Geology Reports⌕ Search

Geology topics

Robert C. Buchmiller

Publications and source records attributed to Robert C. Buchmiller.

6 recordsLinked to original sources
USGS2010

Floods of May and June 2008 in Iowa

An unusually wet winter and spring of 2007 to 2008 resulted in extremely wet antecedent conditions throughout most of Iowa. Rainfall of 5 to 15 inches was observed in eastern Iowa during May 2008, and an additional 5 to 15 inches of rain was observed throughout most of Iowa in June. Because of the severity of the May and June 2008 flooding, the U.S. Geological Survey, in cooperation with other Federal, State, and local agencies, has summarized the meteorological and hydrological conditions leading to the flooding, compiled flood-peak stages and discharges, and estimated revised flood probabilities for 62 selected streamgages. Record peak discharges or flood probabilities of 1 percent or smaller (100-year flooding or greater) occurred at more than 60 streamgage locations, particularly in eastern Iowa. Cedar Rapids, Decorah, Des Moines, Iowa City, Mason City, and Waterloo were among the larger urban areas affected by this flooding. High water and flooding in small, headwater streams in north-central and eastern Iowa, particularly in June, combined and accumulated in large, mainstem rivers and resulted in flooding of historic proportions in the Cedar and Iowa Rivers. Previous flood-peak discharges at many locations were exceeded by substantial amounts, in some cases nearly doubling the previous record peak discharge at locations where more than 100 years of streamflow record are available.

Open-File Report↗
USGS2007

Screening of ground water samples for volatile organic compounds using a portable gas chromatograph

A portable gas chromatograph was used to screen 32 ground water samples for volatile organic compounds. Seven screened samples were positive; four of the seven samples had volatile organic substances identified by second-column confirmation. Four of the seven positive, screened samples also tested positive in laboratory analyses of duplicate samples. No volatile organic compounds were detected in laboratory analyses of samples that headspace screening indicated to be negative. Samples that contained volatile organic compounds, as identified by laboratory analysis, and that contained a volatile organic compound present in a standard of selected compounds were correctly identified by using the portable gas chromatograph. Comparisons of screened-sample data with laboratory data indicate the ability to detect selected volatile organic compounds at concentrations of about 1 microgram per liter in the headspace of water samples by use of a portable gas chromatograph.

Ground Water Monitoring Review↗
USGS2004

Simulation of ground-water flow in the Cedar River alluvial aquifer flow system, Cedar Rapids, Iowa

The Cedar River alluvial aquifer is the primary source of municipal water in the Cedar Rapids, Iowa, area. Since 1992, the U.S. Geological Survey, in cooperation with the City of Cedar Rapids, has investigated the hydrogeology and water quality of the Cedar River alluvial aquifer. This report describes a detailed analysis of the ground-water flow system in the alluvial aquifer, particularly near well field areas. The ground-water flow system in the Cedar Rapids area consists of two main components, the unconsolidated Quaternary deposits and the underlying carbonate bedrock that has a variable fracture density. Quaternary deposits consist of eolian sand, loess, alluvium, and glacial till. Devonian and Silurian bedrock aquifers overlie the Maquoketa Shale (Formation) of Ordovician age, a regional confining unit. Ground-water and surface-water data were collected during the study to better define the hydrogeology of the Cedar River alluvial aquifer and Devonian and Silurian aquifers. Stream stage and discharge, ground-water levels, and estimates of aquifer hydraulic properties were used to develop a conceptual ground-water flow model and to construct and calibrate a model of the flow system. This model was used to quantify the movement of water between the various components of the aluvial aquifer flow system and provide an improved understanding of the hydrology of the alluvial aquifer. Ground-water flow was simulated for the Cedar River alluvial aquifer and the Devonian and Silurian aquifers using the three-dimensional finite-difference ground-water flow model MODFLOW. The model was discretized into 223 rows and 354 columns of cells. Areal cell sizes range from about 50 feet on a side near the Cedar River and the Cedar Rapids municipal wells to 1,500 feet on a side near the model boundaries and farthest away from the Cedar Rapids municipal well fields. The model is separated into five layers to account for the various hydrogeologic units in the model area. Model results indicate that the primary sources of inflow to the modeled area are infiltration from the Cedar River (53.0 percent) and regional flow in the glacial and bedrock materials (34.1 percent). The primary sources of outflow from the modeled area are discharge to the Cedar River (45.4 percent) and pumpage (44.8 percent). Current steady-state pumping rates have increased the flow of water from the Cedar River to the alluvial aquifer by 43.8 cubic feet per second. Steady-state and transient hypothetical pumpage scenarios were used to show the relation between changes in pumpage and changes in infiltration of water from the Cedar River. Results indicate that more than 99 percent of the water discharging from municipal wells infiltrates from the Cedar River, that the time required for induced river recharge to equilibrate with municipal pumpage may be 150 days or more, and that ground-water availability in the Cedar Rapids area will not be significantly affected by doubling current pumpage as long as there is sufficient flow in the Cedar River to provide recharge.

Iowa↗
USGS2001

Ground water near Newton, Jasper County, Iowa

The U.S. Geological Survey, in cooperation with the city of Newton, Iowa, conducted an investigation of the ground-water resources of Jasper County, Iowa, near Newton during 1999-2001. The purpose of the investigation was to provide additional information on the South Skunk River alluvial aquifer from which Newton obtains its present municipal supply and to summarize the available information on other groundwater resources in the county. The South Skunk River alluvial aquifer consists of unconsolidated deposits of sand and gravel of glacial and fluvial origin. These deposits overlie bedrock composed primarily of shale and limestone of Pennsylvanian or Mississippian age. Information on the South Skunk River alluvial aquifer and other Jasper County alluvial aquifers is limited to a few test holes in a few locations. Additional thickness and lithologic information was collected using seismic refraction and test hole drilling to increase the understanding of the South Skunk River alluvial aquifer near Newton. Water-level and water-quality information also was collected. The alluvial deposits along the South Skunk River near Newton range from less than 30 to more than 60 feet thick. Three areas of deposits exceeding 60 feet thick occur near the present city of Newton well field about 5,000 feet west of the present well field, at the present well field, and about 5,000 feet southeast of the present well field. Ground water in the South Skunk River alluvial aquifer near the Newton well field flows toward the municipal well field. Ground-water levels on the well-field side of the South Skunk River were lower than water levels in the river, indicating flow from the river toward the well field. The water quality in the South Skunk River and the alluvial aquifer was similar, except most ground-water samples contained low dissolved oxygen concentrations. The low dissolved-oxygen concentrations in ground water resulted in high concentrations of iron and manganese in some locations and reduced forms of nitrogen.

Iowa↗
USGS2000

Volumes of recent floods and potential for storage in upland watershed areas of Iowa

Substantial flooding at various locations throughout the United States, particularly during and after the Upper Mississippi River Basin flood of 1993, has resulted in analysis and discussion of both structural and nonstructural methods of watershed management to control flooding. The Upper Mississippi River Basin flood of 1993 resulted in the formulation of a Scientific Assessment and Strategy Team (SAST) to assist and advise decision makers about the positive and negative effects of flood-control measures and habitat restoration (Scientific Assessment and Strategy Team, 1994). SAST recognized the role of upland processes and the interconnectivity of a management strategy on other parts of the river system. If upland areas are considered for inclusion in an overall management strategy related to flooding, an analysis of watershed that have been flooded and the amount of runoff generated during those floods is needed. During the autumn of 1997, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, began a study to determine the volume of water associated with recent flood events in parts of the Midwestern United States and a preliminary evaluation of the potential upland areas for storage of flood-waters in selected watersheds. This analysis, although preliminary, may be useful in determining the feasibility of conducting additional, more detailed studies into the role of upland areas in a watershed management strategy. The methods and results of this preliminary hydrologic study are presented in this report.

Iowa↗