Development of a Groundwater Flow Model - Berry Springs
E-Publications; E-Books; PublicationNT; 17/2016
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
Berry Springs Dolostone; Berry Springs aquifer System; Groundwater Flow Model
Department of Land Resource Management
72 pages : colour illustration and maps ; 30 cm.
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Berry Springs Groundwater Flow Model Page viii of 72 solute: any substance derived from the atmosphere, vegetation, soil, or rock that is dissolved in water specific yield: the ratio of the volume of water that will drain under the influence of gravity to the volume of saturated rock or sediment. steady state: steady state flow occurs when the magnitude and direction of flow is constant with time throughout the entire aquifer model domain. The steady state flow conditions simplify the groundwater flow equation significantly. This does not mean that in a steady state system there is no movement of groundwater, it simply means that the amount of water within the domain remains the same, and that the amount of water that flows into the system is the same as flows out. When steady state flow occurs, time is no longer an independent variable and thus the storage term in the groundwater flow equation disappears; since there is no change in the amount of water within the domain (no change in hydraulic head) there is no change in the amount of water stored in the domain. TDS: (total dissolved solids) the sum or all inorganic and organic particulate material. TDS is an indicator test used to measure the mineral content of groundwater. There is a relationship between TDS and conductivity. In general, TDS divided by 0.64 approximates conductivity. Or, conductivity multiplied by 0 .64 approximates TDS. People monitoring water quality can measure electrical conductivity quickly in the field and estimate TDS without doing any lab tests at all. transmissivity: is the ability of an aquifer to transfer water. Determined as saturated thickness of the aquifer multiplied by the hydraulic conductivity of the aquifer. unconfined aquifer: an aquifer in which the water table is the upper boundary. There is no confining layer between the aquifer and the surface and the pressure at the water table is atmospheric. Water level in an unconfined aquifer may move up and down in response to local recharge or discharge. unconsolidated formation: means naturally occurring, loosely cemented, or poorly indurated materials including clay, sand, silt, and gravel. unsaturated zone: The subsurface zone, usually starting at the land surface that is not fully saturated and contains both water and air. water table: the level below the earth's surface at which the ground becomes saturated with water. The surface of an unconfined aquifer which fluctuates due to seasonal precipitation. water table aquifer: (phreatic aquifer) an aquifer confined only by atmospheric pressure (water levels will not rise in the bore above the confining bed). water bore: any artificial excavation constructed for the purpose of exploring for or producing ground water. yield: quantity of water expressed either as a continuous rate of flow (megalitres per day, etc.) or as a volume per unit of time. It can be collected for a given use, or uses, from surface or groundwater sources.