Territory Stories

Sediment Quality Sampling Design for Darwin Harbour

Details:

Title

Sediment Quality Sampling Design for Darwin Harbour

Creator

Brinkman, Richard; Logan, Murray; Northern Territory. Department of Environment and Natural Resources; Australian Institute of Marine Science

Collection

E-Publications; E-Books; PublicationNT; Report Number 44/2019

Date

2020-01-06

Location

Darwin Harbour

Description

In the context of increasing development and associated pressures, this project aims to inform the development of a first systematic, long-term, sediment monitoring program for Darwin Harbour which takes into consideration the physicochemical nature of Darwin Harbour sediment and the oceanographic processes which will influence the movement of contaminated sediment in the Harbour. The rationale for the program is that seabed and estuarine sediments are both an extensive habitat and the ultimate repository for many contaminants that enter waterways. In addition, monitoring of contaminants in sediment may facilitate the identification of increasing contaminant loads in the Harbour which may not be detected by water monitoring programs due to the high flushing rate within Darwin Harbour and infrequent water sample collection.

Notes

Made available by via Publications (Legal Deposit) Act 2004 (NT).

Table of contents

1. Executive summary -- 2. Introduction -- 3. Methods -- 3.1 Overview of methodology -- 3.2 Tidal Hydrodynamics -- 3.3 Wave Dynamics -- 3.4 Sediment Modelling -- 3.5 Sediment sampling design analysis -- 4. Results -- 4.1 Tidal and wave driven hydrodynamic processes -- 4.2 Sediment transport modelling -- 4.3 Sediment characteristics from previous sampling programs -- 4.4 Sediment sampling design analysis -- 4.4.1 Existing chemical sediment data, Outer Harbour sediment monitoring data, and designated sampling sites -- 4.4.2 Hydrodynamic modelling layers -- 4.4.3 Exclusion zone masks -- 4.5 Spatial Model fitting -- 4.5.1 Background on statistical techniques for designing sediment sampling program -- 4.5.2 Results from statistically derived sampling design - East Arm -- 4.5.3 Results from statistically derived sampling design - Outer Harbour -- 4.5.4 Representation of sampling sites mapped with hydrodynamic and sediment modelling parameters -- 4.6 Harbour Sediment Zonation, and conceptual representation: -- 5 Conclusions -- 6 References -- 7 Appendix 1

Language

English

Subject

Sediment quality; Tidal hydrodynamics; sediment sampling; design analysis

Publisher name

Northern Territory Government

Place of publication

Palmerston

Series

Report Number 44/2019

Format

43, 74 pages : colour maps ; 30 cm

File type

application/pdf

ISBN

9781743502303

Use

Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government

License

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

Parent handle

https://hdl.handle.net/10070/755961

Citation address

https://hdl.handle.net/10070/765802

Page content

21 In addition to the long-term monitoring sites, a number of designated sites have been provided. These sites form additional sites and need consideration in the candidate configurations and are illustrated in Figure 10 as red points. Figure 10 Map of Darwin Harbour indicating the spatial configuration of Munksgaard 2012 sediment monitoring sites (dots). Solid dots signify sites within the Outer Harbour and East Arm focal areas. Black circular points represent Munksgaard 2012 sediment sampling sites, square points represent Offset Outer Harbour sediment sites and red points represent designated sites. 4.4.2 Hydrodynamic modelling layers The seabed shear stress products provide spatial modelling of the expected forces acting on the sea bed and provide proxies for the likelihood for sediment erosion, transportation and deposition. These products were used to create masks that exclude areas of high erosive or transportation potential. Masks for East Arm and the Outer Harbour are shown in Figure 11 and Figure 12 ,