Homework 2

Department of Earth Science |Northeastern Illinois University

PRINCIPLES OF HYDROGEOLOGY
ESCI 337
Spring, 2004

Homework #2: Collecting Stream Discharge Data Sanders
(Due January 27, 2004)

In this homework assignment, you will locate and print out one year’s worth of discharge data for a stream gage in Illinois. With your group, you will select gages and time periods that will enable you to compare and contrast data sets collected by the group members.

We will work with the data in class on January 27, so be sure to have your data in hand when you come to class that day!

1) FIND THE SOURCE OF ILLINOIS STREAM GAGE DATA

Keep a map of Illinois handy--a road map is fine, or you can use one of the maps in the classroom. Go to the USGS web site http://water.usgs.gov/. Under "Access to water-resources data..." click “Surface Water”, and then click “Streamflow”. Under “Site Location”, click “State”, and then click “Submit”. Select “Illinois”, and under “Choose Output Format”, select “Table of sites sorted by SITE NAME grouped by COUNTY” (you’ll have to select the words “Site Name” and “County”.) Then, click the “Submit” button.

This will give you a list of all the stream gages in Illinois, grouped by county. (Long streams will flow through several counties, so you may choose to click "Back" and instead of selecting "county", select "hydrologic unit". That will show you all the gages on each stream no matter what county they are in.)

2) BROWSE THE DATA AVAILABLE ON THE WEB.

Pick any stream gage, and click on the Site Number. This will take you to a site specifically for that particular gage. For each gage, it tells you the period of record—in other words, how long the USGS has been keeping records at that site, and the drainage area--the area of the drainage basin for the point on the stream where the gage is located. Get to know the drainage basin by going to “Available data for this site” and selecting such choices as “Station Site Map”, “Station Home Page”, and “EPA Surf Your Watershed” (click GO to visit each of these pages).

3) SELECT A SET OF DATA WITH YOUR GROUP

When you are comfortable navigating the website, with your group, collect and analyze one-year data sets that are related to each other in some way.

As a group, you will need to choose the one-year data sets and the way in which they are related. Here are some examples of ways that data sets might be related:

    * The sets of data are from different gages on the same stream, but for the same years;
    * The sets of data are from the same gage on the same stream, but from different years;
    * The sets of data are from different streams altogether, but the drainage areas for the streams are approximately the same (within plus or minus 10%), and the year for which data are collected is the same;
    * Other (check with me first)

The group should assign each group member the task of collecting data from a certain gage on a certain stream for a certain year-long period. Each group member is responsible for collecting at least one data set.

4) RECORD IMPORTANT INFORMATION ABOUT THE GAGE

Repeat Steps 1 and 2 to select the stream and gage the group has assigned you and get to know it a little better. Before doing anything else, find and record the following information:

    a. Stream name
    b. Location of gaging station (the town/city, the county, and the latitude/longitude)
    c. Drainage area (square miles) (see Step 1, above)
    d. Period of record (see Step 1, above).

5) COLLECT ONE YEAR'S WORTH OF DISCHARGE DATA

On the “Available Data for this Site” menu, click on “Daily Streamflow” and GO. Under “Choose Output Format”, go to the boxes in the “Retrieve data from” line, and enter the beginning and end of a one-year period. Be sure to use the correct format (YYYY-MM-DD). Also, be sure that the dates you enter fall within the period of record!

Select “Tab-Separated Data”, select “Display in Browser”, and then click the Submit button.

Print this list (it may be long--7 pages or more). Bring your data to class with you on January 27.

6) PREPARE A BRIEF REPORT TO HAND IN

As a group, make a list of the stream name, location of gaging station (town and county), drainage area (mi²), period of record, time period of the data set, and name of the person who collected each data set. Write a brief paragraph explaining how the data sets are related to each other--that is, how they are the same, and how they are different. The list and explanatory paragraph should be no longer than a single typewritten page. Hand the report in (one per group) at the beginning of class on January 27. Be sure to bring your data, too. Don't staple it to the report, as you will be working with it in class that day.