Selecting areas with drawing selection tools

1. If you have not already done so, click on the Nat Resources button  in the list of layers to expand the Natural Resource GIS layer group.
2. Find the layer called Soil Moisture-Effective Rainfall by Land Parcel and tick the box to make it visible. You will only be able to do this if the name Soil Moisture-Effective Rainfall by Land Parcel text has turned from grey to white. If it is greyed out, you will need to use the zoom in tool to get closer in before the layer can be made visible.
3. Using the mouse, click the word Soil Moisture-Effective Rainfall by Land Parcel in the list of layers - the background behind it should turn a lighter shade of blue (Figure 9). This makes Soil Moisture-Effective Rainfall by Land Parcel the active layer for searching.
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   Figure 9: Making Layer Active.
4. Click the select rectangle tool   on the toolbar at the top of the page to turn the tool on (it should be highlighted in a white box). 
5. To highlight a single land parcel, use the mouse to click somewhere in the middle of the shape. To highlight multiple land parcels, drag a box with the mouse that touches all of the pieces you are interested in - the dragged box does not have to completely surround the shapes, just overlap them at some point (Figure 10). The land parcels you selected will be highlighted in yellow and a table will appear below the map (Figure 11). If you don’t get this right first time, try again as your new selection will replace the last one.
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   Figure 10: Selecting Soil Units
   
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   Figure 11: Selecting Soil Units and information needed for calculator

Working out the area of a portion of a land parcel

If the area being irrigated is only part of a land parcel, you will need to determine the area of each piece of land with a different PAW and rainfall class (Figure 12). This can be done with a combination of the polygon area and identify tools using the following method.

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Figure 12: Example of an irrigated area that partially covers multiple blocks of land.

1. Click the polygon area tool on the toolbar at the top of the page to turn the tool on (it should be highlighted in a white box).  Three buttons should appear below the map (Figure 13) - Restart, Delete Last Point and Complete Polygon.
2. Click a point on the map to specify the start point of the area you are going to define. A black dot should appear at that location.
   
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   Figure 13: Polygon Tools
3. Click another point on the map to trace around the area you are irrigating making sure you do not cross over any boundaries.  As you mark each point, a black dot should appear at the location clicked, and a green line (labelled with its length in metres) should appear between the two points (Figure 14). If the line you draw is not correct, click the delete last point button and this will delete the line.
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   Figure 14: Adding the polygon boundary line.
4. When you have drawn around the shape that you need, click the Complete Polygon button. The polygon should close and be filled in with a light green colour. The area in square metres of the polygon should be printed on the selected area. To convert this value to hectares, divide it by 10,000. Note down the area in hectares.
5. Click the identify tool  on the toolbar at the top of the page to turn the tool on (it should be highlighted in a white box).
6. Make sure that the Soil Moisture-Effective Rainfall By Land Parcel is set as the active layer (box ticked and text label highlighted so that the background behind it turns a lighter shade of blue).
7. Using the mouse, click on the shape that you drew in step 4. The PAW and Rainfall details for that piece of land should appear in a table under the map (Figure 15). Note down these values next to the area you have previously calculated in step 4.
8. Repeat Steps 1-7 for each partial block of land and record these values.
   
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   Figure 15: Identify Results