Conference Papers

During the past 20 years, the ground-water data base of the U. S. Geological Survey has evolved from paper files in local offices, to a national data base on a central mainframe computer, to a distributed data base on a network of 49 minicomputers throughout the United States. Users in local offices have easy, inexpensive access to the distributed data base. The distributed data base has...

Contrary to the findings of previous studies of channel-controlled stream reaches, it was found that, in four reaches of a small stream characterized by a series of pools and riffles, reaeration coefficients decrease with decreasing discharge. In the reach with the most pool-and-riffle development, the measured rearation coefficient under low-flow conditions was 86 percent less than its...

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In this study, the effects of land subsidence on water-surface elevation and depth profiles during flood conditions were investigated for a large, hypothetical, slope-controlled stream. Subsidence depressions, with a range of vertical magnitudes and areas were imposed on a hypothetical stream reach. Step-backwater computations were made to determine water-surface and depth profiles for a...

The study used data from 43 embankment-dam failures to develop equations that predict breach formation model parameters. These data include the failure mode, embankment characteristics, reservoir conditions at the time of failure, geometry of the final breach, and the time taken to form the breach. Regression equations were developed to predict (1) the average width of a trapezoidal...

Equations to estimate low flows were developed using multiple-regression analysis with a sample of 48 river basins, which were selected from the U. S. Geological Survey's network of gaged river basins in Massachusetts, New Hampshire, Rhode Island, Vermont, and southwestern Maine. Low-flow characteristics are represented by the 7Q2 and 7Q10 (the annual minimum 7-day mean low flow at the 2...

Techniques were used to estimate discharge for the Brandon Road Dam on the Des Plaines River and the Dresden Island, Marseilles, and Starved Rock Dams on the Illinois River in northern Illinois. Tainter gates are operated to regulate streamflow at all dams. Additionally, headgates are used for regulation of the Brandon Road Dam. Stage-discharge, gate-opening relations were developed from...

This field-trip guide describes the common sedimentary structures that occur in eolian sands. The outcrops that are described occur in the Navajo and Entrada Sandstones between the areas of Page, Arizona and St. George, Utah (figure I), but the sedimentary structures of these two sandstones are typical of most eolian deposits. The main part of the guide discusses the geologic setting and...

The loss of professional experience and expertise in the domain of the earth sciences may prove to be one of the most serious outcomes of the boom-and-bust cyclic nature of the volatile energy and mining industries. Promising new applications of powerful computer systems, known as 'expert systems' or 'knowledge-based systems', are predicted for use in the earth sciences. These systems...

The U. S. Geological Survey is developing techniques to estimate and evaluate unit-hydrograph and loss-rate parameter values for rainfall-runoff models using Geographic Information System (GIS) procedures. The data base includes basin, soil, and climatological characteristics that will be stored in a GIS, and unit-hydrograph and loss-rate parameters obtained from calibration of a...

No abstract available

No abstract available