Appendix D Terrestrial and Aquatic Biodiversity - Environment ...

D-3. Desktop Review
3.1 Climate
The project area experiences a tropical climate with a distinct a Wet and Dry season, which strongly
influences temporal variability of faunal activity (and flora/habitat/resource presence) throughout the year.
The Wet season typically occurs between November and April, and the Dry season between April and
November. The Wet season is associated with monsoon troughs and occurrence of tropical lows/cyclones
which produce significant rainfall events, and often result in flood events. In contrast, the Dry season
experiences negligible rain which results in river/creek flow reduction/cessation and billabongs/wetlands
drying up or at least reducing to small pools.
The project area experiences an average rainfall between 600 – 800mm per year. The closest weather
stations to the project area are Ngukurr (Station 14609) and Limmen River (Station 14645), which are
approximately 60km to the north and south respectively.
Mean maximum monthly rainfall ranges between 182 and 252mm (January) and a mean minimum monthly
rainfall ranges between 0.1 and 0.7mm (August) for Ngukurr and Limmen River. The mean daily minimum
temperatures at Ngukurr range from 15.1 to 25.5°C a nd a maximum mean daily temperature range from 29.6
– 38.9 °C. Average annual evaporation is approxima tely 2,400mm for the region which, even in the wettest
of years, exceeds the annual rainfall.
All information was sourced from Bureau of Meteorology in December 2012. More detailed climate
discussion with figures and tables is available in the Roper Bar Iron Ore EIS 2012.
3.2 Bioregion
The Interim Biogeographic Regionalisation for Australia (IBRA) divides Australia into units of broadly similar
landform, geology and biodiversity (Baker et al. 2005). The project falls within two bioregions (Figure 4):
• Gulf Fall and Upland; and
• Gulf Coastal bioregions.
Gulf Falls and Uplands Bioregion
This bioregion includes Lawn Hill (in Queensland), and parts of Elsey NP and the recently established
Limmen NP in the Northern Territory. The Gulf Falls and Uplands bioregion comprises undulating terrain
with scattered low, steep rocky hills. The most extensive vegetation is woodland dominated by Eucalyptus
and Corymbia species with spinifex understorey, and woodland dominated by Eucalyptus species with
tussock grass understorey.
The rocky sandstone ranges of this bioregion have some significant refugial values, and include some
endemic or near-endemic species. Threatened species include the highly localised and endangered
Carpentarian Grasswren (Amytornis dorotheae) and the endangered Gouldian Finch (Erythrura gouldiae),
with additional restricted range species such as Gehyra borroloola and Cryptoblepherus zoticus which are
dependent on rocky range habitat.
Important rivers within this bioregion include the Roper and McArthur Rivers. Riparian areas are generally in
reasonably good condition, but are suffering some degradation from uncontrolled livestock, other feral
animals (buffalo, horses, pigs, and donkey). More localised conservation issues include weed infestations,
pollution associated with mining, and altered fire regimes.
This bioregion supports 10 species listed as threatened federally or in the State/Territory.
(Source: NRETAS website)
Client: Western Desert Resources Ltd Page 36 of 150
Doc No. DW120004-C0302-EIA-R-0036
Doc Title: Appendix D – Terrestrial Biodiversity Technical Report