Geology topics

Jeanne L. De Lanois

Publications and source records attributed to Jeanne L. De Lanois.

4 recordsLinked to original sources

USGS2013

Analysis and inundation mapping of the April-May 2011 flood at selected locations in northern and eastern Arkansas and southern Missouri

Precipitation that fell from April 19 through May 3, 2011, resulted in widespread flooding across northern and eastern Arkansas and southern Missouri. The first storm produced a total of approximately 16 inches of precipitation over an 8-day period, and the following storms produced as much as 12 inches of precipitation over a 2-day period. Moderate to major flooding occurred quickly along many streams within Arkansas and Missouri (including the Black, Cache, Illinois, St. Francis, and White Rivers) at levels that had not been seen since the historic 1927 floods. The 2011 flood claimed an estimated 21 lives in Arkansas and Missouri, and damage caused by the flooding resulted in a Federal Disaster Declaration for 59 Arkansas counties that received Federal or State assistance. To further the goal of documenting and understanding floods, the U.S. Geological Survey, in cooperation with the Federal Emergency Management Agency, the U.S. Army Corps of Engineers–Little Rock and Memphis Districts, and Arkansas Natural Resources Commission, conducted a study to summarize meteorological and hydrological conditions before the flood; computed flood-peak magnitudes for 39 streamgages; estimated annual exceedance probabilities for 37 of those streamgages; determined the joint probabilities for 11 streamgages paired to the Mississippi River at Helena, Arkansas, which refers to the probability that locations on two paired streams simultaneously experience floods of a magnitude greater than or equal to a given annual exceedance probability; collected high-water marks; constructed flood-peak inundation maps showing maximum flood extent and water depths; and summarized flood damages and effects. For the period of record used in this report, peak-of-record stage occurred at 24 of the 39 streamgages, and peak-of-record streamflow occurred at 13 of the 30 streamgages where streamflow was determined. Annual exceedance probabilities were estimated to be less than 0.5 percent at three streamgages. The joint probability values for streamgages paired with the Mississippi River at Helena, Ark., streamgage indicate a low probability of concurrent flooding with the paired streamgages. The inundation maps show the flood-peak extent and water depth of flooding for two stream reaches on the White River and two on the Black River; the vicinities of the communities of Holly Grove and Cotton Plant, Ark.; a reach of the White River that includes the crossing of Interstate 40 north of De Valls Bluff, Ark.; and the Tailwaters of Beaver Dam near Eureka Springs, Ark., Table Rock Dam near Branson, Mo., and Bull Shoals Dam near Flippin, Ark. The data and inundation maps can be used for flood response, recovery, and planning efforts by Federal, State, and local agencies.

Arkansas;Missouri↗

USGS2011

Effects of Simulated Land-Use Changes on Water Quality of Lake Maumelle, Arkansas

Lake Maumelle is one of two principal drinking-water supplies for the Little Rock and North Little Rock metropolitan areas. Lake Maumelle and the Maumelle River (its primary tributary) are more pristine than most other reservoirs and streams in the region. However, as the Lake Maumelle watershed becomes increasingly more urbanized and timber harvesting becomes more frequent, concerns about the sustainability of the quality of the water supply also have increased. Two models were developed to partially address these concerns. A Hydrological Simulation Program-FORTRAN model was developed using input data collected from October 2004 through 2008. A CE-QUAL-W2 model was developed to simulate reservoir hydrodynamics and selected water quality using the simulated output from the Hydrological Simulation Program-FORTRAN model from January 2005 through 2008. The Hydrological Simulation Program-FORTRAN watershed model was calibrated to five streamflow-gaging stations, and in general, these stations characterize a range of subwatershed areas with varying land-use types. Continuous streamflow data, discrete sediment concentration data, and other discrete water-quality data were used to calibrate the Lake Maumelle Hydrological Simulation Program-FORTRAN model. The CE-QUAL-W2 reservoir model was calibrated to water-quality data and reservoir pool altitude collected during January 2005 through December 2008 at three lake stations. In general, the overall simulation for the Hydrological Simulation Program-FORTRAN and CE-UAL-W2 models matched reasonably well to the measured data. In general, simulated and measured suspended-sediment concentrations during periods of base flow (streamflows not substantially influenced by runoff) agree reasonably well for Williams Junction (with differences-simulated minus measured value-generally ranging from -14 to 19 mg/L, and percent difference-relative to the measured value-ranging from -87 to 642 percent) and Wye (differences generally ranging from -2 to 14 mg/L, -62 to 251 percent); however, the Hydrological Simulation Program-FORTRAN model generally does not match the suspended-sediment concentrations for all stations during periods of stormflow (streamflow substantially influenced by runoff). Generally, this is also the case for fecal coliform bacteria numbers and total organic carbon and nutrient concentrations. In general, water temperature and dissolved-oxygen concentration simulations followed measured seasonal trends for all stations with the largest differences occurring during periods of lowest water temperatures (for temperature) or during the periods of lowest measured dissolved-oxygen concentrations (for dissolved oxygen). For the CE-QUAL-W2 model, simulated vertical distributions of temperatures and dissolved-oxygen concentrations agreed with measured distributions even for complex temperature profiles. Considering the oligotrophic-mesotrophic (low to intermediate primary productivity and associated low nutrient concentrations) condition of Lake Maumelle, simulated algae, phosphorus, and ammonia concentrations compared well with generally low measured values.

Scientific Investigations Report↗

USGS2011

Hypolimnetic dissolved-oxygen dynamics within selected White River reservoirs, northern Arkansas-southern Missouri, 1974-2008

Dissolved oxygen is a critical constituent in reservoirs and lakes because it is essential for metabolism by all aerobic aquatic organisms. In general, hypolimnetic temperature and dissolved-oxygen concentrations vary from summer to summer in reservoirs, more so than in natural lakes, largely in response to the magnitude of flow into and release out of the water body. Because eutrophication is often defined as the acceleration of biological productivity resulting from increased nutrient and organic loading, hypolimnetic oxygen consumption rates or deficits often provide a useful tool in analyzing temporal changes in water quality. This report updates a previous report that evaluated hypolimnetic dissolved-oxygen dynamics for a 21-year record (1974-94) in Beaver, Table Rock, Bull Shoals, and Norfork Lakes, as well as analyzed the record for Greers Ferry Lake. Beginning in 1974, vertical profiles of temperature and dissolved-oxygen concentrations generally were collected monthly from March through December at sites near the dam of each reservoir. The rate of change in the amount of dissolved oxygen present below a given depth at the beginning and end of the thermal stratification period is referred to as the areal hypolimnetic oxygen deficit. Areal hypolimnetic oxygen deficit was normalized for each reservoir based on seasonal flushing rate between April 15 and October 31 to adjust for wet year and dry year variability. Annual cycles in thermal stratification within Beaver, Table Rock, Bull Shoals, Norfork, and Greers Ferry Lakes exhibited typical monomictic (one extended turnover period per year) characteristics. Flow dynamics drive reservoir processes and need to be considered when analyzing areal hypolimnetic oxygen deficit rates. A nonparametric, locally weighted scatter plot smooth line describes the relation between areal hypolimnetic oxygen deficit and seasonal flushing rates, without assuming linearity or normality of the residuals. The results in this report are consistent with earlier findings that oxygen deficit rates and flushing-rate adjusted areal hypolimnetic oxygen deficit in Beaver and Table Rock Lakes were decreasing between 1974 and 1994. The additional data (1995-2008) demonstrate that the decline in flushing-rate adjusted areal hypolimnetic oxygen deficit in Beaver Lake has continued, whereas that in Table Rock Lake has flattened out in recent years. The additional data demonstrate the flushing-rate adjusted areal hypolimnetic oxygen deficit in Bull Shoals and Norfork Lakes have declined since 1995 (improved water quality), which was not indicated in earlier studies, while Greers Ferry Lake showed little net change over the period of record. Given the amount of data (35 years) for these reservoirs, developing an equation or model to predict areal hypolimnetic oxygen deficit and, therefore, areal hypolimnetic oxygen content, on any given day during future stratification seasons may be useful for reservoir managers.

Missouri;Arkansas↗

USGS2010

Constituent concentrations, loads, and yields to Beaver Lake, Arkansas, water years 1999-2008

Beaver Lake is a large, deep-storage reservoir used as a drinking-water supply and considered a primary watershed of concern in the State of Arkansas. As such, information is needed to assess water quality, especially nutrient enrichment, nutrient-algal relations, turbidity, and sediment issues within the reservoir system. Water-quality samples were collected at three main inflows to Beaver Lake: the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. Water-quality samples collected over the period represented different flow conditions (from low to high). Constituent concentrations, flow-weighted concentrations, loads, and yields from White River, Richland Creek, and War Eagle Creek to Beaver Lake for water years 1999-2008 were documented for this report. Constituents include total ammonia plus organic nitrogen, dissolved nitrite plus nitrate nitrogen, dissolved orthophosphorus (soluble reactive phosphorus), total phosphorus, total nitrogen, dissolved organic carbon, total organic carbon, and suspended sediment. Linear regression models developed by computer program S-LOADEST were used to estimate loads for each constituent for the 10-year period at each station. Constituent yields and flow-weighted concentrations for each of the three stations were calculated for the study. Constituent concentrations and loads and yields varied with time and varied among the three tributaries contributing to Beaver Lake. These differences can result from differences in precipitation, land use, contributions of nutrients from point sources, and variations in basin size. Load and yield estimates varied yearly during the study period, water years 1999-2008, with the least nutrient and sediment load and yields generally occurring in water year 2006, and the greatest occurring in water year 2008, during a year with record amounts of precipitation. Flow-weighted concentrations of most constituents were greatest at War Eagle Creek near Hindsville than White River near Fayetteville and Richland Creek at Goshen. Loads and yields of most constituents were greater at the War Eagle Creek and White River stations than at the Richland Creek Station.

Scientific Investigations Report↗