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User Guide

Non-Login Site: www.erams.com/hydraulics or www.erams.com/crosssection

The non-log-in site allows a user to access, create, and analyze cross-sections of a river.
    1. This site begins with the map interface, click on the “Channel Cross-Section” tab on the left side of the page.
    2. This tab contains tools to create a stream cross-section/transect by using:
      • The 30-meter USGS National Elevation Dataset (NED)
      • Your own elevation raster
      • A spreadsheet with survey points of a cross-section
    3. Once a cross-section is created, it will show up at the bottom of the left side. Click “View” to launch the cross-section editor interface.

Editing a Cross-Section Help:

      • The 112 icon allows a new point, station (x) and elevation (y) to be added to the cross-section.
      • The Delete icon allows the current point, station (x) and elevation (y), to be removed from the cross-section.
      • Each point’s station (x) and elevation (y) is editable, once you have made a change and hit enter or click off of the box you edited and the graph will update to view the changes.
      • Clicking Append Spreadsheet will allow you to upload a spreadsheet with the below properties and add it to the existing cross-section as more points. See below for file format instructions.
      • Clicking Download Cross-Section download a csv file with the start and end latitudes and longitudes as well as all the cross-section locations (x) and elevations (y).
      • Clicking Save Changes will permanently save the modified version of the cross-section.
      • Clicking Reset will restore the cross-section to its original un-edited version.

River Hydraulic Properties Help:

      • Specify a depth of flow using one of the following methods:
        • User-Defined Flow Depth
          • If you know the depth of flow you are interested in, use this choice.
        • Critical Depth
          • If you know flow conditions cause a critical depth of flow to occur here, specify the discharge in the channel to calculate and use the critical depth at this cross-section.
        • Normal Depth (Manning’s Equation)
          • If you know flow conditions cause a normal depth of flow to occur here; specify the following and a normal depth will be calculated using Manning’s Equation (1891):
            • Discharge in the channel
            • Channel bed slope
            • Manning’s Hydraulic Roughness Coefficient, n
      • Click Calculate to determine the cross-section hydraulic properties based on the flow depth. Click Futher Info. for more information about these hydraulic properties.

River Sediment Transport Help:

      • Select a Sediment Transport Equation
        • See Further Info. after calculation of hydraulic properties for more details on the sediment transport equations.
      • Specify the required inputs
      • Click “Calculate” to calculate sediment transport through the cross-section

Sediment Yield Help:

    • Specify a Flow Duration Curve:
      • Gauge Station Data
        • Search for a near by stream gauging station and use it’s flow record to create a flow duration curve of exceedance values for each flow.
      • Select a Sediment Transport Relationship (see further info. for more details):
        • Specify the required inputs.
        • Click Calculate to use the sediment transport relationship in the calculation of an effective discharge and a half-load discharge.

Login Site: www.erams.com

The login site has all the features of the non-log-in site, but also allows users to retain the cross-sections they have made, saved to the eRAMS user account.
  1. Login to an existing eRAMS account or create a new one
  2. Go to “My Acount” at the top of the page, then click on “Project” on the left hand side
  3. Click “Create Project” and provide a name for it. Select “Channel Cross-Section Analysis” as the “Project Type”. Then click “Okay”
  4. This project is now highlighted in your list of projects as the active project. Click “GIS/Analysis” at the top to go to the map interface to access the tool.
  5. Once on the map interface, click the “Channel Cross-Section” tab on the left side of the page
  6. Now you can follow the instructions for the non-login site to create and retain stream cross-sections.

Further Information

Frequently Asked Questions (FAQs)

Q: Why can’t I see anything when I go to the map on www.erams.com/hydraulics?

A: Some internet browsers have issues displaying the maps of eRAMS. eRAMS has been optimized for Mozilla Firefox and switching to this web browser should correct map display issues.

Q: How do I save an interactive graph?

A: The interactive graphs contain a menu (three grey lines) on the top right of the figure which opens an option to save the graph as any of the provided file types.

Geospatial

USGS National Elevation Dataset (NED):

In addition to being able to use uploaded rasters of elevation data, eRAMS access the 30-meter National Elevation Dataset (NED). Each cross-section point that is calculated accesses this dataset through the NED Point Query Service which calculates the elevation of a point based on its latitude and longitude.

CSV File Format

Cross-section Data

To work with the cross-section editor the uploaded file must be a two-column, comma separated value (CSV) file.

  • The first row must contain a label for the columns like “station (x), elevation (y)”.
  • The remaining rows must contain pairs of station (x) and elevation (y) points of a cross-section with the first row containing station x = 0 (column 1) and its associated elevation (column 2).
  • The units of station (x) and elevation (y) should be meters.

Flow Duration Curve Data (Sediment Yield Tool)

To work with the flow duration curve tool the uploaded file must be a two-column, comma separated value (CSV) file.

  • The first row must contain a label for the columns “flow duration curve, flow (cms)”.
  • The remaining rows must contain pairs of flow exceedances (column 1) and their associated flows (column 2).
  • The units of exceedance are on a percent scale from 0 (the largest flow) to 100 (the lowest flow) and flows should be in cubic meters per second (cms).

Example Outputs

The outputs of then cross-section tool are a graph of the cross-section and the water surface along with a summary of the hydraulic properties and sediment transport results.

Edit Cross-Section Geometry Results

Hydraulic Properties and Sediment Transport Results

Effective Discharge Results

API Notes

REST Access

In addition to the interface for the cross-section tool, both the hydraulic properties, sediment transport, and sediment yield analyses can be accessed using a REST-based protocol. This is because the hydraulics tool is built into the Cloud Service Innovation Platform, CSIP (Lloyd et al., 2012). An input/output example of this REST-based access to CSIP-HYDRAULICS is provided below:

Instructions

  1. A REST “get” call to one of the “Endpoints” in the above links for the analyses, will provide an example JavaScript Object Notation (JSON) of the required inputs for the model.
  2. Replace the values of the various inputs with those desired for a specific cross-section.
  3. A REST “push” call, to the same “Endpoint”, containing the modified JSON object will request a run of the CSIP-HYDRAULICS model with the specified inputs
  4. Once finished running, a return JSON will be sent back with a summary of the outputs from the model. An example result JSON is also available at the above links from the CSIP-HYDRAULICS.

References

Brownlie, William R. 1981. “Compilation of Alluvial Channel Data: Laboratory and Field.” W.M. Keck Laboratory of Hydraulic and Water Resources, Division of Engineering and Applied Science, California Institude of Technology, Pasadena, California. Report KH-R-43B.
Bagnold, RA. 1980. “An Emperical Correlation of Bedload Transport Rates in Flumes and Natural Rivers.” Royal Society of London Proceedings A372:453-473.
Klonsky, L., R.M. Vogel. “Effective Measures of ‘Effective Discharge’.” Journal of Geology 119:1-14.
Manning, R. 1891. “On the flow of water in open channels and pipes.” Transactions of the Institution of Civil Engineers of Ireland 20:161-207.
Martin, Yvonne, Michael Church. 2000. “Re-Examination of Bagnold’s Empirical Bedload Formulae.” Earth Surface Processes and Landforms 25:1011-1024.
Rubey, W.W. 1933. “Equilibrium-Conditions in Debris-Laden Streams” Transactions, American Geophysical Union 14.
Shen, Hsieh Wen, and Pierre Y. Julien. 1993. “Chapter 12: Erosion and Sediment Transport.” The McGraw Hill Handbook of Hydrology. D. R. Maidment, ed., McGraw-Hill New York
Wilcock, Peter R., Stephen T. Kenworthy. 2002. “A Two-Fraction Model for the Transport of Sand/Gravel Mixtures.” Water Resources Research 38(10),1194.
Wolman, M.G., J.P. Miller. 1960. “Magnitude and Frequency of Forces in Geomorphic Processes.” Journal of Geology 68:54-74.
Yang, Chih T., Albert Molinas, Baosheng Wu. 1996. “Sediment Transport in the Yellow River” Journal of Hydraulic Engineering 122:237-244.