Context:
Recently the Scenario family went for a holiday on the Far South Coast of NSW. While visiting Bournda National Park they decided that, since it was a hot day, they would go swimming at a local water body. They chose a nice place towards the southern end of the park. Unfortunately when they got there the water was a little bit unpleasant. The youngest boy in the family looked at the swimming spot and asked the question "Mummy, why is the water green?"
Your task is to find out as much information on the area and to build up a GIS which will help you answer this diappointed child's question.
When you have all your information complete the Local Research Action Plan and decide what you will do with the information you have found.
Start the Program
Start the program by double clicking on the AEJEE icon.
When you have the viewer window open, maximise it you can start adding data themes (called layers in ArcView 9) immediately.Ensure that the viewer is set to Map View and the map units are in metres (see view menu)
Finding Information
You can search for information during your investigation by using the identify button
. Click the button
and then click on features on the map to find out
further information about them.
How do you add data?
Click on the add data button
. When the content chooser
dialog box appears make sure you are looking in the
correct data folder.
Finding the study area
Add the data file "coastline_25k", highlight its name and click OK.
You will notice that the name "Coastline_25k_(polygon) appears in the "Table of Contents" on the left hand side. Click the check box next to "Coastline_25k_(polygon)" so that a tick appears. The South East coastline should appear in the dataframe on the right. If it doesn't appear the highlight the layer in the "Table of Contents" and then click on the "zoom to active layer"
button on the toolbar.
Changing the properties of the layer
Click on the theme name in the TOC to make it the active layer, double click on the highlighted area to the right of the name and the layer's Properties dialog box should appear. You can also use "ctrl -click" on your Mac to bring up a menu, scroll down to Properties.
Change the style setting from Solid Fill to Transparent fill and press OK.
Time to Zoom on in!
Click on Zoom In
and click and drag a
rectangle over the area you want to zoom in on.
And what was the name of that National Park?
Now add more layers to the scene using the same procedure as above.
Add the file "npws_estate.shp"
Again make the layer active by clicking on it and bring up its properties. Click the button for "Draw features using" and scroll down to "unique values" and scroll down the "field for values" list to load "name_short". Notice how each National Park is given a unique colour. Press OK.
Look down the list of National Park names and click on the colour symbol for the National Park you are looking for. You should see the park highlighted in yellow. Use the zoom in function again to zoom in!
What's in a name?
Check you are in the right park by labelling the names of the National Parks. Again go to the layer's properties and this time select "labels". Label the field using "Names_short" and click OK.
Which water body?
Add the data file "Water Bodies.shp" and zoom in to have a closer look. You can also change the colour to blue (maybe it should be green!!) by changing the properties.
Can you label the water bodies? What was the name of the water body they went to go swimming in?
And why would the water be green?
Write down your suggestions for why the water would be green. After all, it's in a National Park so shouldn't the water be clean?
Let's see where the water comes from.
This time find the data file "rivers_25k.shp" and add that to our GIS.
You can change the colour of the rivers shown by using the "Theme Properties" function described above.
What is a catchment?
Use the Internet, dictionary or text-book to find out what a catchment is. Then add the data file "catchmentboundary.shp" which shows the catchment boundary for our water body. What does it tell us? Change the properties of this layer so that it is transparent with a thicker orange line around it.
Possible sources of pollution
Look through the data files and add information on roads and towns. Can you give the towns a large red square and label them and make all the roads red? Does this give us any information about sources of pollution?
Check out the catchment
Add the layer "Sandyimages5.shp" and change the symbol to a larger star. If you click on the "identify" button followed by the "hotlink" button
and then click on the
stars you should be shown a photograph of that
location. Have a look around the catchment. Any likely
sources of pollution.
University studies
In response to concerns about water quality in the lagoon a University has conducted a preliminary study of water quality in the catchment. Add the layer "waterquality_Project.shp" to the map. This time change the properties to graduated symbols using the field "nitrate_pb". This is the concentration of nitrate in the water in parts per billion. Why would nitrate affect water quality? Are there other pollutants shown that might make the water green? How? Change the theme properties to display data on other pollutants. Research the term "eutrophication".
Disclaimer: The study is a preliminary one and the data should not be used to blame any landholder or to directly link any area of the catchment to what is happening in the lagoon. There is a need for further research to further explain what is happening.
What sites appear to be problem areas?
Which areas of the catchment have the lowest readings for nitrate and phosphate?
The highest?
What is the difference in landuse for these areas?
What will you do now? What action should you take.
Use the information in your GIS to help complete the Local Research Action Plan template.
Don't forget to save your work!
Congratulations - You have now built a useful GIS. Use the "layout view" to develop a map for use in your Local Research Action Plan. Instructions on how to do this can be found in the ArcExplorer Java Edition for Education help file.