Appendix 6. Odour Buffer Assessment [As Published] · 132007.2399

                                                                                                                                                               [14]
                 Odour Buffer Assessment
                 StarCo Developments


shown in Figure 5.1. Note that the wind rose data are extracted from a model, and therefore
represent an estimate of the local conditions.

The wind roses show the frequency of occurrence of winds by direction and strength. The bars
correspond to the 16 compass points – N, NNE, NE, etc. The bar at the top of each wind rose
diagram represents winds blowing from the north (i.e., northerly winds), and so on. The length of
the bar represents the frequency of occurrence of winds from that direction, and the widths of the
bar sections correspond to wind speed categories, the narrowest representing the lightest winds.
Thus it is possible to visualize how often winds of a certain direction and strength occur over a long
period, either for all hours of the day, or for particular periods during the day.




                            46.2 %                                14.5 %                                  6.7 %

                            CALM                                  CALM                                    CALM




            No. of Records :- 2184                 No. of Records :- 2184                 No. of Records :- 2184

            0:01 - 6:00                            6:01 - 12:00                           12:01 - 18:00




                                                                                                                .1        2.1     4.1      6.1      8.1      >10
                                                                                                                TO         TO      TO       TO       TO
                                                                                                                                                                             N
                                                                                                                  2        4        6        8       10

                                                                                                                          WIND SPEED m/s



                                                                                                                      0     10       20       30       40
                            38.1 %                                26.4 %                                                  % FREQUENCY
                            CALM                                  CALM
                                                                                                     WIND ROSES
                                                                                                     Noosa Springs
                                                                                                     E:\Ajobs 1800-1899\1898 Noosa Springs Odour Buffer\1898a\modelling\calm WD randomised.m

                                                                                                     Period: 1/ 3 to 12/ 3



                                                                                                     JOB NO.1898a
            No. of Records :- 2184
                                                                                                              PACIFIC AIR
            18:01 - 24:00                            No. of Records :- 8736                                   & ENVIRONMENT
                                                                              ALL HOURS




                                     Figure 5.1: Wind Roses for the Study Area, 2003



Figure 5.1 shows that in the early morning (rose at top left) winds occur most frequently from the
south, but occasionally from other directions. By afternoon (rose at top right), winds are stronger
and most frequently from directions between southeast and northeast representing both common
synoptic scale influences and the seabreeze effect. The wind roses also indicate a significant
amount of calm conditions. Calm conditions, in this instance, are defined as winds as less than 2
km/hr.




1898a report final.doc                                                                             PAE Job Number 1898a