S. Littell, K. B. Aubry, J. R. Squires, S. A. Parks, M.M. Elsner, G.S. Mauger. In press. Climate change predicted to shift wolverine distributions, connectivity, and dispersal corridors. Ecological Applications. Pre-print available here.

Wasserman, T.N., S. A. Cushman, A. S. Shirk, E. L. Landguth , and J. S. Littell. In press. Simulating the effects of climate change on population connectivity of American marten (Martes americana) in the northern Rocky Mountains, USA. Landscape Ecology.

Wenger, S.J., D.J. Isaak, C.H. Luce, H.M. Neville, K.D. Fausch, J.B. Dunham, D.C. Dauwalter, M.K. Young, M.M. Elsner, B.E. Rieman, A.F. Hamlet and J.E. Williams (2011) Flow regime, temperature, and biotic interactions drive differential declines of trout species under climate change. Proceedings of the National Academy of Sciences doi:10.1073/pnas.1103097108


Questions


Questions regarding this dataset can be directed to: