Homework Assignment 6

After running the respective tutorial, read the following set of questions and write half a page paragraph about what you have learned from this lesson. At this point, you should be able to answer these questions or at least have them help you in writing your paragraph.

Post this paragraph, along with a screen capture, or two, developed from the results of the tutorial, to your CE531 homework page, then email the TA (include the URL to your homework page).

Always try to make your assignment page look as nice and professional as possible.

Watershed Delineation With DEMs

What are the three fundamental processes in the watershed delineation with DEMs?

List some of the problems/subtle issues that might be encountered in the delineation from a DEM.

In a DEM of 30m * 30m, how would you interpret a flow accumulation values of a cell to be 0 and 500?

List the WMS steps for watershed delineation using a DEM. For each step identify the importance/objective.

Suppose that you and a colleague at work were given the same piece of DEM and the approximate location of a culvert (to be constructed) in this DEM and you both were asked to model the watershed upstream from culvert. As a first step in the modeling you will delineate the watershed from the given DEM. Would both your computed basin parameters be the same? Why?

Extra Questions:

Here are some extra questions for you to think about.

Discuss when does delineating a watershed using the old conventional way (paper-based) be a "doable" option?

What is the main purpose of using of TOPAZ in watershed delineation?

You are delineating a watershed and you found some long straight lines (mostly orthogonal or slightly tilted) as part(s) of your watershed boundary, why is that happening? how could you overcome that.

Would the threshold value shorten (or even eliminate) the actual stream length? (In other words, would the stream length computed by WMS be affected by the threshold value? why?

You are following the WMS steps for delineation using DEM and reached the point where you define your outlet. The following  step is to convert streams to feature objects, when you do that, if WMS doesn't do anything, what could have gone wrong so far?