Development of a Groundwater Flow Model - Berry Springs
Knapton, Anthony
E-Publications; E-Books; PublicationNT; 17/2016
2016
Berry Springs
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Table of Contents -- List of Figures -- List of Tables -- Acknowledgements -- Glossary of Terms -- Executive Summary -- 1 Introduction -- 1.1 Background -- 1.1 Aim of the study -- 2 Site Description -- 2.1 Study area location -- 2.2 Climate -- 2.2.1 Rainfall data -- 2.2.2 Evaporation data -- 2.3 Hydrology -- 2.4 Land use -- 2.5 Groundwater extraction -- 2.6 Water quality -- 3 Hydrogeology -- 3.1 Geological formations -- 3.1.1 Mount Bonnie Formation (Pso) -- 3.1.2 Unnamed Dolostone Unit (Psd): Berry Springs Dolostone -- 3.1.3 Burrell Creek Formation (Pfb) -- 3.1.4 Depot Creek Formation (Ptd) -- 3.1.5 Petrel Formation (JKp) -- 3.1.6 Darwin Member (Kld) -- 3.2 Geological structure -- 3.3 Aquifer characteristics -- 3.3.1 Hydraulic conductivity -- 3.3.2 Storage coefficient -- 4 Groundwater hydrology -- 4.1 Groundwater flow -- 4.2 Recharge -- 4.2.1 Water balance method -- 4.2.2 Water table fluctuation method -- 4.2.3 Spring discharge -- 4.2.4 Evapotranspiration -- 4.3 Rainfall-runoff modelling -- 4.4 Predicted natural conditions compared to recent observed flows -- 4.5 Groundwater chemistry -- 5 Available data -- 5.1 Climate data -- 5.2 SRTM digital terrain model -- 5.3 Geological data -- 5.4 Groundwater level data -- 5.4.1 Steady state groundwater levels -- Berry Springs Groundwater Flow Model -- 5.4.2 Time series groundwater levels -- 5.5 River discharge data -- 5.5.1 Manual gauging data -- 5.5.2 Continuous recorder data -- 5.6 Pumping data -- 5.7 Data gaps -- 6 Groundwater flow model development -- 6.1 What is a groundwater flow model? -- 6.2 Conceptual model -- 6.3 Modelling approach -- 6.4 Model package -- 6.5 Model mesh geometry -- 6.5.1 Mesh design -- 6.5.2 Mesh generation -- 6.6 Material properties -- 6.7 Fracture flow -- 6.8 Boundary conditions -- 6.8.1 Recharge and Areal ET Flux -- 6.8.2 Constant head BC values -- 6.9 Pumping data -- 6.10 FEFLOW settings -- 6.10.1 Problem class -- 6.10.2 Temporal and control data -- 7 Calibration -- 7.1 Steady state finite element model -- 7.1.1 Steady state model results -- 7.2 Transient finite element model -- 8 Scenarios -- 8.1 Water balance assessment -- 8.2 Scenario A – Historic climate without pumping -- 8.2.1 Water balance under historic climate -- 8.3 Scenario B – Historic climate with current pumping estimates -- 8.3.1 Pumping estimate methodology -- 8.3.2 Water balance under historic climate and current pumping -- 8.3.3 Impacts of pumping on groundwater discharge at Berry Springs -- 8.3.4 Flow duration -- 9 Results and discussion -- 9.1 Measurable impacts -- 9.1.1 Reduced dry season flows -- 9.1.2 Recession slope of dry season flows -- 9.1.3 Groundwater levels -- 9.2 Rainfall, recharge & minimum flows analysis -- 9.3 Impacts of pumping based on zones -- 10 Conclusions -- 10.1 Key performance indicators -- 11 References -- Appendix A - Groundwater level hydrographs -- Appendix B - Calibrated transient model results
English
Berry Springs Dolostone; Berry Springs aquifer System; Groundwater Flow Model
Department of Land Resource Management
Darwin
17/2016
72 pages : colour illustration and maps ; 30 cm.
application/pdf.
9781743501092
Check within Publication or with content Publisher.
https://hdl.handle.net/10070/272355
https://hdl.handle.net/10070/428025
Berry Springs Groundwater Flow Model Page 41 of 72 7 Calibration 7.1 Steady state finite element model The model was calibrated in steady state to obtain initial conditions for the transient model. Steady state conditions were assumed to be represented by groundwater levels from September 1994 (refer Table 7). Table 7 Groundwater levels used for steady state calibration Site Date Observed SWL Simulated SWL Diff [mAHD] [mAHD] metres RN028855 23/09/1994 15.0 13.5 1.5 RN028856 23/09/1994 8.9 14.6 -5.7 RN028858 23/09/1994 14.0 15.9 -1.9 RN028859 23/09/1994 20.0 14.9 5.1 RN028864 23/09/1994 9.8 9.0 0.8 RN028961 23/09/1994 17.7 15.6 2.1 RN028962 23/09/1994 18.0 14.7 3.3 RN028964 23/09/1994 7.6 6.2 1.5 RN028965 23/09/1994 11.3 13.3 -1.9 RN029016 23/09/1994 10.3 13.5 -3.2 RN029019 23/09/1994 9.9 9.3 0.6 RN029382 23/09/1994 3.9 7.8 -3.9 RMSE 2.99 Note: Data obtained from Hydstra February 2010 7.1.1 Steady state model results Using PEST resulted in a reasonable match to the groundwater levels and the observed discharge for each of the rivers used in the calibration process. A comparison of the assumed steady state heads and discharges and the modelled results are presented in Figure 22. Figure 22 Steady state heads RMS error (2.99 m) is approximately the same order as the error associated with the SRTM elevation data.