Wind Rose Diagram

Wind Rose Diagram

Wind rose diagrams show wind data for a particular station. It is in the form of star shape so it is also called star diagram. Wind rose diagram is used to depict the wind direction and average frequency for a particular site. Wind data are generally collected at 10 m above ground and if required at various height for specific purposes. 

They can be prepared for month-wise, season-wise or yearly as needed. Wind velocity can also be shown within this diagram. Sometimes they even include air temperature information. Wind rose diagram is vital for constructing runways in airports. The run way is generally oriented towards the prevailing wind. Wind rose diagram is an essential inclusion in pilots chart and sailing charts. Architects and builders need to analyse the wind rose diagram for proper ventilation. The concept of simple wind rose diagram is given below.

Exercise 4

Draw a wind rose diagram for the following data.

Step 1: Select a suitable scale (in this case 1 cm = 10%)

Step 2: Draw a circle to represent the calm for this scale. (Draw a circle with 0.4 cm radius)

Step 3: Mark the directions in this circle using a protractor as shown in the figure. (considering 0° for north, 45° for NE, 90° for East, 135° for South east, 180° for South, 225° for South west, 270° for West and 315° for North west.

Step 4: Draw a bar with suitable with equal to the length of 2.7 cm in northern direction, 0.9 cm in the north eastern direction and so on to complete the diagram.

Step 5: Mention the calm in the centre, mention the scale chosen to draw the diagram and name the directions as instructed above.

Exercise 5

Draw wind rose diagram for the following stations.