This tutorial has been divided in 5 parts:

1. Region Selection and Data Download (DEM and Blue Lines)
2. Creation of a Database
3. Data import procedures
4. River network extraction from DEM
5. Basin Selection and Analysis

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

For this exercise we will be working on the Burns Creek basin, a 40 km² 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". If you are using Internet Explorer, follow this link for directions.
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)
     
     
     Zoom Level 1 (Zooming on Emporia Region)
     
     
     
     Zoom Level 2 (Zooming on Burns Basin)
     
     
     
     Zoom Level 3 (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
     
     
     
   • 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).
     
     
     
   • 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.
     
     
     
   • 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)
     
     
     
   • 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 "1:100K DLG" menu.
3. Select the "FTP via Graphics" link. A US map will show up.
4. Click on the map close to Wichita, Kansas (South East Kansas region. Take a good guess).
5. A group of layers will be displayed. Click on the one called "EMPORIA, KS"
6. Click the link "EMPORIA,KS West".
7. Click the directory "hydrography/".
8. 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 ...".

II. Creation of a Database

Now that you have download some data, we will proceed to create an populate our Hydrologic Database. Follow this steps to create a new database:

1. Create a new empty directory called "Test_Database" wherever is convenient for you (use a directory different to the one where you downloaded the data). It is a good idea to create it in a place that you can access later (Ask the system administrator for a place where you can keep files).
2. Open CUENCAS. (If you are in Bechtel lab, go to start => All Programs => Geothechnical Tools => CUENCAS)
3. Select the menu File => Create New Database.
4. Once the file selection form pops up, find and select the directory "Test_Database" that you created in step 1.
5. Maximize the CUENCAS window.

III. Data import procedures

Now we are ready to add some data into our Hydrologic Database. We will add the DEM and the blue lines.

1. Importing the DEM:
   • On CUENCAS select "File => Import => Import DEM => From USGS BIL"
   • Find and select the directory where you downloaded and uncompress the USGS DEM. Usually it will be a directory named by 10 digits.
   • Select the repository directory for download (use the default directory).
   • If everything went OK your "Topography Database" tree, on the left panel of CUENCAS should look like this (double click the "Elevation Maps" folder):
     
     
     
2. Importing the Blue Lines:

• This step is even simpler. Just uncompress the "483105.HY.opt.gz" that you downloaded. A file called 483105.HY.opt, will be created. You will have to change the extension to this file from .opt to .dlg. This can be done using the Windows Explorer, by editing the filename.
• Copy the renamed file to the directory "Vectors" inside the "Test_Database" that you previously created.
• Finally, go to "File => Recent Databases => Test_Database" to refresh the Database structure.

IV. River Network Extraction from DEM

Here it is assumed that you have successfully downloaded a DEM from the USGS website.

1. On the "Topography Database" tree, double click the DEM that you imported.
2. The "DEM and Derived Quantities" window should pop up.
   
   
   
3. Click the "Get Network" button. This will activate the "Network Extraction Options" window.
   
   
   
4. Click the "Apply Condition button" and the click "Start". You will be able to see the algorithm progress by checking the Optimization and Extraction progress bars. If you want to see more details about the extraction process you can open your Windows Command Prompt
   
   
   
5. The process takes about 3 minutes for the DEM we downloaded in step I of this tutorial.
6. Once it's done, click the "Exit" button, and the hit the "Open" button on the "DEM and Derived Quantities" window.
7. Click the "Plot Network" icon . and select the "Show All Orders Box". If your CUENCAS Screen looks like the figure below, you have successfully imported and processed your DEM
   
   
   
8. As a final step, display the Blue Lines you imported. First, select the "Vectors" tab in the left panel. Then, check the "483105.HY.dlg" box (located under the "Available DLG files" frame).
   
   
   
9. Your screen should now display all your data.
   
   

V. Basin Selection and Analysis

Now that you have loaded you database with data, and have sucesfully process your DEM it's time for some River Network Analysis.

First a small introduction to how to move around CUENCAS map display window using the projection icons and the mouse:

• Home Icon []: Clicking on this icon will make the map projection come back to its original state, use it every time you lose your map out of sight, or when you want to quicky return the original display projection.
• Zoom In Icon []: Clicking on this icon will double the current image size.
• Zoom Out Icon []: Clicking on this icon will reduce the current image size by half.
• Left-Button-Drag (click and hold): This action allows you to change the center of the display, it is usefull if the features you are interested in are outside the visible range in the display window
• Middle-Button-Drag (click and hold): This action activates the Box Zoom utility. Note: There are some buttons in the interface that will change the default action of the middle button. We will illustrate those changes along this tutorial.
• Middle-Button-Click: This action will execute the currently selected behavior. The Behavior is determined by clicking on any of this icons:
  [], [], or [].
• Left-Button-Click: This action will bring up the interface associated to the active element being clicked. Active elements are usually small squares in the display. We will illustrate the "Basin-Outlet" element later in this tutorial.

For this exercise we will continue working on the Burns Creek basin. You are expected to have a fully loaded database at this point. If you had troubles downloading data and puting together your database, you can download this zip file, which contains the database used in the first part of this tutorial (click here to download).

1. Basin Selection:
   • Open your DEM by double clicking your DEM on the "Topography Database" tree, on the left panel of CUENCAS. Then select Open on the "DEM and Derived Quantities" window when it pops up.
     
     
     
   • Once the map has been displayed, select the "Show all orders" box, under the Plot Network icon []. The box shows up when you click on the icon.
     
     
     
   • Using the "Box Zoom" utitlity (click and drag the middle-button of your mouse) zoom in to the are near the end of the longest dark green stream.
     
     
     
   • Get as close to the end of the stream as you need to.
   • Now click on the "Select Outlet" icon []. It's the third one after the "Show Network" icon []. You will notice that when you click on the icon it changes to a darker grey color. That means that while the button is selected a new behavior for the Middle-Button of you mouse is active. Do not try to "Box-Zoom" after you have activated this button.
   • Click near the end of the stream with your middle button (see figure above), a good place to do it is that direction change in the stream right before the junction.
   • The software automatically finds all the pixel in the terrain, whose drainage path crosses the point we defined, then it outlines the contour around those points (This contour line is the Basin Divide). Click the "Home" icon to get a full view of the basin and the basin divide.
     
     
     
   • Deselect the "Select Outlet" icon [].
     
2. River Network Topologic Analysis
   • Once you have defined your basin outlet, CUENCAS can perform a number of geomorphometric analyses on the River network. To access them, Right-Click on the red spot near the basin outlet. This small square is what we call an active element in the map. Notice that following the procedure outlined before you can select many basin outlets in a region.
   • Right-Clicking on the outlet will launch a menu of options. Click on the "Geomorphology Analysis" button.
     
     
     
   • The "River Network Analysis" module is displayed.
     
     
     
   • Click on the individual tabs to explore the variety of analyses CUENCAS can do. Check the difference between the Geometric and Topologic Width Fucntions, and Horton Ratios for different network properties. (THIS MODULE IS BEING DEVELOPED - EXPECT A SUMARY OF THE NETWORK PROPERTIES IN THE "HTML REPORT" TAB).
   • Click here for some Homework exercises related to this module.
   • Close the "River Network Analysis" module window.
   • Right-Click on the outlet again to get the menu of options. Click on the "Rainfall-Runoff" button. It launches the "Rainfall-Runoff" module.
     
     
     
   • This module gives you a 3D view of your basin, for you to develope a sense of the basin topography and the meaning of flow aggregation on the terrain.
   • Select the "Hillslopes-Links System" tab, to view how CUENCAS decomposes the basin area into smaller pieces called hillslopes.