Geology topics

Chris D. Wilkowske

Publications and source records attributed to Chris D. Wilkowske.

5 recordsLinked to original sources

USGS2008

Methods for estimating monthly and annual streamflow statistics at ungaged sites in Utah

The monthly 80-, 50-, and 20-percent exceedance streamflows were calculated for 266 streamflow-gaging stations in Utah and the surrounding states. Using geographic information systems software, 24 physiographic and climatic basin characteristics were computed for each gaging station location. Using these data, regional regression equations were created to predict monthly 80-, 50-, and 20-percent streamflow and annual mean streamflow at ungaged sites in Utah. The state of Utah was divided into seven distinct geohydrologic regions on the basis of a variety of physiographic, climatic, and hydrologic characteristics. Separate regression equations were developed for each region except region 3, which was combined with region 5 because of the small number of gaging stations in region 3. Root mean square error percent for the equations ranged from 34 to 379 percent. The equations are more reliable for predicting high-streamflow statistics (20-percent exceedance) than for predicting the low-streamflow statistics (80-percent exceedance). In general, the mean annual streamflow equations had smaller errors than the monthly predicting equations. The developed equations documented in this report will be implemented in StreamStats, a USGS Web-based tool that allows users to obtain a variety of streamflow statistics and basin characteristics by selecting a location on a map interface.

Utah↗

USGS2007

Methods for estimating magnitude and frequency of peak flows for natural streams in Utah

Estimates of the magnitude and frequency of peak streamflows is critical for the safe and cost-effective design of hydraulic structures and stream crossings, and accurate delineation of flood plains. Engineers, planners, resource managers, and scientists need accurate estimates of peak-flow return frequencies for locations on streams with and without streamflow-gaging stations. The 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence-interval flows were estimated for 344 unregulated U.S. Geological Survey streamflow-gaging stations in Utah and nearby in bordering states. These data along with 23 basin and climatic characteristics computed for each station were used to develop regional peak-flow frequency and magnitude regression equations for 7 geohydrologic regions of Utah. These regression equations can be used to estimate the magnitude and frequency of peak flows for natural streams in Utah within the presented range of predictor variables. Uncertainty, presented as the average standard error of prediction, was computed for each developed equation. Equations developed using data from more than 35 gaging stations had standard errors of prediction that ranged from 35 to 108 percent, and errors for equations developed using data from less than 35 gaging stations ranged from 50 to 357 percent.

Utah↗

USGS2004

Seepage study of Mapleton Lateral Canal near Mapleton, Utah, 2003

A study was conducted during the summer of 2003 on Mapleton Lateral Canal near Mapleton, Utah, to determine gain or loss of flow in the canal from seepage. Measurements were made in May, June, July, and September of 2003. The uppermost reach of the canal had an apparent average loss of 2.6 cubic feet per second. The next reach downstream showed an apparent average gain of 1.4 cubic feet per second. The next three downstream reaches had apparent average losses of 2.4, 2.5, and 2.7 cubic feet per second. The apparent average net loss from the canal was 8.8 cubic feet per second, or a loss of 30 percent of the total discharge measured at the head of the canal.

Utah↗

USGS2003

Drought conditions in Utah during 1999-2002: A historical perspective

Utah’s weather is prone to extremes – from severe flooding to multiyear droughts. Five major floods occurred during 1952, 1965, 1966, 1983, and 1984, and six multiyear droughts occurred during 1896-1905, 1930-36, 1953-65, 1974-78 (U.S. Geological Survey, 1991), and more recently during 1988-93 and 1999-2002. The areal extent of floods generally is limited in size from one to several watersheds, whereas droughts generally affect most or all of the state. Southern Utah, in particular the Virgin River drainage basin, began experiencing drought conditions during the winter of 1998-99. By 2000, drought conditions were evident throughout all of Utah. The current drought (1999-2002) is comparable in length and magnitude to previous droughts; however, with population growth and increased demand for water in Utah, the general effect is more severe. During 2002, the fourth straight year of nearly statewide drought conditions, some areas of Utah experienced record-low streamflows. Several record-low streamflows occurred in streams with records dating back to the 1900s. The U.S. Geological Survey (USGS) uses streamflow data from eight long-term streamflow-gaging stations for comparison of hydrologic conditions in Utah (fig. 1).

Utah↗

USGS2001

Selected hydrologic data for the field demonstration of three permeable reactive barriers near Fry Canyon, Utah, 1996-2000

Three permeable reactive barriers (PRBs) were installed near Fry Canyon, Utah, in August 1997 to demonstrate the use of PRBs to control the migration of uranium in ground water. Reactive material included (1) bone-char phosphate, (2) zero-valent iron pellets, and (3) amorphous ferric oxyhydroxide coated gravel. An extensive monitoring network was installed in and around each PRB for collection of water samples, analysis of selected water-quality parameters, and monitoring of water levels. Water temperature, specific conductance, pH, Eh (oxidation-reduction potential), and dissolved oxygen were measured continuously within three different barrier materials, and in two monitoring wells. Water temperature and water level below land surface were electronically recorded every hour with pressure transducers. Data were collected from ground-water monitoring wells installed in and around the PRBs during 1996-98 and from surface-water sites in Fry Creek.

Utah↗