A Record of Change—Science and Elder Observations on the Navajo Nation is a 25-minute documentary about collaborative studies using conventional physical sciences, combined with tribal elder observations to show that local knowledge and conventional science partnerships can effectively document ecosystem change and determine the resulting challenges to livelihoods.&
What causes drought?
A drought is a period of drier-than-normal conditions that results in water-related problems.
The amount of precipitation at a particular location varies from year to year, but over a period of years the average amount is fairly constant. In the deserts of the Southwest, the average precipitation is less than 3 inches per year. In contrast, the average precipitation in the Northwest is more than 150 inches per year.
When little or no rain falls, soils can dry out and plants can die. When rainfall is less than normal for a period of weeks to years, streamflows decline, water levels in lakes and reservoirs fall, and the depth to water in wells increases. If dry weather persists and water-supply problems develop, the dry period can become a drought.
Learn more:
Related
When does a drought begin and end?
Where in the Nation are droughts or very low flows occurring now? How can I see these sites on a map and get to the data?
Why doesn't a drought end when it rains?
What are the long-term effects of climate change?
How can climate change affect natural disasters?
What is the difference between global warming and climate change?
What are some of the signs of climate change?

A Record of Change—Science and Elder Observations on the Navajo Nation is a 25-minute documentary about collaborative studies using conventional physical sciences, combined with tribal elder observations to show that local knowledge and conventional science partnerships can effectively document ecosystem change and determine the resulting challenges to livelihoods.&
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
The surface level of Lake Mead in Nevada and Arizona has fallen to a historic low as 16 years of ongoing drought in the American Southwest continue to impact the Colorado River Basin.
The surface level of Lake Mead in Nevada and Arizona has fallen to a historic low as 16 years of ongoing drought in the American Southwest continue to impact the Colorado River Basin.

A scientist from the University of California, Berkeley climbs a giant sequoia to measure its drought stress.
A scientist from the University of California, Berkeley climbs a giant sequoia to measure its drought stress.
A hydrologic technician from the USGS Idaho Water Science Center measures streamflow in Lightning Creek at Clark Fork, ID. The USGS is collecting data at hundreds of sites on rivers and streams in six western states to document the 2015 drought. USGS scientists will analyze the data to identify which rivers and streams may be most vulnerable to future droughts.
A hydrologic technician from the USGS Idaho Water Science Center measures streamflow in Lightning Creek at Clark Fork, ID. The USGS is collecting data at hundreds of sites on rivers and streams in six western states to document the 2015 drought. USGS scientists will analyze the data to identify which rivers and streams may be most vulnerable to future droughts.

California's Central Valley Hydrologic Science
by Claudia Faunt, USGS Hydrologist
California's Central Valley Hydrologic Science
by Claudia Faunt, USGS Hydrologist
Stillwater Creek in drought conditions
Stillwater Creek in drought conditions
The white colored rock (approximately 100ft high) shows the drop in the water level of Lake Mead as a result of the ongoing 10-year drought along the Colorado River.
The white colored rock (approximately 100ft high) shows the drop in the water level of Lake Mead as a result of the ongoing 10-year drought along the Colorado River.
The Vegetation Drought Response Index (VegDRI) incorporates satellite observations of vegetation to monitor at a finer spatial detail than other commonly used drought indicators.
The Vegetation Drought Response Index (VegDRI) incorporates satellite observations of vegetation to monitor at a finer spatial detail than other commonly used drought indicators.
Dead molluscs and raccoon tracks are concentrated in cracks in mud in the substrate of a dried-down tidal pond. Increased frequency and duration of droughts are predicted by some climate models.
Dead molluscs and raccoon tracks are concentrated in cracks in mud in the substrate of a dried-down tidal pond. Increased frequency and duration of droughts are predicted by some climate models.
California's hotter drought has already killed millions of trees, particularly in low-elevation forests.
California's hotter drought has already killed millions of trees, particularly in low-elevation forests.
U.S. Geological Survey National Groundwater Climate Response Network
Drought as an emergent driver of ecological transformation in the twenty-first century
2022 drought in New England
Water priorities for the Nation—U.S. Geological Survey Integrated Water Prediction science program
USGS integrated drought science
The role of snowpack, rainfall, and reservoirs in buffering California against drought effects
Flood- and drought-related natural hazards activities of the U.S. Geological Survey in New England
U.S. Geological Survey Climate and Land Use Change Science Strategy—A Framework for Understanding and Responding to Global Change
Drought Monitoring with VegDRI
Climate change and wildlife health: direct and indirect effects
Water availability for the Western United States--Key scientific challenges
Related
When does a drought begin and end?
Where in the Nation are droughts or very low flows occurring now? How can I see these sites on a map and get to the data?
Why doesn't a drought end when it rains?
What are the long-term effects of climate change?
How can climate change affect natural disasters?
What is the difference between global warming and climate change?
What are some of the signs of climate change?

A Record of Change—Science and Elder Observations on the Navajo Nation is a 25-minute documentary about collaborative studies using conventional physical sciences, combined with tribal elder observations to show that local knowledge and conventional science partnerships can effectively document ecosystem change and determine the resulting challenges to livelihoods.&
A Record of Change—Science and Elder Observations on the Navajo Nation is a 25-minute documentary about collaborative studies using conventional physical sciences, combined with tribal elder observations to show that local knowledge and conventional science partnerships can effectively document ecosystem change and determine the resulting challenges to livelihoods.&
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
The surface level of Lake Mead in Nevada and Arizona has fallen to a historic low as 16 years of ongoing drought in the American Southwest continue to impact the Colorado River Basin.
The surface level of Lake Mead in Nevada and Arizona has fallen to a historic low as 16 years of ongoing drought in the American Southwest continue to impact the Colorado River Basin.

A scientist from the University of California, Berkeley climbs a giant sequoia to measure its drought stress.
A scientist from the University of California, Berkeley climbs a giant sequoia to measure its drought stress.
A hydrologic technician from the USGS Idaho Water Science Center measures streamflow in Lightning Creek at Clark Fork, ID. The USGS is collecting data at hundreds of sites on rivers and streams in six western states to document the 2015 drought. USGS scientists will analyze the data to identify which rivers and streams may be most vulnerable to future droughts.
A hydrologic technician from the USGS Idaho Water Science Center measures streamflow in Lightning Creek at Clark Fork, ID. The USGS is collecting data at hundreds of sites on rivers and streams in six western states to document the 2015 drought. USGS scientists will analyze the data to identify which rivers and streams may be most vulnerable to future droughts.

California's Central Valley Hydrologic Science
by Claudia Faunt, USGS Hydrologist
California's Central Valley Hydrologic Science
by Claudia Faunt, USGS Hydrologist
Stillwater Creek in drought conditions
Stillwater Creek in drought conditions
The white colored rock (approximately 100ft high) shows the drop in the water level of Lake Mead as a result of the ongoing 10-year drought along the Colorado River.
The white colored rock (approximately 100ft high) shows the drop in the water level of Lake Mead as a result of the ongoing 10-year drought along the Colorado River.
The Vegetation Drought Response Index (VegDRI) incorporates satellite observations of vegetation to monitor at a finer spatial detail than other commonly used drought indicators.
The Vegetation Drought Response Index (VegDRI) incorporates satellite observations of vegetation to monitor at a finer spatial detail than other commonly used drought indicators.
Dead molluscs and raccoon tracks are concentrated in cracks in mud in the substrate of a dried-down tidal pond. Increased frequency and duration of droughts are predicted by some climate models.
Dead molluscs and raccoon tracks are concentrated in cracks in mud in the substrate of a dried-down tidal pond. Increased frequency and duration of droughts are predicted by some climate models.
California's hotter drought has already killed millions of trees, particularly in low-elevation forests.
California's hotter drought has already killed millions of trees, particularly in low-elevation forests.