Hydrologic Change

On a global scale, wetland systems have been affected by climate extremes, changing sea level, and population growth, reducing their capacity to moderate storm surge, filter contaminants, store carbon, and provide habitats for fish and wildlife. This research takes a long-term perspective on the resilience of wetlands to a range of climatic and human-induced changes and provides critical data to...

Mountain glaciers are dynamic reservoirs of frozen water closely coupled to ecosystems and climate. Glacier change in North America has major socioeconomic impacts, including global sea level change, tourism disruption, natural hazard risk, fishery effects, and water resource alteration. Understanding and quantifying precise connections between glaciers and climate is critical to decision makers...

The term environmental streamflows refers to the magnitude, frequency, seasonal timing, duration, and rate of change of streamflows needed to sustain freshwater and estuary ecosystems and human wellbeing. It is important that environmental streamflow assessments by water managers consider changes in climate, land use, and water management; this cannot be done effectively without understanding...

This project focuses on development of new interdisciplinary modeling capabilities of long-term time series that capture interactions among climate, land use, water use, and water availability. Research builds on expanding the USGS Forecasting Scenarios of Land Use (FORE-SCE) model and integrating with spatially explicit models from other disciplines. Interdisciplinary models will be co-developed...

Warming and thawing of permafrost soils in the Arctic is expected to become widespread over the coming decades. Permafrost thaw changes ecosystem structure and function, affects resource availability for wildlife and society, and decreases ground stability which affects human infrastructure. Since permafrost soils contain about half of the global soil carbon (C) pool, the magnitude of C losses...

Drought and fire are powerful disturbance agents that can trigger rapid and lasting changes in the forests of western North America. Over the last decade, increases in fire size and severity coincided with warming, drought, and earlier snowmelt, factors that projected climatic changes are likely to exacerbate. However, recent observations are brief relative to the lifespans of trees and include...

Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited...

In the intermountain west, seasonal precipitation extremes, combined with population growth, are creating new challenges for the management of water resources, ecosystems, and geologic hazards. This research contributes a comprehensive long-term context for a deeper understanding of past hydrologic variability, including the magnitude and frequency of drought and flood extremes and ecosystem...

Estuaries and their surrounding wetlands are coastal transition zones where freshwater rivers meet tidal seawater. As sea levels rise, tidal forces move saltier water farther upstream, extending into freshwater wetland areas. Human changes to the surrounding landscape may amplify the effects of this tidal extension, impacting the resiliency and function of the upper estuarine wetlands. One visible...

Climate model forecasts indicate an increase in extreme hydrologic events, including floods and droughts, for California and the western U.S. in the future. To better understand what the consequences of this future change in climate may be, USGS scientists are studying the frequency, magnitude, and impacts of past hydroclimate variability and extremes in the region. This project produces well...

While research into eutrophication has been a cornerstone of limnology for more than 100 years, only recently has it become a topic for the remote alpine lakes that are icons of protected national parks and wilderness areas. National park lakes in the western U.S. are threatened by global change, specifically air pollution, warming, and their interactions, and the problem is quickly worsening...

The Southeastern U.S. experiences recurring hydrologic droughts, which can reduce water availability for human consumption and ecosystem services, leading to plant stress and reduced plant growth. This project examines relationships between drought and the water cycle in the Southeast with data from the Panola Mountain Research Watershed (PMRW) near Atlanta, Georgia and other Southeastern sites...