David M Wolock, Ph.D.

No abstract available.

A monthly water balance model (WB model) is used with CRUTS2.1 monthly temperature and precipitation data to generate time series of monthly runoff for all land areas of the globe for the period 1905 through 2002. Even though annual precipitation accounts for most of the temporal and spatial variability in annual runoff, increases in temperature have had an increasingly negative effect...

A water‐balance model is used to simulate time series of water‐year runoff for 4 km × 4 km grid cells for the conterminous United States during the 1900–2008 period. Model outputs are used to examine the separate effects of precipitation and temperature on runoff variability. Overall, water‐year runoff has increased in the conterminous United States and precipitation has accounted for...

Human impacts on watershed hydrology are widespread in the US, but the prevalence and severity of stream-flow alteration and its potential ecological consequences have not been quantified on a national scale. We assessed streamflow alteration at 2888 streamflow monitoring sites throughout the conterminous US. The magnitudes of mean annual (1980–2007) minimum and maximum streamflows were...

The maps and graph in this summary describe streamflow conditions for water-year 2010 (October 1, 2009 to September 30, 2010) in the context of the 81-year period 1930-2010, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's (USGS) National Streamflow Information Program. The period 1930-2010 was used because prior to 1930, the number...

Stream flow is a controlling element in the ecology of rivers and streams. Knowledge of the natural flow regime facilitates the assessment of whether specific hydrologic attributes have been altered by humans in a particular stream and the establishment of specific goals for stream-flow restoration. Because most streams are ungaged or have been altered by human influences, characterizing...