Contribution by Paola Mazzoglio (PM)

Luca Brocca received the M.Sc. degree in Environmental Engineering and the Ph.D. degree in Civil Engineering, both with excellence, from the University of Perugia, Italy, in 2003 and 2008, respectively. Since 2009 he is a Researcher at the National Research Council (CNR), Research Institute for Geo-Hydrological Protection (IRPI) of Perugia (Italy). Since 2019 he is the Director of Research at the same institute. The main research interest of Luca Brocca lies in the development of innovative methods for exploiting satellite observations for hydrological applications (webpage).

PM. Can you tell us a little bit about your background and education? Was becoming a scientist your career plan when you were a student?

LB. I always enjoyed mathematics and environmental science, that’s why I have selected environmental engineering in my city, Perugia. I started studying hydrology because I did my master thesis in this field, then as soon as I got my degree I was selected at CNR-IRPI for a scholarship in Hydrology, and here I am. I did my PhD for studying soil moisture spatial-temporal variability and its use for hydrological modeling, all my career so far has been around the soil moisture topic. The long-term satellite soil moisture product (ESA CCI soil moisture) started in November 1978, the month I was born; I don’t think this is by chance! By the way, I am not a typical researcher as I did my studies and I always worked in my city (with just a very short period abroad)!

PM. Did you envision yourself as a professor at any point? Or do you prefer to work outside academia?

LB. Currently no, I prefer working outside academia. We built a relatively young research group which is doing a great job. I already had many young colleagues who grew and took their path in science; this is very rewarding. Of course, working in a research group is not simple; many problems are there every week (even every day!). But working in this team has been the reason for my “success” in science. Honestly, I have many outstanding colleagues (within and outside our research group) and our research activities/projects together are very exciting. I am now seeing the results of these project/science activities and new challenges are ahead that I would love to address in the near future being at CNR.

PM. You spent about 10 years developing several rainfall products obtained from satellite soil moisture data through the SM2RAIN algorithm. How did you come up with the idea of this approach? Where do you find inspiration or motivation for your work?

LB. SM2RAIN was “born” in 2012 during a trip to Saint Petersburg (Russia, ERB conference). During the flight I wrote the algorithm in my paper notebook and as soon as I arrived in the hotel I coded and I tested it with real observations. Quite surprisingly, SM2RAIN was working well in its first implementation (it usually doesn’t happen!). It was (and it is) great to see how a very simple idea can evolve in science and how many activities, collaborations and projects came up from that. For example, our irrigation from space research activity is a “child” of SM2RAIN. This is probably the main reason why I love being a scientist. Today, we have published multiple global and regional rainfall datasets based on the SM2RAIN algorithm freely available (see here), and they are being used by many people worldwide. The value of publishing free datasets is extremely high.

PM. Which major challenge in the hydrology and remote sensing fields are you most interested in tackling?

LB. I am now working on two big challenges: high-resolution hydrology and the assessment of the human impact on the water cycle. I believe the two challenges are strongly related. We have today, for the first time, new observation capabilities for the water cycle, mainly thanks to remote sensing technology but also to improved computational and storage facilities, allowing us to build high-resolution hydrological modeling. At high-resolution, the human impact on hydrological fluxes is more important, and we have to resolve the multiple connections caused by humans, and we need to simulate human processes such as reservoir management and irrigation. Modeling human behavior is much more difficult than modeling physical processes – that is already not solved – therefore we need new concepts and observations to address these challenges.

PM. Many open questions remain after centuries of research spent in the quantification of the components of the water cycle. How do you see the future of hydrology? Which technologies do you think will be essential for hydrology in the next decade?

LB. When I was an early career scientist I attended a great seminar from Prof. Murugesu Sivapalan in Rome. In the second slide there was a man trying to see beyond a wheat field, but he could not as the plants were too high. In Hydrology we have the same problem, we are not able to observe several components of the water cycle at the appropriate spatial and temporal resolution. For instance, precipitation is usually sampled with a (very) limited number of rain gauges. Even worse, we don’t see below the ground and hence (1) we miss to describe the soil geometry, and (2) we don’t observe the water movement in the soil. As we learn from the history of science discoveries, new observations are the keystones for developing new concepts and theories. As mentioned above, I believe we are in a new era for hydrology with observations, from remote sensing and new ground-based techniques, of the different components of the water cycle, partly also below the ground. The challenge will be to exploit as best as we can such observations and I advocate an interdisciplinary approach to get that target. We need to target the description of the water cycle as a whole, including energy and carbon cycle, and specifically the human component that has become crucial.

PM. You and your research group are quite active on social media. I see that you are involved in several national and international projects. Can you summarize the main projects/topics you are working on?

LB. It is extremely difficult to summarize our projects, we are currently involved in 28 projects, several of them as a prime partner. Our projects are addressed to exploit ground and satellite observations for improving hydrological applications such as flood and landslide prediction, water resources management, drought monitoring, and irrigation water management. We are now looking at all components of the water cycle (soil moisture, precipitation, evaporation, river discharge, snow), together with our international partners, and we aim to integrate them in advanced modeling systems. The Digital Twin Earth Hydrology project funded by the European Space Agency, that we are leading, and Open-Earth-Monitor Cyberinfrastructure funded by the European Commission are two examples of large scale and integrated projects in which we are involved.

PM. Seems interesting! Will there be open positions for ECS in the upcoming months?

LB. Due to the many research projects we are running, there were always open positions in our group. Specifically now we are opening 3-year positions as a researcher (first position is already out: see here) that are very good opportunities to come working with us in our exciting research team.

PM. Good, maybe you will reach people interested in working on these topics with this post. Before concluding, I have another question. Do you have any advice for early career and aspiring hydrologists?

LB. My suggestion is be humble, study a lot what other good scientists are doing and try to find your “research brand identity” (but without stress). Being humble and developing our own careers is tremendously challenging, with many obstacles and falls. So, be patient (I tell this to myself as well)!

About the author

Paola Mazzoglio is a Research Assistant at Politecnico di Torino working on geographically-based approaches to the statistical analysis of rainfall extremes. She is also a teaching assistant at the same university. Paola is a member of the Blog Committee as part of the Young Hydrologic Society (YHS) board (2022-2023). Correspondence to paola.mazzoglio@polito.it.