Estimated 100-year peak flows and flow volumes in the Big Lost River and Birch Creek at the Idaho National Engineering Laboratory, Idaho

The purpose of this report is to provide estimates of the 100-year peak flows and flow volumes that could enter the INEL area from the Big Lost River and Brich Creek are needed as input data for models that will be used to delineate the extent of the 100-year flood plain at the INEL. The methods, procedures and assumptions used to estimate the 100-year peak flows and flow volumes are described in this report

Tidal resource extraction in the Pentland Firth, UK : Potential impacts on flow regime and sediment transport in the Inner Sound of Stroma

Large-scale extraction of power from tidal streams within the Pentland Firth is expected to be underway in the near future. The Inner Sound of Stroma in particular has attracted significant commercial interest. To understand potential environmental impacts of the installation of a tidal turbine array a case study based upon the Inner Sound is considered. A numerical computational fluid dynamics model, Fluidity, is used to conduct a series of depth-averaged simulations to investigate velocity and bed shear stress changes due to the presence of idealised tidal turbine arrays. The number of turbines is increased from zero to 400. It is found that arrays in excess of 85 turbines have the potential to affect bed shear stress distributions in such a way that the most favourable sites for sediment accumulation migrate from the edges of the Inner Sound towards its centre. Deposits of fine gravel and coarse sand are indicated to occur within arrays of greater than 240 turbines with removal of existing deposits in the shallower channel margins also possible. The effects of the turbine array may be seen several kilometres from the site which has implications not only on sediment accumulation, but also on the benthic fauna

Detailing the impact of the Storegga Tsunami at Montrose, Scotland

The Storegga tsunami, dated in Norway to 8150$30 cal. years BP, hit many countries bordering the North Sea. Run-ups of >30 m occurred and 1000s of kilometres of coast were impacted. Whilst recent modelling successfully generated a tsunami wave train, the wave heights and velocities, it under-estimated wave run-ups. Work presented here used luminescence to directly date the Storegga tsunami deposits at the type site of Maryton, Aberdeenshire in Scotland. It also undertook sedimentological characterization to establish provenance, and number and relative power of the tsunami waves. Tsunami model refinement used this to better understand coastal inundation. Luminescence ages successfully date Scottish Storegga tsunami deposits to 8100$250 years. Sedimentology showed that at Montrose, three tsunami waves came from the northeast or east, over-ran pre-existing marine sands and weathered igneous bedrock on the coastal plain. Incorporation of an inundation model predicts well a tsunami impacting on the Montrose Basin in terms of replicate direction and sediment size. However, under-estimation of run-up persisted requiring further consideration of palaeotopography and palaeo-near-shore bathymetry for it to agree with sedimentary evidence. Future model evolution incorporating this will be better able to inform on the hazard risk and potential impacts for future high-magnitude submarine generated tsunami events

Intelligent Decimation of River Geometry Data for Manageable Use in Surface-Water Models

Two genetic algorithms (GA) for reducing river geometry data are presented. These algorithms effectively remove “redundant” and/or “nonessential” points from large datasets. The resulting smaller, less dense datasets makes the information more manageable and easier to work with. The first genetic algorithm reduces stream channel cross section data, and the second reduces bathymetry/LiDAR data. The cross-section genetic algorithm was used to reduce stream channel cross section data. A hypothetical example consisting of 41 data points and 10 cross sections on the Kootenai River in northern Idaho were reduced. Cross sections from the Kootenai River that are representative of meander, straight, braided, and canyon reaches were used to evaluate the reduction methods. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. Results indicated that the genetic algorithm successfully reduced the data. However, the original genetic algorithm does not account for varying distances between the data points. To account for irregularly-spaced data, the fitness function was modified and used in subsequent analyses. Fitness values from the modified genetic algorithm were lower (better) than in the original genetic algorithm and those that used the standard method of reducing cross-section data. Visual and hydraulic analyses were also used to assess the methods. The genetic algorithm reduced cross sections approximated the shape of the original cross sections better than the standard-reduced cross sections. Also a greater number of cross-sectional data points were needed for reduced cross sections in the straight reach and even more in the meander reach because a greater amount of data points are needed to adequately define cross sections that have greater topographic variability. The effects of reduced cross-sectional data points on steady flow profiles were also analyzed. A portion of the original steady-flow model of the Kootenai River was used, consisting of thirty-five cross sections. These cross sections were reduced to 10, 20, and 30 data points by the standard and modified genetic algorithm methods, that is, six test were completed for each of the thirty-five cross sections. Differences were smaller for reduced cross sections developed by the genetic algorithm (modified) method than the standard algorithm method. Generally, differences from the original water-surface elevation were smaller as the number of data points in reduced cross sections increased, but not always, especially in the braided reach. A genetic algorithm to decimate bathymetry and Light Detection and Ranging (LiDAR) datasets was also developed. These datasets can be used in two- and three-dimensional surface-water models. A hypothetical example consisting of 961 regularly spaced data points (x, y, and z) and data taken from an actual bathymetric and LiDAR dataset (10,080 data points) were reduced. Results indicated that the genetic algorithm successfully reduced the data. Terrains produced by the genetic algorithm are fairly representative of the original data and had smaller differences (better) than standard procedures of decimating LiDAR. Hypsometric curves of volume between the GA runs and original dataset were quite similar while the curves from standard reduction methods were quite different than the original. Other x-y data also can be reduced in a method similar to that for cross section data. Also the LiDAR/bathymetric genetic algorithm should decimate equally as well on any terrain data that is expressed in x, y, and z coordinates.doctoral, Ph.D., Civil Engineering -- University of Idaho - College of Graduate Studies, 2018-0

Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed

USGS Hurricane Storm-Surge Monitoring Networks: An Example from Hurricane Rita

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

Effects of well discharges on hydraulic heads in and spring discharges from the geothermal aquifer system in the Bruneau area, Owyhee County, southwestern Idaho /

Shipping list no.: 93-0574-P.Includes bibliographical references (p. 56-58).Mode of access: Internet