How does your professional and personal experience relate to water?
My fascination for water started at a significantly young age. I still remember the day when I realized how grateful I should be for having easy access to fresh water. It was while watching a documentary on TV about children living in a rural area, who must trek long distances to collect water at the expense of attending classes or playing with their friends, just to meet their families’ most basic needs. This episode seemed like a revelation with a taste of remorse and an inexplicable feeling of guilt. Before this marking moment and given the fact that I grew up in an urban area where water was always taken for granted, I never thought about the scarcity of water and its impact on the wellbeing of inhabitants in many regions around the globe.
Over the years, my interest in the importance of water kept on growing and I was introduced to a variety of practices and pseudo-sciences. Eventually, one day during a visit to one of my relative’s farms, I had the chance to encounter a professional dowser; someone who handles a divining rod to tell the location where to find groundwater at shallow depths. He was using a Y-shaped olive branch and explained that if I grab the two tips of the Y-shaped olive branch and walk over groundwater the remaining tip on the branch points up, and sometimes starts rotating in the presence of a strong groundwater flow. He also mentioned that other experts use eggs instead. However, my knowledge about modern practices for sustainable water management remained incomplete and did not exceed the traditionally widespread and used techniques.
Fast-forward years later, I had the chance to attend the Space Applications course given by Dr Friedrich Teichmann – Lecturer at the University of Applied Sciences Wiener Neustadt and Director of the Geospatial Institute of the Austrian Armed Forces. These classes were insightful and an excellent opportunity to learn about space-based technologies, such as Satellite Navigation, Earth Observation, and telecommunication. Over the course of a semester, we were initiated to the capabilities of Earth Observation via Remote Sensing from space, from accessing free satellite data, to processing hyperspectral images by selecting the right combination of bands to satisfy the requirements at hand. With the pristine guidance of Dr Teichmann, we had gradually become aware of the role of satellites in monitoring the health of our planet, as well as their importance in responding to the United Nations Sustainable Development Goals. As a conservative estimate, six of these goals are somehow related to water. Therefore, my very first step into the use of space-based technologies to resolve issues related to life sciences started with a university project, in which the main tasks consisted on the analysis of satellites images for the identification and detection of environmental changes.
Currently, with the fundamentals of remote sensing that I have acquired, I am at least capable of pursuing an independent research project. In this research, I aim at shedding light on how remote sensing and space applications, in combination with modern trends in technology, can help alleviate inevitable global challenges arising from the natural phenomena of land degradation and anthropogenic contributors to climate change. Modern technology like the Internet of Things (IoT), for example, can include monitoring of various physical phenomena, real-time tracking, and automated preprogramed events.
Once this research yields satisfactory results, I plan to put them into practice. The project aims at implementing a systematic AI based approach to ceaselessly identify the regions that are most likely vulnerable to land degradation. Thereupon, analyse the contributing factors and autonomously execute real-time curative and preventive interventions. Multiple sub-projects shall follow, that essentially will focus on sustainable water resource management, which plays a major role in preventing the occurrence of land degradation.
As an Aerospace Engineer what was the most interesting thing you have learnt about designing satellites aimed at measuring water related parameters?
The measurement of water-related parameters is a common discipline within the realm of Earth Observation. Throughout history, aerospace engineering and remote sensing equipment have been walking hand in hand to improve the quality of data records. Sometimes constraints faced by aerial/space vehicles can be compensated by enhancing sensors and vice versa.
It all started more than 150 years ago, when engineers used to attach cameras to balloons for topographic mapping, to capture features and show variations in the terrain. Thereafter, mounting cameras on airplanes became an important source of information. With the rise of space technologies around the 1960s, artificial earth satellites used cameras with film canisters, which were protected by re-entry capsules and dropped back to earth to be caught mid-air by airplanes. In 1972 NASA launched Landsat 1 and set up the first continuous archive of Earth Observation that is still growing today. So, it is impossible to talk about earth observation without mentioning the involvement of aerospace engineering.
The quality of water-related parameters depends on the resolution of measurements carried out by the onboard instruments, to be precise, the spatial, radiometric and spectral resolution of the images, as well as the temporal resolution of images. The latter is defined by the amount of time that passes between imagery collection periods for a given surface location. It is directly associated to the satellite’s altitude and orbital plane, which influence the revisit time and latency. Latency indicates how readily available data are in near real time. Besides, the number of satellites utilised to monitor any given area can reduce the revisit time through the superposition of images from all the available satellites. Nowadays, in the New Space era, we are witnessing the emergence of large constellations of satellites. Although small in size, they are capable of providing images at any time, especially when using Synthetic Aperture Radar (SAR) that are very efficient against darkness and cloud coverage.
While a huge part of measurements are carried out by onboard instruments, another important part lies within the ground segment infrastructure; hardware to store and compute the massive size of datasets and smart algorithms to sort and process data that is relevant to the requirements of the end-users. Ground Processing requires an organized and well-defined structure for finding and reusing metadata, otherwise engineers might encounter inconsistencies in terms of data and storage. Once the infrastructure is set in place, data analysts can start building models designated for the measurement of parameters related to water resources.
Among the models commonly used are change detection algorithms that aim at detecting changes among pictures along with other qualitative factors. Also, histograms which are statistical distributions of values in a dataset can be used for everything from enhancing contrast in an image to serving as a basis for object classification and image comparison. An instance for the latter would be to distinguish between variations in levels of chlorophyll, fluorescence, salinity, and sea surface temperature to classify objects in images into different categories. Sometimes, it is necessary to compare the levels of each parameter to correctly predict the nature of objects on an image. The value of one parameter is not usually enough for classification. Two different objects on an image, for example, might have equal values of chlorophyll, but different values of fluorescence. One parameter usually cannot be conclusive for classification.
Together with feature extraction algorithms, which are techniques used to digitize features in an image to points, lines, and polygons, it is possible, for example, to extract a coastline from a satellite image over several years and hence monitor the erosion or any changes that are happening along this coastline. Another interesting water-related algorithm is the Normalized Difference Water Index “NDWI”, which geospatial analysts apply in drought affected areas to monitor the plant water content. NDWI is a very good proxy for plant water stress and can be used in the field of irrigation management. On the other hand, the Normalized Difference Vegetation Index “NDVI”, another graphical indicator of vegetation, is used to show relative health by highlighting the chlorophyll density in plants. When combined with other metrics, the health of plants becomes an indirect indicator for soil moisture and water retention under the vegetation canopies.
Hydrologists rely on very complex and powerful geospatial models to estimate the impact of a flood and implement mitigating disaster management measures before the flood actually happens. Sometimes flood control systems can be very expensive, however there are some simple and easy-to-grasp flood inundation models that can be life saving for first responders and flood victims. The principle of these models exploits elevation data. Starting from a single point the simulation fills the area on the map with the maximum volume of water that can enter the area as a preventive worst-case scenario.
You researched the reasons for desertification in the region of Tinfu Dunes which is located in the south-east region of Morocco, at one of the gates to the Sahara. What do you see as the main reasons for desertification and land degradation in Morocco?
Based on an initially modest analysis of the Tinfu Dunes region (See Figure 1) , I have correlated four main aspects to the occurrence of desertification: soil erosion, vegetation , soil moisture, and urban/population growth (See Figure 2). As a result, it could be observed that the increase in land degradation along with population growth was proportional to the decline in soil moisture, vegetation, and water absorption. Regardless of the conclusions we might draw from the analysis, it would be naïve to assume that population growth is the only reason for desertification, despite population usually being the main reason for depletion of water resources. In turn, the scarcity of water resources has a major impact on vegetation health, which is the quintessence of preventing soil erosion and sand encroachment. In general, desertification remains a complex process by which land degrades in arid, semi-arid, and sub-humid areas. It involves multiple and various processes that are difficult to quantify. Nevertheless, it all boils down to the symbiotic relationship between human activities and glocal (reflecting or characterized by both local and global considerations) climatic variations that constitute a major threat to the entire planet.
Are these causes similar to those in other regions suffering from desertification?
The United Nations Convention to Combat Desertification (UNCCD) reports that over 168 countries across the world are affected by severe land degradation with an estimated 110 states already at risk. The drylands in question cover approximately 40 percent of the world’s land area. They host around two billion people. Indirect implications of land degradation affect the lives of more than 3.2 billion of the world’s population. Developing countries show the highest dependence on dryland resources. Any deterioration or loss of the productive capacity of soil is impeding development and threatens the dauntless attempts to improve vital conditions in these countries. Women and children are most vulnerable to the effects that land degradation and drought have on the socio-economical gear.
The degradation of land is not an issue that can be treated individually. As mentioned before, desertification is intertwined with climate variability. These two have mutual ricocheting effects on each other and form a pressing environmental situation that is doomed to worsen if no remedial action is being taken. When land is degraded, greenhouse gases that are supposed to be stored in soil are released into the atmosphere, moving land degradation to the top in the list of most important contributors to climate change. The population growth is predicted to increase by about 35 percent in 2050, which is 9.7 billion earthlings. On the other hand, if the trend continues, earth could lose 95 percent of its land due to degradation. Moreover, in order to support the required food production, the world will need an additional 120 million hectares of agriculture land; that is a new farm the size of South Africa.
The aforementioned aspects are all somehow associated to desertification and have cascading consequences; the decrease in land that can be cultivated will force local inhabitants to seek new areas for pastoralism and agricultural activities at the expense of forests and wild vegetation, providing an expedient solution to a problem that only takes a short time to backlash in a much fiercer way. This is because deforestation reduces carbon storage, eventually increases the rate of climate change and brings along undesirable issues ranging from a decrease in precipitations, depletion of groundwater, expansion of wildfire, to poverty and hunger, etc. Ultimately, desertification is part of an intricate, vicious cycle that feeds itself to amplify the severity over time.
Fortunately, the international community is striving to mitigate land degradation through joint efforts intended to understand the different mechanisms of desertification combined with the effects of climate change. The objective is to invest in Sustainable Land Management and to encourage practices that help with the restoration and rehabilitation of dryland areas. First through policy frameworks aiming at the implementation of Land Degradation Neutrality policies and allowing populations to avoid, reduce and reverse desertification. Secondly, via the use of regionally specific technological solutions based on scientific innovation and indigenous local knowledge. Furthermore, the support of land users in terms of agricultural advisory services, access to credits, securing land tenure rights and other incentive encourage the spreading of Sustainable Land Management philosophy.
Would nano-satellites or CubeSats (2) be suitable to monitor desertification?
In the past, the use of traditional earth observation satellites required a substantial compromise between spatial and temporal resolution. One had to choose between regular data at low spatial resolution, or occasional high-resolution data. With the emergence of constellations of CubeSats, it is possible to overcome the spatiotemporal trade-off that used to limit the effectiveness of remote sensing for land monitoring and precision agriculture applications. Satellite engineers have been able to exploit the yearly doubling miniaturization of digital electronics and off-shelf components so that they can provide cost-effective alternatives to traditional satellite missions.
Thanks to CubeSat/nanosatellite constellations, we are able to reduce the temporal resolution from 16 days, as was the case with Landsat and Sentinel, to daily and real-time monitoring, with a satisfying spatial resolution down to 30cm per pixel. Due to the small dimensions of a standard CubeSat unit (approx. 10x10x10cm), the cost of launching multiple CubeSats is relatively cheap compared to standard earth observation satellite missions. It is true that most CubeSats can only provide optical imagery, however they can capture snapshots in the following bands of the electromagnetic spectrum: blue, green, red, and near-infrared. This is sufficient for the measurement of a variety of factors related to desertification. Other onboard sensors such as Synthetic Aperture Radar (SAR) or Light Detection and Ranging (LIDAR) can deliver more accurate data, but require larger satellites because of compactness challenges. Nevertheless, there is a growing trend in transitioning space-based SAR/LIDAR platforms from large to small satellites.
Take the example of Reaktor Space, a Finland-based company that launched the smallest hyperspectral imager in 2018. It is a 2U CubeSat(2) with 100 bands and 22m spatial resolution designated for agriculture applications. The field is still fertile for technological innovation and we will definitely see more and more use of CubeSats in coming years.
You designed and manufactured a 3-axis mechanism to measure the magnetic field within a Helmholtz Coils Test-Setup for nanosatellites. Can you explain to our audience what that means?
Helmholtz Coils, as the name indicates, are a pair of copper coils, that when placed apart at an axial distance equal to their own radius and fed with the same magnitude and direction of current, will create a homogeneous magnetic field between them, with orientation normal to the coils. Most of the satellites that orbit the Earth are either inside or above the ionosphere. This outer part of Earth atmosphere is electrically conducting and contains currents that contribute to Earth’s magnetic field. Any satellite in this orbit experiences a field which is different from the field measured at the surface of Earth. For a space mission engineer, determining the value of the magnetic field at every position in orbit is important information that can be used in an Attitude Determination & Control System (ADCS) to steer the spacecraft by generating a magnetic moment that reacts with the intrinsic local magnetic field of the Earth and produces torque. Therefore, the aim of this project was to use Helmholtz Coils to generate a homogeneous magnetic field and simulate many different magnetic environments on Earth without the necessity to take a Nano-satellite into orbit.
What could you read from the data analysis you performed afterwards in Python Programming Language?
The interpretation of results via Python offered a powerful tool for the evaluation of measurement data, which were converted into meaningful plots and graphs. Without this step, it would have been impossible to visualize and realize the in homogeneousness of the magnetic field where the tests took place. Subsequently, the measurements revealed that the reasons for inhomogeneity emanate from the presence of many parasite sources of magnetic fields. My contribution to this project stopped at this stage and I believe that succeeding students were able to take up the challenge and improve the operability of the test setup.
Does measuring a generated magnetic field in settings not related to this experiment also allow us to say something about water? If so, what?
This Test-Setup cannot tell us anything about water related questions. It is exclusively targeted to simulate the orbital magnetic environment of the Nano-satellite. However, Helmholtz Coils enable a precise use of magnetorquers(3) and hence would help to extend the lifetime of a water monitoring mission by consuming less fuel for orbit maintenance and attitude control.
What drives/defines the design of satellite sensors? How do you increase the scope of what is measurable, in terms of granularity, but also in terms of physical reality?
The typical kind of instruments that are usually found onboard of satellites to measure water related properties are split in two types: Passive and active sensors. Passive sensors are sensors that intercept radiation naturally emitted or reflected by an object or region on earth. This could be visible or infrared sensors for optical data or radiometer sensors for microwave data. Active sensors on the other hand emit energy toward the earth and then intercept and measure the strength and time delay of the return signal. For optical data, we can use LIDAR and for microwave data we can use Scatterometer(4), Altimeter, and Synthetic Aperture Radar.
The unprecedented availability of high-resolution data offered by remote sensing has significantly increased the scope of what is measurable. The levels of information start from precise information about optimized irrigation management, crop monitoring or large surface water resources, and go down to approximative outputs on disease , pest management, or the application of nutrients in the form of chemical fertilizers and animal manure, etc. The merger of remote sensing with in-situ measurements allows a seamless interpretation of data. The only drawback is that in-situ data is not readily obtainable. Despite these challenges, the timing is perfect to pick an early ride with Industry 4.0 and emerging cyber-physical systems. A system of sensors connected to a large network of devices can be implemented to provide a permanent presence of humans and machines to bring immediate interventions, such as a real-time notification platform to inform local authorities, let’s say, to implement physical barriers in the most distant areas around the globe.
What do you need to innovate and what would your ideal working environment look like?
I think a purpose driven attitude and persistence is what helps every engineer to have no choice but to be innovative. Some of us struggle and reinvent the wheel, but in the presence of mentorship and guidance from experts who preceded us in the field, research and innovation become much more frequent and efficient. I also believe that the key success element to continuously providing innovative solutions lies in always staying alert to recent technological advances and scientific breakthroughs. Being at the crossroads between unrelated disciplines is also an important factor. It allows inventors to use unconventional methods to bridge the gap between the realms of the known and the unknown. It is needless to mention the role funding plays for conducting research and facilitating mobility to stay in touch with the scientific community.
For me an ideal work environment would be a place that provides the assets to tackle global challenges regardless of their constantly varying nature. Something that is at the forefront of solving complex issues on Earth by using space technologies and ultimately delivering solutions to issues humanity has been facing helplessly for thousands of years.
What do you think is poorly understood in the field of aerospace engineering and where do you see unharnessed potential for water resource management?
The first problem with poor water resources management is that most of the local authorities in regions suffering from this issue are not aware of the technological capabilities that are available today. Therefore, they continue to waste time and financial resources in traditional and defective strategies and that are not valid anymore. This also explains the huge gap between the identification of market requirements and the large part of the industry that is still pumping outdated solutions into the market. Sustainable water resources management can be readily boosted with modern technologies. Currently, knowledge, flow of information, and efforts are still fragmented and segregated, whereas the expansion of remotely sensed information and proper exploitation of data can help improving the capacities to enable effective adaptation and mitigation responses. Efforts of the community should go into introducing the concerned entities to the potential of Remote Sensing, Drones, CubeSats, etc., which are offered at low cost. Only then can we construct a heterogeneous sphere where users know what they need, engineers what to design, and environmentalist what technologies to use.
On the other side of the coin, many outstanding young engineers have a hard time finding the right path and figuring out their passion at work. Most of their potential remains unharnessed, because usually no one is willing to trust in their capabilities, or they fail at making themselves noticeable. So, to cope with life’s basic needs, they continuously reshape their skills to adapt to the job market and fit where they do not belong. However, if we teach them networking skills at the early stages of their career, starting from university, if we had experts who can identify these young people and put them in environments that foster their knowledge and skills, we would be able to harness a lot of great potential.
What is your favourite aggregate state of water and why?
I personally find it hard to discriminate any aggregate state of water. I would say that the interest changes according to the circumstances and the time of the year. I have a slight inclination on favouring liquid water because of its importance in maintaining the balance of body fluids. Again, during summer liquid water is what makes swimming an enjoyable activity. In winter, I am enthralled by the diversity in the types of snowflakes when it snows. But I also feel grateful towards the evaporation of water and its role in driving the water cycle and ultimately being responsible for the fruits and vegetables on our plates.