Water Resources of Colorado
Water, Energy, and Biogeochemical Budgets (WEBB)
Hydrological, biological, and geological processes control ecosystem behavior and the response of ecosystems to outside perturbations. A thorough understanding of these processes in relatively undisturbed basins, such as the WEBB study sites, is needed in order to better understand the effects of disturbance on natural and impacted ecosystems.
The health of alpine/subalpine ecosystems is a primary concern for resource managers responsible for protecting aquatic ecosystems in the Rocky Mountains. Lakes and streams in the Rockies form the headwaters of many important watersheds in the Western United States, including the Colorado, Rio Grande, Missouri, and Arkansas; seasonal snowpacks in the Rockies provide drinking and irrigation water for at least a dozen States in the west. National parks and wilderness areas in the Rockies, in which alpine/subalpine landscapes are common, receive special protection under various federal laws. Thus, land managers in the Department of Interior and other federal agencies need to understand the effects of disturbance in order to balance regional needs for economic development with protection of ecosystem health.
A principal objective of research at the Loch Vale WEBB site is to understand fundamental hydrologic processes that control the flux of water, chemicals, and sediment in the alpine/subalpine environment. These processes include snow accumulation, snowmelt, hydrologic flowpaths, ground-water/surface-water interactions, rainfall runoff, and streamflow generation. Many fluxes are controlled by climate in alpine and subalpine ecosystems, and there is large potential for subtle changes in climate, such as seasonal shifts between snow and rainfall, to alter the timing and magnitude of water discharge and biogeochemical fluxes from the ecosystem. Biologic processes affect fluxes of nutrients such as carbon and nitrogen. Carbon and nitrogen cycles have many complex feedbacks and interactions, so an understanding of each is necessary in order to understand the other, and to understand ecosystem function as a whole. Geochemical processes, such as cation exchange and mineral weathering, also play an important role in ecosystem health because they are the main sources of base cations and alkalinity. An understanding of controls on spatial and temporal variations on solute fluxes is needed to predict ecosystem response to natural and anthropogenic stresses. Changing flowpaths during snowmelt, for example, may bring flowing water in contact with different biologic and geologic materials than during low-flow conditions. We seek to better understand how flowpaths change seasonally, and how those changing flowpaths control fluxes of solutes from various watershed compartments.
Our goal for the future is to continue to improve our understanding of hydrologic and biogeochemical processes in Loch Vale and to transfer techniques and insight developed by the WEBB Project to other areas and studies. The USGS is using some of the WEBB methods in the Mississippi River/Gulf of Mexico hypoxia study and in a study of the effects of atmospheric deposition on aquatic resources in the Mt. Zirkel Wilderness Area. Proposed studies using methods developed by the WEBB program include determination of sources of alkalinity and base cations to high-elevation lakes in the Rocky Mountain region, and identification of source areas of atmospheric deposition to Rocky Mountain National Park. The process-level work at the Loch Vale WEBB site complements related long-term monitoring projects, such as the U.S. Geological Survey Hydrologic Benchmark Network and the National Atmospheric Deposition Network, and regional synoptic survey projects, such as the annual Rocky Mountain snowpack chemistry survey.
This page is at URL: http://co.water.usgs.gov/lochvale/res-obj.html
Please send questions and (or) comments about the Colorado WEBB project to: co.lochvale@usgs.gov
Maintained by: webmaster_co@usgs.gov
Last Modified: 01/29/2002