Cunge, J

Photograph

Jean A. Cunge (*16.03.1934 - 02.10.2023) was a Polish-born hydraulics engineer working in France. He is known for his contributions to the field of numerical modelling and simulation of open channel flows. He is particularly known for his work on an algorithm for calculating flow propagation in rivers and canals, known as the Muskingum-Cunge method.

Biography

Early life

Cunge was born Jan Andrzej Cunge in 1934 in Łódź, Poland, to Stanislaw Cunge and his wife Emanuela (née Faust). He attended Warsaw University of Technology from 1951 to 1956, earning a Master’s in Hydraulics. After several months working for Hydroproject (Russian: Институт «Гидропроект»), he went to England and earned a Diploma of Membership to Imperial College London (DIC) in Space Structures in 1957-58.

In 1966, he earned his doctorate in numerical analysis (Dr.-Ing, Analyse Numerique) at the Université Joseph Fourier (Grenoble I). The topic was: A study on a finite difference scheme applied to numerical integration of a certain type of hyperbolical runoff equations (Étude d’un schéma de différences finies appliqué à l’intégration numérique d’un certain type d’équations hyperboliques d’écolouement). He defended it on May 27th 1966 in front of a jury composed of J. Kuntzmann, N. Gastinel, and P. Laurent.

SOGREAH

Cunge spent the majority of his professional life working at the Société Grenobloise d'Études et d'Applications Hydrauliques (SOGREAH), a French engineering company based in Grenoble. He got the position by chance. When his English visa ran out after earning his DIC, he travelled to Paris, where he spent several months learning French. At the time, there was a dearth of engineers in France and when he applied at SOGREAH in 1959, he was offered a six-month internship by Alexandre Preissmann, even though he was not yet fully proficient in the language.

Under Preissmann, a mathematician and pioneer in computational hydraulics, Cunge developed skills as a systems engineer. He learned to code using the IBM650 which SOGREAH had acquired in the 1950s, as the first enterprise in France to own a computer.

Working with Preissmann, Cunge became involved in several groundbreaking projects in computational hydraulics, first and foremost the development of the Mekong Delta Model and the Système Hydrologique Européen (SHE).

His work at SOGREAH was also conducted in collaboration with his junior colleagues, especially Jacques Zaoui.

Laboratoire d’Hydraulique de France

From 1987 to 1999, Cunge served as the director of the Laboratoire d’Hydraulique de France, a common subsidiary of SOGREAH at Grenoble University. In 1999, it was absorbed into SOGREAH.

Teaching Activities

Throughout his career, Cunge was keen to share his knowledge and experience with students and other hydraulics professionals. He was a visiting professor at Colorado State University in 1972-73. In 1975, he further helped organize a summer school on computational hydraulics in Colorado, with over 200 members of the US Army Corps of engineers in attendance. This helped launch computational approaches in hydraulics in the US, as they had been primarily practised in Europe before that date. Furthermore, Cunge taught at the universities at Grenoble INP, Nice Sophia Antipolis, and the UNESCO centre at IHE Delft in the Netherlands.

In 1980, he published the seminal textbook Practical Aspects of Computational River Hydraulics, together with Forrest M. Holly, who later became president of the IAHR, and Andri Verwey.

From 2004 to 2016, he was a member of the management board of the Euro-Aquae MSc course in Hydro-Informatics and Water Management, a cooperation between Newcastle University and Polytech Nice. From 2013, Cunge was a member of the technical committee of the Société Hydrotechnique de France. He was furthermore an honorary member of IAHR.

Retirement

After his retirement, Cunge had an active social media presence on LinkedIn until 2019. He engaged in technical debates with hydraulics engineering practitioners. He passionately advocated against calibrating manning's n, and instead encouraged the use of field knowledge. Furthermore, he argued that it is often better to accept a bad model and investigate the causes for its poor performance rather than to calibrate the model. Many of his other comments on LinkedIn capture the essence of his decades of knowledge and opinions related to modelling practices. Jean Cunge died on October 2nd 2023 at LaTronche near Grenoble at the age of 89.

Hydrological Achievements

Jean Cunge was resistant to the label of hydrologists and considered himself to be a hydraulic engineer. However hydrologists will recognize the approximate routing method for calculating the propagation of flow waves in canals and rivers known internationally as the "Muskingum-Cunge method".

His hydraulic expertise was used also in the development of the numerical model used as part of the Mekong River Commission, including one of the first implementations of two dimensional depth averaged hydraulic modelling.

Together with Forrest M. Holly, who trained in engineering with Jean and later became President of the IAHR, and Adri Verwey, he also produced the pioneering book "Practical Aspects of Computational River Hydraulics". This book is still a benchmark in the teaching of computational hydraulics.

The Mekong Delta Model

One of the biggest and most significant projects in which Cunge was involved at SOGREAH was the first computational model built of a delta, the Mekong Delta Model. In the early 1960s, plans existed to build a dam across the Tonlé Sap river in Cambodia to modify wet season inundation dynamics across the delta of the Mekong, which stretches across Southern Cambodia and Vietnam. Before construction could begin, though, UNESCO, which funded the project, wanted to verify its efficaciousness and published a tender to evaluate the project.

In response, Francis Biesel of SOGREAH travelled to Paris to propose a model, but it was thanks to Cunge that the project came to be, as he himself described in a paper he later wrote about Preissmann (Cunge and Hager, 2015):

Biesel, without contacting anybody, went to Paris to discuss the subject and to face two competitors: Delft Hydraulics proposing a scale model and the Americans (Jim Harding from Berkeley) offering an analogue electrical model. During the day, Biesel called Grenoble asking for Preissmann, who was out of the office. Then Biesel told his interlocutor (the first author of this paper): “Do you think that we can elaborate a numerical simulation model? Since Preissmann is not there I shall call you in one hour for an answer.” The problem was never tackled in any way. How to answer such a question in one hour at age 26? It reflected the “SOGREAH spirit”, and Preissmann would be back and he certainly would find the way. So one hour later, the young engineer answered Biesel: “Yes, we can do it. We have never done it before, but we can.”

In 1961, the tender was awarded to SOGREAH and work began on the Mekong Delta Model, with engineers embarking on fieldwork in Cambodia and Vietnam, rendered dangerous due to the ever-worsening conflict in the region.

Cunge and Preissmann, in the meantime, worked in Grenoble on elaborating the numerical simulation, first in several sub-models based on existing data, later using field data. Throughout the model’s development, they also worked together with colleagues from Cambodia and Vietnam who came to France to learn how to use the IBM on which the model would be run, using punch cards and magnetic tape.

The project was successfully completed in 1967. In the final report, Cunge is listed as a systems analyst. He travelled to Thailand for several weeks for the handover of the model, supervising as local engineers carried out a simulation at the mathematical laboratory of the Centre d’Études Nucléaires. This test was also attended by representatives of UNESCO.

In a series of papers introducing the model published in La Houille Blanche in 1968 (Zanobetti and Lorgeré 1968 a, b, c), Preissmann and Cunge contributed a section on calculation principles (analysis and programming). In 1970, the two also contributed to a publication in the Journal of the Waterways, Harbors and Coastal Engineering Division, further outlining the construction of the mathematical program.

Furthermore, Cunge was involved in the later transcription of the Mekong Delta Model into Fortran, once programming languages became current.

Système Hydrologique Européen

A second major project in which Cunge was involved was the development of the Système Hydrologique Européen (SHE).

In 1976, three institutions formed a consortium to develop a unified framework for hydrological modelling - the Institute of Hydrology (UK), the Danish Hydraulic Institute (DHI), and SOGREAH. At DHI, the driving force behind the project was Mike Abbot. At SOGREAH, it was Alexandre Preissmann and Jean Cunge. First scientific applications became possible in the early 1980s. Beginning in 1986, SHE found widespread practical applications as well. Its successors, SHETRAN (Newcastle University) and MIKE SHE (DHI), are still widely used.

The Muskingum-Cunge Method =

The basis of the flood-routing approach now widely known as the Muskingum-Cunge method was first developed in the Muskingum River Basin in Ohio in the 1930s, where flood protection schemes were being implemented. It was originally based on differential equations of storage, with storage given as a linear inflow-outflow function. However, it involved time-intensive parameter determination and lacked predictive capabilities.

In 1969, Cunge proposed an improved version by eliminating the need for calibration. In a paper published in the Journal of Hydraulic Research, he outlined how the Muskingum formula was also a finite-difference approximation of a differential equation that could be derived from the Saint-Venant equations if one neglected the inertia terms. He further proceeded to demonstrate the solution to this equation which allowed for flood wave dampening (Cunge 1969).

Sources

LinkedIn profile: https://www.linkedin.com/in/jean-cunge-b9b796a/?originalSubdomain=fr

IAHR Obituary: https://www.iahr.org/index/detail/1146

Canal Blog obituary: http://scingsimu.canalblog.com/archives/2023/10/09/40065170.html

SHF Obituary: https://www.shf-hydro.org/jean-cunge/

Selected Publications

Cunge, Jean A., Forrest M. Hooly Jr, Adri Verwey, 1980 : Practical Aspects of Computational River Hydraulics

Zanobetti, D., and H. Lorgeré. “Le modèle mathématique du Delta du Mékong: Première partie.” La Houille Blanche 1 (1968): 17-30.

Zanobetti, D., and H. Lorgeré. “Le modèle mathématique du Delta du Mékong: Deuxième partie.” La Houille Blanche 4 (1968): 255-269.

Zanobetti, D., and H. Lorgeré. “Le modèle mathématique du Delta du Mékong: Troisième partie.” La Houille Blanche 5 (1968): 363-378.

Cunge, J. A. 1969, “On the subject of a flood propagation computation method (Muskingum method).” Journal of Hydraulic Research 7.2): 205-230.

Zanobetti, D., Lorgeré, H., Preissmann, A. and Cunge, J.A. 1970, “Mekong delta mathematical model program construction.” Journal of the Waterways, Harbors and Coastal Engineering Division 96(2): 181-199.

Cunge, Jean A. 1972, “Discussion by ‘Deposition of Sediment in Transient Flow.’” Journal of the Hydraulics Division 98, no. 2 (1972): 399–402. https://doi.org/10.1061/JYCEAJ.0003241.

Cunge, Jean A., and Marc Erlich.1999, “Hydroinformatics in 1999: What Is to Be Done?” Journal of Hydroinformatics 1, no. 1 (July 1, 1999): 21–31. https://doi.org/10.2166/hydro.1999.0003.

Cunge, J. A., 2003, “Of Data and Models.” Journal of Hydroinformatics 5, no. 2 (March 1, 2003): 75–98. https://doi.org/10.2166/hydro.2003.0007.

Cunge, J. A., 2014, “River Hydraulics – a View from Midstream.” Journal of Hydraulic Research 52, no. 1 (January 2, 2014): 137–38. https://doi.org/10.1080/00221686.2013.855269.

Cunge, J. A. 2014. “What Do We Model? What Results Do We Get? An Anatomy of Modelling Systems Foundations.” In Advances in Hydroinformatics: SIMHYDRO 2012 – New Frontiers of Simulation, edited by Philippe Gourbesville, Jean Cunge, and Guy Caignaert, 5–18. Springer Hydrogeology. Singapore: Springer, 2014. https://doi.org/10.1007/978-981-4451-42-0_2.

Cunge, J. A., and Willi H. Hager. 2015, “Alexandre Preissmann: his scheme and his career.” Journal of Hydraulic research 53.4: 413-422.