Observing the Earth from space: a global vision

Imagine being able to peer down at Earth from space, like a benevolent giant. This is what satellites allow us to do, offering us a large-scale overview both fresh and salt water resources. Thanks to them, for continental hydrology, we can observe:

• Extent of water surfaces : lakes, rivers, wetlands…
• Water level variations : floods, droughts, intermittents…
• Water quality : turbidity, presence of pollutants, etc.
• Flows

Satellites thus offer global geographic coverage, making it possible to monitor large regions, including remote or difficult to access areas. They are excellent observers of natural phenomena (floods, droughts, etc.) on a large scale, both spatial and temporal.

Return to Earth for a precise measurement

However, observation from space is not enough. Satellite observations are frequent but limited by revisit periods. Thus, satellite passages can be separated by several days.

To refine our knowledge and validate spatial data, it is essential to return to Earth. This is where the in situ data, collected by sensors and ground stations.

These highly precise field measurements allow us to:

• Measuring parameters not observable by satellite: ocean salinity, surface speed and river flow, etc.
• Capturing local and sudden variations like floods.
• Provide continuous, fine-scale monitoring, essential for resource management and decision-making in the event of an emergency.
• Calibrate and validate satellites to ensure the reliability of their data.

A marriage of data for better understanding

It is by combining spatial and in situ data that we get the most out of these two approaches. Their complementarity is a major asset for continental hydrological observation and monitoring. By combining the extensive coverage of satellites with the precision and continuity of in-situ measurements, we obtain more complete and precise vision water resources and hydrological processes. Water cycle modeling becomes more reliable and makes it possible to best predictions. Finally, new decision-making tools serving resilient water management can emerge for civil protection, agriculture, energy, tourism, etc.

vorteX-io, a major player in Cal/Val satellites

The calibration and validation of satellites (also called Cal/Val) is an essential step, which ensures the accuracy and reliability of the collected data, in order to meet the scientific and operational requirements for which they are intended.

Calibration aims to characterize and correct errors in measurements which may arise in particular from environmental conditions, the aging of the instrument or even data processing algorithms. Validation consists of assessing the accuracy and reliability of spatial data by comparing them to independent references. This is where in situ measurements come in!

You will have understood, Cal/Val is of capital importance for ensuring the quality and correct interpretation of data and thus support scientific research and the development of new products and services. vorteX-io plays an essential role in this domain. Thanks to our expertise in collecting in situ hydrological data in real time, we contribute to the Cal/Val phases of large missions or projects, in close collaboration with space agencies and experts in charge of Cal/Val.

Among them are SWOT (Surface Water and Ocean Topography), St3TART (Sentinel-3 Topography mission Assessment through Reference Techniques) and St3TART Follow On.

• The SWOT mission

SWOT, a Franco-American mission operated jointly by the National Center for Space Studies (CNES) and the National Aeronautics and Space Administration (NASA), aims to measure the level of continental surface waters (lakes, reservoirs and rivers) and their widths, and also estimate the flow of the main rivers. It would also enable us to determine the level of the oceans and seas. 90% of the planet’s water surfaces are scrutinized by SWOT to better understand the water cycle, better control this resource and improve climate models.

In 2022, vorteX-io deployed around twenty micro-stations and conducted 4 drone campaigns with its altimeter VTX-1 on two sections of the Garonne: one between the north of Toulouse and the confluence with the Tarn, the other between Aiguillon (Lot-et-Garonne) and La Réole (Gironde). During a collaboration with the University of Caen, data was also collected on these two sections with a LiDAR on board an aircraft, then reprocessed by vorteX-io. Through these deployments, we were able to collect 300,000 water height measurements, which were compared with those measured by the SWOT satellite .

• The St3TART and St3TART Follow On projects

The project St3TART is funded by the European Union and operated by the European Space Agency (ESA). It aims to define what exactly is a reference measurement, in order to validate satellite measurements on three new types of surfaces being studied: inland waters (lakes, reservoirs, rivers, estuaries, etc.), sea ​​ice and land ice (ice caps, mountain glaciers). As an extension, the project St3TART Follow On intends to operationally produce these reference measurements, in support of the validation activities of the Sentinel-3 satellites of the Copernicus Sentinel-3 Surface Topography Mission (STM).

In this context and among the numerous campaigns carried out, a specific campaign was realized on the Canal du Midi , near the town of Trèbes in the south of France. This site was chosen because the Canal du Midi has a controlled water surface height and an ideal geometry (the channel is perpendicular to the Sentinel-3 track): a perfect site to evaluate the best possible performances that can be achieved by Sentinel-3! In May 2022, a vorteX-io micro-station was therefore installed on a bridge crossing the Canal du Midi, just under the passage of the satellite. The precise water heights collected by the station could be used to operationally calculate a reference measurement and compare it to Sentinel-3 data.

The comparison results obtained demonstrated the excellent performance of Sentinel-3 on this site, in accordance with the mission requirements.

The surroundings of the French town of Marmande, located on the Garonne in Lot-et-Garonne, had been identified as another ideal site for Cal/Val project activities, thanks to the favorable orientation and location of a Sentinel-3A ground trace, and the location of a nearby Sentinel-3A crossover point. The site is also flown over by a Sentinel-6 track, which is of great interest for cross comparisons between several missions. Several in-situ instruments provide water levels along the river (Vigicrues and vorteX-io micro-stations) making it possible to refine local comparisons with satellite altimeter measurements.

In addition, on February 8, 2022, a drone equipped with the altimeter VTX-1, with an embedded LiDAR and camera, was deployed by vorteX-io to measure the height of surface water on a section of approximately 20 km along the Garonne. Overflights of the Vigicrues station in Marmande were also carried out for comparison. These measurements were used to determine the slope of the river, identify local specificities (waterfalls, ponds, etc.) and ensure accurate calibration and validation satellite altimetry over rivers.

The campaign took place during a period of low water level, which is quite common for this river. Two other campaigns were therefore carried out to estimate the slope of the river and its characteristics under different water level and flow conditions, in June 2022 and March 2023. The data collected during these flights also served for the Cal/Val of the SWOT satellite.

Hydrological observation: a crucial issue for the future

Thanks to its technical skills and advanced technologies, vorteX-io actively contributes to the advancement of space remote sensing capabilities. As water challenges increase with climate change, complementarity of spatial and in situ data is becoming more essential than ever. For water stakeholders (scientists, managers, public authorities, etc.), this integrated approach represents a powerful tool to better understand the water cycle and its evolution, predict natural disasters and adapt our resource management systems accordingly.

The issue of sustainable water resource management is more topical than ever. Faced with the growing challenges of climate change, such as the intensification of droughts and floods, it is crucial to have reliable, real-time hydrological data to better protect property and populations. In this context, vorteX-io’s WHYLD project is an innovative solution.

Launched in March 2023 with the support of the European Innovation Council, WHYLD aims to deploy a network of 1,000 in-situ measurement micro-stations by the end of 2024 in France and Croatia, and a further 2,000 by 2026 across Europe. These micro-stations, veritable river sentinels, will collect invaluable hydrological parameters essential for monitoring and forecasting rivers: water level, velocity, flow, surface temperature…

And there’s more to come!

Fundraising to support deployment

To support the accelerated deployment of the WHYLD project, vorteX-io raised 2.9 million euros in May 2024, in addition to the 2.5 million euros initially granted by the European Innovation Council. This fund-raising will enable us to finance the installation of new micro-stations, strengthen our teams to effectively manage the growth of our network, and support our Research & Development activities.

vorteX-io’s ambition is to become Europe’s leading provider of real-time, in-situ hydrological data.

European deployment underway

For several months now, in parallel with the manufacture of the industrial version of the micro-stations, our teams have been meticulously analyzing numerous sites to ensure their perfect suitability for the instrumentation: sufficient sunlight to power the solar panel, good GSM reception to enable data transmission, sufficient height to ensure that the most frequent floods do not reach the station, installation beyond the reach of potential acts of vandalism… They then proceeded to apply for the authorizations required for any installation.

In France, 500 sites will be equipped with micro-stations by January 2025, of which over 200 by the end of summer 2024, mainly in the Ile-de-France, South-West and South-East regions in France. In Croatia, thanks to our collaboration with the Croatian Water Agency (Hrvastske Vode), 500 sites will also be equipped this year, with almost 300 completed by the end of the summer period.

The WHYLD project thus illustrates the exemplary cooperation between vorteX-io and public water stakeholders in France and Croatia, to achieve a common goal: better monitoring of watercourses to better protect property and populations, and improve water management.

International ambitions

The WHYLD project is part of the ambitious global initiative “Early Warning for Allinitiative, launched by the United Nations in November 2022 at COP27 and led by the World Meteorological Organization (WMO). This international effort aims to provide 100% of the world’s population with access to early warning systems by the end of 2027, protecting them from the dangers of extreme meteorological, hydrological and climatic phenomena.

In this context, vorteX-io works closely with the WMO and the Global Water Partnership. This partnership aims to support the activities of the Associated Programme on Flood Management (APFM), which promotes an integrated flood management approach.

Growing teams

The WHYLD project requires a strong team to support the company’s rapid expansion! In just one year, the number of employees who have joined the vorteX-io adventure has more than doubled. Today, 35 men and women bring together all the skills needed to design, develop, support and promote our innovative solutions.

A dozen more recruitments are underway for 2024, and we plan to double our workforce by 2026 to almost 80 employees.

A promising future for Europe’s first river forecasting service

With its burgeoning European deployment and solid financial backing, the WHYLD project is set to play a crucial role in the revolution in real-time hydrological monitoring.

It demonstrates the potential oftechnological innovation and international cooperation to meet the major challenges of water resource management. We would like to thank the European Innovation Council, which has made a significant contribution to the project’s success by opening up numerous avenues for collaboration throughout Europe!

The adventure continues…

Find out more about WHYLD

France, an ambitious player on the international space scene

The French space industry employs over 17,000 people and has achieved major technological and commercial successes. In response to the space ambitions of other nations and the private sector, this sector of excellence in France’s industry is now embarking on an era of innovation and growth, thanks to the space component of France 2030.

The objective? Keep France among the world’s leading space nations. The government has earmarked a budget of over 80 million euros to support emerging companies in the sector and their innovative solutions, through the launch of several calls for tenders covering a wide range of topics, including mini and micro launchers, in-orbit services, space surveillance andhydrology.

France has a major ambition:

• Ensuring France’s autonomous access to space.
• Take strategic positions and prepare the industry for the new challenges of space.
• Position the ecosystem favorably in new space markets and applications.

The “Hydrology” call for tenders: optimizing water resource management using spatial data

Spatial data is currently little used by hydrological monitoring specialists. And yet, their processing is an invaluable tool in the fight against climate change and the management of its consequences, providing accurate and regularly updated information about our planet. The French spatial data ecosystem has what it takes to position itself among the world leaders in this field, and to demonstrate its cutting-edge national expertise. A case in point is the Franco-American SWOT mission (Surface Water Ocean Topography), conducted jointly by NASA and CNES. The goal? Probe 90% of the Earth’s surface waters with hitherto unrivalled precision, enabling the scientific community to better understand the dynamics of the oceans and surface waters (lakes, rivers and reservoirs). This understanding is fundamental to meeting the major global challenge of resilience in the face of climate change, and improving the global management of a resource that has become strategic: water.

In the wake of the Water Plan, CNES, in partnership with the Water and Biodiversity Department (DEB) of the French Ministry of Ecological Transition and Territorial Cohesion, has launched a call for tenders for the use of space data to monitor and manage the quantity and quality of water, as part of the space component of France 2030.

The 3-year services will enable us to monitor the volumes of water stored in dam reservoirs, as well as the dynamics of water bodies and rivers. Complementary services will monitor water quality in lakes and rivers, irrigated agricultural plots and intercropping plant cover density. They will be addressed to government departments and all local players involved in the issue.

The services of the “use of spatial data for water monitoring and management” call for tenders:

1. Monitoring water surface areas and volumes stored in reservoirs

2. Monitoring water quality in surface water bodies

3. Detection of irrigated agricultural plots and monitoring of vegetation cover density for water protection

4. Accessing, using and analyzing spatial hydrological data

The winners, of which vorteX-io is proud to be a part, were unveiled at the official launch of the “Spatial hydrology: qualitative and quantitative management of surface water” project on February 2, 2024 at the Ministry of Ecological Transition and Territorial Cohesion in Paris.

It should be noted that most of the project leaders in this call for tenders are members of the Hydroventurethe first operational space hydrology center for global water monitoring and management. Through this partnership, they are committed to developing an industry of excellence in space hydrology, and helping to support the ambitions of the France 2030 plan.

VorteX-io chosen by the French government to provide spatial hydrology services

Jean-Christophe Poisson, co-founder and CEO, and Jérémy Hahn, Platform team manager, were present at the event to represent vorteX-io, selected by the French government and CNES to provide the following two services.

Monitoring water quality in surface water bodies

This service is designed to meet the need for regularly updated information on the temperature, chlorophyll-a and microalgae content (particularly cyanobacteria), turbidity and suspended solids of surface waters. This applies to water bodies over 3 hectares in size, as well as watercourses over 30 meters wide. The data will be presented in dashboards at different scales (territorial and temporal), providing invaluable decision-making supportand optimal information for the players involved, whether public or private.

The Magellium (project leader, in charge of spatial data processing) / vorteX-io (co-contractor) consortium, supported by three scientific laboratories (Pôle Écosystème Lacustre, Géosciences Environnement Toulouse and Laboratoire d’Océanographie de Villefranche), was chosen to provide this service, thanks to its complementarity in space and in situ.

Water resource management requires theuse of hydrometric data, mainly from in situ stations. And yet, satellite data can enrich water resource monitoring and meet a wide range of objectives (global strategic management, facility management, flood and low-water forecasting, etc.) thanks to one major advantage: regular coverage of the entire world, including territories that are difficult to access.

In order to validate their accuracy, satellite measurements require calibration data from ground-based measurements. Within the framework of this call for tenders, vorteX-io will complete the existing network of in situ measurements with theinstallation of around thirty micro-stations which will mainly analyze water temperature and, in time, its turbidity.

Focus on the vorteX-io micro-station

Inherited from space altimetry, the innovative technology of the vorteX-io micro-stationmicro-station technology overcomes the limitations of traditional in-situ instruments (instrument drift, flood damage, vandalism, inaccessibility, financial resources for maintenance, etc.). With no contact with the water and powered by solar energy, our sensor guarantees the highest precision of hydrological parameters measured autonomously and without human intervention in the field, just like a satellite. Its durability and measurement stability are therefore superior to those of immersed sensors. What’s more, each of our micro-stations is automatically controlled remotely and in real time to guarantee optimum operation (on-board software updates, integration of new functions, monitoring of battery health and charge level, etc.). This type of fleet management, fully operated by vorteX-io, considerably reduces costs and offers highly competitive rates.

Access, use and analysis of space-based hydrological data

Carried out by the vorteX-io (project leader) / Numérisk (co-contractor) consortium, this service makes available all the data produced by the other three lots of the call for tenders, via a single portal. It will also offer complementary tools based on the interpretation of combined data, such as the visualization of areas exposed to water stress, enabling rapid and precise identification of areas at risk.

VorteX-io has distinguished itself through its expertise in the technical development of the platform. Maelstrom® platformplatform, its in-depth knowledge of spatial data and its ability to analyze hydrological data in great detail. This unique combination of skills, combined with Numérisk’s know-how, guarantees the successful implementation of this crucial tool for the appropriation of the products and services offered, by all players.

Backed by the official recognition of our expertise by the French government and CNES, we are continuing to innovate to meet the growing need for knowledge and forecasting of watercourses, and to support the resilience of local authorities in their sustainable management of this vital resource.

The importance of knowing the flow rate of a watercourse

To assess a watercourse, there are two important criteria to evaluate: its quality and its quantity. After telling you about our work on measuring water quality, today we’d like to tell you about our progress on quantitative measurements. For this purpose, there is a key metric to measure: its flow rate, which is the volume of water passing through the cross-section of a watercourse.

The knowledge of a watercourse’s flow rate is important for various purposes, including flood characterization (or low-flow, drought), management of hydraulic structures, agriculture (through irrigation), survival of aquatic species, and many other subjects. This knowledge is all the more crucial in addressing broader challenges such as climate change, water sharing, and biodiversity.

Current flow rate measurement techniques

There is currently no universal method or instrument for flow measurement. The choice between various methods depends on a multitude of factors such as resource availability, required accuracy, and specific morphological characteristics of the watercourse.

The various existing methods are :

• Velocity field gauging methods (the most common ones): These involve exploring the velocity field, meaning flow velocities are measured at various points across the flow section (both horizontally and vertically). For this, there are numerous methods, the main ones being the hydrometric wading rod method (measuring the flow velocity of the watercourse using a propeller rotating proportionally to the local flow velocity), the ADCP method (based on the Doppler effect, involving the emission of acoustic pulses into the water and analyzing changes in their frequency upon reception), gauging stations (permanent installations equipped with flow measurement instruments, which can include pressure sensors, acoustic sensors, electromagnetic sensors, etc.), or satellite remote sensing systems (using satellite data to monitor changes in water surface, allowing flow rate estimates, although this is more commonly used for large rivers or extensive areas).
• Tracer dilution gauging: this involves the controlled introduction of a chemical product, such as salt or a colored tracer, into the watercourse. The assessment of the degree of tracer dilution then allows the calculation of the watercourse’s flow rate by measuring the tracer concentration at a sufficient distance from the injection point, where the tracer mixing is considered complete. This approach is relevant for relatively modest flow rates, reaching a few cubic meters per second, and proves particularly suitable for turbulent flows that facilitate efficient dispersion of the tracer.
• The capacity gauging method consists in assessing the flow of a watercourse by measuring the time required to fill a container of predetermined volume. Although this approach offers a direct measurement of flow, it should be noted that its range of application is relatively restricted, limited by constraints inherent in the method. Furthermore, its implementation, especially in a river environment, can be complex due to various operational factors.

The combination of the measured velocity with the cross-sectional area allows the reconstruction of instantaneous flow rate at a specific point. By repeating these measurements under various hydrological conditions and correlating them with the water height at the time of measurement, rating curves are established. While they provide an estimate of the flow rate based on a single water height measurement, these curves require regular updates. Indeed, the shape of riverbeds can evolve over time due to various factors such as vegetation, human intervention, floods, etc.

Our approach involves combining data already measured by the vorteX-io micro-stations.

Our micro-stations already provide two essential real-time data points: water height and surface flow velocity.

The precision of water height measurement is ensured by a LiDAR, allowing centimeter-level measurement without contact with the watercourse and without measurement drift over time (thanks to the use of LiDAR technology). As vorteX-io micro-stations are securely mounted on robust structures such as bridges, maintenance needs are significantly reduced, and the quality of measurements is improved.

Regarding surface flow velocity, it is assessed by applying an algorithm to the video footage captured by the micro-stations. This approach, based on state-of-the-art technology, provides an accurate and reliable estimate of surface current velocity.

… and a fresh innovation

The remaining element to determine is thus the geometry of the flow section, crucial information for quantifying the volume of water in transit and, consequently, for generating an estimate of the flow rate.

By default, vorteX-io micro-stations do not provide bathymetry. However, the use of an iterative process makes up for this shortcoming. We use a Machine Learning algorithm, which we have previously and extensively optimized, to identify water-occupied areas in the captured images. This automatic detection allows for creating a ‘water mask’ to retain only the image surface actually occupied by water. Given that the water height is known for each image, this allows for calculating the planar geometry of the watercourse at that specific height. By combining water height measurements with the complete history of captures at different levels, it becomes possible to reconstruct the precise geometry occupied by the water surface in overlapping horizontal “layers“.

This approach not only allows for the updating of bathymetry closest to the terrain but also ensures consistently updated flow rate measurements. This revolutionary method ensures the accuracy of the flow rate estimates obtained by the vorteX-io network’s micro-stations.

Transforming these measurements into flow rate estimation

The combination of the surface velocity field, water height, and watercourse geometry then allows for a precise estimation of the flow rate under the micro-station.

This estimation plays a crucial role in establishing and updating the rating curves specific to each station. These curves thus provide an estimate of the flow rate correlated with the measured water height, even when the image capture conditions do not allow for a direct assessment of flow velocities. Thus, we can provide the flow rate of a watercourse at the same frequency as other data we measure: that is, one to four times per hour under normal conditions and four to six times per hour in the case of threshold exceedance (these frequencies are defined by the user).

The real-time estimation of river flow rate enabled by these measurements represents a major advancement for continental hydrology, and the resulting applications are numerous and significant. This innovation will soon enhance the prevention of natural water-related risks (floods and droughts) and improve water resource management, both at the local and large-scale levels.
The continual improvement of this knowledge forms the very foundation of the development of a pioneering river forecasting system deployed by vorteX-io in Europe through its WHYLD project.

While these two types of extreme hydrological phenomena can cause immense damage, they appear to be at opposite ends of the spectrum. Although they appear to be completely different, there are links between periods of drought and episodes of flooding, which under certain conditions can amplify each other. That’s why it’s important to consider hydrological cycles as a whole.

Devastating floods

Flooding is becoming more frequent throughout Europe, with increasingly disastrous consequences. Heavy rains and sudden floods result in river and coastal flooding, often causing human casualties, massive population displacement, and significant material damages. Climate change, with its impact on precipitation patterns, is one of the major factors contributing to this intensification.

However, it should also be pointed out that rapid urbanization and the modification of watersheds considerably increase the risk of flooding. Indeed, under the pressure of land and real estate development, the construction of buildings and infrastructure is often allowed in areas that are prone to flooding. There is also an observed alteration of the land due to human activities such as agriculture and deforestation, which contribute to an increase in vulnerability to floods. Furthermore, the expansion of urban areas and the creation of impermeable surfaces reduce the soil’s capacity to absorb water, thereby increasing the risk of flooding during heavy precipitation events.

Prolonged droughts

Over the past year, we have witnessed a cruel intensification of droughts in many European regions, which has sometimes led to water restrictions, reduced crop yields due to lack of irrigation, sanitation and drinking water supply problems, and even concerns about the cooling of certain nuclear power plants.

Under the growing influence of climate change, scorching summers and unusually dry winters play a key role in this intensification.
Insufficient precipitation, combined with the overexploitation of water resources, deplete underground reserves of the water table and heavily impact the flow of rivers. It is also observed that drought and increasing temperatures significantly worsen the extent of forest fires worldwide, thereby exacerbating soil erosion and reducing their capacity to absorb precipitation.

Droughts and floods: two sides of the same coin

The existing links between these two extreme hydrological phenomena demonstrate a paradoxical relationship that requires in-depth study to develop effective measures for prevention and resilience in the face of environmental risks.

How drought periods can cause floods

Contrary to what logic might intuitively lead us to think, severe drought periods can significantly contribute to causing this type of flooding. During a drought period, the dry and hard soil loses much of its capacity to absorb water when it rains again. In this case, non-infiltrated water accumulates on the surface or flows downhill, causing extremely sudden and often devastating floods.

These are known as runoff floods, also called surface floods or rain floods.

Understanding how drought periods can contribute to causing floods is crucial in order to take preventive measures to minimize risks and potential impacts.

How floods can worsen drought periods

Although lack of precipitation is always at the root of drought, flooding can play a part in worsening it. Indeed, during a flood, when the power of the water unleashes on rich and deep soils, it can carry away sediments and nutrients that are essential for plant growth. The impoverishment of soils affected by this phenomenon can make future plant growth more difficult. In some cases, this can locally contribute to the deforestation of impacted areas, thus exacerbating the harmful effects of new drought periods.

According to the NGO Global Forest Watch (GFW), ” all major watersheds on the planet have lost 22% of their forest cover in just the past 14 years“.

Moreover, floods can also disrupt ecosystems by altering water quality, nutrient quantity, and the composition of plant and animal communities. Flood episodes can lead to increased water turbidity, which can affect the photosynthesis of algae and aquatic plants. Additionally, nutrients and sediments carried by floods can deposit in lakes and rivers, altering water chemistry and affecting the habitat quality of aquatic organisms.
These changes can contribute to the proliferation of algae and aquatic plants, leading to decreased oxygen in the water and the death of part of the established fauna and flora. Once again, these disruptions in wetland habitats can contribute to weakening their resilience during future drought periods.
In most situations, floods are not directly responsible for droughts, but they can have impacts on water balance and soil fertility if appropriate management measures are not implemented.

The role of jet streams

Another element to consider in explaining extreme hydrological and meteorological phenomena lies in the disturbance of jet streams. These high-altitude atmospheric currents, located between 4.5 and 10 miles above the ground, are conditioned by both the rotation of the Earth and the temperature differences between the poles and the equator. Over the past decades, these temperature differentials have decreased, leading to a rise in average temperatures on land and sea, as well as a rapid decrease in ice at the North Pole. This phenomenon results in slowing down the air masses of the jet streams and intensifying the north-south undulations of these massive currents.

These changes translate into the strengthening of climatic events and a slowdown in their movement. Episodes of precipitation, heatwaves, and heatwaves become more intense and last longer in the areas they affect.
This is one concrete explanation for the radicalization of the climate, not only in Europe but also globally.

Jet streams: atmospheric currents over Europe © CARBON BRIEF, NASA

The situation in Europe

May 2023: Italy hit by floods in Emilia-Romagna

From May 16th to 18th, 2023, the region of Emilia-Romagna in northeastern Italy witnessed a series of deadly floods. They were caused by unprecedented torrential rains that fell in just a few days. These exceptional precipitations caused rivers to overflow, inundating 23 municipalities in the region, including Modena, Bologna, and Ferrara, and triggering over 300 landslides.
The Italian Civil Protection Agency indicated that the floods affected 14 rivers simultaneously, hence the magnitude of the disaster.

The human toll from the floods is 14 deaths and 36,000 displaced.

The floods also caused extensive damage to infrastructure, including roads, bridges and power lines. Numerous homes, shops and businesses were also damaged or destroyed, and a significant proportion of the crops were wiped out. The floods have had a major impact on the region, and authorities and experts alike agree that it will take many years for the Emilia-Romagna region to recover from this.

As a reminder, Emilia-Romagna had already suffered heavy rainfall just two weeks earlier, with flooding and landslides claiming two lives.

Regarding vorteX-io, although our network of in-situ hydrological micro-stations does not yet have measuring points in the Emilia-Romagna region, our sensors located on the Po River, at a distance of approximately 150 to 200 km from the center of the floods, allow us to get an idea of the intensity of the floods that occurred between May 16th and 18th, 2023, in Emilia-Romagna.

Indeed, on this graph, available on our hydrological platform Maelstrom®, we can observe a radical increase in the water level of the Po River of nearly 13 feet in just 36 hours, approximately one week after the torrential rains in the Emilia-Romagna region. The flood wave took several days to reach the two vorteX-io micro-stations located several tens of miles away from the devastated areas. It is important to note that the Po River is the longest and largest river in Italy, and at the measurement points, its width is approximately 650 feet. A 13-feet rise in its level within such a short period of time speaks volumes about the intensity of the flood episode from May 16th to 18th, 2023.

Balkans: Bosnia-Herzegovina and Croatia also affected

May 2023 was a month of great dangers in the western part of the Balkans as well. Just like in Italy, Bosnia and Herzegovina, Croatia, and Serbia were severely affected by heavy rainfall that triggered serious flooding. The rains, originating from a depression centered over the northern Adriatic, caused several rivers to overflow, leading to road closures, landslides, and the evacuation of populations in several areas of Croatia, where the military was mobilized for assistance.

Croatia regularly suffers devastating floods that cause extensive damage and human losses, such as those that occurred in 2014. In its commitment to improving flood monitoring in Europe, vorteX-io will deploy 500 of its hydrological micro-stations in Croatia over the next two years. This operational deployment will take place as part of the WHYLD project, which is subsidized by the European Innovation Council (EIC) and will double the number of existing measurement points in the country. The collaboration between Croatian authorities and vorteX-io in collecting and analyzing large-scale, real-time in situ data will contribute to better understanding and anticipation of such phenomena.

April-May 2023: Period of Historic Drought in Southern France, Spain, and Portugal

Meanwhile, on a continental scale, Europe is facing a prolonged and concerning drought episode for this time of year in several regions.

The situation is historically severe in Spain and southern Portugal, where heat records (and consequently drought records) were broken in late April 2023, with average temperatures exceeding +6°C and locally reaching up to +12°C across the Iberian Peninsula.

The northwest of the Maghreb is also affected by this situation, experiencing equally exceptional anomalies due to an air mass coming from the Sahara.

Such air mass temperatures are similar to those encountered during summer heatwaves and had never been observed in April in Spain before, with peaks approaching 40°C during the period from April 24th to 30th, 2023.

As seen on the maps and reports released by the European Drought Observatory (EDO), these thermal and hydrological anomalies are also severely impacting southern France, particularly the Pyrénées-Orientales area.

(Move the vertical slider to compare the state of drought in 2022 and 2023 during the first 10 days of May)

At the end of April, the Prefect of Pyrénées-Orientales was compelled to convene a “water resource” crisis committee consisting of local authorities, users, experts, associations, and government services. This committee was able to “confirm, based on objective and shared data, a historically severe drought situation unprecedented since the beginning of meteorological records (1959) and, probably, even further back.”

Consequently, the Prefecture of Pyrénées-Orientales issued an order declaring a “drought crisis” for the catchment basins and aquifers of Agly and Têt, as well as the Aspres and coastal border aquifers, from May 10th to June 13th.

Last February, the SMBVA (Mixed Union of the Agly Catchment Basin) requested vorteX-io to install three of our micro-stations above the Agly River. Thanks to the Maelstrom® platform, the SMBVA team can now monitor the river in real-time and receive alerts in case the customized thresholds they have set are exceeded.

In contrast to the measurements taken in the Po River basin during the same period, from May 15th to 24th, 2023, the results are clear: water is absent, and the river is completely dried up.
This fact is confirmed by water level measurements as well as real-time images captured by vorteX-io micro-stations.

Conclusion

In recent decades, the frequency and intensity of climate-related events such as floods and droughts have increased in Europe. The interplay between these water-related natural disasters is the result of a complex interaction, with these phenomena influencing each other.
Human activities heavily contribute to climate change, which is a key factor in this vicious cycle of alternating floods and droughts. Greenhouse gas emissions, population growth, urbanization, and changes in land use practices all contribute to this detrimental dynamic by profoundly altering the environment and its natural cycles.

Implementing measures to minimize the number of floods and reduce their impact on populations, property, economic activities, and the environment is of crucial importance. This requires integrated watershed management, with a focus on soil conservation, wetland preservation, and sustainable water resource management.

Additionally, improving infrastructure by investing in flood protection systems such as levees, dams, and drainage systems is necessary. Adequate land use planning is also paramount, avoiding construction in high-risk flood areas and promoting sustainable agricultural practices. Deploying real-time and large-scale early warning systems helps quickly detect flood risks and provide warnings to populations. This is the goal of the WHYLD project led by vorteX-io and supported by the European Commission.
It’s worth mentioning that the scientific community places great hope in the French-American space mission SWOT, which aims to understand the global water cycle.

Raising awareness and educating individuals about safety measures are also essential in strengthening preparedness and resilience against water-related natural hazards.

Lastly, to address these significant challenges and secure a more resilient future, strong international cooperation at the European level is absolutely crucial. Sharing knowledge, best practices, hydrological data, and resources will enable Europe to effectively prevent and manage the alternation of floods and droughts, which do not recognize borders.

The objective of this exciting environmental research and development project is to develop innovative methods for remotly measuring the water quality of rivers and hydrological networks.
We are very pleased to announce that future micro-stations in the vorteX-io network will be equipped with unprecedented features that allow them to remotely and in real-time measure two essential parameters for water quality:
– surface temperature
– turbidity

Stream temperature measurement

Among the various metrics measured in the field of water quality, water temperature is one of the most important. It is indeed a key factor in the habitat and metabolism of aquatic species and thus in the biodiversity of wetlands in general. Some aquatic organisms have specific temperature requirements for reproduction and even survival. As such, an increase in temperature can directly affect their growth and development and, by extension, weaken entire sections of the food chain in these fragile ecosystems.

Water temperature also has a significant impact on the amount of dissolved gas in the water. In general, the higher the temperature of the water, the less able it is to dissolve gases. A watercourse can thus undergo a drastic decrease in the dissolved oxygen content in its waters, which can have harmful consequences on the aquatic fauna and flora.

Moreover, water temperature is an important variable for both agriculture and industry, and even in the energy sector.

In this regard, power/nuclear plants, for example, use large quantities of water to cool their equipment. The temperature of the incoming water and the temperature of the discharged one are therefore a major factor in this process and can have a significant impact in terms of nuclear safety.

Close monitoring of temperature variations in rivers and lakes also allows the detection of potential sources of pollution.

Finally, on a larger scale, this metric is one of the key indicators for assessing the impacts of climate change on continental aquatic ecosystems.

Turbidity measurement

The turbidity of a liquid refers to the presence of undissolved matter in suspension that affects its transparency.

In a watercourse, suspended particles can be either of natural origin (sediments, algae, organic matter, etc.) or of anthropogenic origin (chemical pollutants, waste, etc.). That’s why an increase in turbidity can be an important indicator of water quality degradation.

The amount of suspended matter in water can have a direct impact on human health as high levels of turbidity can be associated with health risks, such as waterborne diseases. Turbidity measurement allows the detection of human health risks related to the consumption ofpotentially contaminated water (bacteria, viruses, parasites and toxic chemicals).

Furthermore, episodes of flooding and drought have a direct influence on the turbidity levels of a watercourse. During a flood, high flows bring with them large amounts of sediment, organic matter and soil from the riverbed, banks and submerged lands.
On the other hand, in the case of an acute drought episode, especially during heat waves, when water evaporates due to heat, the suspended matter particles become concentrated in the small remaining amount of water. In some cases, turbidity can then rise exponentially.

Turbidity is an important parameter for many applications, especially for drinking water treatment and industrial and municipal effluent monitoring. By measuring turbidity, fluctuations in water quality can be detected early and action taken to protect the environment and human health.

In the coming weeks, and still within the framework of the contract that binds us to the Adour-Garonne Water Agency, a second series of tests will be carried out to measure turbidity by remote sensing as well. This will be the second metric measured by the future versions of our micro-stations.

Water agencies and water quality measurement in France

In France, the measurement of water quality in rivers is mainly carried out by the 6 water agencies, which are public institutions in charge of water resource management.

The water agencies oversee the water quality measurement network, which includes:
–field measurements
– automated measuring stations

© www.lesagencesdeleau.fr

During field measurements, water samples are manually collected and then analyzed in a laboratory.

Automated measuring stations are equipped with sensors that continuously measure parameters such as temperature, turbidity, pH, etc.
The data is then automatically transmitted to the water agencies.

These water quality data are used to assess the condition of streams, track trends, identify areas at risk, and guide actions to protect and restore aquatic environments.

Unfortunately, although essential, measuring the water quality of rivers requires a lot of human time for manual sampling and is extremely costly in terms of automated sampling equipment.

It should be noted that while submerged devices (probes, stations) are highly effective, they are also by definition particularly exposed to the vagaries of watercourses. Flood events, severe weather, impacts caused by driftwood, ice, etc. are all causes of failures and drift in the quality of the data collected.

This is why thescale of the human and financial resources required to ensure their maintenance weighs heavily on the budget of the french water agencies in charge of these measures.
The cost of the equipment, its installation and maintenance can largely explain why the number of sensors currently deployed on the French territory does not exceed 800.

The vorteX-io approach: remote sensing

In contrast to these immersed sensors, vorteX-io’s idea is to develop its network of hydrological micro-stations, mainly installed on bridges spanning rivers, towards new functionalities.

In addition to the measurements already carried out (water height, surface velocity, image/video capture), the vorteX-io micro-stations will soon be able to measure the surface temperature as well as the turbidity of the water.
As micro-stations are located several meters above the water, they are by definition sheltered from the hazards suffered by submerged collectors. As the measurements are made at a distance from the water, it is called remote sensing.

Another major advantage of vorteX-io micro-stations is their low cost, as they require virtually no maintenance. Actually, thanks to their unique design, directly inherited from the space domain, their vital constants are automatically monitored, remotely and in real time. Once installed, no human intervention is required and their operation is fully automated.
The internal battery is powered by a solar panel. This energy autonomy ensures their long-term internal operation, that of the embedded measuring instruments, but also thetransmission of telemetry and the reception of commands, firmware updates, etc.

The advantages of being located away from the water are numerous, but the downside is that this method excludes the possibility of taking water samples.
Chemical measurements (pH, conductivity, dissolved oxygen, nutrients, metals, bacteria, pesticides, etc.) will therefore remain the prerogative of underwater instruments.

How to measure water quality without being immersed?

Remote sensing of water surface temperature is performed in the thermal infrared range using the sensors embedded in the new version of the vorteX-io micro-station (v.2.1).

The validation of the “vorteX-io measure” in real conditions has been taking place since the beginning of 2023 on the Girou, a small river in Haute-Garonne (in the Southwest of France). The site corresponds to the necessary validation criteria since it was already equipped with operational submerged probes, dedicated to temperature measurement and used by the Adour-Garonne Water Agency. It was the ideal place to compare the measurements made by the two devices.

Remote measurements are more complex than those made with immersed instruments. Thus, one of the problems to be solved in order to obtain reliable measurements with thermal imaging cameras, lies in the fact thatit is necessary to take into account only the water surface. To avoid that the calculations are distorted by the temperature of possible emergent objects (banks, floating obstacles, bridge and other fixed structures …), a “software mask” must be applied to keep only the parts of the image that correspond to the water.

By applying to the images a Deep Learning algorithm specially developed by our R&D team, and applied to the optical images, we can concentrate the measurements only on the water surface.
An average calculation is then applied to obtain accurate results.

The images below detail the process of creating the “software water masks” used in the surface temperature calculations.

Conclusion

The results obtained regarding water temperature measurements are already very encouraging. R&D is still underway for the automatic measurement of turbidity by remote sensing and we will present the results shortly.

These innovations will allow for the real-time measurement of surface temperature and turbidity of watercourses at a lower cost and at a scale previously unimaginable.

Already at the forefront of hydrological measurements in terms of quantitative data on rivers, vorteX-io is now preparing to complete the scope of its offer by adding the qualitative dimension. These innovations are part of our goal to create the first hydrological database at the European scale, which can be consulted via Maelstrom®our platform dedicated to hydrology.

Protection of wetland biodiversity, monitoring potential sources of pollution, better management of water resources (consumption and sanitation), evaluation of the impacts of climate change on hydrological systems and ecosystems: the issues related to water quality data are numerous and increasingly relevant.

The summer of 2022 proved to be exceptionally hot, one of the most scorching ever recorded by national weather records from various countries. In Western Europe, France, the United Kingdom, Spain, and Portugal experienced intense heat episodes with temperatures reaching 40°C on several occasions with varying durations. This is nothing new, one might say, as summer is regularly the scene of extreme heatwaves, whether in Europe, the United States, India, Australia, Brazil, etc. Indeed. But the intensity and frequency of these suffocating peaks is rapidly increasing, as records from meteorologists around the world attest. The World Meteorological Organization (WMO), a specialized agency of the United Nations, reported that July 2022 was one of the hottest months on record globally.

These periods of intense droughts are also particularly sensitive regarding the risk of fires, particularly forest fires. No debate on this point, every summer brings its sad procession of forests ravaged by fire and 2022 has unfortunately distinguished itself on this front. Even though the media largely covered the dramatic news on a daily basis, there are however other ecological risks, largely less known and also linked to periods of heatwaves and droughts.

Huge networks at risk

These risks concern the fast and catastrophic degradation, in terms of quality and quantity, of lakes, rivers, and all aquatic environments and wetlands. These complex ecosystems are experiencing much the same fate on territories extending to the scale of entire countries and even beyond.

When extremely high temperatures extend over long periods of time and are compounded by a severe lack of rainfall, water levels drop and at the same time water temperature rises. Almost all natural aquatic environments thus end up in a situation of stress, even fragility and danger. Due to the interplay of watersheds and the interconnection of waterways, this situation can quickly spread and extend to huge territories.
Especially since the risks threatening natural aquatic environments can accumulate and aggravate each other.

Excessive fish mortality rate

The first victims of these extreme climate periods are usually the fish populations in the hydrological systems we are talking about.
The decrease in the water volume in rivers causes a forced concentration of fish fauna, a major stress factor for fish, especially for fish larvae, which are more fragile and easily exposed to their predators. The drop in water level is usually combined with a rise in temperature, increasing the risk exponentially.

As with all other gases, the amount of dissolved oxygen in water is closely related to the temperature of the water. The solubility of oxygen in wetland water decreases when the temperature increases. 20°C water temperature is already synonymous with significant stress for most common fish species in our watercourses. When the water reaches 23°C, the situation becomes critical, and beyond 25°C,their very lives are in danger.

Eutrophication of environments and alteration of water quality

The scarcity or even disappearance of rainfalls combined with evaporation due to heat are directly responsible for the appearance of another risk. The eutrophication of aquatic environments is a pollution phenomenon, the origin of which can be natural or due to human activity, caused by the excessive concentration of nutrients certain algae can assimilate. Matter in excess leads to the proliferation of certain species of aquatic plants, phytoplankton and aerobic bacteria, which causes a disequilibrium in the environment due to the overconsumption of oxygen it causes. This alteration of water quality can cause an impoverishment, then literally death by asphyxiation of an aquatic ecosystem. Heat and droughts considerably increase this eutrophication phenomenon in the environment, since when flows decrease significantly, the water concentration in nitrogen, carbon, nitrates, and phosphates accelerates proportionally. It is therefore a major risk in terms of ecology and biodiversity of aquatic environments and wetlands.

Bank erosion

Banks of lakes and watercourses are the buffer zone between aquatic and terrestrial environments. This transitional situation makes banks extremely rich environments in terms of biodiversity, but also particularly fragile because it is subject to strong constraints throughout the annual cycles. The constant variations of humidity-flooding-drought, temperature, and flow, put a strain on these sensitive areas and expose them ongoing erosion.

If it seems obvious that flooding episodes are particularly violent for the banks of natural aquatic environments, one could however easily underestimate the impact that periods of drought and heatwaves have on them.
The bank soil constitutes a most favorable support for the establishment and development of numerous plant species, the riparian woodland. This flora provides important functions of shading and water filtering, favoring the natural regulation of temperature and the water quality of aquatic environments, reducing the risk of eutrophication. When heatwaves and droughst reach dramatic levels, like those of the summer of 2022, many riparian woodland plants dry out and eventually die, no longer providing their regulatory function. Their root system loses strength and then disappears, and with it its soil stabilization function, seriously accentuating the risk of erosion caused by future floods, rainfall runoff and human activities. The repeated swelling/contraction cycles of the banks due to alternating periods of flooding and droughts also play an important role in the fragility of this sensitive transition area.

Monitoring tools and the role of prevention in drought risk management

Throughout the history of humanity climatic hazards have of course always been part of the cyclical risks borne by each civilization, and the 21st century is no exception to this law. Each passing season brings with it its share of chaotic episodes. We are bearing the brunt of the effects of global, rapid, and increasingly brutal climate change. But there is no point in giving in to sterile catastrophism, on the contrary, there is still time to act, with the aim of preventing, anticipating, and minimizing the effects of climate change, particularly the risks of water-related natural disasters. Science allows us to better understand the water cycles, locally as well as globally.
Oceanography, hydrology, and fluviology allow us to better understand nature and how to palliate its instabilities, at least partially.

The means of knowledge and technologies at the disposal of our modern societies are numerous and more and more efficient. Hydraulic structures, reasoned management of water resources, ecology of natural environments, progress in Earth observation space missions dedicated to hydrology, the development of monitoring networks (via in-situ hydrological stations and intelligent and communicating field sensors) are powerful tools at our disposal to measure, understand and finally act. We must also add to this “arsenal” the constant progress of predictive computer models and hydrological applications. The development of Artificial Intelligence has greatly contributed to this progress.
In addition to these technical tools, we can also be legitimately confident in the change that is taking place (somewhat forcibly, it must be said) in the way we perceive our relationship with the planet. Realizing a little more each day how much we are an integral part of nature and how much we are intimately dependent on it can only push us to change our paradigm. Quickly.