David M Wolock, Ph.D.
David Wolock is a Supervisory Hydrologist with the USGS Water Resources Mission Area.
Science and Products
Filter Total Items: 13
Data Release for: Empirical Models for Estimating Baseline Streamflows in California and their Likelihood of Anthropogenic Modification
The dataset contain estimates of natural monthly streamflow for 135,118 stream segments in California, USA, from 1950 to 2012. Segments are identified per the medium resolution National Hydrography Dataset (NHD), Version 1. The dataset also contains observed monthly streamflows and estimates of natural monthly streamflows for 894 USGS stream gages in California, USA.
Filter Total Items: 129
Water balance of the turn-of-the-century drought in the Southwestern United States
Analysis of the water balance of the southwestern United States (SWUS) during 1900 through 2018 was used to evaluate the magnitude of the turn-of-the-century (TOC) drought in the SWUS. Results indicate that the warm season (April through September) soil moisture and runoff during the TOC drought were among the lowest values of the 1900 through 2018 period. Additionally, increases in temperature we
Authors
Gregory J. McCabe, David M. Wolock
Streamflow—Water year 2019
The maps and graphs in this summary describe national streamflow conditions for water year 2019 (October 1, 2018, to September 30, 2019) in the context of streamflow ranks relative to the 90-year period of water years 1930–2019. Annual runoff in the Nation’s rivers and streams during water year 2019 (13.62 inches) was much higher than the long-term (1930–2019) mean annual runoff of 9.37 inches for
Authors
Xiaodong Jian, David M. Wolock, Harry F. Lins, Steven J. Brady
Multi-year hydroclimatic droughts and pluvials across the conterminous United States
Time series of water‐year runoff for 2,109 hydrologic units (HUs) across the conterminous United States (CONUS) for the 1900 through 2014 period were used to identify drought and pluvial (i.e., wet) periods. Characteristics of the drought and pluvial events including frequency, duration, and severity were examined and compared. Additionally, a similar analysis was performed using gridded tree‐ring
Authors
Gregory J. McCabe, David M. Wolock
Spatial and temporal patterns of low streamflow and precipitation changes in the Chesapeake Bay Watershed
Spatial and temporal patterns in low streamflows were investigated for 183 streamgages located in the Chesapeake Bay Watershed for the period 1939–2013. Metrics that represent different aspects of the frequency and magnitude of low streamflows were examined for trends: (1) the annual time series of seven‐day average minimum streamflow, (2) the scaled average deficit at or below the 2% mean daily s
Authors
Brandon J. Fleming, Stacey A. Archfield, Robert M. Hirsch, Julie E. Kiang, David M. Wolock
Hydro-climatic drought in the Delaware River Basin
The Delaware River Basin (DRB) supplies water to approximately 15 million people and is essential to agriculture and industry. In this study, a monthly water balance model is used to compute monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff [R]) for the DRB for the 1901 through 2015 period. Water‐year R is used to identify drought periods i
Authors
Gregory J. McCabe, David M. Wolock
Prioritizing river basins for intensive monitoring and assessment by the US Geological Survey
The US Geological Survey (USGS) is currently (2020) integrating its water science programs to better address the nation’s greatest water resource challenges now and into the future. This integration will rely, in part, on data from 10 or more intensively monitored river basins from across the USA. A team of USGS scientists was convened to develop a systematic, quantitative approach to prioritize c
Authors
Peter C. Van Metre, Sharon L. Qi, Jeffrey R. Deacon, Cheryl A. Dieter, Jessica M. Driscoll, Michael N. Fienen, Terry A. Kenney, Patrick M. Lambert, David P. Lesmes, Christopher Allen Mason, Anke Mueller-Solger, MaryLynn Musgrove, Jaime A. Painter, Donald O. Rosenberry, Lori A. Sprague, Anthony J. Tesoriero, Lisamarie Windham-Myers, David M. Wolock
Basinwide hydroclimatic drought in the Colorado River basin
The Colorado River basin (CRB) supplies water to approximately 40 million people and is essential to hydropower generation, agriculture, and industry. In this study, a monthly water balance model is used to compute hydroclimatic water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff) for the period 1901–2014 across the entire CRB. The time series of mon
Authors
Gregory J. McCabe, David M. Wolock, Connie A. Woodhouse, Gregory T. Pederson, Stephanie A. McAfee, Stephen Gray, Adam Csank
The water-year water balance of the Colorado River Basin
Model‐estimated monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff (R)) for 146 United States (U.S.) Geological Survey 8‐digit hydrologic units located in the Colorado River Basin (CRB) are used to examine the temporal and spatial variability of the CRB water balance for water years 1901 through 2014 (a water year is the period from October
Authors
Gregory J. McCabe, David M. Wolock
Severity and extent of alterations to natural streamflow regimes based on hydrologic metrics in the conterminous United States, 1980–2014
Alteration of the natural streamflow regime by land and water management, such as land-cover change and dams, is associated with aquatic ecosystem degradation. The severity and geographic extent of streamflow alteration at regional and national scales, however, remain largely unquantified. The primary goal of this study is to characterize the severity and extent of alterations to natural streamflo
Authors
Ken Eng, Daren Carlisle, Theodore E. Grantham, David M. Wolock, Rosaly L. Eng
Flow modification in the Nation’s streams and rivers
This report summarizes a national assessment of flowing waters conducted by the U.S. Geological Survey’s (USGS) National Water-Quality Assessment (NAWQA) Project and addresses several pressing questions about the modification of natural flows in streams and rivers. The assessment is based on the integration, modeling, and synthesis of monitoring data collected by the USGS and the U.S. Environmenta
Authors
Daren Carlisle, David M. Wolock, Christopher P. Konrad, Gregory J. McCabe, Ken Eng, Theodore E. Grantham, Barbara Mahler
Streamflow—Water year 2018
The maps and graphs in this summary describe national streamflow conditions for water year 2018 (October 1, 2017, to September 30, 2018) in the context of streamflow ranks relative to the 89-year period of water years 1930–2018. The illustrations are based on observed data from the U.S. Geological Survey National Streamflow Network. Annual runoff in the Nation’s rivers and streams during water yea
Authors
Xiaodong Jian, David M. Wolock, Steven J. Brady, Harry F. Lins
Regional-scale associations between indicators of biological integrity and indicators of streamflow modification
Although streamflow is widely recognized as a controlling factor in stream health, empirical relations between indicators of anthropogenic modification of streamflow and ecological indicators have been elusive. The objective of this report is to build upon specific findings reported in recent publications by providing a library of empirical models that describe the relations between streamflow mod
Authors
Daren Carlisle, Theodore E. Grantham, Ken Eng, David M. Wolock
Science and Products
Filter Total Items: 13
Data Release for: Empirical Models for Estimating Baseline Streamflows in California and their Likelihood of Anthropogenic Modification
The dataset contain estimates of natural monthly streamflow for 135,118 stream segments in California, USA, from 1950 to 2012. Segments are identified per the medium resolution National Hydrography Dataset (NHD), Version 1. The dataset also contains observed monthly streamflows and estimates of natural monthly streamflows for 894 USGS stream gages in California, USA.
Filter Total Items: 129
Water balance of the turn-of-the-century drought in the Southwestern United States
Analysis of the water balance of the southwestern United States (SWUS) during 1900 through 2018 was used to evaluate the magnitude of the turn-of-the-century (TOC) drought in the SWUS. Results indicate that the warm season (April through September) soil moisture and runoff during the TOC drought were among the lowest values of the 1900 through 2018 period. Additionally, increases in temperature we
Authors
Gregory J. McCabe, David M. Wolock
Streamflow—Water year 2019
The maps and graphs in this summary describe national streamflow conditions for water year 2019 (October 1, 2018, to September 30, 2019) in the context of streamflow ranks relative to the 90-year period of water years 1930–2019. Annual runoff in the Nation’s rivers and streams during water year 2019 (13.62 inches) was much higher than the long-term (1930–2019) mean annual runoff of 9.37 inches for
Authors
Xiaodong Jian, David M. Wolock, Harry F. Lins, Steven J. Brady
Multi-year hydroclimatic droughts and pluvials across the conterminous United States
Time series of water‐year runoff for 2,109 hydrologic units (HUs) across the conterminous United States (CONUS) for the 1900 through 2014 period were used to identify drought and pluvial (i.e., wet) periods. Characteristics of the drought and pluvial events including frequency, duration, and severity were examined and compared. Additionally, a similar analysis was performed using gridded tree‐ring
Authors
Gregory J. McCabe, David M. Wolock
Spatial and temporal patterns of low streamflow and precipitation changes in the Chesapeake Bay Watershed
Spatial and temporal patterns in low streamflows were investigated for 183 streamgages located in the Chesapeake Bay Watershed for the period 1939–2013. Metrics that represent different aspects of the frequency and magnitude of low streamflows were examined for trends: (1) the annual time series of seven‐day average minimum streamflow, (2) the scaled average deficit at or below the 2% mean daily s
Authors
Brandon J. Fleming, Stacey A. Archfield, Robert M. Hirsch, Julie E. Kiang, David M. Wolock
Hydro-climatic drought in the Delaware River Basin
The Delaware River Basin (DRB) supplies water to approximately 15 million people and is essential to agriculture and industry. In this study, a monthly water balance model is used to compute monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff [R]) for the DRB for the 1901 through 2015 period. Water‐year R is used to identify drought periods i
Authors
Gregory J. McCabe, David M. Wolock
Prioritizing river basins for intensive monitoring and assessment by the US Geological Survey
The US Geological Survey (USGS) is currently (2020) integrating its water science programs to better address the nation’s greatest water resource challenges now and into the future. This integration will rely, in part, on data from 10 or more intensively monitored river basins from across the USA. A team of USGS scientists was convened to develop a systematic, quantitative approach to prioritize c
Authors
Peter C. Van Metre, Sharon L. Qi, Jeffrey R. Deacon, Cheryl A. Dieter, Jessica M. Driscoll, Michael N. Fienen, Terry A. Kenney, Patrick M. Lambert, David P. Lesmes, Christopher Allen Mason, Anke Mueller-Solger, MaryLynn Musgrove, Jaime A. Painter, Donald O. Rosenberry, Lori A. Sprague, Anthony J. Tesoriero, Lisamarie Windham-Myers, David M. Wolock
Basinwide hydroclimatic drought in the Colorado River basin
The Colorado River basin (CRB) supplies water to approximately 40 million people and is essential to hydropower generation, agriculture, and industry. In this study, a monthly water balance model is used to compute hydroclimatic water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff) for the period 1901–2014 across the entire CRB. The time series of mon
Authors
Gregory J. McCabe, David M. Wolock, Connie A. Woodhouse, Gregory T. Pederson, Stephanie A. McAfee, Stephen Gray, Adam Csank
The water-year water balance of the Colorado River Basin
Model‐estimated monthly water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff (R)) for 146 United States (U.S.) Geological Survey 8‐digit hydrologic units located in the Colorado River Basin (CRB) are used to examine the temporal and spatial variability of the CRB water balance for water years 1901 through 2014 (a water year is the period from October
Authors
Gregory J. McCabe, David M. Wolock
Severity and extent of alterations to natural streamflow regimes based on hydrologic metrics in the conterminous United States, 1980–2014
Alteration of the natural streamflow regime by land and water management, such as land-cover change and dams, is associated with aquatic ecosystem degradation. The severity and geographic extent of streamflow alteration at regional and national scales, however, remain largely unquantified. The primary goal of this study is to characterize the severity and extent of alterations to natural streamflo
Authors
Ken Eng, Daren Carlisle, Theodore E. Grantham, David M. Wolock, Rosaly L. Eng
Flow modification in the Nation’s streams and rivers
This report summarizes a national assessment of flowing waters conducted by the U.S. Geological Survey’s (USGS) National Water-Quality Assessment (NAWQA) Project and addresses several pressing questions about the modification of natural flows in streams and rivers. The assessment is based on the integration, modeling, and synthesis of monitoring data collected by the USGS and the U.S. Environmenta
Authors
Daren Carlisle, David M. Wolock, Christopher P. Konrad, Gregory J. McCabe, Ken Eng, Theodore E. Grantham, Barbara Mahler
Streamflow—Water year 2018
The maps and graphs in this summary describe national streamflow conditions for water year 2018 (October 1, 2017, to September 30, 2018) in the context of streamflow ranks relative to the 89-year period of water years 1930–2018. The illustrations are based on observed data from the U.S. Geological Survey National Streamflow Network. Annual runoff in the Nation’s rivers and streams during water yea
Authors
Xiaodong Jian, David M. Wolock, Steven J. Brady, Harry F. Lins
Regional-scale associations between indicators of biological integrity and indicators of streamflow modification
Although streamflow is widely recognized as a controlling factor in stream health, empirical relations between indicators of anthropogenic modification of streamflow and ecological indicators have been elusive. The objective of this report is to build upon specific findings reported in recent publications by providing a library of empirical models that describe the relations between streamflow mod
Authors
Daren Carlisle, Theodore E. Grantham, Ken Eng, David M. Wolock