Climate Variability

The Willamette River Basin reflects the conflicting water demands between humans and ecosystems—particularly salmon— and the challenge resource managers face throughout the Pacific Northwest.

Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Upper Colorado River Basin, the USGS will conduct a focused assessment of how snowpack and snowmelt influence hydrology and water quality, and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.

Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Delaware River Basin, the USGS will conduct a focused assessment of increasing freshwater salinity and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.

Wildfires pose a substantial risk to water supplies because they can lead to severe flooding, erosion, and delivery of sediment, nutrients, and metals to rivers, lakes, and reservoirs. The USGS works with federal and state land managers and local water providers to monitor and assess water quality after wildfires in order to help protect our Nation’s water resources.

Click the image cards below to learn more about the effects of projected climate trends on humans, fish and wildlife populations, and habitats. Our researchers work with cooperators to better understand potential implications and to reduce uncertainty so that managers can better evaluate future scenarios and management options.

The Delta of the Sacramento and San Joaquin rivers provides drinking water supplies to two-thirds of Californians, and is a fragile ecosystem home to threatened and endangered species. The CASCaDE project builds on several decades of USGS science to address the goals of achieving water supply reliability and restoring the ecosystems in the Bay-Delta system.

The U.S. Geological Survey is integrating its water science programs to better address the Nation’s greatest water resource challenges. At the heart of this effort are plans to intensively study at least 10 Integrated Water Science (IWS) basins — medium-sized watersheds (10,000-20,000 square miles) and underlying aquifers — over the next decade. The IWS basins will represent a wide range of...

The Next Generation Water Observing System provides high-fidelity, real-time data on water quantity, quality, and use to support modern water prediction and decision-support systems that are necessary for informing water operations on a daily basis and decision-making during water emergencies. The Illinois River Basin provides an opportunity to implement the NGWOS in a system challenged by an...

The Next Generation Water Observing System (NGWOS) provides high-fidelity, real-time data on water quantity, quality, and use to support modern prediction and decision-support systems that are necessary for informing water operations on a daily basis and decision-making during water emergencies. The headwaters of the Colorado and Gunnison River Basins provide an opportunity to implement NGWOS in a...

Together with partner organizations, the USGS is involved in data collection, analysis, and synthesis to improve estimates of coastal wetland carbon fluxes. This research will help improve science and data availability across a wide range of topics.

Declining snow cover is playing a key role in decreasing the flow of the Colorado River, “the lifeblood of the Southwest,” by enabling increased evaporation. As the warming continues, increasingly severe water shortages are expected.

The USGS National Hydrologic Model (NHM) infrastructure supports the efficient construction of local-, regional-, and national-scale hydrologic models. The NHM infrastructure consists of: 1) an underlying geospatial fabric of modeling units with an associated parameter database, 2) a model input data archive, and 3) a repository of the physical model simulation code bases.