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) Model Design & Construction CloudGMS 73 n = hydraulic conductivity exponent The UZ gravity module employs a pF log scale for representing soil matric potential. Thus, pF = log10(-100y) where y is the matric potential in metres of water and y is always negative under unsaturated conditions. As identified above in Table 15, each soil profile is composed of at least 2 different soil types and a total of 9 soil types were used to describe the 8 soil profiles defined in the model domain (refer above to Figure 5-8). Unsaturated flow parameters are difficult to obtain from sub-surface samples, therefore, the soil texture has been used as a proxy to determine unsaturated flow parameters. Several catalogues of soil texture to water retention parameters can be found in the literature (Carsel & Parrish, 1988; Rawls, Brakenstiek, & Saxton, 1982; Schaap, 2000; Schaap, Leij, & van Genuchten, 2001). Schaap (2000) collated much of this work and provides soil texture classes and the corresponding average van Genuchten parameters. The averaged parameters are employed as initial estimates for the soils identified in the Western Davenport WCD area. The final unsaturated zone parameters determined for the WDWCD model are presented below in section 6.6. 5.2.10. Saturated zone flow (SZ) Settings specific to the saturated zone during transient model runs are presented below in Table 16. Table 16 MIKE SHE saturated zone settings Saturated zone settings Value Unit Include pumping wells Yes Include subsurface drainage Yes Drainage routed downhill based on adjacent drain levels Yes Drainage level -1.0 mBGL Drainage time constant 1e-07 sec-1 Saturated zone parameter distribution The saturated zone hydraulic parameters are applied using Geological unit codes. The distribution of each geological unit for layers 1-4 are presented below in Figure 5-9 a d respectively. Each layer is referred to by the upper most geological unit represented in each of the layers.