Homework #7                                                                                                                      Sanders

This assignment is due October 25, 2001.

The assignment this week is to 1) complete the geology section, 2) write a section on how you
calculated the streamflow in and out values for your water budget, and 3) catch up on missing sections.

GEOLOGY: The geology section will go in your Introduction chapter.  (No Intro, Methods,
Results, Discussion sections here--just one section that will go in your first chapter!)  Be sure to
describe the bedrock, the sediments, and the soils in your study area.  This section need not be
lengthy, but it must be complete and accurate.  Don't forget to cite any sources you use--including
geologic maps!

STREAMFLOW: Write Introduction, Methods, Results, and Discussion sections that describe
how you calculated the streamflow in and streamflow out values for your water budget.  Remember
that these values should be expressed in terms of inches, so that they can be compared to the
precipitation, evaporation, and ET values that you have already calculated.  Remember, this is a draft,
so don't get too stressed about having the exact right numbers!  We will polish them in the upcoming
weeks.

CATCHING UP:  Another major draft of the hydrologic report is going to be due soon, so now is
a good time to get completely caught up!  In particular, many people seem to be behind on Evaporation
and ET.  So please be sure that your report sections on the following are complete:

  *  Evaporation: Be sure you have calculated an annual average value of depth of evaporation by using
        the Thiessen method and data for the DeKalb and Chicago Botanic Garden stations (the West
        Chicago group only needs the Chicago data, of course).  You'll also need to measure and report
        the area of open water (lakes and ponds) in your basin, and then find the total volume of evaporation
        that occurs in your basin by multiplying this value by the average depth of evaporation that you
        found using the Thiessen method.  Finally, divide this volume by the total basin area to find the
        depth of evaporation; this value goes in your water budget.

    * Evapotranspiration: Use the Thornthwaite method to calculate PET.  You should come up with an
        annual value of PET that will go in your water budget.  Given that the calculations are detailed, it
        probably will help to tabulate your results in a manner similar to the example that was handed out
        in class.  You might find it fairly simple at this point to calculate a yearly PET value for each year in
        your period of record (1988-present for Naperville, 1961-present for West Chicago, and
        1968-present for Warrenville), and that might come in handy later on, but don't sweat it if you
        don't have it.

Last updated October 18, 2001.