The Influence of Climatic, Watershed, and Water-use Changes on Extreme Low Streamflows in the United States Active
Extreme low streamflows impact water availability for human systems and ecosystems. Numerous researchers have analyzed trends in low streamflows in the U.S. There is no known published work, however, on historical trends over time in the most extreme low streamflows—the flows with the largest impacts on human systems and ecosystems. The current study attempts to fill this gap. The wealth of historical U.S. Geological Survey streamflow, watershed, and water-use data across the country provides a great opportunity to better understand this critical issue.
Our Research: We aim to provide better understanding of the effect of historical climatic changes, human watershed changes (such as urbanization and reservoir storage), and water-use changes on extreme low flows in the United States.
Why this Research is Important: Hydrologic drought in the United States can have severe impacts on agriculture, municipal water supply, and ecosystems. It is important to know whether extreme low flows have been changing over time and why, to better inform future drought flows.
Objective(s):
- Hydrologic drought in the United States can have severe impacts on agriculture, municipal water supply, and ecosystems. It is important to know whether extreme low flows have been changing over time and why, to better inform future drought flows.
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Identify the climatic influences and direct human influences on extreme low streamflows in the United States by examining trends and variability in extreme low streamflows for both least-disturbed and disturbed basins across the country.
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Investigate the influence of winter and spring groundwater recharge on summer low streamflows.
Methods: Research continues with project collaborators to select the best statistical methods for each project objective.
Below are publications associated with this project.
Changes in the magnitude of annual and monthly streamflows in New England, 1902-2002
Changes in the number and timing of days of ice-affected flow on northern New England rivers, 1930-2000
Summer low flows in New England during the 20th Century
Changes in the proportion of precipitation occurring as snow in New England (1949-2000)
Historical trend in river ice thickness and coherence in hydroclimatological trends in Maine
Changes in the timing of high river flows in New England over the 20th Century
Historical changes in lake ice-out dates as indicators of climate change in New England, 1850-2000
Below are news stories associated with this project.
- Overview
Extreme low streamflows impact water availability for human systems and ecosystems. Numerous researchers have analyzed trends in low streamflows in the U.S. There is no known published work, however, on historical trends over time in the most extreme low streamflows—the flows with the largest impacts on human systems and ecosystems. The current study attempts to fill this gap. The wealth of historical U.S. Geological Survey streamflow, watershed, and water-use data across the country provides a great opportunity to better understand this critical issue.
Our Research: We aim to provide better understanding of the effect of historical climatic changes, human watershed changes (such as urbanization and reservoir storage), and water-use changes on extreme low flows in the United States.
Why this Research is Important: Hydrologic drought in the United States can have severe impacts on agriculture, municipal water supply, and ecosystems. It is important to know whether extreme low flows have been changing over time and why, to better inform future drought flows.
Objective(s):
- Hydrologic drought in the United States can have severe impacts on agriculture, municipal water supply, and ecosystems. It is important to know whether extreme low flows have been changing over time and why, to better inform future drought flows.
-
Identify the climatic influences and direct human influences on extreme low streamflows in the United States by examining trends and variability in extreme low streamflows for both least-disturbed and disturbed basins across the country.
-
Investigate the influence of winter and spring groundwater recharge on summer low streamflows.
Methods: Research continues with project collaborators to select the best statistical methods for each project objective.
- Hydrologic drought in the United States can have severe impacts on agriculture, municipal water supply, and ecosystems. It is important to know whether extreme low flows have been changing over time and why, to better inform future drought flows.
- Publications
Below are publications associated with this project.
Filter Total Items: 19Changes in the magnitude of annual and monthly streamflows in New England, 1902-2002
Selected annual and monthly streamflow statistics for 27 streamflow-gaging stations in New England were computed and tested for changes over time. These 27 stations were considered to be free of substantial human influences such as regulation, diversion, and land use-changes and have an average of 71 years of record. The longest streamflow record extended from 1902 to 2002. March mean streamfloAuthorsGlenn A. Hodgkins, Robert W. DudleyChanges in the number and timing of days of ice-affected flow on northern New England rivers, 1930-2000
Historical dates of ice-affected flows for 16 rural, unregulated rivers in northern New England, USA were analyzed. The total annual days of ice-affected flow decreased significantly (p < 0.1) over the 20th century at 12 of the 16 rivers. On average, for the nine longest-record rivers, the total annual days of ice-affected flow decreased by 20 days from 1936 to 2000, with most of the decrease occuAuthorsG.A. Hodgkins, R. W. Dudley, T.G. HuntingtonSummer low flows in New England during the 20th Century
High springtime river flows came earlier by one to two weeks in large parts of northern New England during the 20th Century. In this study it was hypothesized that late spring/early summer recessional flows and late summer/early fall low flows could also be occurring earlier. This could result in a longer period of low flow recession and a decrease in the magnitude of low flows. To test this hypotAuthorsGlenn A. Hodgkins, R. W. Dudley, Thomas G. HuntingtonChanges in the proportion of precipitation occurring as snow in New England (1949-2000)
The ratio of snow to total precipitation (S/P) is a hydrologic indicator that is sensitive to climate variability and can be used to detect and monitor hydrologic responses to climatic change. Changes in S/P ratio over time could influence the magnitude and timing of spring runoff and recession to summer baseflow. The S/P ratio for 21 U.S. Historical Climatology Network sites in New England was exAuthorsT.G. Huntington, G.A. Hodgkins, B.D. Keim, R. W. DudleyHistorical trend in river ice thickness and coherence in hydroclimatological trends in Maine
We analyzed long-term records of ice thickness on the Piscataquis River in central Maine and air temperature in Maine to determine whether there were temporal trends that were associated with climate warming. The trend in ice thickness was compared and correlated with regional time series of winter air temperature, heating degree days (HDD), date of river ice-out, seasonal center-of-volume date (SAuthorsT.G. Huntington, G.A. Hodgkins, R. W. DudleyChanges in the timing of high river flows in New England over the 20th Century
The annual timing of river flows is a good indicator of climate-related changes, or lack of changes, for rivers with long-term data that drain unregulated basins with stable land use. Changes in the timing of annual winter/spring (January 1 to May 31) and fall (October 1 to December 31) center of volume dates were analyzed for 27 rural, unregulated river gaging stations in New England, USA with anAuthorsG.A. Hodgkins, R. W. Dudley, T.G. HuntingtonHistorical changes in lake ice-out dates as indicators of climate change in New England, 1850-2000
Various studies have shown that changes over time in spring ice-out dates can be used as indicators of climate change. Ice-out dates from 29 lakes in New England (USA) with 64 to 163 years of record were assembled and analysed for this study. Ice-out dates have become significantly earlier in New England since the 1800s. Changes in ice-out dates between 1850 and 2000 were 9 days and 16 days in theAuthorsG.A. Hodgkins, Ivan James, T.G. Huntington - News
Below are news stories associated with this project.