PRÉVOIR ET PRÉVENIR LES PROLIFÉRATIONS D’ALGUES NUISIBLES DANS VOTRE COMMUNAUTÉ
EAU CLAIRE À VENIR
LE PROBLEME
LA SOLUTION
QUE POUVEZ-VOUS FAIRE?
La Floride a perdu 2,7 milliards de dollars de revenus touristiques en une seule année à cause des proliférations d'algues nuisibles.
(Alvarez et al., 2024)
Les proliférations d’algues nuisibles étaient 59,2 % plus fréquentes et 13,2 % plus importantes en 2020 qu’en 2003.
(Dai et al., 2023)
À Toledo, dans l'Ohio, 400 000 personnes se sont retrouvées sans eau potable en raison d'une prolifération d'algues nuisibles en 2014.
(Fondation nationale des sciences, 2019)
Les proliférations d’algues nuisibles, également appelées HAB, sont des événements au cours desquels un plan d’eau subit une eutrophisation, entraînant une grande quantité de croissance d’algues sur une courte période.
L'eutrophisation se produit lorsqu'un plan d'eau s'enrichit d'un excès de nutriments, provenant généralement de sources telles que le ruissellement agricole, les déchets industriels et les eaux usées. Cette accumulation de nutriments favorise la croissance incontrôlée des algues, ce qui entraîne des proliférations d'algues nuisibles (HAB). Si certaines proliférations se produisent naturellement, la grande majorité est provoquée par les activités humaines.
La prolifération rapide des algues peut perturber les écosystèmes aquatiques, nuire aux plantes et aux animaux en réduisant les niveaux d’oxygène et en bloquant la lumière du soleil. Au-delà des dommages environnementaux, ces proliférations peuvent poser de graves risques pour la santé publique, comme la contamination de l’eau potable et des fruits de mer.
Sur le plan économique, les HAB peuvent dévaster les industries locales, en particulier le tourisme et la pêche, entraînant des pertes financières importantes et des défis économiques à long terme pour les communautés touchées.
définir
PROLIFÉRATION D'ALGUES NUISIBLES
RÉSOUDRE les proliférations d’algues nuisibles
Apprentissage automatique
Télédétection
Informations géographiques
Systèmes (SIG)
Contributeurs aux proliférations d'algues nuisibles
Multispectrale
ou
Hyperspectral ?
How do we observe Harmful Algal Blooms?
Harmful algal blooms (HABs) are monitored through satellite observations and direct field measurements. Satellites equipped with specialized sensors detect changes in water color and composition caused by algae, providing a broad view of bloom locations and their development over time.
Meanwhile, scientists collect water samples and deploy sensors in affected areas to measure nutrient levels, chlorophyll concentration, and other parameters that indicate bloom severity. These combined approaches enable timely identification of HABs, guiding effective management strategies to safeguard aquatic ecosystems and public health.
What are Spectral Bands?
Remote sensing involves using sensors equipped on satellites or aircraft to detect and record specific ranges or portions of the electromagnetic spectrum called spectral bands from the Earth's surface or atmosphere. These bands, measured in nanometers (nm), range from the visible to the infrared, thermal infrared, and microwave regions of the electromagnetic spectrum. Each spectral band provides information about different properties of the observed objects or areas, which is processed and analyzed to extract meaningful information.
What are Multispectral Sensors?
Multispectral sensors capture data in broader wavelength bands, anywhere from four to thirty-six spectral bands, across significantly more limited ranges of the electromagnetic spectrum, providing significantly less detailed spectral information compared to hyperspectral sensors. Despite the advantages of hyperspectral sensors, multispectral sensors are still much more commonly used due to their earlier establishment, lower operation costs, and lower complexity data outputs.
What are Hyperspectral Sensors?
Hyperspectral satellites refer to data-gathering satellites equipped with hyperspectral sensors. Hyperspectral sensors capture hundreds or even thousands of contiguous spectral bands, which provides a much finer spectral resolution as well as higher volumes of spectral data. Hyperspectral Images (HSIs) allow for better discrimination between different materials or features in the scene being imaged and enable more accurate analysis and interpretation of the data (Signoroni et al., 2019).
Unlike multispectral sensors which are generally utilized as satellite instruments, hyperspectral sensors are more commonly equipped on unmanned aircraft such as drones or other aerial vehicles.
Which is the better sensor?
Hyperspectral imaging offers advantages over multispectral imaging due to its ability to capture a wider range of spectral bands with narrower intervals, providing more detailed and precise information about the composition and characteristics of objects or environments. This finer spectral resolution allows hyperspectral sensors to distinguish subtle differences in materials or biological entities, making it particularly effective for applications such as environmental monitoring, agriculture, and remote sensing of harmful algal blooms (HABs), where accurate identification and analysis of specific spectral signatures are crucial.
Contributeurs aux proliférations d'algues nuisibles
Le changement climatique intensifie la prolifération d’algues nuisibles en réchauffant les eaux et en augmentant le ruissellement riche en nutriments provenant de tempêtes plus fréquentes.
Changement climatique
La pollution agricole, notamment celle due aux engrais, surcharge les plans d’eau en nutriments, alimentant directement la prolifération d’algues nuisibles.
Pollution agricole
Le ruissellement urbain, transportant des polluants tels que du pétrole, des produits chimiques et des déchets, dégrade la qualité de l’eau, créant des conditions idéales pour la prolifération d’algues nuisibles.
Ruissellement urbain
Les déchets industriels introduisent des produits chimiques nocifs et des nutriments en excès dans les systèmes d’eau, accélérant ainsi la croissance des proliférations d’algues toxiques.
Déchets industriels
GIS (Geographic Information Systems) helps prevent harmful algal blooms by mapping where these blooms occur and analyzing factors like water temperature, nutrient levels, and water flow. By understanding where and when blooms are likely to happen, scientists can take preventive measures such as adjusting nutrient inputs or monitoring water quality more closely.
GIS also aids in predicting bloom behavior, allowing for early warnings to protect drinking water sources and aquatic ecosystems, ultimately safeguarding public health and the environment from the impacts of these blooms.
The use of artificial intelligence for analyzing sensor data is a powerful and innovative approach to environmental monitoring. Artificial intelligence can be used to analyze data to identify patterns and indicators that lead to harmful algal blooms.
As new sensor technologies and predictive algorithms have developed, remote sensing-based machine learning models have become increasingly successful in forecasting harmful algal blooms worldwide.
Remote sensing is the science and technology of acquiring information about objects or areas from a distance, typically from the atmosphere or space.
Different species of algae will have distinct characteristics from regular water, which can be used to determine non-HABs from HABs as well as identify which species of algae are present. In February 2024, NASA launched the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite, which carries advanced instruments that will greatly improve the monitoring of harmful algal blooms (HABs) from space.
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PROLIFÉRATION D'ALGUES NUISIBLES
Early Warning Systems
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Develop strong early warning systems by combining hyperspectral remote sensing data with advanced machine learning models like CNNs, RNNs, and random forests.
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Utilize high-resolution hyperspectral sensors (e.g., NASA's PACE OCI) to detect and predict harmful algal bloom (HAB) occurrences early.
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Use machine learning to analyze environmental factors such as nutrient levels and weather data to forecast the likelihood of HABs.
Targeted Mitigation Actions
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Use early warning data to plan specific actions in affected water bodies.
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Implement strategies to manage nutrients, like reducing runoff from farms and cities, to control algal bloom growth.
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Apply localized methods such as aeration, circulation, or chemical treatments in identified HAB hotspots.
Decision Support and Resource Allocation
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Combine remote sensing data, machine predictions, and GIS analysis to guide decisions and allocate resources for preventing HABs.
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Prioritize efforts and distribute resources based on predicted severity and potential impacts in different regions or bodies of water.
Collaboration and Data Sharing
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Promote collaboration among researchers, agencies, and stakeholders by sharing remote sensing data, model results, and analyses for HAB monitoring and prevention.
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Establish platforms and protocols for sharing data to coordinate prevention efforts across affected regions.
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These strategies leverage advanced technology to enhance early detection, targeted action, informed decision-making, and cooperative efforts in preventing harmful algal blooms.
What can you do?
Reduce.
Reduce how much fertilizer you use on your lawn or garden. Excess nitrogen and phosphorus run off into waterways, fueling harmful algal blooms. Choose phosphate-free household products.
Manage.
Manage yard runoff. Plant buffer strips of grass or shrubs along water edges to absorb nutrients. If you can, install rain barrels to capture stormwater and prevent it from carrying pollutants into drains.
Fix.
Fix your septic system. Ensure your septic system is regularly inspected and working properly. Leaking systems can send nutrients into nearby water bodies, promoting algae growth.
Use.
Use permeable materials for driveways or paths to allow rain to soak into the ground. Rain gardens can also help capture runoff, reducing the flow of nutrients into waterways.
Dispose.
Dispose of waste properly. Never dump chemicals, oils, or paint down storm drains. These can contribute to water pollution and encourage algal growth. Take them to a proper disposal site.
Report.
Report algal blooms. If you see unusual green or scummy water, report it to local authorities. Monitoring helps manage and prevent the spread of harmful algal blooms.
Conserve.
Reducing water use at home means less runoff. Use water-saving appliances and fix any leaks to prevent excess water from carrying pollutants into waterways.
My name is Jay Kapoor. I wrote this research paper during my Sophomore year at River Hill High School.
During the 2023-2024 school year, I explored the complex world of harmful algal blooms and remote sensing.
I've learned that harmful algal blooms are becoming a rapidly growing problem globally due to climate change and pollution. We must innovate and find new solutions and prevention measures to combat this deep issue.
I plan to continue my research into my junior and senior year of high school.
Multispectrale
