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 89 7 Water balances 7.1. Introduction 7.1.1. MIKE SHE water balance util ity The water balance utility is a post-processing tool for generating water balance summaries from MIKE SHE simulations and has been used to assess the impacts of the various pumping scenarios. The water budget tool can provide whole catchment water balances and sub-catchment water balances. Water balance outputs include area normalised flows as storage depths, storage changes, and model errors for individual model components (e.g., unsaturated zone, evapotranspiration, saturated zone by layer etc.). 7.1.2. Units for the water balance The values in the water balance are presented as storage depth in millimetres over the area used to calculate the water budget. This normalisation allows water balances for different models or model areas to be more easily compared. The storage depth values can be converted to volume by multiplying by the area of the internal model cells within the sub-catchment of interest. 7.1.3. Total catchment water balance The total catchment water balance provides the inflows, outflows and storages changes for a defined catchment or sub-catchment. However, the total water balance does not include the exchanges between the various flow process modules. To obtain these exchanges other water balance options are available such as a detailed water balance for the saturated zone (SZ) described below. The catchment water balance gives an overview of the inflows and outflows to the model domain, it also provides a quantitative indicator of model performance. Best practice guidelines presented in Table 23 identify that a value less than 1% should be achieved and reported at all times and cumulatively over the whole simulation and ideally the error should be much less. 7.1.4. Saturated zone water balance items The impacts of groundwater development on the water resources in the saturated zone, which includes all water below the water table, is the main focus of the modelling study. The impacts of the various scenarios have been assessed by comparing changes in the saturated zone water balance components. The saturated zone water balances have been extracted using the Saturated Zone detailed water balance option (DHI, 2016). The Saturated Zone detailed water balance option is depth-integrated and provides the inflows, outflows and storage changes to all layers in the saturated zone and includes items for recharge and evapotranspiration. The items in the water balance relate to specific exchanges between the overland flow (OL), unsaturated zone flow (UZ + ET) and the saturated zone flow (SZ), the various items are described below in Table 24.