Geology topics

J. W. Gibbs

Publications and source records attributed to J. W. Gibbs.

3 recordsLinked to original sources

USGS1985

Runoff characteristics and washoff loads from rainfall-simulation experiments on a street surface and a native pasture in the Denver metropolitan area, Colorado

Rainfall-runoff simulation studies were conducted in conjunction with the Denver Regional Urban Runoff Program to: (1) Compare runoff characteristics from two different intensities of simulated rainfall on street-surface plots, (2) document a first flush of constituent washoff loads in runoff from 1,000-sq-ft street-surface plots, (3) compare runoff characteristics from the street surface plots with those from a 69-acre urban mixed land use subjected to natural rainfall, (4) perform statistical analysis of washoff loads, and (5) compare quantity and quality of runoff from 400-sq-ft plots of native pasture subjected to simulated rainfall and from a 405-acre basin of native pasture subjected to natural rainfall. Experiments on the street surface showed that higher intensity simulated rainfall produced a higher percentage of runoff than lower intensity rainfall, and a first flush of constituent loads occurred for most constituents. The event mean constituent concentrations in the street-surface runoff from simulated storms were generally much smaller than those in the runoff from an adjacent urban basin. Simulated rainfall in small native pasture plots produced runoff-to-rainfall ratios similar to runoff-to-rainfall ratios from a larger native pasture subject to natural rainfall. (USGS)

Colorado↗

USGS1984

Analysis of urban storm-runoff data and the effects on the South Platte River, Denver metropolitan area, Colorado

Denver was selected for inclusion in the Nationwide Urban Runoff Program, sponsored by the U.S. Environmental Protection Agency and the U.S. Geological Survey. This report, prepared in cooperation with the Denver Regional council of governments, contains a synopsis of previous urban runoff studies in the Denver metropolitan area. The report includes a description of the monitored basins, a summary of storm runoff-to-rainfall ratios and estimates of impervious retention, and constituent loads and concentrations from seven small basins. The data from six small and five tributary basins to the South Platte River are analyzed using regression analysis, resulting in two sets of regression equations to predict storm runoff volume and selected constituent loads. The regression equations may be used to estimate storm-runoff volume and constituent loads from unmonitored basins from 15 to 16,000 acres with effective impervious areas of 15 to 90 percent. The effects of urban runoff on the South Platte River in the Denver area are described in three ways. The three methods indicated that storm runoff was a significant contributor of total suspended solids, total organic carbon, total lead, and total zinc to the South Platte River.

Colorado↗

USGS1983

Hydrologic data for the drainage basins of Chatfield and Cherry Creek Lakes, Denver metropolitan area, Colorado

Chatfield and Cherry Creek Lakes are flood control lakes constructed by the U.S. Army Corps of Engineers and leased to the Colorado Division of Parks and Recreation. Both lakes are in the Denver metropolitan area and provide a variety of recreational activities, including boating, camping, fishing, picnicking, and swimming. The projected increase of urban development in the drainage basins of Chatfield and Cherry Creek lakes could increase the constituent loads delivered to the lakes. Due to the eutrophic condition of Cherry Creek Lake and the potential eutrophic condition of Chatfield Lake, increased constituent loads could affect the suitability of the lakes for recreation. A monitoring program was started to determine the constituent loads of the drainage basins to both lakes. A network of monitoring stations was established to collect ambient water quality samples, storm runoff water quality samples, precipitation, and stream discharge. In the Cherry Creek basin 12 observation wells were established in the alluvium upgradient from Cherry Creek lake. Water levels and water quality data were collected to determine the quantity and quality of groundwater entering Cherry Creek lake. Data were collected from January through December 1982. The data may be used to evaluate the present and projected impact of urbanization in the drainage basins and the effect of increased constituent loads delivered to Chatfield and Cherry Creek lakes. (Author 's abstract)

Open-File Report↗