Digital flood-inundation polygon shapefiles for an 8.8-mile reach of the North Platte River, from 1.5 miles upstream of the Highway 92 bridge to 3 miles downstream of the Highway 71 bridge, were created by the U.S. Geological Survey (USGS) in cooperation with the Cities of Scottsbluff and Gering. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science website at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Platte River at Scottsbluff, Nebr. (station 06680500). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at https://doi.org/10.5066/F7P55KJN or from the National Weather Service Advanced Hydrologic Prediction Service (site SBRN1) at https://water.weather.gov/ahps2/.
Flood profiles were computed for the stream reach by means of a ...

The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 104 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The Republican River Basin is about 25,000 square miles and is located in northeast Colorado, northern Kansas, and southwest Nebraska. The Republican River Basin overlies the High Plains aquifer for 87 percent of the basin area. This dataset consists of a raster of water-level changes for the High Plains aquifer, in the Republican River Basin, 2002 to 2015. This digital dataset was created using water-level measurements from (1) 977 wells, which are located in the Republican River Basin, and (2) 546 wells, which are located within 20 miles outside the boundary of the Republican River Basin. These 1,523 wells were measured in both 2002 and in 2015. The map was reviewed for consistency with the relevant data at a scale of 1:1,000,000.

The base flow recession time constant (tau) is a hydrologic index that characterizes the ability of a ground-water system to supply flow to a stream draining from that system. Tau and other correlated hydrologic indices have been used as explanatory variables to greatly improve the predictive power of low-flow regression equations. Tau can also be used as an indicator of streamflow dependence on groundwater inflow to the channel. Tau values were calculated for 10 streamgages in the Niobrara National Scenic River study area. The calculated tau values were then used to create a kriged map. Kriging is a geostatistical method that can be used to determine optimal weights for measurements at sampled locations (streamgages) for the estimation of values at unsampled locations (ungaged sites). The kriged tau map could be used (1) as the basis for identifying areas with different hydrologic responsiveness, with differing potential to demonstrate the effects of management changes and (2) in the development of regional low-flow regression equations. The Geostatistical Analyst tools in ArcGIS Pro version 2.5.2 (Environmental Systems Research Institute, 2012) were used to create the kriged tau map and perform cross validation to determine the root mean square error (RMSE) of the tau map.

The Digital Geologic-GIS Map of Niobrara National Scenic River and Vicinity, Nebraska is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) an ESRI file geodatabase (niob_geology.gdb), a 2.) Open Geospatial Consortium (OGC) geopackage, and 3.) 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. The file geodatabase format is supported with a 1.) ArcGIS Pro map file (.mapx) file (niob_geology.mapx) and individual Pro layer (.lyrx) files (for each GIS data layer). The OGC geopackage is supported with a QGIS project (.qgz) file. Upon request, the GIS data is also available in ESRI shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) a readme file (niob_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (niob_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (niob_geology_metadata_faq.pdf). Please read the niob_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. Google Earth software is available for free at: https://www.google.com/earth/versions/. QGIS software is available for free at: https://www.qgis.org/en/site/. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri.htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (niob_geology_metadata.txt or niob_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:100,000 and United States National Map Accuracy Standards features are within (horizontally) 50.8 meters or 166.7 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in Google Earth, ArcGIS Pro, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

This digital spatial data set consists of the aquifer base elevation contours (50-foot contour interval) for part of the High Plains aquifer in the central United States. This subset of the High Plains aquifer covers the Republican River Basin in Nebraska, Kansas, and Colorado upstream from the streamflow station on the Republican River near Hardy, Nebraska, near the Kansas/Nebraska border. In Nebraska, the digitized contours extend to the South Platte, Platte, and Little Blue Rivers. In Colorado and Kansas, the digital contours extend to the edge of the High Plains aquifer. These boundaries were chosen to simplify boundary conditions for a computer simulation model being used for a hydrologic study of the Republican River Basin.

description: This map is showing the designated national recreation river segments on the Niobrara River, Missouri River and Verdigre Creek in Nebraska and border of South Dakota.; abstract: This map is showing the designated national recreation river segments on the Niobrara River, Missouri River and Verdigre Creek in Nebraska and border of South Dakota.

This is a compilation of test FIM maps made from a model we received from USACE (ERDC) of the North Platte River. Please don't use this data except for testing purposes.

Geologic mapping, in support of the USGS Omaha-Kansas City Geologic Mapping Project, shows the spatial distribution of artificial-fill, alluvial, eolian, and glacial deposits and bedrock in and near Omaha, Nebraska. Artificial fill deposits are mapped chiefly beneath commercial structures, segments of interstate highways and other major highways, railroad tracks, airport runways, and military facilities, and in landfills and earth fills. Alluvial deposits are mapped beneath flood plains, in stream terraces, and on hill slopes. They include flood-plain and stream-channel alluvium, sheetwash alluvium, and undivided sheetwash alluvium and stream alluvium. Wind-deposited loess forms sheets that mantle inter-stream areas and late Wisconsin terrace alluvium. Peoria Loess is younger of the two loess sheets and covers much of the inter-stream area in the map area. Loveland Loess is older and is exposed in a few small areas in the eastern part of the map area. Glacial deposits are chiefly heterogeneous, ice-deposited, clayey material (till) and minor interstratified stream-deposited sand and gravel. Except for small outcrops, glacial deposits are covered by eolian and alluvial deposits throughout most of the map area. Bedrock is locally exposed in natural exposures along the major streams and in quarries. It consists of Dakota Sandstone and chiefly limestone and shale of the Lansing and Kansas City Groups. Sand and gravel in flood plain and stream-channel alluvium in the Platte River valley are used mainly for concrete aggregate. Limestone of the Lansing and Kansas City Groups is used for road-surfacing material, rip rap, and fill material.

This resource is a repository of the map products for the Annual Irrigation Maps - Republican River Basin (AIM-RRB) dataset produced in Deines et al. 2017. It also provides the training and test point datasets used in the development and evaluation of the classifier algorithm. The maps cover a 141,603 km2 area in the northern High Plains Aquifer in the United States centered on the Republican River Basin, which overlies portions of Colorado, Kansas, and Nebraska. AIM-RRB provides annual irrigation maps for 18 years (1999-2016). Please see Deines et al. 2017 for full details.

Preferred citation: Deines, J.M., A.D. Kendall, and D.W. Hyndman. 2017. Annual irrigation dynamics in the US Northern High Plains derived from Landsat satellite data. Geophysical Research Letters. DOI: 10.1002/2017GL074071

Map Metadata Map products are projected in EPSG:5070 - CONUS Albers NAD83 Raster value key: 0 = Not irrigated 1 = Irrigated 254 = NoData, masked by urban, water, forest, or wetland land used based on the National Land Cover Dataset (NLCD) 255 = NoData, outside of study boundary

Training and test point data sets supply coordinates in latitude/longitude (WGS84). Column descriptions for each file can be found below in the "File Metadata" tab when the respective file is selected in the content window.

Corresponding author: Jillian Deines, jillian.deines@gmail.com

As part of the U.S. Geological Survey's (USGS) National Water-Quality Assessment Program (NAWQA), an investigation of the Missouri River Basin is being conducted to document trends in surface-water quality, specifically for trends in nutrients and suspended sediment. Surface-water samples were collected from streams at specific sampling stations. Water-quality characteristics at each station are influenced by the natural and cultural characteristics of the drainage area upstream from the sampling station. Efficient quantification of the drainage area characteristics requires a digital map of the drainage area boundary that may be processed, together with other digital thematic maps (such as geology or land use), in a geographic information system (GIS). Digital drainage-area boundary data for one stream-sampling station in the Missouri River Basin (MRB4) study area is included in this data release. The drainage divides were identified chiefly using 1:24,000-scale hypsography.

This geologic map area of 5,430 km2 spans a reach of the lower Missouri River valley and adjoining uplands for about 100 kilometers east of Gavins Point Dam, the easternmost mainstem dam on the Missouri River. Understanding the surficial geologic history of the valley is relevant to natural resource management of the Missouri National Recreational River and is foundational to improved understanding of hydrology and ecology. This geodatabase is a synthesis of recent FEDMAP, EDMAP, and STATEMAP work of the National Cooperative Geologic Mapping Program with previously published maps of the geologic surveys of South Dakota, Nebraska, Iowa, and the USGS. Other data sources utilized for this map include NAIP ortho-imagery (especially for the modern river system), a photogrammetrically-produced DEM of the Missouri River Valley, and NRCS Soil Survey data. Mapping herein is based on geomorphic and other surficial characteristics as well as sedimentary and stratigraphic characteristics from exposures and borehole data. Quaternary glacial and nonglacial deposits up to 100 meters thick predominate the surface geology. Cretaceous sedimentary bedrock (largely from a former marine interior seaway) forms relatively limited exposures along valley margins of the uplands and underlies all Quaternary deposits of the map area. Assemblages of Quaternary map units and associated landscapes vary markedly between three sectors in the map area: 1) the Missouri River valley proper, 2) late Pleistocene glacial deposits of South Dakota uplands, and 3) dissected uplands in northern Nebraska, western Iowa, and southeast South Dakota. The Missouri River valley is predominantly covered by postglacial fluvial deposits overlying glaciofluvial sediments that dominate the lower part of the valley fill. The western 70 percent of the South Dakota uplands in the map area are primarily late Wisconsinan glacial deposits of the James lobe Lobe of the Laurentide Ice sheet. The remainder of the uplands, including all uplands south of the Missouri River Valley, are mantled with a discontinuous to locally thick and continuous late Quaternary loess over pre-Wisconsinan glacial and nonglacial deposits; these uplands are dissected by a surficial valley network pattern with a predominantly northwesterly orientation. The northeast side of the Missouri River valley is dominated by backswamp mud, in contrast to the southwest side, which is dominated by point bar sand and other fluvial facies deposited in proximal association with past positions of the laterally migrating Missouri River channel. Postglacial aggradation of at least 7 meters has largely buried the earlier valley fill (about 20-25 meters thick) of Pleistocene outwash composed of gravelly sand. The oldest known abandoned river meanders with surficial expression are late Holocene. About 15% of the valley floor was reworked by lateral migration of the Missouri River between ca. 1892 and 1941 during a period of decreasing channel sinuosity. After construction of the large Missouri River dams (mostly during the 1950s), a decrease in sediment load transformed the river to an incising regime that generally does not supply overbank sediment to the valley floor, in contrast to the paleo-environments indicated from the geologic record.

These data are the survey results from a five-mile section of the Platte River at, and upstream of the Nebraska Army National Guard Camp Ashland Training Site including the side channel chutes on the east bank. All survey data were collected along planned transect lines that were spaced 492.125 US survey feet apart beginning near the mouth of the Elkhorn River and ending near the U.S. Highway 6 bridge. An effort was made to get complete elevation data for each transect from top of bank to top of bank. Survey grade Global Navigation and Satellite Systems (GNSS) receiving antennas connected to a real time network (RTK high precision network https://hprtk.net) were used to measure elevation along the transects, at the top of banks, along the slope of the banks, at control structures, on islands and sandbars and on the streambed in areas of the wetted channel that were wadable. GNSS data collection methods followed level 3, RTN procedures as described by (Rydlund and Densmore, 2012). An acoustic Doppler current profiler (ADCP) was used to measure streambed elevation in areas of the wetted channel that were not wadable. ADCP data were processed using Velocity Mapping Toolbox (Parsons and others, 2013) to convert measured depths to elevation. This data release contains two comma separated value files. The CSV file named PlatteRiver_GNSS_SurveyData_20200924-20210402.csv contains the GNSS survey data. The CSV file named Bathy_ADCP_final_data_SPCS.csv contains bathymetric survey data.

The Pine Ridge in northwestern Nebraska is the only area with evidence of a resident reproducing population. The Nebraska Game and Parks Commission documented the first instance of reproduction here in 2007 when a kitten was photographed with a female for the first time. The Pine Ridge is the largest area of suitable habitat in Nebraska with the beautiful buttes, cliffs, canyons and forests creating prefect habitat for mountain lions. Other areas like the Niobrara River Valley and Wildcat Hills have excellent habitat and many confirmations of mountain lions but lack proof of reproduction at the present time.

This dataset contains base-flow recession time constant (tau) contours that are interpreted from tau values calculated at streamgages in the Niobrara National Scenic River study area. The contours were created by interpolating the calculated tau values using geostatistical kriging methods. Kriging is a geostatistical method that can be used to determine optimal weights for measurements at sampled locations (streamgages) for the estimation of values at unsampled locations (ungaged sites). The kriged tau map could be used (1) as the basis for identifying areas with different hydrologic responsiveness, and (2) in the development of regional low-flow regression equations. The Geostatistical Analyst tools in ArcGIS Pro version 2.5.2 (Environmental Systems Research Institute, 2012) were used to create the kriged tau map and perform cross validation to determine the root mean square error (RMSE) of the tau map. The results of the kriging were then exported from ArcGIS to contours.

These data are high-resolution bathymetry (riverbed elevation) and depth-averaged velocities in ASCII format, generated from hydrographic and velocimetric surveys of the Missouri River near structure L0098 on U.S. Highway 136 at Brownville, Nebraska, in 2011, 2014, and 2018. Hydrographic data were collected using a high-resolution multibeam echosounder mapping system (MBMS), which consists of a multibeam echosounder (MBES) and an inertial navigation system (INS) mounted on a marine survey vessel. Data were collected as the vessel traversed the river along planned survey lines distributed throughout the reach. Data collection software integrated and stored the depth data from the MBES and the horizontal and vertical position and attitude data of the vessel from the INS in real time. Data processing required computer software to extract bathymetry data from the raw data files and to summarize and map the information. Velocity data were collected using an acoustic Doppler current profiler (ADCP) mounted on a survey vessel equipped with a differential global positioning system (DGPS). Data were collected as the vessel traversed the river along planned transect lines distributed throughout the reach. Velocity data were processed using the Velocity Mapping Toolbox (Parsons and others, 2013), and smoothed using neighboring nodes.

The 2005 Kansas Land Cover Patterns (KLCP) Mapping Initiative was a two-phase mapping endeavor that occurred over a three-year period (2007-2009). Note that while the processing occurred during the 2207-2009 period, all satellite data used in the project was acquired in 2005. Concurrent with mapping the state of Kansas, the Kansas River Watershed was also mapped. The Kansas River Watershed extends into southern Nebraska and includes a portion of eastern Colorado. During Phase I a Modified Level I map was produced. In Phase II a series of maps, Modified Level II through IV, were produced. All KLCP 2005 map products were produced at four spatial extents: the state of Kansas plus a 300 meter buffer, a DEM-derived watershed boundary of the Kansas River, the Kansas River watershed boundary plus a 1,000 meter buffer, and a combined dataset of the state of Kansas plus 300 meter buffer and the watershed plus 1,000 meter buffer.These extents are annotated in the file names with the extentions k, w, wb, and kwb respectively. The goal of Phase II was to map subclasses for grassland and cropland, classes which were mapped during Phase I. For the Level II map, cool- and warm-season grasslands were mapped along with Spring Crop, Summer Crop, Alfalfa, Fallow, and Double-Crop classes. For the Level III map, the Summer Crop subclasses Corn, Soybean, and Sorghum were mapped, and the Spring Crop class was reassigned to Winter Wheat. In the Level IV map, irrigation status was mapped and added to the Level III crop type map.The Kansas Land Cover Patterns Level IV map contains twenty-four land use/land cover classes and has a positional accuracy and spatial resolution appropriate for producing 1:50,000 scale maps. The minimum map unit (MMU) varies by land cover class and ranges from 0.22 to 5.12 acres. In general, the mapping methodology used a hybrid, hierarchical classification of multi-temporal, multi-resolution imagery to develop modified Anderson Level II through Anderson Level IV land cover maps of the Kansas River Watershed and the State of Kansas. More specifically, multi-seasonal Landsat Thematic Mapper (TM) imagery from the 2004 and 2005 growing season was used to map the grassland subclasses (cool- and warm-season grasslands). while MODIS NDVI time-series imagery from the 2005 growing season was used to map cropland subclasses. The land use/land cover classes in the Level IV map are coded hierarchically to allow aggregation of land use and land cover classes as needed by the end-user. For example, a user can aggregate the Level IV map classes to a Level III classification by ignoring or eliminating the last digit of each land use/land cover class. Likewise, a Level II and Level I map can be created from the Level IV map by eliminating the last two and three digits, respectively, from each Level IV land use/land cover class. A formal accuracy assessment found the Level II, Level III, and Level IV maps to have overall accuracy levels of 86.3%, 82.0%, and 74.3%, respectively. User and Producer (per-class errors of commission and omission) accuracies vary by land cover class and users are encouraged to reference the reported accuracy levels in the final report and/or metadata when using the Kansas Land Cover Patterns map series. Digital versions of the map, metadata, and accuracy assessment can be accessed from the Data Access Support Center (http://www.kansasgis.org/) or the Kansas Applied Remote Sensing Program (http://www.kars.ku.edu/).

The Digital Geologic-GIS Map of the 39-Mile Reach of Missouri National Recreational River and Vicinity, Nebraska and South Dakota is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) a 10.1 file geodatabase (mrtn_geology.gdb), a 2.) Open Geospatial Consortium (OGC) geopackage, and 3.) 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. The file geodatabase format is supported with a 1.) ArcGIS Pro map file (.mapx) file (mrtn_geology.mapx) and individual Pro layer (.lyrx) files (for each GIS data layer), as well as with a 2.) 10.1 ArcMap (.mxd) map document (mrtn_geology.mxd) and individual 10.1 layer (.lyr) files (for each GIS data layer). The OGC geopackage is supported with a QGIS project (.qgz) file. Upon request, the GIS data is also available in ESRI 10.1 shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) A GIS readme file (mnrr_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (mrtn_mapinfo.xlsx) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (mrtn_geology_metadata_faq.pdf). Please read the mnrr_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. Google Earth software is available for free at: https://www.google.com/earth/versions/. QGIS software is available for free at: https://www.qgis.org/en/site/. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri,htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: University of Nebraska-Lincoln. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (mrtn_geology_metadata.txt or mrtn_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in Google Earth, ArcGIS, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

description: In 2006, a cooperative study was established to compile reliable data describing groundwater and surface-water interactions in the Elkhorn and Loup River Basins. The purpose of the study was to address state legislation that requires a sustainable balance between long term water supplies and uses of surface water and groundwater. A groundwater-flow model [hereinafter referred to as the Elkhorn-Loup Model (ELM)] was constructed as part of the first two phases of that study as a tool for understanding the effect of groundwater pumpage on stream base flow and the effects of management strategies on hydrologically connected groundwater and surface-water supplies. The third phase of the study was implemented to gain additional geologic knowledge and update the ELM with enhanced water-budget information and refined discretization of the model grid and stress periods. As part of that effort, the ELM is being reconstructed to include two vertical model layers, whereas phase-one and phase-two simulations (Peterson and others, 2008; Stanton and others, 2010) represented the aquifer system using one vertical model layer. The goal for defining the base of the upper model layer was to divide the model vertically so that the upper layer could have different water transmitting and storage characteristics than the lower layer. Texture descriptions were used in most cases to identify the depth in a test-hole, water-well, or surface-geophysical log at which dividing the aquifer produced contrasting texture characteristics for the upper and lower model layers. The study area covers approximately 30,000 square miles, and extends from the Niobrara River in the north to the Platte River in the south. The western boundary roughly coincides with the western boundary of the Upper Loup NRD, and the eastern boundary roughly coincides with the approximate location of the westernmost extent of glacial till in eastern Nebraska (University of Nebraska, 2005). This data release consists of a point shapefile attributed with values representing the elevation of the base of the upper layer of the two-layer phase-three Elkhorn-Loup Model (ELM) above the vertical datum (National Geodetic Vertical Datum of 1929).; abstract: In 2006, a cooperative study was established to compile reliable data describing groundwater and surface-water interactions in the Elkhorn and Loup River Basins. The purpose of the study was to address state legislation that requires a sustainable balance between long term water supplies and uses of surface water and groundwater. A groundwater-flow model [hereinafter referred to as the Elkhorn-Loup Model (ELM)] was constructed as part of the first two phases of that study as a tool for understanding the effect of groundwater pumpage on stream base flow and the effects of management strategies on hydrologically connected groundwater and surface-water supplies. The third phase of the study was implemented to gain additional geologic knowledge and update the ELM with enhanced water-budget information and refined discretization of the model grid and stress periods. As part of that effort, the ELM is being reconstructed to include two vertical model layers, whereas phase-one and phase-two simulations (Peterson and others, 2008; Stanton and others, 2010) represented the aquifer system using one vertical model layer. The goal for defining the base of the upper model layer was to divide the model vertically so that the upper layer could have different water transmitting and storage characteristics than the lower layer. Texture descriptions were used in most cases to identify the depth in a test-hole, water-well, or surface-geophysical log at which dividing the aquifer produced contrasting texture characteristics for the upper and lower model layers. The study area covers approximately 30,000 square miles, and extends from the Niobrara River in the north to the Platte River in the south. The western boundary roughly coincides with the western boundary of the Upper Loup NRD, and the eastern boundary roughly coincides with the approximate location of the westernmost extent of glacial till in eastern Nebraska (University of Nebraska, 2005). This data release consists of a point shapefile attributed with values representing the elevation of the base of the upper layer of the two-layer phase-three Elkhorn-Loup Model (ELM) above the vertical datum (National Geodetic Vertical Datum of 1929).

description: The U.S. Geological Survey and its partners have collaborated to complete airborne geophysical surveys for areas of the North and South Platte River valleys and Lodgepole Creek in western Nebraska. The objective of the surveys was to map the aquifers and bedrock topography of selected areas to help improve the understanding of groundwater-surface-water relationships to be used in water management decisions. Frequency-domain (2008 and 2009) and time-domain (2010) helicopter electromagnetic surveys were completed, using a unique survey flight line design, to collect resistivity data that can be related to lithologic information for refinement of groundwater model inputs. To make the geophysical data useful for multidimensional groundwater models, numerical inversion is necessary to convert the measured data into a depth-dependent subsurface resistivity model. This inversion model, in conjunction with sensitivity analysis, geological ground truth (boreholes), and geological interpretation, is used to characterize hydrogeologic features. The two- and three- dimensional interpretation provides the groundwater modeler with a high-resolution hydrogeologic framework and a quantitative estimate of framework uncertainty. This method of creating hydrogeologic frameworks improved the understanding of the actual flow path orientation by redefining the location of the paleochannels and associated bedrock highs. The improved models represent the hydrogeology at a level of accuracy not achievable using previous data sets.; abstract: The U.S. Geological Survey and its partners have collaborated to complete airborne geophysical surveys for areas of the North and South Platte River valleys and Lodgepole Creek in western Nebraska. The objective of the surveys was to map the aquifers and bedrock topography of selected areas to help improve the understanding of groundwater-surface-water relationships to be used in water management decisions. Frequency-domain (2008 and 2009) and time-domain (2010) helicopter electromagnetic surveys were completed, using a unique survey flight line design, to collect resistivity data that can be related to lithologic information for refinement of groundwater model inputs. To make the geophysical data useful for multidimensional groundwater models, numerical inversion is necessary to convert the measured data into a depth-dependent subsurface resistivity model. This inversion model, in conjunction with sensitivity analysis, geological ground truth (boreholes), and geological interpretation, is used to characterize hydrogeologic features. The two- and three- dimensional interpretation provides the groundwater modeler with a high-resolution hydrogeologic framework and a quantitative estimate of framework uncertainty. This method of creating hydrogeologic frameworks improved the understanding of the actual flow path orientation by redefining the location of the paleochannels and associated bedrock highs. The improved models represent the hydrogeology at a level of accuracy not achievable using previous data sets.

description: The U.S. Geological Survey (USGS), in collaboration with the Platte River Recovery and Implementation Program, collected capacitively coupled (CC) resistivity data and six direct push sediment cores to identify the coarsest alluvial deposits underlying the Morse properties in central Nebraska to supplement the subsurface geologic information, for the purposes of proper siting of intentional recharge structures, and to improve current understanding of groundwater movement. The subsurface geology is described in three different data sets in varied file formats. First, for the direct-push cores, data are given as detailed descriptions of core lithology and texture and are provided in Comma Separated Values (CSV) file format. Second, the inverted CC-resistivity profiles collected are displayed using standardized color ramps and vertically exaggerated scales. Direct-push sediment cores are displayed near each profile and the lithology is described using the Unified Soil Classification System. An index map showing the location of the indicated profile and direct-push sediment cores is provided. The data are provided in pdf file format. Third, the depth-averaged resistivity from the inverted CC-resistivity profiles is provided as an ESRI shapefile.; abstract: The U.S. Geological Survey (USGS), in collaboration with the Platte River Recovery and Implementation Program, collected capacitively coupled (CC) resistivity data and six direct push sediment cores to identify the coarsest alluvial deposits underlying the Morse properties in central Nebraska to supplement the subsurface geologic information, for the purposes of proper siting of intentional recharge structures, and to improve current understanding of groundwater movement. The subsurface geology is described in three different data sets in varied file formats. First, for the direct-push cores, data are given as detailed descriptions of core lithology and texture and are provided in Comma Separated Values (CSV) file format. Second, the inverted CC-resistivity profiles collected are displayed using standardized color ramps and vertically exaggerated scales. Direct-push sediment cores are displayed near each profile and the lithology is described using the Unified Soil Classification System. An index map showing the location of the indicated profile and direct-push sediment cores is provided. The data are provided in pdf file format. Third, the depth-averaged resistivity from the inverted CC-resistivity profiles is provided as an ESRI shapefile.