- Title
- Monthly recharge modelling for the Gnangara Mound
- Creator
- Brown, Anthony; Kuczera, George; Cui, Lijie; Xu, Chengchao; Milligan, Neil; Canci, Mike; Jeeveraj, Charles; Donnelly, Michelle
- Relation
- Hydrology and Water Resources Symposium 2014. Proceedings of the Hydrology and Water Resources Symposium 2014 (Perth, W.A. 24-27 February, 2014)p. 541-548
- Publisher
- Engineers Australia
- Resource Type
- conference paper
- Date
- 2014
- Description
- Perth is facing significant water resource pressures as a result of a growing population and a drying climate. To evaluate sustainable future options, the Integrated Water Supply Scheme (IWSS) model is being upgraded to include a significantly more detailed representation of the Gnangara groundwater system, one of the major sources of water for the Perth IWSS. The objective of this study is to emulate the daily biophysical recharge model used in the PRAMS model of the Gnangara system. The emulator will use a computationally efficient monthly recharge model for use in the IWSS model.Two conceptual models were developed to simulate the monthly recharge fluxes into and out of the Gnangara superficial aquifer. The "Recharge In" model utilised a non-linear Nash Cascade to delay the component of rainfall becoming recharge. In some zones where the depth to water table was considerable, the aquifer showed considerable memory delaying recharge by many months. In contrast, other zones with a shallow depth to water table showed a strong correlation between current rainfall and recharge. By varying the number of Nash reservoirs and conductivity, the model adequately described all recharge behaviours. The "Recharge Out" model used potential evapotranspiration and a linear relationship with groundwater level with threshold cutoff to simulate the monthly flux out of the aquifer. The nonlinear conceptual models produced an average R² of 0.70 for 26 zones, a significant improvement over linear regression models which produced an average R² of 0.59 but performed poorly for zones exhibiting persistence. The study showed that the conceptual monthly models can emulate the high resolution daily biophysical model with reasonable accuracy.
- Subject
- water; modelling; Perth; engineering; hydraulic engineering; environmental engineering
- Identifier
- http://hdl.handle.net/1959.13/1293460
- Identifier
- uon:18598
- Identifier
- ISBN:9781922107190
- Language
- eng
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