OceanAlpha has published an article detailing the deployment of its uncrewed surface vessels (usvs) for autonomous water quality monitoring in a Hong Kong reservoir.
As 2017, the Water Supplies Department (WSD) of Hong Kong has acquired five autonomous water sampling and monitoring vessels from OceanAlpha. These unmanned boats are tasked with the routine assessment of water quality in a key reservoir.
Plover Cove Reservoir (PCR) holds the distinction of being the largest impounding reservoir in Hong Kong. Serving as the main source of drinking water, the freshwater stored in PCR can sustain the needs of approximately 7 million residents for nearly 100 days.However, the water quality can be influenced by various environmental factors or unforeseen events. For example, shifts in whether conditions may trigger excessive algal blooms, adversely affecting water quality.
The WSD conducts regular monitoring and sampling of water quality in the reservoir too track any fluctuations, ensuring compliance with the World Health organization (WHO) standards for drinking water safety.
Workflow of the USV system for monitoring and sampling water quality
The USVs employed by the WSD are based on OceanAlpha’s ESM30 model, equipped with advanced water quality monitoring technology. These vessels measure various parameters, including temperature, conductivity, turbidity, dissolved oxygen, pH levels, chlorophyll-a, and blue-green algae concentrations.With integrated GPS and obstacle avoidance systems, the USVs can navigate around obstacles during their operations.
These vessels are capable of surveying different sections of the 12 square kilometer surface area of PCR, effectively recording the distribution and variations in water quality. Conventional vessels previously required several days to cover the entire area, but the USVs can complete the task in just one day.
Utilizing USVs for water quality monitoring offers several benefits:
Simple operation and Deployment – USVs can be managed by a trained technician, unlike traditional vessels that necessitate a licensed operator. This allows for rapid deployment of the USV system in response to water quality emergencies across various reservoirs.
Enhanced Efficiency – Due to their compact size, USVs can access narrower or shallower regions of impounding reservoirs. Thay can also monitor multiple points simultaneously, significantly improving operational efficiency.
Comprehensive Measurement – The USV system can produce graphical reports on water quality, utilizing topographic maps of the reservoirs to facilitate the analysis of data distribution and trends.
Eco-Friendly Operation – OceanAlpha’s ESM30 USV is powered by renewable energy sources, minimizing pollution and safeguarding drinking water. In the case of PCR,a solar panel system installed outside the USV storage area generates the necessary electricity for its operations.
