18/10/2021 - Next INTERCOH Conference Update :

The 17th edition of the conference INTERCOH, held between 18-22 September, 2023 in Incheon, South Korea, organized by the Inha University. More information cooming soon.

16/11/2020 - Next INTERCOH Conference Update :

The 16th edition of the conference INTERCOH (www.intercoh2021.org), held between 14-17 September, 2021 in Delft, organized by the Delft water institutes (Delft University of Technology, Deltares and UNESCO-IHE). More details about registration, submission and guidance can be found at www.intercoh2021.org.

20/04/2020 - Publication in memory of Emmanuel Partheniades :

In Memoriam: Emmanuel Partheniades , Ashish J. Mehta and William H. McAnally, Journal of Hydraulic Engineering, Vol. 146, No. 6, June 2020

14/04/2020 - Next INTERCOH Conference:

INTERCOH 2021 will be held in the Netherlands, more information coming soon.

11/11/2019 - Obituary Prof. Emmanual Partheniades (1927-2019)\

Prof. Emmanual Partheniades (1927-2019)

Emmanuel Partheniades, recognized by all in the know about the scour of clayey sediment beds by flowing water, passed on October 31, 2019 in Gainesville, Florida, just short of his 93rd birthday. As one of the only two students of Professor Hans Albert Einstein at Berkeley who worked on the physics of movement of flocculated fine-grained particles, Partheniades and the other student, the late Ray B. Krone, were pioneers in the US in introducing phenomenological interpretations of the physics of cohesive sediment transport, which until about then was mainly reliant on empirical formulations.

At the time of his death a professor emeritus at the University of Florida, Partheniades was born in Athens, Greece on November 3, 1926. During his teen years his education was interrupted by the war in Europe, and as a result he finally received his undergraduate degree in Civil Engineering at the age of twenty-five from the Technical University of Athens in Greece in 1952. This was followed by MS (1955) and PhD (1962), both in Civil Engineering, at Berkeley. From 1952 to 1954 and again during 1955-59, he worked with various engineering firms in Greece, and in the San Francisco Bay area including Dames & Moore, in structures, irrigation and soil mechanics. That experience convinced him that academics was his calling; he never again worked or consulted on engineering projects outside university-based research.

His first academic assignment was as a teacher at Cal State College in San Jose in 1963, and in 1964 went to MIT as a post-doctoral fellow under Prof. John F. Kennedy in civil engineering. Following an academic position at the State University of New York in 1965, he joined the University of Florida in 1966 as professor in the Department of Coastal and Oceanographic Engineering. After a ten-year hiatus (1973-83) during which he returned to Greece as chair of hydraulic structures at the University of Thessaloniki, he returned to the University of Florida, this time joining Engineering Sciences, which was later renamed Aerospace and Mechanical Engineering. He was a member of the American Society of Civil Engineers and served as an academic consultant and lecturer in, among other countries, Venezuela, Paraguay, Argentina, Portugal, India and Canada.

He was fond of European history and passionate about operas and classical music in general. He met his Peruvian wife Dora Gutierrez, who shared many of his interests, while he was a student at Berkeley, and she was employed on the campus. He was deeply devoted to her and to his faith, and was also quite active in the Greek community of Gainesville. Following her death 2014 he gradually withdrew from most academic interests, and at the time of death left behind his elder sister in Athens as the only close survivor.

Partheniades’ most noteworthy contribution to cohesive sediment transport was his journal article in 1965 on the erosion of soft beds of flocculated mud collected from San Francisco Bay. He prepared two types of beds in a hydraulic flume, one consisting of natural well-mixed mud placed on the flume bottom and another prepared by depositing suspended Bay mud in the same flume. The cohesive resistance of the placed bed to erosion was independent of depth in the bed whereas the resistance of the deposited bed increased with depth. Under turbulent flow it was found that the erosion flux at the surface of the placed bed was independent of time, whereas the flux at the surface of the deposited bed decreased until almost no erosion occurred after several hours. From these observations he concluded that unlike in the case of a sand bed subjected to steady flow, at the surface of which erosion and deposition fluxes quickly become equal after the onset of a test, when a cohesive bed erodes no redeposition of the deposited material occurs. According to him this behavior could be explained by reinterpreting one part of Einstein’s stochastic development of the well-known bedload function describing erosion only, while ignoring the other part representing deposition.

The 1965 summary article was somewhat unusually published with Partheniades as the sole author, as Einstein withheld his approval to be include as a co-author because he firmly believed that somehow deposition had to be included in the analysis. Subsequent work on cohesive sediment erosion has revealed that both Partheniades and Einstein had got some assumptions in the assessment of erosion right while others were contradictory. In broad terms it turns out that cohesive sediment transport cannot be described without considering the dynamics of floc growth and breakup of depositing and eroding flocs, and erosion is a more complex process than described by the Partheniades formula.

That formula of the 1965 did not receive as much recognition as it deserved. Instead, about a decade later a linear, purely empirical version named Partheniades Equation by a student of Krone became well-known because it was simple to use even though it had no theoretical underpinning. While on the one hand lively and even humorous in company, Partheniades could be feisty and judgmental about his academic beliefs. He was wont to insist on his objection to anyone misquoting anything related to any work of his. However, once he came to know that an erosion formula, even though quite different from his own physics-based equation, was named after him he remained reticent about whether he had any contributive share in the development of the eponymous formula.

The first five-year stay at the University of Florida was also his most productive period during which he introduced and taught a sequence of three graduate courses on estuarine transport processes and constructed a wind flume as well as an annular rotating flume meant to study cohesive sediment deposition in water. This latter flume was a larger version of a similar apparatus built earlier at the Parsons Lab at MIT, a brainchild of Prof. Kennedy with input from Partheniades. Its somewhat complex design and operating procedure were meant to avoid the problem in typical flow-recirculating flumes in which suspended flocs reaching the downstream end of the flume are chewed up by high shear rates in the return flow pump. The Florida version was peculiar in the sense that its use required students to climb up a ladder with a platform that looked a bit like one used to climb onto a small aircraft. This nuance came about as follows. As part of instructions to the lab machinist, Partheniades handed the design blueprint of the MIT annular flume indicating that it had to be doubled in size. As it wasn’t clear what that meant the machinist doubled all the dimensions including the height of the metal framework supporting the flume. Within years such flumes appeared elsewhere, especially in the Far East, that were nearly identical copies also designed with similar ladders, perhaps because it was believed that there probably was some underlying scientific purpose. As the MIT flume was soon demolished, the one in Florida became the Model-T which was replicated in several other countries with suitable modifications and sophisticated instrumentation for operation and measurements. It also found popular application in studies involving mud with biota.

At the University of Florida Partheniades guided altogether two doctoral theses, one in cohesive sediment transport and another in salinity intrusion. In 2009 he published a monograph summarizing his lifelong work. Conservative in thinking, harking back on science as practiced until about mid-twentieth century, he was a champion of basic laboratory work but remained apprehensive about field work and especially numerical modeling as a research tool. After his return to Gainesville in1983 he largely abandoned experimental work and chose instead to teach statics, dynamics and fluid mechanics. His decades of professional tenure coincided with the growth of cohesive sediment transport as a major subarea of hydraulics.