MANUAL No - Forest and Wood Products Australia

Manual No. 8: Termite Attack 4
4.3 The Practical Model ..................................................................................................... 46
5 COMPUTATION MODEL .............................................................................................. 49
5.1 Concept ......................................................................................................................... 49
5.2 Calibration of the Model .............................................................................................. 49
5.3 The Coefficient of Variation ........................................................................................ 52
6 RISK ASSESSMENT EQUATIONS .............................................................................. 54
6.1 Hazard Parameters ........................................................................................................ 54
6.2 Supplementary Hazard Parameters .............................................................................. 56
6.3 Expanded definitions of hazard parameters ................................................................. 57
6.3.1 Procedure for assessing the hazard h4 due to the quantity of wood occurring in a
garden and under a house .................................................................................................... 57
6.3.2 Definition of ground contact .................................................................................... 58
6.3.3 Hazard level h6 related to type of construction material ......................................... 58
6.3.4 Hazard h4 related to exposure of timber .................................................................. 59
6.4 Computational Procedure ............................................................................................. 59
6.4.1 Computing the mean time to attack mean(t) ............................................................ 59
6.4.2 Computed Risk and Hazard Score ........................................................................... 60
6.5 Computing Risk ............................................................................................................ 65
6.6 Acceptable Risk ............................................................................................................ 66
6.7 Risk Management ......................................................................................................... 67
6.7.1 Cost Assumptions ..................................................................................................... 67
6.7.2 Comparative Costs of Termite Protection Strategies ............................................... 67
6.8 Some Computed Examples .......................................................................................... 67
6.8.1 Applications to Risk Assessments ............................................................................. 67
6.8.2 Applications to Risk Management ............................................................................ 68
6.8.3 Comment ................................................................................................................... 69
7 APPLICATION FOR DESIGN GUIDE .......................................................................... 70
7.1 Procedure to compute risk ............................................................................................ 70
7.2 Hazard score components ............................................................................................. 70
7.3 The Hazard Score Total ................................................................................................ 72
7.3.1 Comment on Hazard Zone A (Tasmania) ................................................................. 72
7.4 Parameters for the risk equation ................................................................................... 73
7.5 Acceptable Risk ............................................................................................................ 73
8 APPLICATION FOR TIMBERLIFE .............................................................................. 75
8.1 Procedure to compute risk ............................................................................................ 75
8.2 Hazard score components ............................................................................................. 75
8.3 The Hazard Score Total ................................................................................................ 77
8.3.1 Comment on Hazard Zone A (Tasmania) ................................................................. 77
8.4 Parameters for Evaluating the Risk Equation .............................................................. 78
8.5 Risk Management procedure ........................................................................................ 78
8.5.1 Cost Components ...................................................................................................... 78
8.5.2 Effective Cost of Termite Protection Strategies ....................................................... 79
REFERENCES ......................................................................................................................... 80
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