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At least 163 records · Page 9Linked to original sources
USGS1983

Slides showing quantitative models for mineral-resource assessment of the Rolla 1 degree x 2 degrees Quadrangle, Missouri

Th.is report consists of nineteen 35-mm color slides sh.owing digital synthesis and quantitative modeling of five geologic recognition criteria for assessment of Mississippi Valley-type resource potential in the Rolla 1° x 2° quadrangle, Missouri. The digital synthesis and quantitative modeling (Pratt and others, 1982) was done to supplement an earlier manual synthesis and evaluation (Pratt, 1981). The five criteria synthesized in this study, and the sources of data used, are that most known deposits are: In dolomite of the Bonneterre Formation, near the limestone-dolomite interface, which is defined as ls:dol = 1:16 (Thacker and Anderson, 1979; Kisvarsanyi, 1982); Near areas where insoluble residues of "barren" Bonneterre Formation contain anomalously high amounts of base metals (Erickson and others, 1978); Near areas of faults and fractures in the Bonneterre Formation or in underlying rocks (Pratt, 1982); In "brown rock" (finely crystalline brown dolomite) near the interface with "white rock" (coarsely recrystallized, white or very light gray, vuggy, illite-bearing dolomite) (Kisvarsanyi, 1982); Near or within favorably situated digitate reef-complex facies (Kisvarsanyi , 1982).

Open-File Report↗
USGS2014

Monitoring of levees, bridges, pipelines, and other critical infrastructure during the 2011 flooding in the Mississippi River Basin

During the 2011 Mississippi River Basin flood, the U.S. Geological Survey evaluated aspects of critical river infrastructure at the request of and in support of local, State, and Federal Agencies. Geotechnical and hydrographic data collected by the U.S. Geological Survey at numerous locations were able to provide needed information about 2011 flood effects to those managing the critical infrastructure. These data were collected and processed in a short time frame to provide managers the ability to make a timely evaluation of the safety of the infrastructure and, when needed, to take action to secure and protect critical infrastructure. Critical infrastructure surveyed by the U.S. Geological Survey included levees, bridges, pipeline crossings, power plant intakes and outlets, and an electrical transmission tower. Capacitively coupled resistivity data collected along the flood-protection levees surrounding the Omaha Public Power District Nebraska City power plant (Missouri River Levee Unit R573), mapped the near-subsurface electrical properties of the levee and the materials immediately below it. The near-subsurface maps provided a better understanding of the levee construction and the nature of the lithology beneath the levee. Comparison of the capacitively coupled resistivity surveys and soil borings indicated that low-resistivity value material composing the levee generally is associated with lean clay and silt to about 2 to 4 meters below the surface, overlying a more resistive layer associated with sand deposits. In general, the resistivity structure becomes more resistive to the south and the southern survey sections correlate well with the borehole data that indicate thinner clay and silt at the surface and thicker sand sequences at depth in these sections. With the resistivity data Omaha Public Power District could focus monitoring efforts on areas with higher resistivity values (coarser-grained deposits or more loosely compacted section), which typically are more prone to erosion or scour. Data collected from multibeam echosounder hydrographic surveys at selected bridges aided State agencies in evaluating the structural integrity of the bridges during the flood, by assessing the amount of scour present around piers and abutments. Hydrographic surveys of the riverbed detected scour depths ranging from zero (no scour) to approximately 5.8 meters in some areas adjacent to North Dakota bridge piers, zero to approximately 6 meters near bridge piers in Nebraska, and zero to approximately 10.4 meters near bridge piers in Missouri. Substructural support elements of some bridge piers in North Dakota, Nebraska, and Missouri that usually are buried were exposed to moving water and sediment. At five Missouri bridge piers the depth of scour left less than 1.8 meters of bed material between the bottom of the scour hole and bedrock. State agencies used this information along with bridge design and construction information to determine if reported scour depths would have a substantial effect on the stability of the structure. Multibeam echosounder hydrographic surveys of the riverbed near pipeline crossings did not detect exposed pipelines. However, analysis of the USGS survey data by pipeline companies aided in their evaluation of pipeline safety and led one company to further investigate the safety of their line and assisted another company in getting one offline pipeline back into operation. Multibeam echosounder hydrographic surveys of the banks, riverbed, and underwater infrastructure at Omaha Public Power District power plants documented the bed and scour conditions. These datasets were used by Omaha Public Power District to evaluate the effects that the flood had on operation, specifically to evaluate if scour during the peak of the flood or sediment deposition during the flood recession would affect the water intake structures. Hydrographic surveys at an Omaha Public Power District electrical transmission tower documented scour so that they could evaluate the structural integrity of the tower as well as have the information needed to make proper repairs after flood waters receded.

Missouri River Basin, Mississippi River Basin↗
USGS2010

Age, genesis, and paleoclimatic interpretation of the Sangamon/Loveland complex in the Lower Mississippi Valley, USA

For more than a century, the Sangamon paleosol (the Sangamon) has been an integral part of geologic and pedologic investigations in the central United States, including the Upper Mississippi and Lower Missouri River Valleys. Compositional, pedologic, micromorphologic, stratigraphic, and age data indicate that the prominent reddish paleosol developed in silt-rich deposits of the Lower Mississippi Valley, from southernmost Illinois to northwestern Mississippi, represents multiple periods of soil formation, and is wholly or in part time equivalent to the Sangamon of the central United States. Thermoluminescence data, for localities where the Sangamon developed in loess, indicate that the primary period of loess deposition was from 190 to 130 ka (oxygen isotope stage, OIS6), that loess deposition continued intermittently from 130 to 74 ka (OIS5), and that deposition was wholly or in part coeval with Loveland loess deposition in the central United States. Beryllium-10, chemical, and pedologic data indicate that in the Lower Mississippi Valley: (1) the Sangamon represents a minimum time period of 60-80 k.y.; (2) there were at least two periods of soil formation, ca. 130-90 ka and 74-58 ka (OIS4); and (3) rates of weathering and pedogenesis equaled or exceeded the net loess-accumulation rate until at least 46 ka (OIS3) and resulted in development of a paleosol in the overlying basal Roxana Silt. Along a N-S transect from southern Illinois to western Mississippi, Sangamon macroscopic characteristics as well asthe micro-morphology, chemistry, and mineralogy, suggest a regional paleoclimate during periods of soil formation that: (1) was warm to hot, with a wider range in temperature, precipitation, and evapotranspiration than present; (2) had seasonal to decadal or longer periods of drought; and (3) had down-valley (southward) trends of increasing temperature and precipitation and decreasing seasonality and variation in annualto decadal precipitation. ?? 2011 Geological Society of America.

Geological Society of America Bulletin↗
USGS2007

Soil and sediment chemistry in the Mississippi River Delta following Hurricane Katrina

In October 2005, the U.S. Geological Survey's (USGS) Mid-Continent Geographic Science Center and the University of Missouri-Rolla's (UMR) Environmental Research Center for Emerging Contaminants partnered to collect perishable environmental data along the Mississippi River Delta to catalog the effects of Hurricane Katrina, a category 3 storm that caused nearly complete destruction to the delta's population support structure and industry. The data presented here begin the process of characterizing the chemical composition of sediments and soil along the delta following this significant natural disaster.

Louisiana↗
USGS2024

Inset groundwater-flow models for the Cache and Grand Prairie Critical Groundwater Areas, northeastern Arkansas

The water resources in the Mississippi alluvial plain, located in parts of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas, supports a multibillion-dollar agricultural industry that relies heavily on pumping of groundwater for irrigation of crops and aquaculture. The primary source of groundwater for agricultural-related pumping is the Mississippi River Valley alluvial aquifer, which has declined in storage for decades; secondary groundwater sources include the middle Claiborne aquifer and Wilcox aquifer system. Two areas in northeastern Arkansas that lie within the Mississippi alluvial plain, part of the Cache and Grand Prairie regions, have been designated as Critical Groundwater Areas owing to decades of groundwater declines that resulted from past and current water use. The multidisciplinary Mississippi Alluvial Plain project, led by the U.S. Geological Survey, and funded by their Water Availability and Use Science Program, included objectives to develop numerical groundwater models in focus regions, including the part of the Cache and Grand Prairie regions of northeastern Arkansas. Two inset models were developed using the child model capabilities of MODFLOW 6, the U.S. Geological Survey’s Modular Hydrologic Model simulation software. Both models, called the Cache model and Grand Prairie model, simulated the groundwater system and surface-water/groundwater interactions for the Mississippi River Valley alluvial aquifer and underlying Tertiary-age aquifers and confining units to the Midway confining unit. Each model was spatially discretized into 500-meter x 500-meter orthogonal cells on a grid with 5-meter constant-thickness vertical layers that represented the Mississippi River Valley alluvial aquifer and increasing thickness layers for the aquifers and confining units below the alluvial aquifer. The Cache and Grand Prairie models were calibrated with the PEST++ iterative ensemble smoother Version 5 and employed high dimensional parameterization schemes of 13,740 and 30,436 parameters, respectively. The Cache mean absolute residual for groundwater-level observations within each model domain for the priority well was 1.58 meters. Grand Prairie mean absolute residuals for the alluvial aquifer and middle Claiborne aquifer groundwater-level observations were 2.71 and 10.78 meters, respectively. The groundwater budgets for the Cache and Grand Prairie models were characterized by substantial outflows to irrigation wells, which constituted about 52 and 54 percent of all outflows, with the primary source of water to those wells being releases from unconfined aquifer storage.

Arkansas↗
USGS2009

Review of the geologic history of the Pontchartrain Basin, northern Gulf of Mexico

The Pontchartrain Basin extends over 44,000 km² from northern Mississippi to the Gulf of Mexico and includes one of the largest and most important estuarine systems in the United States. The basin supports a variety of environments, from woodlands in the north to wetlands in the south, and a growing socioeconomic infrastructure that has led to rapid development of the southern half of the basin over the past two centuries. To properly administer this infrastructure, managers need to understand the complex geologic framework of the basin and how it will respond to continued sea-level rise, variable rates and magnitudes of land subsidence, and human alteration of the landscape. This article summarizes the body of work that describes the regional evolution and stratigraphic architecture of the Pontchartrain Basin. The northern two-thirds of the basin is underlain by a stratigraphy of undifferentiated sands and clays deposited throughout the Plio-Pleistocene by glacially influenced rivers. These deposits were weathered and incised by rivers during sea-level low stands, forming a series of terraces that increase with age from south to north. The southern third of the basin is composed of estuaries formed during the Holocene, while shoreline processes created a series of sandy barriers that restricted communication to the Gulf of Mexico. The Mississippi River completed the geologic development of the basin by building a sequence of subdelta lobes along this southern margin over the past 5000 years, further sealing it from the open Gulf of Mexico. Presently, the modern Mississippi River bypasses the estuarine environment and only contributes sediments during flood events when the river overtops the levee system. Sea-level rise, subsidence within the Holocene delta-plain deposits, and movement along numerous fault systems are the active natural processes that continue to affect basin geomorphology.

Louisiana, Mississippi↗
USGS1981

Water resources data for Mississippi, water year 1979

Water resources data for the 1979 water year for Mississippi consist of records of stage and discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels of wells. This report contains discharge records for 80 gaging stations; stage records for 17 of these gaging stations; stage only for 3 gaging stations; contents for 4 lakes; water quality for 25 gaging stations, and 162 wells; and water levels for 360 observation wells. Also included are data for 94 crest-stage partial-record stations. Additional Water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗
USGS1977

Water resources data for Mississippi, water year 1976

Water resources data for the 1976 water year for Mississippi consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels of wells. This report contains discharge records for 79 gaging stations; stage records for 15 of these gaging stations; stage only records for 4 gaging stations; contents for 4 lakes and reservoirs; water quality for 20 gaging stations and 1 miscellaneous site; and water levels for 168 observation wells. Also included are data for 138 crest-stage partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗
USGS1981

Water resources data for Mississippi, water year 1980

Water resources data for the 1980 water year for Mississippi consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This report contains records of water discharge at 82 gaging stations; stage records for 17 of these gaging stations; stage only at 4 gaging stations; contents for 4 lakes; water quality for 32 gaging stations, and 105 wells; and water levels for 360 observation wells. Also included are peak-discharge data for 94 crest-stage partial-record stations and water quality data at 19 partial record or miscellaneous sites. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗
USGS1982

Water resources data Mississippi, water year 1981

Water resources data for the 1981 water year for Mississippi consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This report contains records of water discharge at 82 gaging stations; stage records for 18 of these gaging stations; stage only at 4 gaging stations; contents for 4 lakes; water quality for 33 gaging stations, and 123 wells; and water levels for 324 observation wells. Also included are peak-discharge data for 91 crest-stage partial-record stations and water quality data at 18 partial-record or miscellaneous sites. Locations of these sites are shown on Figures 3-5. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗
USGS2010

Low-flow characteristics of the Mississippi River upstream from the Twin Cities Metropolitan Area, Minnesota, 1932-2007

The U.S. Geological Survey, in cooperation with the Metropolitan Council, conducted a study to characterize regional low flows during 1932?2007 in the Mississippi River upstream from the Twin Cities metropolitan area in Minnesota and to describe the low-flow profile of the Mississippi River between the confluence of the Crow River and St. Anthony Falls. Probabilities of extremely low flow were estimated for the streamflow-gaging station (Mississippi River near Anoka) and the coincidence of low-flow periods, defined as the extended periods (at least 7 days) when all the daily flows were less than the 10th percentile of daily mean flows for the entire period of record, at four selected streamflow-gaging stations located upstream. The likelihood of extremely low flows was estimated by a superposition method for the Mississippi River near Anoka that created 5,776 synthetic hydrographs resulting in a minimum synthetic low flow of 398 cubic feet per second at a probability of occurrence of 0.0002 per year. Low-flow conditions at the Mississippi River above Anoka were associated with low-flow conditions at two or fewer of four upstream streamflow-gaging stations 42 percent of the time, indicating that sufficient water is available within the basin for many low flows and the occurrence of extremely low-flows is small. However, summer low-flow conditions at the Mississippi River above Anoka were almost always associated with low-stage elevations in three or more of the six upper basin reservoirs. A low-flow profile of the Mississippi River between the confluence of the Crow River and St. Anthony Falls was completed using a real-time kinematic global positioning system, and the water-surface profile was mapped during October 8?9, 2008, and annotated with local landmarks. This was done so that water-use planners could relate free-board elevations of selected water utility structures to the lowest flow conditions during 2008.

Scientific Investigations Report↗
USGS1974

Water resources data for Mississippi, water year 1973

Water resources data for the 1973 water year for Mississippi including records of streamflow or reservoir storage at gaging stations, partial-record stations, and miscellaneous sites, and records of water-quality data on the chemical and physical characteristics of surface water, are given in this report. In Part 1, records are included for 79 gaging stations of which 75 are streamflow discharge stations, and 4 are reservoir or lake stations; also are included records for 58 low-flow partial-record stations, 139 crest-stage partial-record stations, and 79 miscellaneous sites. Locations of gaging stations are shown in Figure 1. In Part 2, data on the quality of surface water (chemical and temperature) were collected from designated sampling sites at predetermined intervals such as monthly, or less frequently. Records are given for 70 sampling stations of which 32 are continuous record stations, 26 are partial-record stations, and 12 are miscellaneous sites. Locations of water-quality stations are shown in Figure 1. A few pertinent stations (not included above) furnished by bordering States are also included in this report. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of L. E. Carroon, district chief. These data represent that portion of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗
USGS1972

Water resources data for Mississippi, water year 1971

Water resources data for the 1971 water year for Mississippi including records of streamflow or reservoir storage at gaging stations, partial-record stations, and miscellaneous sites, and records of water-quality data on the chemical and physical characteristics of surface water, are given in this report. In Part 1, records are included for 71 gaging stations of which 67 are streamflow discharge stations, and 4 are reservoir or lake stations; also are included records for 27 low-flow partial-record stations, 143 crest-stage partial-record stations, and 91 miscellaneous sites. Locations of gaging stations are shown in Figure 1. In Part 2, data on the quality of surface water (chemical and temperature) were collected from designated sampling sites at pre-determined intervals such as monthly, or less frequently, and at one site data were recorded on punched paper tape at 60-minute intervals. Records are given for 55 sampling stations of which 5 are continuous record stations, 26 are partial-record stations, and 3 are miscellaneous sites. Locations of water-quality stations are shown in Figure 1. A few pertinent stations (not included above) in bordering States are also included in this report. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of L. E. Carroon, district chief. These data represent that portion of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗
USGS2021

Initial estimates of net infiltration and irrigation from a soil-water-balance model of the Mississippi Embayment Regional Aquifer Study Area

The Mississippi embayment encompasses about 100,000 square miles and covers parts of eight States. In 2016, the U.S. Geological Survey began updating previous work for a part of the embayment known as the Mississippi Alluvial Plain to support informed water use and agricultural policy in the region. Groundwater, water use, economic, and other related models are being combined with field surveys and observations to create a quantitative framework for evaluating regional groundwater withdrawals and their effects on long-term water availability in the Mississippi Alluvial Plain. As part of this effort, the U.S. Geological Survey’s Soil-Water-Balance code (version 2.0) is being used to model potential groundwater recharge and irrigation water use, as necessary inputs to the long-term groundwater modeling efforts. The Soil-Water-Balance code is designed to estimate the distribution and timing of net infiltration leaving the root zone. Soil-Water-Balance makes use of gridded datasets of elevation, soils, land use (including specific crop types), and daily weather datasets to calculate other components of the root-zone water balance, including soil moisture, reference, actual evapotranspiration, snowfall, snowmelt, and canopy interception. Parameters on plant height and growing-season water needs are used to estimate crop-water demand and potential irrigation water use. This report documents the initial construction, calibration, and application of a Soil-Water-Balance model of the Mississippi Embayment Regional Aquifer Study area for simulations running from 1915 to 2017. Further refinements of the model calibration for an expanded model area are planned.

Alabama, Arkansas, Illinois, Kentucky, Louisiana, ↗
USGS2015

Movements of wild pigs in Louisiana and Mississippi, 2011-13

The prolific breeding capability, behavioral adaptation, and adverse environmental impacts of invasive wild pigs ( Sus scrofa ) have increased efforts towards managing their populations and understanding their movements. Currently, little is known about wild pig populations and movements in Louisiana and Mississippi. From 2011 to 2013, the U.S. Geological Survey investigated spatial and temporal movements of wild pigs in both marsh and nonmarsh physiographic regions. Twenty-one Global Positioning System satellite telemetry tracking collars were installed on adult wild pigs captured with trained dogs and released. Coordinates of their locations were recorded hourly. We collected 16,674 hourly data points including date, time, air temperature, and position during a 3-year study. Solar and lunar attributes, such as sun and moon phases and azimuth angles, were not related significantly to the movements among wild pigs. Movements were significantly correlated negatively with air temperature. Differences in movements between seasons and years were observed. On average, movements of boars were significantly greater than those of sows. Average home range, determined by using a minimum convex polygon as a proxy, was 911 hectares for boars, whereas average home range for sows was 116 hectares. Wild pigs in marsh habitat traveled lesser distances relative to those from more arid, nonmarsh habitats. Overall, results of this study indicate that wild pigs in Louisiana and Mississippi have small home ranges. These small home ranges suggest that natural movements have not been a major factor in the recent broad-scale range expansion observed in this species in the United States.

Louisiana, Mississippi↗
USGS2016

Post-Hurricane Isaac coastal oblique aerial photographs collected along the Alabama, Mississippi, and Louisiana barrier islands, September 2–3, 2012

The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms (Morgan, 2009). On September 2-3, 2012, the USGS conducted an oblique aerial photographic survey along the Alabama, Mississippi, and Louisiana barrier islands aboard a Cessna 172 (aircraft) at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect post-Hurricane Isaac data for assessing incremental changes in the beach and nearshore area since the last survey, flown in September 2008 (central Louisiana barrier islands) and June 2011 (Dauphin Island, Alabama, to Breton Island, Louisiana), and the data can be used in the assessment of future coastal change. The photographs provided in this report are Joint Photographic Experts Group (JPEG) images. ExifTool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. The photograph locations are an estimate of the position of the aircraft at the time the photograph was taken and do not indicate the location of any feature in the images (see the Navigation Data page). These photographs document the state of the barrier islands and other coastal features at the time of the survey. Pages containing thumbnail images of the photographs, referred to as contact sheets, were created in 5-minute segments of flight time. These segments can be found on the Photos and Maps page. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet. In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML files were created using the photographic navigation files. These KML file(s) can be found in the kml folder.

Alabama, Mississippi, Louisiana↗
USGS2017

Post-Hurricane Katrina coastal oblique aerial photographs collected from Panama City, Florida, to Lakeshore, Mississippi, and the Chandeleur Islands, Louisiana, August 31, 2005

The U.S. Geological Survey (USGS), as part of the National Assessment of Storm-Induced Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms. On August 31, 2005, the USGS conducted an oblique aerial photographic survey from Panama City, Florida, to Lakeshore, Mississippi, and the Chandeleur Islands, Louisiana, aboard a Piper Navajo Chieftain aircraft at an altitude of 500 feet and approximately 1,000 feet offshore. This mission was flown to collect post-Hurricane Katrina data, which can be used to assess incremental changes in the beach and nearshore area and can be used to assess future coastal change. The photographs in this report are Joint Photographic Experts Group (JPEG) images. These photographs document the state of the barrier islands and other coastal features at the time of the survey.

Florida↗
USGS2019

Flood-inundation maps of the Meramec River from Eureka to Arnold, Missouri, 2018

Libraries of digital flood-inundation maps that spanned a combined 37.2-mile reach of the Meramec River that extended upstream from Eureka, Missouri, to downstream near the confluence of the Meramec and Mississippi Rivers were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Army Corps of Engineers, Metropolitan St. Louis Sewer District, Missouri Department of Transportation, Missouri American Water, Federal Emergency Management Agency Region 7, and the cities of Pacific, Eureka, Wildwood, and Arnold. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science website at https://water.usgs.gov/osw/flood_inundation/ , depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the cooperative USGS streamgages for the Meramec River near Eureka, Mo. (USGS station 07019000), the Meramec River at Valley Park, Mo. (USGS station 07019130), the Meramec River at Fenton, Mo. (USGS station 07019210), and the Meramec River at Arnold, Mo. (USGS station 07019300). Near-real-time stage data at these streamgages may be obtained from the USGS National Water Information System at https://doi.org/10.5066/F7P55KJN or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at https://water.weather.gov/ahps/ , which also forecasts flood hydrographs at these sites (listed as NWS sites erkm7, vllm7, fnnm7, and arnm7, respectively). Flood profiles were computed for the stream reach by means of a calibrated one-dimensional step-backwater hydraulic model. The model was calibrated using a stage-discharge relation at the Meramec River near Eureka, Mo., streamgage (USGS station 07019000) and documented high-water marks from the flood of December 2015 through January 2016. The calibrated hydraulic model was used to compute water-surface profiles: 1 set for the Meramec River near Eureka, Mo., streamgage (USGS station 07019000); 1 set for the Meramec River at Valley Park, Mo., streamgage (USGS station 07019130); 7 sets for the Meramec River at Fenton, Mo., streamgage (USGS station 07019210) for a range of Mississippi River conditions; and 8 sets for the Meramec River at Arnold, Mo., streamgage (USGS station 07019300) for a range of Mississippi River conditions. The water-surface profiles were produced for stages at 1-foot (ft) intervals referenced to the datum from each streamgage and ranging from the NWS action stage, or near bankfull discharge, to the stage corresponding to the estimated 0.2-percent annual exceedance probability (500-year recurrence interval) flood, as determined at the Meramec River near Eureka, Mo., streamgage (USGS station 07019000). The simulated water-surface profiles then were combined with a geographic information system digital elevation model (derived from light detection and ranging data having a 0.28-ft vertical accuracy and 3.28-ft horizontal resolution) to delineate the area flooded at each simulated 1-ft stage increment. Previously published flood-inundation maps were updated and incorporated in the flood map libraries for USGS stations 07019130 and 07019210 to complete the map sets corresponding to eight Mississippi River conditions. The availability of these maps, along with internet information regarding current stage from the USGS streamgages and forecasted high-flow stages from the NWS, will provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures and for postflood recovery efforts.

Missouri↗