Territory Stories

Development of a Groundwater Model for the Western Davenport Plains

Details:

Title

Development of a Groundwater Model for the Western Davenport Plains

Creator

Knapton, Anthony; CloudGMS Pty Ltd

Commissioned by

Northern Territory. Department of Environment, Parks and Water Security

Collection

E-Publications; E-Books; PublicationNT; WRD Technical Report 27/2017

Date

2018-03

Location

Western Davenport Water Control District

Abstract

CloudGMS has been commissioned by DENR to develop a numerical groundwater model of the aquifers within the central area of the WDWCD to improve confidence in the sustainability of the groundwater resources, as this is the area within the WCD with greatest potential for intensive development.

Notes

Made available by via Publications (Legal Deposit) Act 2004 (NT); Prepared for Dept Environment and Natural resources

Table of contents

Executive summary -- 1 Background -- 2 Physical -- 3 Available data -- 4 Conceptual model -- 5 Model design & construction -- 6 Parameter estimation -- 7 Water balances -- 8 Sensitivity analysis -- 9 Predictive scenarios -- 10 Conclusions -- 11 Reference -- 12 Document history and version control -- Appendix A - Groundwater level hydrographs - Appendix B - Alek range horticultural farm sub-regional modelling

Language

English

Subject

Groundwater; Northern Territory; Western Davenport Water Control District; Conceptual mode

Publisher name

Northern Territory Governmnet

Place of publication

Palmerston

Edition

version 2.0

Series

WRD Technical Report 27/2017

Format

ix, 127 pages : colour illustration and maps ; 30 cm

File type

application/pdf

ISBN

9781743502976

Use

Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government

License

https://creativecommons.org/licenses/by/4.0/

Related links

https://hdl.handle.net/10070/842058 [LANT E-Publications: Development of a Groundwater Model for the Western Davenport Plains, version 1.1]

Parent handle

https://hdl.handle.net/10070/858845

Citation address

https://hdl.handle.net/10070/858846

Page content

Western Davenport WCD Groundwater Model (v2.0) Water Balance CloudGMS 90 Table 24 MIKESHE saturated zone water balance components. Item Description Sign convention sz.qrech Recharge to SZ via the UZ soil matrix. Recharge is a vertical downward flow, thus in the negative direction. This is the same sign as the water balance convention of negative inflow. Inflow - negative sz.qOlSzPos Upward flow directly from SZ to ponded water. This is non-zero only when the groundwater table is at or above the ground surface. Outflow - positive sz.qOlSzNeg Downward flow directly from ponded water to SZ. This is non-zero only when the groundwater table is at or above the ground surface. Inflow - negative sz.EtSz Evapotranspiration directly from SZ. Positive - outflow sz.qSzIn Inflow to SZ storage across the boundary of the model, or inflow across the boundary of the water balance sub-area. Inflow from internal fixed head cells is also included in this term. Inflow - negative sz.qSzOut Outflow from SZ storage across the boundary of the model, or outflow across the boundary of the water balance sub-area. Outflow to internal fixed head cells is also included in this term. Positive - outflow sz.dSzSto Change in SZ storage Positive when storage increases sz.qSzAbsEx Groundwater pumping from SZ. Outflow - positive sz.qSzDrIn SZ drainage to local depressions in the current water balance area from areas outside of the current water balance sub-area. Inflow - negative sz.qSzDrOut SZ drainage to the model boundary, SZ drainage removed directly from the model. Outflow - positive Error SZ water balance error. Positive if water generated (storage + Outflow > Inflow) The sz.qrech component describes the recharge to the water table, but also includes evaporation occurring where the water table is close to the surface. The sz.EtSz component is the evapotranspiration due to vegetation accessing groundwater directly from the water table and is related to the vegetation root depth. 7.1.5. Western Davenport water management zones The sub-catchment zones used in determining the water balances are mostly coincident with the management zones presented as part of the Water Allocation Plan (NRETAS, 2011). The notable difference from the zonation in the 2011 WAP is the combination of three zones designated Northwest Zone, Central Zone and Southeast Zone into a single management zone referred to as the Central Zone. The locations of the current zones used to generate the sub-catchment water balances are presented below in Figure 7-1. The management zones, their corresponding grid codes and areas in square kilometres are presented below in Table 25. To convert the reported storage depth values in millimetres the relevant subcatchment zone area value minus the boundary cells should be used. The Southwestern zone of the model domain covers approximately 50% of the 8512 km2 covered by the South Western or Southern Ranges zone declared in the WAP. Similarly, the north-eastern zone of the model domain covers about 60-70% of the Davenport Ranges zone. The water balance results from these management zones could be scaled up to provide indicative values of the water resources