Calculating the Area of a Feature Mr Daly 16/01/2019 5:32 AM16/01/2019 5:32 AM Calculating the Area of a Feature A feature is an object on the map. The point of this exercise is to estimate the area it take up. A Feature, lets say… a Pond. A Feature, lets say… a Barn. A Feature, lets say… a Forest.

Calculating the Area of a Feature This is a lot of guess work and math, so lets go through it step by step We want to know the area of the pond in Rivertown, shown here 200m We want to find and look at the Scale, show here 200m We now we now will roughly measure the pond We now we now know that the pond is roughly smaller than 200m wide by 200m long Area = Length x Width Area = 200 x 200 40,000 m²

Calculating the Area of a Feature We know the pond is less than 40,000 m² Lets get more precise… Next, divide the pond into segments. Colour code them… Red = Full Yellow = (3/4) Three quarters Full Green = (1/2) Half Full Blue = (1/4) A Quarters Full Red = 40 1/1 squares Yellow = 9 4/3 squares Green = 8 1/2 squares Green = 11 1/4 squares

Calculating the Area of a Feature Red = 40 1/1 squares We now enter our data into our table. You can find the multiplier by converting the fraction into a decimal. (use a calculator) Yellow = 9 4/3 squares We then enter the multipliers. This will help us calculate the exact area of the pond Green = 8 1/2 squares Green = 11 1/4 squares The multiplier should match the type of square it is, for example, ¾ = 0.75 Number of Squares Multiplier Calculation Full squares 40 x 1.00 ¾ Squares 9 x 0.75 6.75 ½ Squares 8 x 0.50 4 ¼ Squares 11 x 0.25 2.75 We then complete the table… We then add the calculations together to figure out how many squares the pond is total… 40 + 6.75 + 4 + 2.75 = 53.5

Calculating the Area of a Feature We know that the Grid Area is 40,000 m² 40,000 m² 40,000 divided by 100 squares equals We know the Grid consists of 100 squares 1 square = 400m² We know that the Pond Area is 53.5 squares 53.5 squares x 400m² 21,400 m² We know the pond is approximately