Aquatic Ecosystem Science and Applications Seminar

“Water quality estimation and monitoring with open satellite data infrastructure“

András Zlinszky
Sinergise Solutions


Wednesday 15 May, 12:30-13:30


SR D1 - MENH [SR Hydrobiologie] (MENH-DG/08)

Bio: András Zlinszky is a limnologist, remote sensing scientist and sciencecommunication expert. He is graduating in biology and GIS science in Budapest, and he has done a PhD research focusing on wetland conservation mapping in Hungary. Currently Community Evangelist at Sinergise Solutions, M. Zlinszky is working as a science communicator and educator for the official data network of the Sentinel Satellites.

Abstract: Water bodies play a vital role in supporting ecosystems, providing habitats for diverse
species, and sustaining human livelihoods. Moreover, it contributes to climate regulation,
water and carbon cycling (ANSPER-TOOMSALU, ALIKAS, NIELSEN, TUVIKENE and
KANGRO, 2021). From a purely human point of view, they offer recreational opportunities,
such as swimming, boating, and fishing, enhancing quality of life for communities around the
world. Additionally, water bodies serve as sources of drinking water, irrigation for agriculture,
transportation routes and drive human economic development. Recognizing the importance
of water bodies is crucial for promoting their conservation, ensuring their sustainable use,
and safeguarding the countless benefits they provide to both nature and society.
During the recent decades, water bodies quality has been changing rapidly due to
human activities such as fishing, the increase in maritime trade, tourism, agricultural
drainage returns flows, and industrial waste discharges. As a result, it is mandatory to
monitor the area’s water quality. Estimating water quality is crucial for ensuring the safety
and health of humans and the environment. Various parameters such as pH levels,
temperature, turbidity, dissolved oxygen, and presence of contaminants are measured to
assess the quality of water bodies. Such information is essential for political decisions
regarding water resources management, pollution control, and public health protection. This
data can be analyzed to create detailed maps and models, provide insights into the health of
aquatic ecosystems and help identify areas that require attention or intervention. These
informations help in determining if the water is suitable for drinking, irrigation, recreational
activities or aquatic life. Monitoring water quality also plays a key role in identifying potential
pollution sources and taking necessary actions to protect water resources. Overall, accurate
estimation of water quality is essential for maintaining a sustainable and clean water supply
for current and future generations.
Traditional methods for assessing and monitoring water quality rely on in-situ
measurements, water sample collection, and subsequent laboratory analysis. However,
these methods are expensive, time-consuming, and labor-intensive, with limitations in
covering large areas and capturing water dynamics over time. New satellite missions with
advanced sensors offer an opportunity to use remotely sensed data for rapidly and
cost-effectively monitoring water quality on a large scale (DILIPKUMAR and SHANMUGAM,
Easy to use satellite-based water quality visualizations are crucial for monitoring and
understanding water bodies on a global scale with minimal human intervention. Data from
satellites like Sentinel-2 and Sentinel-3, with high spatial resolution and frequent imaging,
are used for this purpose. These visualizations are user-friendly and expected to contribute
significantly to monitoring remote water bodies and enhancing our understanding of physical
limnology and aquatic ecology (ZLINSZKY and PADÁNYI-GULYÁS, 2020).
Satellite data tools involve the use of satellite sensors to detect and measure
electromagnetic radiation reflected or emitted from the Earth's surface. Different types of
sensors, such as optical, thermal, and radar sensors, are used to gather data related to
water bodies.
Optical sensors measure the intensity of sunlight reflected from the Earth's surface at
different wavelengths, to know for example the percentage of absorption of light by water
(LIEW, 2001).
Radar sensors emit microwave pulses towards the Earth's surface and measure the strength
and time delay of the returning signals. They are particularly useful for water monitoring
because microwave radiation can penetrate clouds and vegetation, allowing for all-weather
and day-and-night observations. Radar sensors can detect changes in water level, surface
roughness, and even monitor the extent of floods (ESA, 2023).
Global Navigation Satellite Systems (GNSS) such as GPS (Global Positioning System) are
satellite-based navigation systems that provide accurate positioning and timing information.
They can be used in conjunction with other satellite data tools to monitor water levels, track
water movement, and assess changes in water distribution over time (GPS.GOV, 2021).
For example, OpenET is a tool that uses satellite data from NASA and the U.S. Geological
Survey to provide free information on evapotranspiration helpful in the water and forestry
sectors (VIDAD and OZMENT, 2023).
Satellite datasets complement traditional monitoring methods by providing coverage
over larger areas and often real-time data on various water-related parameters. Additionally,
satellite imagery is becoming more and more popular as a tool for raising awareness of
water quality problems for various uses : research, industry, agriculture and so on.
A Case Study from the Evros Rivereos (Eastern Mediterranean) evaluated for the
first time, a groundwater pollution risk mapping technique using satellite observations and an
extensive dataset of field measurements covering different seasons and many years, to
avoid the difference in atmospheric conditions and detect seasonal variations. Assessing the
groundwater pollution risk at a catchment scale is a common practice, imposed by both
environmental policies and the demand for improved public health protection. (ELIAS,
However, despite its immense potential, the effective utilization of open satellite data
infrastructure for water quality estimation and monitoring present certain limitations. These
include data processing and interpretation complexities, the need for technical training, and
ensuring data accuracy and reliability. Addressing these limitations requires concerted efforts
from governments, research institutions, and the private sector to develop standardized
protocols, enhance data sharing mechanisms, and invest in technological innovation and
human capital development.
In summary, open satellite data infrastructure has huge potential to improve how we
estimate and monitor water quality globally. By using satellite data, we can better, easier and
faster understand how water bodies behave and make smarter decisions for managing it
sustainably for the well-being of current and future generations.

PDF File

Further presentations within the summer semester:

19.6.2024 "Sustainable fishery to ensure a future for fish but also for those who depend on them for nutrition, livehoods and culture" De Martins da Silva Luiz Gustavo