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Assessment of the Jabiluka Project : report of the Supervising Scientist to the World Heritage Committee



Assessment of the Jabiluka Project : report of the Supervising Scientist to the World Heritage Committee


Johnston, A.; Prendergast, J. B.; Bridgewater, Peter


E-Publications; E-Books; PublicationNT; Supervising Scientist Report; 138




Alligator Rivers Region

Table of contents

Main report--Appendix 2 of the Main Report. Submission to the Mission of the World Heritage Committee by some Australian Scientists ... --Attachment A. Johnston A. and Needham S. 1999. Protection of the environment near the Ranger uranium mine--Attachment B. Bureau of Meteorology 1999. Hydrometeorological analysis relevant to Jabiluka--Attachment C. Jones, R.N., Hennessy, K.J. and Abbs, D.J. 1999. Climate change analysis relevant to Jabiluka--Attachment D. Chiew, F and Wang, Q.J. 1999. Hydrological anaysis relevant to surface water storage at Jabiluka--Attachment E. Kalf, F. and Dudgeon, C. 1999. Analysis of long term groundwater dispersal of contaminants from proposed Jabiluka mine tailings repositories--Appendix 2 of Attachment E. Simulation of leaching on non-reactive and radionuclide contaminants from proposed Jabiluka silo banks.




Uranium mill tailings - Environmental aspects - Northern Territory - Alligator Rivers Region; Environmental impact analysis - Northern Territory - Jabiluka; Uranium mines and mining - Environmental aspects - Northern Territory - Jabiluka; Jabiluka - Environmental aspects

Publisher name

Environment Australia

Place of publication

Canberra (A.C.T.)


Supervising Scientist Report; 138


1 volume (various pagings) : illustrations, maps

File type






Copyright owner

Environment Australia



Parent handle


Citation address


Related items

https://hdl.handle.net/10070/462403; https://hdl.handle.net/10070/462400; https://hdl.handle.net/10070/462405; https://hdl.handle.net/10070/462406; https://hdl.handle.net/10070/462408; https://hdl.handle.net/10070/462409; https://hdl.handle.net/10070/462411

Page content

26 3.3.1 Pan factors Wasson et al (1998) note the use by ERA of two simple seasonal factors to estimate pond evaporation from pan measurements; 0.6 in the Dry season (MayOctober) and 0.75 in the Wet season (NovemberApril). They assert that there is a need to check these factors by appropriate modelling that incorporates existing solar radiation data and that the extensive evaporation study conducted at Manton Dam, south of Darwin, needs to be taken into account. The approach outlined above was adopted by ERA in the draft EIS in 1996 but Wasson et al (1998) seem to have been unaware that ERA adopted a more sophisticated approach in the PER for the Jabiluka Mill Alternative. It was the proposal for the Jabiluka Mill Alternative, presented in 1998, which was the subject of investigations conducted by the Mission of the World Heritage Committee to Kakadu. ERA outlined in Appendix B1 of the PER the procedure adopted in estimating evaporation from the retention pond. Pan factors for each month of the year were adopted following a review of all existing evaporation data relevant to the region by CSIRO (Hatton 1997). The conclusion of Hatton (1997) was that, with the exception of the two months of April and October, the pan factors derived by the Supervising Scientist (Vardavas 1987) should be used in all water balance calculations. 100 150 200 250 300 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug M on th ly e va po ra ti on ( m m ) x PPE APE pan evaporation x pan factor Figure 3.3.1 Comparison of average monthly storage evaporation estimates and point potential and areal potential evapotranspiration rates Vardavas (1987) modelled the seasonal variations of net solar and net terrestrial radiation and evaporation for water bodies in the wet-dry tropics of northern Australia. The input to the model consisted of short-term and long-term average meteorological data describing the seasonal changes in atmospheric conditions. He compared his calculations of radiation and evaporation with those determined in the 2-year field study at Manton Dam and 15 years of solar radiation measurements at Darwin and found excellent agreement between his calculations and the measured variables. He then applied the model to the specific case of evaporation from ponds at the Ranger mine at Jabiru. Hence, all of the suggestions of Wasson et al (1998) had already been taken into account in the evaporation calculations presented by ERA in its hydrological modelling of the water management system for the