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I. Region Selection and Data Download

 

A Cuencas screenshot.

A Cuencas screenshot.

I. Region Selection and Data Download (DEM and Blue Lines)

For this exercise we will be working on the Burns Creek basin, a 40 kmĀ² basin located in southeast Kansas, near the town of Burns. We are going to download the 30 meters (1 arcsec) DEM provided by the USGS at http://seamless.usgs.gov/website/Seamless/. CUENCAS has been extensively tested on these DEMs. We will also download Blue Lines for this region from the EROS Data Center at http://edc.usgs.gov/geodata/.

First, we will get the DEM using the software provided by the USGS. It offers two ways to obtain the portion of terrain of interest: a) using the graphical interface to define the region or b) by defining the area by coordinates. We will provide steps for both this methods (we recommend to try both methods so that you familiarize with the Seamless Data Distribution System):

  1. Defining Region by Coordinates:
    This is the easiest method. It is very useful if you know in advance the coordinates of a “bounding box” that covers the basin of interest.

    • On the Seamless website click on the link (image) that points to “View and Download United States Data”
    • Once the software has loaded (it may take 20 seconds) select icon on the left side of the page, under the “Download ” section.
    • Clicking on the icon launches the interface shown below. Type the following coordinates (correspond to the Burns basin) in the bounding boxes:
      LAT: Bottom: 38 01 10, Top: 38 07 10
      LON: Left: 96 57 42, Right: 96 51 08
    • Click on the Select Area button. This will launch the “SDDS Request Summary Page”. Go to step 3 to complete the download process. If a window doesn’t pop up, you may have the “Pop Up blocker” feature active. If you are using FireFox, double click the window icon at the bottom left of the navigator and select “Unblock Popups from this site”. Instructions using Internet Explorer, are available online.
  2. Defining region using the graphic tools:
    This method requires more time, but it’s very useful if you have doubts about the region covered by the basin you are interested in processing.

    • On the Seamless website select the link (image) that points to “View and Download United States Data”
    • Once the software has loaded begin by zooming in the area of interest. The figures below should give you an idea of the zoom levels for the Burns Creek basin:
    • Zoom Level 0 (Zooming on Kansas)

      Zooming on Kansas.

      Zooming on Kansas.

    • Zoom Level 1 (Zooming on Emporia Region)

      Zooming on Emporia Region.

      Zooming on Emporia Region.

    • Zoom Level 2 (Zooming on Burns Basin)

      Zooming on Burns Basin.

      Zooming on Burns Basin.

    • Zoom Level 3 (Final zoom level)

      Final Zoom Level.

      Final Zoom Level.

    • On the Display tab on your right, expand the Hydrography menu and select the “National Atlas and NHD Streams” box. Your image should now look like this:
      USGS-Zoom-BurnsCreek-Rivers 5
    • Now select the icon “Define Download Area” , and create a bounding box containing our basin as shown in the figure below. Use the coordinates displayed in the status bar (at the bottom of the navigator window) as a guide, and create a box with the following coordinates: Upper left corner: (83.12,-96.95) and lower right corner (38.02, -96.84).

      Define download area.

      Define download area.


    • When you finish creating your selection box, the “SDDS Request Summary Page” will launch. Go to step 3 to complete the download process.
  3. Getting data from the “SDDS Request Summary Page”:
    • If you got to this point it means that you are ready to download the area that you defined (either by entering the coordinates or by graphically selecting the region). Notice that if a window hasn’t pop up, it means that you have the “Block Pop-Ups” feature of your navigator active. If you are using FireFox, double click the window icon at the bottom left of the navigator and select “Unblock Popups from this site”. If you are using Internet Explorer, follow this link for directions.
    • On the “SDDS Request Summary Page” window (shown below) click the “Modify Data Request” link

      Modify data request.

      Modify data request.


    • The ” SDDS Request Options Page” (shown below) appears. Select the options that indicate the kind of data that you want to download and the data format. (THIS IS A CRITICAL STEP IN THE PROCESS)

      SDDS Request options page.

      SDDS Request options page.


    • Select the “National Elevation Dataset (NED) 1 Arc Second ” box, and deselect all other boxes. Also, select the “BIL” option in the Data Format menu. Once you are done, scroll down and click the “Save Changes & Return to Summary” button.
    • Now you can press the “Download” button and the USGS starts processing your order.
    • Finally, the navigator asks you to open or save the file. Save the file in a temporary directory (you can use the “My Documents” folder), and then uncompress it.

Now download Blue Lines for this region. Blue lines are vector files containing traces of the rivers in a particular region. They are usually obtained from aerial photographs.

  1. Go to the EROS website at http://edc.usgs.gov/geodata/.
  2. Select the “1:100,000 Scale Digital Line Graphs (DLG)” menu.
  3. Go to the Aphabetical list .
  4. Select the folder “E/”, and then find the folder “emporia-w_KS/”
  5. Click on the directory “hydrography/”.
  6. Now download the file “483105.HY.opt.gz“. Put it in the same temporary directory where you downloaded your DEM. To uncompress the GZ file, download and install the winzip from http://www.winzip.com/downwz.htm. Then go the the file and rigth click on it. Select the option “WinZip => Extract to here …”.
Last modified on January 18th, 2013
Posted on January 17th, 2013