Hydrological Sciences

GeoTalk: Nilay Dogulu, Early Career Scientist Representative

GeoTalk: Nilay Dogulu, Early Career Scientist Representative

In addition to the usual GeoTalk interviews, where we highlight the work and achievements of early career researchers, this month we’ll also introduce one of the Division early career scientist representatives (ECS). They are responsible for ensuring that the voice of EGU ECS membership is heard. From organising short courses during the General Assembly, through to running and attending regular ECS representative meetings, their tasks in this role are varied. Their role is entirely voluntary and they are all active members of their research community, so we’ll also be touching on their scientific work during the interview.

Today we are talking to Nilay Dogulu, ECS representative for the Hydrological Sciences (HS) Division and past chair of the Young Hydrologic Society.

Before we get stuck in, could you introduce yourself and tell us a little more about yourself, your involvement with EGU and how you became interested in hydrology?

I am a PhD candidate at the Middle East Technical University (METU) in Ankara, Turkey, researching clustering methods for data-driven hydrology at the Water Resources Laboratory. This year I attended the General Assembly (GA) in Vienna for the fifth time in a row. Since 2014, the Assembly has been the one and only conference that I have persistently and willingly participated in. The Hydrological Sciences (HS) division’s scientific programme at the GA had a special role in shaping my career as a researcher, so I would like to share my journey in the hydrological sciences lightened up by the EGU GA and its HS community.

First, little about me. I am a civil engineer by training. I was a third year (BSc) student at METU (ODTU) when I took the course “Engineering Hydrology.” It was the first time I learned about the terms catchment, basin and hydrograph. In that very semester I had the opportunity to participate in the 5th World Water Forum in Istanbul. That was it. I was determined to specialize in water for my future career.

To broaden my understanding of hydrological processes and gain a critical view of the latest hydrology topics, I gathered the courage—as only a BSc student at the time—to attend the 6th National Hydrology Congress and the 2nd National Flood Symposium. Then a three-month internship at the State Hydraulic Works of Turkey introduced me to the wider community of hydrological sciences in the world.

My class notes from the Engineering Hydrology course back in March 2009 (Credit: Nilay Dogulu)

In Fall 2011, I joined the FLOODRisk Master to study floods, from modelling them to understanding their socio-economic effects. This two-years programme enriched my academic background on flood risk management and provided me with different insights into water-related problems.

Could you tell me about your first experience with the EGU General Assembly?

With EGU HS Division president Elena Toth (right) and president-elect Maria-Helena Ramos (left) at EGU 2018

The EGU GA brings together researchers from all around the world. The EGU Hydrological Sciences Division is EGU’s largest division with a diverse and comprehensive scientific programme at the GA, large enough to fill in the whole second (red) floor of the conference venue.

The EGU HS division is a great platform aimed at addressing current research challenges in hydrology. During the GA, one can follow up with the latest research on various topics within these areas and network with members (of all stages) of this great community. At the 2018 EGU GA, hydrological sciences programme had 2350 abstracts submitted to 91 HS-lead sessions (66 oral and poster sessions, 6 poster only sessions, 19 PICO sessions)—equivalent to 13.5% of total EGU GA submissions.

Given this, I was very motivated to experience the General Assembly for the first time! I submitted an abstract summarizing part of my MSc research—on predictive uncertainty estimation for flood forecasting using data-driven modelling techniques; and once it was accepted, I started to get ready for EGU and Vienna! Flight and accommodation booked, poster printed, weekly conference schedule prepared. This was the first poster presentation of my career and I was quite excited. Luckily, all went really well.

EGU Hydrological Sciences Division

I remember having a busy week at EGU 2014: from presenting my first poster, working on a manuscript with my co-authors, as well as attending project meetings, sessions on flood forecasting and flood risk management, and short courses organized by the Young Hydrologic Society (YHS).

There were many interested people visiting my poster and asking questions. There were many posters I visited too—I have to admit, sometimes I asked so many questions that the presenters thought  I was an OSPP Award judge.

Throughout the week I listened presentations, many of which were given by researchers I cited in my master’s thesis. Matching the papers with authors’ faces was amazingly so much fun! Moreover, I arranged a small meeting with my co-authors to discuss the manuscript draft (which has been later published in HESS) that we had only been working on remotely before then.

At the time, I was also working for the EU-FP7 project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). The EGU GA is an excellent time for research project teams, editorial boards of journals, etc. to schedule meetings.  ASTARTE team (26 partners from 16 countries) also took this opportunity to meet up to discuss the progress following the project’s first 6-months period. During this meeting, I presented one of the very important deliverables of the project which focused on tsunami resilience from a social sciences perspective.

On the Saturday after the conference there was the Vienna Catchment Science Symposium organized by the Vienna University of Technology Centre for Water Resources Systems. It proved to be a very enlightening symposium for a young hydrologist.

Sounds like a great first experience! How has your time at the GA changed over the years?

After enjoying the academic fun of EGU 2014, I wanted to come back to Vienna for EGU 2015. Another reason was that I was very curious why people were heading to the conference venue on the very last hours of the last day (Friday): I left around 5 pm and many people were coming out of metro!

METU Water Resources Lab researchers at EGU 2016

In 2015 I had one PICO presentation and two short course convenerships, How to write (and publish) a scientific paper in hydrology and Hydroinformatics for Hydrology. Both were co-organized with the Young Hydrologic Society and proved to be very successful!

Without any hesitation, I decided to attend EGU 2016 and EGU 2017 in the next years. Although I didn’t have any presentations in 2016, listening to presentations covering my research interests helped me stay updated and synthesise various perspectives on overarching problems in hydrology. The sessions kept me thinking about some questions that had been tingling my mind—which later became the research questions in my PhD thesis proposal.

At EGU 2017, my poster presentation was a literature review on application of clustering methods in hydrology, and actually it attracted more people than I expected. EGU poster sessions provide an excellent way to bring together early career researchers while they stand in front of their posters, paving the way for interesting discussions.

Memories from EGU 2017

My fifth year at the EGU GA last April was great too: including two posters, sessions to co-/convene, YHS events (from short courses to PICO sessions), the EGU ECS Representatives Workshop, YHS Hydrodrinks, the HS division meeting, medal lectures and many other activities. Being an experienced EGU GA participant, I also served as a mentor as part of the EGU mentoring programme designed to help novice conference attendees navigate their first EGU experience.

Almost forgot! On Friday evening, the conveners’ reception (and party, with a different theme every year) takes place at the ACV.

In addition to being an EGU ECS representative, you also are involved with the Young Hydrologic Society (YHS). Could you tell me more about this organisation and your role in YHS?

YHS is a bottom-up initiative that aims to help early career hydrologists interact and actively participate within the hydrological sciences community and beyond. We are a group of motivated PhDs and postdocs who enjoy serving our very own community, considering the needs and interests of young hydrologists.

The YHS is most actively involved with the EGU GA, where we organizing short courses, scientific sessions and social events. The full list of all events that YHS has organized for the EGU GA since 2013 can be found on the YHS webpage. The open call for session proposals for EGU GA 2019 has just closed (deadline 6 September) – there have been quite a number short course submissions (in cooperation with YHS) that will play a significant role in shaping the HS programme for ECSs. YHS Hydrodrinks event held annually at the EGU GA is now a 5-year-old tradition where we meet our new team members. If you are planning to come to EGU 2019, don’t miss the chance to meet fellow hydrologists at the Hydrodrinks (however, please note that this is not a sponsored event). Contributing to the academic and social development of early career hydrologists by organising activities at the EGU GA is a unique and rewarding experience, so get involved!

YHS Hydrodrinks at EGU 2014 (Credit: The waiter)

I joined YHS after meeting the team at EGU 2014. Since then I couldn’t help myself but contribute to the aims of the society in many ways—like organizing short courses at conferences (e.g. Hydroinformatics for Hydrology at the EGU GA), managing and contributing to the YHS Blog (Streams of Thought and Hallway Conversations), and acting as a Board member (secretary 2015-16, chair 2016-17).

Right: EGU 2018 Poster 1—Clustering approaches for analysing similarity in ungauged catchments: input variable selection for hydrological predictions Left: EGU 2018 Poster 2—Input variable selection for hydrological predictions in ungauged catchments: with or without clustering? Bottom Centre: YHS team at EGU 2018 (with only a few missing! It is not east to arrange a common time for everyone, even for a group photo)

I also took over the role of EGU ECS Rep for HS division from Shaun Harrigan at EGU 2017. Being elected as the EGU ECS Rep, I became more enthusiastic about advancing the hydrologic science community equally (and globally) in support of, primarily, the ECS. The ECS Rep is expected to contribute to sustainable and inclusive growth of the EGU HS division by fostering the active participation and integration of ECS and the hydrologic science community globally under the umbrella of EGU, keeping in mind the necessity of creating equal opportunities for ECS to enhance their research and communication skills.

EGU ECS Reps at the EGU GA 2018

The ECS Rep for HS division works in close collaboration with YHS to initiate and support inspirational and intelligent ideas in line with the emerging needs of ECS. You also meet with ECS Reps of other EGU divisions and help the EGU community thrive together with its early career members. My term ends in April 2019. So keep your eye on EGU and YHS websites (and twitter) in early 2019—and apply to become the next EGU ECS Representative (April 2019-April 2021) for the HS division!

Do you have any parting words about your time involved with EGU?

It has been a very long post but now here are the last words. The EGU GA means seeing old friends and past professors, meeting fellow hydrologists and listening to presentations from enthusiastic researchers… plus the annual Hydrodrinks event among many other scientific sessions and short courses organized by YHS! I am glad to serve as the EGU ECS Rep for the Hydrological Sciences division – for the wonderful and inspiring people of the red floor:)

Acknowledgements: I would like to express my sincere thanks to Young Hydrologic Society, especially to Wouter Berghuijs, Shaun Harrigan, Hannes Müller and Tim van Emmerik, for their enthusiasm and support over the last five years.

Interview by Olivia Trani, EGU Communications Officer


Imaggeo on Mondays: A Colombian myth with geologic origins

Imaggeo on Mondays: A Colombian myth with geologic origins

This photograph shows El salto del Tequendama, a natural waterfall of Colombia, located in the Department of Cundinamarca at an altitude of 2400 metres above sea level and approximately 30 kilometres southwest of the country’s capital, Bogotá.

The Salto del Tequendama is a space of transit and connectivity between the warm lands of the Magdalena river basin and the cold lands of the Sumapaz paramo, a Neotropical alpine tundra located at 4,000 metres above sea level.

Dutch-Colombian geologist Thomas Van der Hammen concluded that approximately 60,000 years ago the entire savannah of Bogota (populated today by 9 million people) was covered by a large lake, known as the Humboldt Lake, and the associated wetland plants instead of the paramo vegetation seen today.

Over time, the climate became warmer and the bottom of the Humboldt Lake began to rise. 30,000 years ago, the lake’s waters were channelled through the Bogota River and led to the Salto del Tequendama, a real climate event that we Colombians received through the myth of Bochica, a legendary hero to the Colombian indigenous group the Muisca. Here is the summarised myth of Bochica and the Tequendama jump:

“… As the Muiscas had lost respect for the gods, they offended Chibchacum, who had previously been the most beloved of their gods. He decided to punish them by flooding the savanna, for which he gave birth to the Sopo and Tivito rivers, which joined their rivers to the Funza (former name of the Bogotá River). The flood ended with many crops and human lives, until the people clamored with fasting and sacrifices to Bochica to free them from that calamity. The sage Bochica appeared on the rainbow and with his golden scepter, hit the rocks allowing the water to form a gigantic waterfall. So Bochica created the Tequendama jump.”

The large lake was partially dried and separated into smaller wetlands, where Andean plants, deer, foxes, weasels and more than 100 bird species made their home.

The waterfall, famous for its size, surrounding vegetation and vapourous waters, has been widely studied since 1668, when the Bishop of Panamá, Lucas Fernández de Piedrahíta made the first written record of its mythical origin story.

During the 18th and 19th centuries in particular, the Salto was one of the most famous natural attractions both locally and worldwide, due to the waterfall’s 157-metre drop onto a circular rocky abyss in a wooded region of permanent haze.

In the 19th century, large estates, also known as haciendas, were built on the region’s wetlands, and the natural environment was converted into places for fishing, hunting and logging. Through drainage channels, communities dried up the land to establish livestock and agricultural systems. In the last century, as the city of Bogota grew in population and size, the wetlands were filled to build neighborhoods, streets and avenues.

Like many Bogotanos, on a family weekend trip to relieve the stress generated by the chaos of the city and in search of clean air, I took this picture. The Salto was and always has been a fundamental part of the Bogota family mythology.

By Maria Cristina Arenas Bautista, National University of Colombia, Department of Civil Engineering and Agricultural (Bogotá)

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at

Imaggeo On Mondays: Reservoir in the Italian Alps

Imaggeo On Mondays: Reservoir in the Italian Alps

Mountain natural streams and reservoirs have a relevant hydrological and ecological importance since they represent reliable sources of freshwater supply to lowland regions and high-quality habitats for fish and cold-water communities. Moreover, streams in mountain environments are of significant importance for users in several socio-economic sectors, such as agriculture, tourism and hydropower.

Given the vulnerability of mountain streams and catchments to the impact of climate changes and the increasing concern about water supply in mountain regions, there is the urgent need for scientists to face integrated, multidisciplinary catchment-scale studies addressing implications of climate change on water resources management and flow regimes.

Description by Daniele Penna, as it first appeared on

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at

Top ten tourist beaches threatened by tsunamis

Top ten tourist beaches threatened by tsunamis

December 2004 saw one of the deadliest natural disasters in recorded history. 228,000 people were killed when an earthquake off the coast of the Indonesian island of Sumatra triggered tsunami waves up to 30 m high. The destruction was extreme as the waves hit 14 different countries around the Indian Ocean. Economic losses totalled over 10 billion US dollars. The tourism industry in particular suffered a significant blow. In Phuket, a province of Thailand, a quarter of the island’s hotels had closed six months after the tsumani.

“The 2004 Sumatra tsunami and some of the recent Pacific Island tsunamis have shown their devastating impact on beaches and beach-related tourism,” says Andreas Schaefer, a researcher from the Karlsruhe Institute of Technology (KIT). But where is disaster likely to strike next? And can we be prepared for it?

Schaefer and his colleagues are trying to find out. “We asked the question: can we quantify potential tsunami losses to tourism industries along beaches?” he says. The number of tourists visiting the most exotic locations in the world, places such as Thailand, Indonesia, Colombia and Costa Rica, are rising twice as fast as the global average. In some cases, visitor numbers are growing by as much as 11 percent each year.

This rise in tourism in tsunami-prone locations is potentially a cause for real concern. “We compiled the first ever global loss index for the tourism industry [associated with beaches],” continues Schaefer. His findings were presented last month at the European Geosciences Union General Assembly in Vienna .

Beaches can be affected by tsunamis in a variety of ways. As well as the immediate threat to human life, a tsunami wave can leave behind piles of debris or offshore sand that can damage a beach environment. Alternatively, large swathes of beach sand might be removed by erosion. And in cases where an earthquake is very close to the shore, the beach itself may be down-thrust or uplifted during the event, leaving it either permanently submerged underwater or high and dry.

To quantify the locations in the world that are most at risk, Schaefer and his colleagues used two large datasets: tourist information and earthquake statistics.

Tourism-derived GDP per capita across the world. (Image credit: Andreas Schaefer)

To calculate the human exposure, “we compiled a global tourism destination database,” he explains. This database includes over 200 countries, at least 10,000 tourist destinations, more than 24,000 beaches, and almost a million hotels from all around the globe.

“It was important to get the latest and best tourism and hotel information,” says James Daniell, another member of the KIT research team. “Tourism contributes over 6 trillion [US] dollars directly and indirectly to the global economy every year.”

The research team then calculated tsunami probabilities all around the world using earthquake statistics and tectonic modelling. Chile, central America, Indonesia and Japan are the main countries that frequently experience large tsunamis.

Over longer time periods, the Caribbean and Mediterranean are also likely to be affected by rarer events. To put the numbers in perspective, if you spend a day on the coast of Mexico you have a one in 60,000 chance of seeing a tsunami; in Crete, this decreases to one in 600,000.

To model the tsunamis, it is also important to have a good understanding of the shape of the seafloor in the vicinity of the tourist sites. In the deep ocean, big tsunamis can have gaps between waves of as much as 200 km and wave heights as small as 1 m; ships are often unable to feel them passing. But as they approach the shore, the water shallows, causing the waves to slow down and pile up. The wave spacing decreases to less than 20 km, whilst the wave heights can grow to tens of metres. Hence, what looks like an innocuous fluctuation at sea can cause major damage when it reaches land. The depth of the adjacent seafloor plays a major role in this.

Simulated tsunamis across the world showing maximum potential wave heights. (Image credit: Andreas Schaefer)

Given the large number of variables at play, tsunami modelling involves many calculations and typically requires the use of a supercomputer. But in a paper published last year, Schaefer helped to develop a new simulation framework called TsuPy, which allows for quick modelling of tsunamis on personal computers. With this in place, he could rapidly simulate more than 10,000 tsunamis all around the world, calculate the expected wave heights at the tourist sites in his database, and estimate the likely economic losses.

The researchers estimate 250 million US dollars in global annual loss to the tourism industry from tsunami waves. Furthermore, every 10 years they expect a single $1 billion event.

Of all the tourist destinations, “Hawaii is the number one,” says Schaefer. This is “because of all the potential tsunamis that come from around the Pacific Ring of Fire,” he explains. “There are so many [tsunami] sources all around, that, even though they are far away, they have an effect.”

The last major tsunami to strike Hawaii was as a result of the biggest earthquake ever recorded: the 1960 magnitude 9.6 Valdivia earthquake on the coast of Chile. 60 people on Hawaii were killed and the damage amounted to 500 million US dollars in today’s terms.

Top ten locations on the global risk index for beach tourist destinations threatened by tsunamis. (Image credit: Andreas Schaefer)

Other notable locations on the top ten list include Valparaiso (Chile), Bali (Indonesia), and Phuket (Thailand). “Locations that are known for their tourism are at the top of the list because there is a lot [of existing infrastructure] that could be damaged,” explains Schaefer.

Slightly surprisingly, southwest Turkey is also high on the list. Furthermore, places like Tonga and Vanuatu are particularly at risk. They have rapidly developing tourist industries and large projected losses per dollar of tourism-related business, so they feature highly on Schaefer’s list. “They are mostly small island nations with a significant need for tourist dollars,” explains Daniell.

For many parts of the world, the results are not necessarily good news. But they are a first step inasmuch as they highlight the locations that are currently thought to be at greatest risk. “We hope, with these results, to raise awareness among tourists. But they do not need to be afraid,” says Schaefer. With adequate preparation and evacuation planning, it is hoped that future disaster on the scale of the 2004 event might be averted.

By Tim Middleton, EGU 2018 General Assembly Press Assistant


Schaefer, A., Daniell, J., and Wenzel, F. Beach Tsunami Risk Modelling – A probabilistic assessment of tsunami risk for the world’s most prominent beaches. Geophysical Research Abstracts, Vol. 20, EGU2018-11955, 2018, EGU General Assembly 2018 (conference abstract)

Schaefer, A. and Wenzel, F. TsuPy: Computational robustness in Tsunami hazard modelling. Computers & Geosciences, 102, 148-157, 2017