Severe Weather Calls for New Flood Warning System

Inundation from flood waters is an annual occurrence for many living in Far North Queensland. For a remote community located an hour west of the Atherton tablelands, a rain event during a monsoon will often make it impossible for half the town’s population to get to the local pub for over a week, a severe event could have a much larger impact as the local water supply is sourced at a dam located upstream from the creek that runs through the middle of town. Significant rainfall could cause a quiet creek to become a raging torrent in just a short time.

Until recently, the community has only had the sound of running water and predicted water heights to make critical evacuation decisions. Implementation of a siren network and current conditions, display controlled by local disaster response teams makes use of incoming real time data from the dam spillway upstream. Warning SMS messages are transmitted to disaster management coordinators in extreme weather events.

The reality of severe weather events such as floods in south east Queensland in 2011 and category 5 Cyclone Yasi in North Queensland just a month later has prompted the installation of a flood warning system to protect the population from sudden inundation during a severe weather event. Real time data is measured at the dam spillway and provided to the evacuation planning centre to assist evacuation action plan procedures. A siren network throughout the town can be activated at a moment’s notice and SMS warning messages are sent to regional disaster management coordinators.

Measurements are taken at the Dam spillway by existing Campbell Scientific equipment. A CR1000 data logger takes water condition and depth readings from bubblers in the catchment and downstream from the dam over a V-notch flume. An RF450 spread spectrum radio network relays real time data through repeaters to external databases using a cell phone modem in a strong signal area, data also transmits to a CR800 data logger at the emergency planning centre. This CR800 is capable of controlling the siren network throughout town by analysing data and is connected to a PC running Campbell Scientific LoggerNet software with an RTMC user interface capable of displaying water levels and controlling siren functions.

The system will react to a severe weather event when flood waters exceed a critical predetermined upstream water level, this is communicated to the evacuation centre data logger. The system is capable of initiating the evacuation sirens automatically or manually by the evacuation coordinators using the RTMC interface in the evacuation centre. The availability of real time flood condition data provides a critical tool for evacuation coordinators and the siren network gives a reliable method of initiating evacuation procedures.

Coastal Water Quality Monitoring Network - Yantai-China

Yantai, China, is the pilot location for an innovative Coastal Water Quality monitoring network being jointly developed by Greenspan, Haicheng, the Chinese Academy of Science and the National Marine Agency.

Located on the Bohol Sea, the Yellow River basin is home to almost 350 million people. This large population, heavy industry and being one of the busiest seaports in the world all combine to potentially stress the natural environment.  Coupled with extensive mariculture and oil & gas reserves being explored in the sea, the potential for water quality problems are high.

Recognising the risks, proactive steps are being taken to monitor the water quality and detect any issues before the problems spread undetected.  Greenspan has delivered a water quality monitoring station that integrates a variety of water quality instruments into a real-time online system.

The station includes in-situ monitoring for:

Physical Parameters (YSI Sonde): 

• Temperature, Salinity, pH, Dissolved Oxygen, Turbidity

Nutrients (EnviroTech Instruments AutoLAB): 

• Nitrate, Ammonia, Phosphate using a wet chemistry analyser as Ion Selective Electrodes are ineffective in the marine environment

Biological Activity (YSI Sonde):

• Chlorophyll, Blue Green Algae

Pollutants (Turner Designs):

• Oil (Crude and Refined)

Traditionally, instruments performing these measurements require frequent maintenance, however the system uses an innovative multi-depth flow through sampling system that keeps the instruments protected on shore, dry in between measurements and in light proof chambers.  This solves the problems of bio-fouling, maintaining instruments without divers and obtaining measurements at multiple depths through the profile while minimizing hardware costs.  With the same instrument being used to measure water quality conditions at various depths, instrument variability has been eliminated, providing meaningful depth inter-comparison beyond the accuracy of most instruments.

Above: Crude oil reaction to rainfall event

In terms of the measurement system, the Campbell Scientific CR1000 provides all the measurement and control for full remote operation, including various modes such as:

• Low Temperature Shutdown.  The site can experience freezing conditions in the coastal waters so to protect the instruments the system is configured with a low temperature shutdown which stops water sampling, to be resumed only when the conditions warm up sufficiently

•  Manual mode.  All instruments can be run at higher sampling frequencies or in continuous recording to sample the water conditions during suspicious events
  
• Onboard instrument calibration.  The Nutrient analyser is equipped with reagents and standards for automatic calibration.  As both the instrument performance and the quality of the reagents/standards may change over time, automatic routines are used to run the standards through the system and use these to automatically correct the measured data for decay and drift.  The data logger is programmed with the routines for determining calibration coefficients for each parameter, in real time.

Above: Greenspan and Chinese Academy of Science staff checking the system performance

The CR1000 also manages the provision of data to various sources in real time – with a base station running Greenspan’s EnviroSCADA (with native Chinese support) and ENVAULT (www.envault.com.au) both receiving data in real time.  Aquatic Informatics Aquarius is also used to process the data for gaps, drift and other corrections before reporting to national agencies.

Above:Site inside hut with floating arm visible-Yantai Harbour

From the initial performance of the system, the benefits of the flow through system have been clearly demonstrated.  As shown by the photos below, there has been significant growth in the high nutrient and high light warmer waters near the surface, while the instrument inside the flow through system has no visible growth or degradation of the instrument condition.

Above: The intake arm with growth after 6 weeks

Above: The YSI before cleaning after the same period of time

The inter-comparison data between two nearby depths (in this case for blue green algae) also demonstrates the ability to detect small but discernible differences in the measurements beyond the accuracy of the instrument, even when the absolute value of the measurement is very small.


 For more information on the project, visit Greenspan’s Gallery & Videos at http://www.greenspan.com.au.