Development Application part 2 Application Forms REC11/0145

            Step 2: Assessment of slope

    A3.15   Studies have shown that fires burn more quickly and with greater intensity up slopes,
            generally doubling every 10 degrees of slope. Also, the steeper the slope the more
            difficult it is to construct ring roads, firebreaks and provide access for emergency crews.
            Trees situated downhill from structures will have their crowns close to the structures. This
            presents buslitire hazards particularly for exposed structures such as timber decks. Fable
            A3.2 presents the hazard scores for different categories of slope.

            Table A3.2: Hazard scores for slope


             Gorges and mountains (>30%)                                        5
             Steep Hills (>200.%o to 30%)             _                         4
             Rolling Hills (>10% to 20%)                                        3
              Undulating (>5% to 10%)                                            2
              Plain (0°%o to 5%)                                                 1

            ['Vote: For site-specific assessment of Mesh/ire hazard, i/'the site is downhill from the hazard, the slope
            effect may be taken as zero as the f re intensity will he less. However, burning heavy /irels may roll downhill
            and tires may fall down, so recommended setbacks from the hazard still need to be observed.]



            Step 3: Assessment o aspect

    A3.16   Aspect affects bush tire hazard due to the effects that exposure to direct sunlight has on
            different vegetation communities, including the drying rates of fuels. Aspect also
            correlates closely with exposure to low humidity winds that increase bushfire intensity. In
            extremely broken country where there is a variety of aspects, the predominant aspect
            should be used.

    A3.17   As aspect has only a minor influence on flatter land, aspect is not considered to be
            significant on land with a slope less than 5%. Table A3.2 lists the hazard score for
            different aspects and Figure A3. I illustrates the compass degree ranges for each aspect
            category.

P           Table A3.2: Hazard score for aspect


             North to North-Wes
             North-West to West                                                  3
             West to South
             North to East                                                       1
             East to South and all land under 5" ,% slope




    si
         See Appendix LO for the methodology for calculating slope.




    SPP Guideline 1/03                                                                                        June 2003
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