Calculate TPZ incursions according to AS4970 (2009) (V.1.0 2012)

See DBH Info See Measurements DBH Info Diagram

Step 1

Enter DBH (cm) at 1.4m above ground level

TPZ radius (m)	TPZ Area
000	000

For SRZ, enter diameter at base (cm), above root flare.

Structural Root Zone (m)	SRZ Area (Sq m)
000	000

Select the incursion type, based on the diagram below

Type 1Type 2 Incursion Type 1 Incursion Type 2

Enter distance from tree to works (m)

Distance from tree to works

TPZ radius (m)	00.0
TPZ area (Sq m)	00.0
Structural root zone (m)	00.0
Distance (m) required from tree to make incursion 10%	00.0
% of TPZ lost	00.0

Change to Incursion Type 2

Enter distance from tree to works (m)

Distance from tree to works


A	B