Alice Springs recreational dam hydrology report project 6
Jackson, D.; Paige, D.
E-Publications; E-Books; PublicationNT; Report no. 12/1979
1979-10-01
Date:1979-10
English
Northern Territory Government
Darwin
Report no. 12/1979
application/pdf
Attribution International 4.0 (CC BY 4.0)
Northern Territory Government
https://creativecommons.org/licenses/by/4.0/
https://hdl.handle.net/10070/228346
https://hdl.handle.net/10070/674275
Technical Report WRD79012 Viewed at 00:02:46 on 18/02/2010 Page 64 of 153. I I I I I I I I I I I I I I I I I I I I 39 This suggests that differences in suspended sediment transport yates between the higher 1965 rates and the lower 1979 rates ma.y be due to differE~nces in catch-ment condition, raliler th~n to differences in contributing area. NO correction factor has been applied to transfer suspended sediment data at Wills Terrace to the damsite for two reasons. Firstly there is insufficient data to separate the contribution of the Charles Catchment to suspended sediment load at wills Terrace. Secondly a large proportion of fine sediment is probably originating in the northern section of the Todd Catchment where even in 1979 vegetation is sparse. The suspended sediment data for 1979 shows a fall in transport rate for a given discharge for the three floods. This effect may be due to: 1) influence of different contributing areas 2) a general decrease in sediment supply after successive floods. 3) a decrease in sediment supply available for transport on the falling stage of the hydrograph as the peak flow increases. Without further measurements these effects cannot be isolated .. If there is a general decrease in transport rate for successive floods, any analysis which assumes independent flood events will overestimate suspended sediment load. For analysis, each flow event was assumed to be independent and power relationships were fitted to the 1965 (drought conditions) and the 1979 (wet conditions) data respectively. Transport rates under 1965 conditions are approximately ten times those under 1979 conditions for equivalent flows. Bed load transport upstream of the impoundment was assumed to follow the relaticnship for 1979 suspended sediment data. The power relaticnships are plotted in figure 2.