CE 547 - GIS in Water Resources Engineering

Assignment #5

 CE 547, Spring 2009

 Due 03/09/09

  Retrieve huc13.e00, strm13.e00, and 13res.e00 from the cegis account.

 Import  huc13 (huc13.e00), streams (strm13.e00), reservoirs (13res.e00).

 Using ArcToolbox > Coverage Tools > Conversion > Import from Interchange File.  (Alternatively, you may use the ArcGIS8.* tools from ArcCatalog.)

Use the browse buttons to select the input and output.  Remember, if you can’t see the directories that you want, you need to use the Connect To Folder button.

If you keep a Windows Explorer window open you’ll see the three coverages appear as they are imported.  Remember that a coverage is a file folder and additional information for the coverage is contained in the info folder within the same workspace. 

Open ArcMap with a new empty map.  Use the Add data button to add the three coverages. Change the symbology to something more pleasing.  Note that you can select “More Symbols” from the Symbol Selector window.

 Right click huc13 and select Properties.  From the Layer Properties dialogue box, choose the Definition Query tab.  Click Query Builder and use the query “HUC” = 13060001 to access the headwaters of the Rio Pecos.

Click OK on the Query Builder and click OK on the Definition Query.

To create a shapefile of HUC = 13060001 (the Pecos Headwaters), right click huc13 and select Data > Export Data.  Name your new shapefile pecoshuc.

  Choose Selection > Select by Location

The Select By Location dialogue box allows you to select features a number of different ways.  Select features from your coverages of reservoirs and streams that are completely within pecoshuc.  Note that I haven’t been consistent with my names of these coverages because I did my screen captures during different ArcMap sessions.    

Click Apply.  Click Close.

Did you select all of the features that you expected to? 

Note that the furthest upstream portion of the Rio Pecos was not selected.  Play with the “Select By Location”.  Is there a way to have this upper stream included in the selection?  Change symbology.  Also note that pecoshuc does not include the entire watershed above Ft. Sumner Lake.  The Pintada Arroyo watershed is HUC 13060002.

 
  I managed to select the upper part of the Pecos River but I couldn’t do it with Select by Location.  Explore the Selection pulldown menu until you are able to select the rivers.

  Now we’d like to add some stream gage data to our watershed.

The USGS is a tremendous resource for flow data.  The web address for the Water Resources Division of the USGS in New Mexico is : http://waterdata.usgs.gov/nm/nwis/sw.  Go to this web page and choose Annual.  Set the Site Selection Criteria to Hydrologic Unit.  Click Submit.  On the next screen, you'll be able to select 13060001 as the hydrologic unit.  Under Choose Output Format select Site description information displayed in ... Press the down arrow to display the information as tab separated.   Depress the control key so that you can select multiple fields under "Select fields to include in site-description output".  Make sure that you select number, name, decimal latitude, decimal longitude, and altitude.  If you can figure out a way to select average annual flow here that would be great!  (I couldn't figure out an easy way.)  Click Submit.

Stephen Kissock was able to select flow data:  After going to the web page (http://waterdata.usgs.gov/nm/nwis/sw) and selecting Annual, set the Site Selection Criteria to Hydrologic Unit. Click Submit. On the next screen, you'll be able to select 13060001 as the hydrologic unit ... Select fields to include in site-description output.  This page has, at the bottom, "Retrieve USGS Surface-Water Annual Statistics for Selected Sites". Toggle this option on, click Submit. The next webpage will bring up site selection allowing the requested data for multiple sites within the watershed (including discharge data dating back in some cases to 1911!). There are other options at the bottom of this screen as well.  On the next screen there will be a hyperlink to tab-separated data which can then be added to ArcGIS as the instructions describe.

The USGS will process your request to look something like below.  Use Edit > Select All to select all of the text.  Then choose Edit > Copy. 

Open Excel.  Select Edit > Paste Special, then choose text.  Your table should now have the appropriate columns.  Select at least seven stations and copy those cells to Sheet 2 where you can change the formatting so that you can save as a dbf.  Change column widths appropriately. Change the format of the cells with numbers from General to Number so that you can retain decimal places.

Before you save your file as a dBASE file, you need to have the correct column headings and every number must be a value (not a formula.)   Before you save the file as dBASE it should look something like that shown below.  Select the portion of the worksheet you want to save, then click File > Save As.   Make sure to save the file in your workspace and in the "Save as type" box, scroll to DBF 4.

 Once the pecos.dbf file is in your workspace, return to ArcMap.  You can add a table the same way you add a coverage or a shapefile.  Simply select the Add Data icon. Using 9.3, you should be able to add a table directly from Excel.  If you use this method, make sure that you format all the columns appropriately, i.e. the coordinates must be numbers not strings of text.

  Once the table is shown in your Table of Contents (Source tab), right click the table to open the context menu.  Click Display XY Data.

 
  The Display XY Data box will request the name of the X Field and Y Field.  If you placed a row with these field names in your dBASE file they'll be automatically selected by ArcMap.  (Note that longitude is the x field and latitude is the y field.)  The new layer will be called pecos Events.  You created an XY Event Layer.  This layer will be saved in your ArcMap document.  If ArcMap does not use the spatial reference of your layers to show where the points are located, then you will need to project the layer.

However, if you plan to use the layer in other documents, you may want to save it as a shapefile. Furthermore, you'll have better luck projecting the data if you save it as a shape file. (Right click for context menu, Data > Export Data).  To project the shapefile, open the ArcToolbox and go to Data Management Tools > Projections and Transformations > Feature > Project.  Note that you are projecting from NAD83 geographic coordinates to an Albers projection such that the data will be the same as the huc.  Change the symbology so that your layout will look nicer.  Label your gages.  Spend some time on your layout.

  Yeah!  Another one done!