Territory Stories

Alice Springs recreational dam hydrology report project 6



Alice Springs recreational dam hydrology report project 6


Jackson, D.; Paige, D.


E-Publications; E-Books; PublicationNT; Report no. 12/1979







Publisher name

Northern Territory Government

Place of publication



Report no. 12/1979

File type



Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government



Parent handle


Citation address


Page content

Technical Report WRD79012 Viewed at 00:02:46 on 18/02/2010 Page 150 of 153. I I I I I I I I I I I I I I I I I I I I 47 In the event of an extended wet period with sustained flows or an overall drop in demand for river sand, another sediment trap somewhere further upstream could be constructed~ 3.6 Downstream Scour 3.6.1 Moveable Bed Computer Model A programme based on an alluvial bed transient model (Ponce, Garcia and Simons, 1979) was written to examine the effects of downstream scour. The model solves the equations of water motion, water continuity and sediment continuity using an implicit finite difference scheme. The equations are solved simultaneously at each time step. The model is one bed level only. the D50 size and account is taken calculated using dimensional and calculates changes in Sediment transport is characterised by is not routed by size fractions. No of armouring phenomena. Roughness is the DarCy-Weisbach friction factor. Hydrographs are divided into a series of discrete steady state flow rates. At the beginning of each steady state flow, a backwater calculation gives the initial depth of flow at each cross-section. The simultaneous finite difference equations are then solved at time increments within the steady flow time period to give flow depth,' energy slope, bed load transport rate and bed elevation at each cross-section. Problems were encounted in the solution algorithm and also in meeting the convergence and stability criteria. Convergence and stability criteria for the model have been estimted using time periods of years and degradation lengths of miles. To meet similar criteria on the Todd River, increments of the order of 5 minutes and SOm are requiredi the main constraint being the short time base of typical flood hydrographs. It was planned to run the model with different return period floods to give an estimate of the location and depth of scour downstream of the spillway. There has been insufficient time to properly define a suitable discretization scheme and to test the model on the river without the dam. However initial model runs suggest that the majority of scour will be very localised; within 100m of the spillway for a 1 in 10 year flood.

Aboriginal and Torres Strait Islander people are advised that this website may contain the names, voices and images of people who have died, as well as other culturally sensitive content. Please be aware that some collection items may use outdated phrases or words which reflect the attitude of the creator at the time, and are now considered offensive.

We use temporary cookies on this site to provide functionality.
By continuing to use this site without changing your settings, you consent to our use of cookies.