Beginning the workbook

» Preparation
» Acquiring a map
» Reading the map
» Calculating scale on an aerial photograph
» Measuring length
» Measuring area
» Recording site features using overlays
» Materials

Preparation

It is helpful to follow a sequence of activities to complete the Grassy Ecosystems Management Plan workbook:

  1. Locate recording sheets, suggested references, field guides and sources of assistance.
  2. Acquire an aerial photograph, satellite image or topographic map of the site. This may need to be enlarged to a suitable scale.
  3. Acquire other materials that are to be used regularly. These are listed on page 3.
  4. Briefly review each Step. Check if additional materials are required.
  5. Follow the methods in the order that they are presented.
  6. Seek advice to help with site assessment and management decisions.

Acquiring a map

Aerial photographs and topographic maps are available from various state departments. Addresses are provided in the reference section. Topographic maps at 1: 25 000 are available at some newsagents, camping and sports stores.

The following information helps when ordering photographs: Name, address and details of property, including portion numbers (found on rate notices), parish name and county name and the scale of map required.

Images of 1:25 000 or 1:10 000 are usually the most useful scale. In some cases maps can be enlarged to a suitable scale.

Reading the map

Spend a little time studying the map to locate features of the site such as gullies, creeks and boundary fences.

Work out the average scale of the map if this is not known. Draw this as a  scale bar on the map. This is important if paddock areas or fence lengths are to be calculated. Information on how to draw a scale bar and calculate
area is included below.

Calculating scale on an aerial photograph

If the scale of an aerial photo enlargement is not known it is possible to calculate this. Refer to the aerial photo as well as a topographic map of the same area and use the following method.

On the topographic map find two points that can also be found on the aerial map. Measure the distance between the two points on both maps. Measurements should be in millimetres.

Calculate the scale of the photograph as follows:

Distance on aerial photo (mm)
_________________________
Distance on topo map (mm)
X scale of map

= scale of aerial photo

Repeat this calculation three times using three different sets of points at different parts of the photograph. The average of the three answers is the scale of the aerial photo. The repetition is necessary because scale is distorted across the aerial photograph.

Example using a 1: 25 000 topographic map:

25mm
___________

= 1
_______
= scale 1: 10 000
10mm x 2500 10 000

Sorghum leiocladumMeasuring length

A scale of 1: 10 000 means that one centimetre on the aerial photo equals 10 000 cm or 100 m on the ground.

Measuring area

If one centimetre on the map equals 100 m on the ground, then 1cm x 1cm on the map equals 10 000 m2 on the ground (100m x 100m).

To show this in hectares, divide the area by 10 000.
That is: 1 hectare

Recording site features using overlays

Plastic overlays are used to record information about a site without cluttering the map with too many details. Overlays can be added or removed as needed and each has a specific purpose. Keys and colours are suggested to record site features. Clearly label each overlay to show its purpose and include the keys that are used. Plastic overlays can be acquired from newsagents and stationers.

Hypericum gramineumMaterials

Assemble the materials for the Steps before beginning the activities.

Symbols identify resources as well as reference material and worksheets as preparation for each Step. The symbols also show at what stage of the activities the materials are required. Symbols used in the text to identify materials required are identified in the box below.

Additional materials, such as marking tape or star pickets may be used for some activities.  These will be identified at the relevant Step.


 

Materials list

Aerial photograph An aerial photograph, satellite image or topographic map of the site. This may need to be enlarged to a suitable scale.
Overlays Clear plastic overlays the size of the site map.
Field guide Field guides for plants and animals.
Markers

Fine, coloured, felt tipped markers for plastic overlays.
 

Pencil Pencil and eraser.
Camera Camera.
Binoculars Binoculars.
Recording sheet Recording sheet.

Wahlenbergia communis, Cymbopogon refractus

Lomandra bracteata, Ranunculus lappaceus