Geology topics

R. B. Zelt

Publications and source records attributed to R. B. Zelt.

5 recordsLinked to original sources

USGS2007

Simulation and mapping of soil-water conditions in the Great Plains

Soil-water conditions provide valuable insight into the hydrologic system in an area. A soil-water balance quantitatively summarizes soil-water conditions and is based on climatic, soil, and vegetation characteristics that vary spatially and temporally. Soil-water balances in the Great Plains of the central United States were simulated for 1951-1980. Results of the simulations were mean annual estimates of infiltration, runoff, actual evapotranspiration, potential recharge, and consumptive water and irrigation requirements at 152 climatic data stations. A method was developed using a geographic information system to integrate and map the simulation results on the basis of spatially variable climatic, soil, and vegetation characteristics. As an example, simulated mean annual potential recharge was mapped. Mean annual potential-recharge rates ranged from less than 0.5 inch in much of the north-central and southwestern Great Plains to more than 10 inches in parts of eastern Texas and southwestern Arkansas.

Water Resources Bulletin↗

USGS1999

Element concentrations in bed sediment of the Yellowstone River basin, Montana, North Dakota, and Wyoming — A retrospective analysis

Chemical data for bed sediment were analyzed as part of the U.S. Geological Survey National Water-Quality Assessment Program investigation of the Yellowstone River Basin in parts of Montana, North Dakota, and Wyoming. The primary data set consisted of about 13,000 samples collected during 1974-79 for the National Uranium Resource Evaluation program. Data were available for 50 elements, although not all samples were analyzed for all elements. Element concentrations varied spatially and were associated with geologic settings or ecoregions. Factor analysis indicated three groups of associated elements: factor 1 elements were strongly correlated with basaltic rocks, factor 2 elements were strongly correlated with granitic rocks, and factor 3 elements were strongly correlated with carbonate rocks. Scores for factor 1 were highest for bed-sediment samples associated with volcanic rocks of Tertiary and Cretaceous age in the Absaroka volcanic field and crystalline rocks of Precambrian age in the Beartooth Mountains. Scores for factor 2 were highest for samples associated with volcanic rocks of Quaternary age on the Yellowstone Plateau, crystalline rocks of Precambrian age, and sedimentary rocks of Tertiary age in the Wyoming Basin ecoregion. Scores for factor 3 were highest in samples associated with sedimentary rocks of Paleozoic age and volcanic rocks of Cretaceous and Tertiary age. Descriptive statistics are presented to serve as a baseline for element concentrations in bed sediment associated with eight geologic settings or ecoregions in the study unit. Some of the concentrations of chromium, copper, lead, nickel, and zinc in bed-sediment samples from areas of crystalline rocks in the Beartooth Mountains and other formations in the western part of the study unit exceeded sediment-quality assessment values associated with toxic effects to aquatic life.

Idaho, Montana, North Dakota, South Dakota, Wyomin↗

USGS1998

Water quality in the central Nebraska basins, Nebraska, 1992-95

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Central Nebraska Basins Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in waterresource management. Indeed, this report addresses many of the concerns raised by regulators, water-utility managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to the USGS during this NAWQA Study-Unit investigation. Yet, the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live.

Nebraska↗

USGS1995

Land-cover sampling designs, data-collection procedures, and land-cover data for the Central Nebraska Basins, 1993-94

Within the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program, land-cover data are used in characterizing drainage areas upstream from surface-water sampling sites and areas selected for spatially distributed ground-water sampling. During the period of time when the initial 20 NAWQA study study-unit investigations were evaluating existing land-cover data, a Prototype 190 Conterminous U.S. land Cover Characteristics Data Set was produced by the Survey's EROS Data Center in Sioux Falls, South Dakota. As part of the Central Nebraska Basins (CNB) study-unit investigation, a method was developed to estimate the areal extent of the principal land-cover types within selected seasonally distinct land-cover (SDLC) regions defined in the 1990 prototype data set. This report describes the sampling designs and methods used to collect land-cover data in the CNB study unit. Data collected at 309 sampling sites during the summers of 1993 and 1994 are presented and statistically summarized. Eleven land-cover categories were quantified, including major field crops and broad noncropland cover types.

Open-File Report↗

USGS1995

Isopachs of Quaternary deposits, Fremont 1- by 2- degree Quadrangle and part of Omaha Quadrangle, Nebraska, digitized from a published 1:250,000-scale geologic map

A geologic map showing the isopachs of Quaternary deposits in the Fremont and part of the Omaha, Nebraska, 1- by 2-degree quadrangles was published at a scale of 1:250,000 in 1975 (Burchett and others, 1975). This report describes the conversion of Quaternary thickness data into a digital geographic data set. A film separation of the published isopachs was scan-digitized and processed to produce digital geographic data. Geographic feature attributes and data-set documentation also are included in the digital data set. The digital data set are formatted for distribution with accordance with the Spatial Data Transfer Standard approved by the U.S. National Institute of Standards and Technology.

Open-File Report↗