Development and Applications of GNSS Drifters with Water Quality - - PowerPoint PPT Presentation

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Development and Applications of GNSS Drifters with Water Quality - - PowerPoint PPT Presentation

Nov 13, 2023 371 likes •630 views

Development and Applications of GNSS Drifters with Water Quality Measurements in Shallow Rivers and Estuaries Charles Wang Richard Brown Kabir Suara Yanming Feng 1 Background Why studying shallow water bodies? about 60% of global population

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Development and Applications of GNSS Drifters with Water Quality Measurements in Shallow Rivers and Estuaries

Charles Wang Richard Brown Kabir Suara Yanming Feng

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Background

Why studying shallow water bodies?

  • about 60% of global population live along coast
  • more than 8 in 10 Australians (85%) lived within 50 km of the coastline
  • f Australia (ABS, 2001 population estimate)

Photo credit: Visit Brisbane: http://www.visitbrisbane.com.au/

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Environmental Flow

WATER EVENTS

  • Natural
  • Man Made

POLLUTION

  • Urban
  • Industrial
  • Agricultural

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  • 1. Drifter design and calibration

Design Application

  • 2. Integration of water and air quality sensors
  • 3. Deployment of the real time data acquisition,

processing and management

  • 4. Field deployment
  • 5. Assimilation of Lagrangian data into Eulerian

based models

  • 6. Hydrodynamic and transport modelling

Management of estuarine systems

Advances in real‐time satellite monitoring of flow in rivers and estuaries (RTFLOW)

  • ARC Linkage 2016‐2019
  • QUT and USC research

collaboration with Sunshine Coast Council

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Overview of drifter fleet capability

  • Preliminary challenges
  • Waterproofing, post‐processing and

noise removal

  • Choice of coordinate and extraction
  • f Lagrangian time and length scales

Scales of interest in estuary Drifter capabilities High resolution Medium resolution

  • Low. Res

(Off‐the‐shelf) O [1 m] Position error ~ 2 cm* ~ 20 cm* ~ 3 m* O [0.01 Hz] Frequency 10 Hz 1 Hz 1 Hz Cut‐off freq 1 Hz ‐ 0.01 Hz

* Position error RT‐Flow

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  • Raspberry Pi 3
  • Ublox M8T receiver and antenna
  • 4G wifi hotspot
  • 20000mAh power bank

High positioning accuracy

  • Atlas Scientific sensors: pH, Dissolve oxygen

and Conductivity

  • Turbidity and temperature sensor
  • Voltage isolation boards

Water quality measurements

  • NeCTAR cloud server
  • Thingsboard IoT platform

Tracking and monitoring

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Single frequency RTK solution (10 cm) Continuous WQ measurement (0.5 Hz) Real‐time visualization and management

  • Operation in shallow rivers and estuaries
  • Simplicity and affordable
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Sensor Integration

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WQ Sensor Calibrations

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1 2 3 4 5 6 7 8 9 10 11 12 4 7 8.012 8.421 10

Measured pH Value (pH) Calibration Solution (pH)

Water Quality Sensor Comparison QUT Waspmote Atlas

QUT Sensor (Multi 3430)

  • Computer Integrated Tracking
  • pH, Conductivity, DO and

Temperature Sensor

  • Approx $3500 AUD
  • Developed by WTW a Xylem Brand
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WQ Sensor Calibrations

0.05 0.1 0.15 0.2 0.25 0.3 0.35 4 7 8.012 8.421 10

Measured pH Value Change (pH) Calibration Solution (pH)

Water Quality Sensor Noise Comparison

QUT Waspmote Atlas

10 20 30 40 50 60 70 80 90 4 7 8.012 8.421 10

Time (seconds) Calibration Solution (pH)

Water Quality Sensor Response Time Comparison

QUT Waspmote Atlas

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Turbidity Sensors

  • Amount of cloudiness in water

caused by sand, salt, bacteria and chemical precipitates, etc

  • Commercial turbidity sensors are

relatively large and expensive (> $3000)

SOLUTION

  • Washing machines!

METHODOLOGY

  • Turbidimetric

BENEFITS

  • Cheap ($20 ‐ $30)
  • Operating Range (0‐4000 NTU)

CHALLENGES

  • Calibration
  • Operating conditions
  • Water quality relationships

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Circuit evolution

  • Drifter project microcontroller:
  • Connection: Through the General

Purpose Input Output (GPIO)

  • Analog to Digital Converter (ADC): 16‐bit
  • Stable power: Step‐up/Step‐down DC

voltage converter

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Calibration

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Cloud Tracking and Monitoring Server

  • Nectar Cloud facility
  • Thingsboard IoT platform – open source
  • Data collection
  • MQTT, CoAP, HTTP
  • Data visualization
  • Real‐time charts and maps
  • Data processing
  • Define processing rules
  • Device management
  • Event trigger and alarm
  • Horizontal scalability

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  • http://203.101.225.66:8080/home

Currimundi Lake Epapah Creek

Field Trips

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Proof of concept for drifters with water quality sensor

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pH

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Proof of concept for drifter with water quality sensor

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Dissolve oxygen (mg/L)

50 minutes deployment of RT‐Flow at Currimundi Lake during opening

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Application 1: height with HR‐drifter

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  • GPS drifter vertical

position component validated using fixed location tidal height measurements.

  • This shows that the

GPS drifter data is sensitive to height measurement and thus could be used to monitor both both velocity change and height during flood .

1.34 1.36 1.38 1.4 1.42 1.44 1.46 x 10

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  • 1
  • 0.5

0.5 1

Time from 00:00 on 29/09/2013(sec) Local Tidal Elevation (m AHD)

Drifter measured elevation Fixed local station 0.5 1 1.5 2 2.5 x 10

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  • 1
  • 0.5

0.5 1 Fixed local station Drifter measured elevation

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Application 2: Streamwise velocity estimates

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  • Quality controlled
  • DOF > 5.
  • Run test : passed
  • Max time = 100 s
  • Max distance = 60 m
  • Very good correlation (R2 > 0.9) in streamwise direction
  • Correlation reduces with distance from the surface
  • Poor correlation (R2 < 0.2) in cross stream direction
  • Cause by quick change in direction of flow within the chosen radius
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Application 3: Mixing and Water quality

Effect of mouth conditions and opening operation on dynamics of Currimundi Lake

  • Baseline experiment 1: open inlet (April)
  • Tide, rivers, wind and run ‐offs
  • Tide dominated
  • Baseline experiment 2: closed inlet (September)
  • Wind, river and run‐offs
  • Limited tidal influence
  • Mouth opening operation

(October)

Questions are:

  • What is mixing quality?
  • Magnitude of diffusivity?
  • What are the dominant

mechanisms governing dispersion in the system?

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Results : Flow velocity variability (u)

Open inlet experiment containing trajectories driven by for both ebb and flood tides Closed inlet condition, drifters travelled in ebb‐ward direction about 20o aligned with dominant surface wind direction North

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0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1

Mean horizontal velocity magnitude (m/s)

10-2 10-1 100 101

Mean dispersion coefficient (m2/s)

Open inlet ( Ebb) Open inlet ( Flood) Closed inlet

Closed inlet dispersion Open inlet - Flood dispersion Open inlet- Ebb dispersion

Mixing parameter: Dispersion coefficients (K)

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Evolution

  • Custom PCB to reduce electronic footprint
  • Additional sensors (Temperature, Nitrate, etc)
  • Simplified operation for field staff with provision of operation

manual

  • Event trigger and alarm
  • Configuration options for different application
  • Lora & Lorawan gateway, zigbee
  • Low‐power module for up to a month operation
  • Solar power for permanent placement

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Capabilities

  • Solution is extendable to include additional sensor
  • Can provide valuable tool to locate source of pollutants into waterways
  • Lower cost compared to fixed instruments for equivalent area

coverage

  • Better spatial coverage
  • Adaptability to individual need
  • The GNSS monitoring system offers a flexible and low maintenance

alternative to current fixed station

  • RTK solution provides Lagrangian measurement which may be useful

to improve water modelling in the case of climate changes and flood events.

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