Solutions for Ex4.


I have had a number of questions about the solution to Ex4.   Here are some emails from Dr Tarboton with responses to questions:


“The GIS in Water Resources Exercise 4 refers to a file named

Rey_Watersheds.csv.  This should have read ReyStreamGages.csv.  This is a file containing the locations of the stream gages that serve as a basis for Batch Watershed delineation.  The file ReyStreamGages.csv is in the file (but Rey_Watersheds.csv is not).  I will correct the online version of the exercise to reflect this change.” (10/2)


“I learned (from several of you) that exercise 4 was incorrect in the specification of coordinate system for the importing of stream gages.

In Exercise 4 at the display XY step for displaying stream gages you should select a predefined coordinate system and browse to Projected Coordinate Systems/UTM/NAD 1927/NAD_1927_UTM_Zone_11N.  (It does not work if you go to a geographic coordinate system as the exercise originally said).  I have corrected this in the exercise on the website.” (10/3)


I have also heard that some students have had trouble executing the exercise in the LRC.  Please use the computers in ECJ 3.301 if possible since these have the latest tools on them.  I have just learned that there is an incompatibility between the ArcGIS 8.3 Fill Sinks function and the Model Builder add-on that I had planned to use for Exercise 6.  The LRC are reinstalling ArcGIS 8.3 to get around this.  If you reach a glitch and cannot get past a step in the exercise, there is a solution file set available at This is 92MB.   A downloaded and unzipped version is available in the LRC in /class/maidment/giswr2003/ex4.


The exercise is due in on Thurs Oct 9.  If you have trouble completing all steps, do what you can, explain where you got stuck and turn in the result.