Webinar on International Levee Databases

Last week TU Delft hosted a webinar on their International Levee Performance Database, as well as similar initiatives from France and the USA. The webinar also discussed the applications of such databases and the necessity for closer collaboration in developing them.

Over 150 participants joined online from around the world, representing private consultancies, academic and research institutes and local and national authorities.

A recording of the event can be found through the below link, as well as links to videos on the use of the ILPD;

Webinar:                                                                                                         https://www.youtube.com/watch?v=lVSmvdaCVCE
ILPD in general:                                                                                           https://youtu.be/p4B6biRk0EM
Assessment and design (In Dutch,with English subtitles)  https://youtu.be/3wQk77_vuiU
Crisis management:                                                                                   https://youtu.be/eecNYsiJh6k
Data Science:                                                                                                 https://youtu.be/k2_IcEISeWA

We hope to continue this initiative, and welcome any comments or suggestions through our email: leveefailures@tudelft.nl.

I.S. Rivers conference

The 4th International Conference  IS. Rivers will take place from June 21 to 25, 2021.
I.S.Rivers is an international conference focused on research and action in the service of large rivers in Europe and the world, a meeting between scientists and practitioners.
The French National Dams Committee CFBR is a partner of this event. More details here : http://www.graie.org/ISRivers/a_index.php

SafeLevee webinar on failure databases

Dear colleagues,

Over the last 5 years the SAFElevee project team at TU Delft has investigated levee failures and has set up an open-access database (the international levee performance database – ILPD) with over 1500 levee failure and performance cases.

You are warmly invited to attend a webinar on the SafeLevee project and ILPD database.
The event will be held on Friday 25th September from 13.30 – 15.30 CEST, and the program outline is as follows (further details will be made available at a later stage).

Block 1: SAFElevee, the international levee performance database and its use for levee managers

  • Introduction to the program, SAFElevee project and International Levee Performance Database
  • The use of levee performance information for levee managers (design, crisis management etc.) – 4 short videos on this theme have been prepared by HKV consultants and will be shown
  • Open discussion on use by levee managers with contributions from Rijkswaterstaat and other levee managers and participants.

 

Block 2: International collaboration in collecting, sharing and analysing levee failures

  • Short Introduction (Bas Jonkman, TU Delft)
  • Presentations by other similar database initiatives (EDF, France and others)
  • Panel and open discussion on future use and sharing of levee failure and performance data

Please confirm your attendance by emailing leveefailures@tudelft.nl, and feel free to share with others you think may be interested. More details will be provided to attendees prior to the event, including a detailed agenda and access details.

Free ICFM webinar on flood events China, JP, USA (26 Aug)

Under the title “The Flood Challenge to Resilience” ICFM will share the experience with (i) major flooding in China that affected/s millions of people and hundreds of river basins; (ii)  flooding in Japan caused by truly extraordinary amounts of rain falling over the island of Kyushu; and (iii) flooding in Michigan (US) that interacted with aging infrastructure and resulted in failure of two dams.

Three highly regarded speakers – Professor Jun XIA, Professor Toshio KOIKE and Dr. Molly FINSTER –  will introduce these topics and set the stage for the discussion by the audience. See the webinar invitation/registration page at www.icfm.world/Webinars.

Building a resilient flood protection system, including to overtopping. Summer 2019: creating openings in an existing railway

History of the project

On the left bank of the south of the Rhône river (in France), between the cities of Tarascon and Arles, a railway embankment has performed for many years as a flood protection structure although it was not a role falling under its owner (the French National Railway company) responsibility. In December 2003, because of breaches in appurtenant embankments, the north of the city of Arles was flooded for many weeks.

Fig. 1: breaches on appurtenant embankments in 2003

In the aftermath of this centennial flood, the State and local authorities have put in place a vast flood prevention plan at the scale of the catchment area, called Plan Rhône, which notably provides for the complete renovation of the levees of the Rhône Delta over 20 years. Among this ambitious program, was decided the creation of a levee resistant to overtopping up to the 100 year flood, parallel to the railway embankment, and the creation of 10 openings (concrete structures) in the railway in order for it to be “hydraulically transparent” (see Fig. 2). This segment of levee and the reinforcement of the rest of the system against all other deterioration and failure mechanisms allows the whole levee system to withstand floods up to the 1000 year with a 50 cm margin (the crest level of the levees not-resistant to overtopping). Floods above the protection level (100 year) will flood the protected area in a controlled way and with many times less water volume and speed than any previous scenario with the same probability (see Fig. 3). A second line levee will prevent the flood going over the new levee to reach the densely inhabited suburbs of Arles.

Fig. 2: schematics of. the future overtopping resistant levee and the railway embankment with the transparency structures

Fig. 3: compared modelled consequences of the historic flood (1856 – 250 years event) before and after the project (Source: SYMADREM)

References  on the design of the system: 

Cheetham, M., Mallet, T., Chastel, E., Tourment R., Robustelli, P., Pelt, P., - - 2015. Building a resilient system of defence against flooding from the Rhône. Proceedings of the Institution of Civil Engineers-Water Management, vol. 168, n° 2, p. 74-84

Cheetham, M., Tourment, R., Pelt, P. - 2016. Risk assessment and economic appraisal of protection methods for the Tarascon-Arles railway embankment. 3rd European Conference on Flood Risk Management FLOODrisk 2016 17/10/2016-21/10/2016, Lyon, FRA. E3S Web Conf. Volume 7, 2016. 3rd European Conference on Flood Risk Management (FLOODrisk 2016). 8 p.

Summer 2019

During the summer of 2019, over two periods of barely more than 48 hours, five out of the ten opening structures(like the one in figure 4)  were put in place in the railway embankment. The planning of these operations started years in advance, as it involved the disruption of the rail traffic on a major line of train transport for both passengers and goods. The five other ones are being constructed now at a short distance along on the side of the railway embankment and will be put in place during the summer of 2020. During each of these sequences of non-stop operation, the following steps have to be successively completed:

  • Cutting the rails
  • Creating an opening in the embankment (Fig.5),
  • Adding a layer of material to support the structure,
  • Moving the concrete structure in its final place and checking its proper placement (Fig. 6), as well as smaller parts on each side, also prefabricated (Fig. 7),
  • Filling the space between the embankment and the concrete with new embankment and compacting it (Fig. 8)
  • Adding railway ballast
  • Repairing the rail line and setting it to ensure its performance (Fig.9)

The hazard of a flood happening during these crucial phases was considered and measures were taken to minimize the risks, including being able to close the embankment openings in case of a flood not foreseen when the operation started.

The openings are temporarily closed until the new levee is completely built, in order to keep ensuring the current protection level (Fig. 10). Afterwards stilling basins can be added (Fig. 11)

Marseille 2021 ICOLD Congress

During the Marseille 2021 ICOLD congress, one of the field trips will be organised in this area and the whole complex system will be presented: overtopping resistant levee, opening structures, second line of defence and flood water management.

Fig. 4: one of the opening structures and the equipment used to move it

Fig. 5: open railway embankment

Fig. 6: moving the structure and controlling its placement

Fig. 7a & 7b: additional prefabricated concrete structures for the bottom of the slopes of the embankment

Fig. 8a, 8b & 8c: placing and compacting the new material between the existing embankment and the concrete structure

Fig. 9: the specific engine in charge of placing the railway ballast in order to ensure performance of the rails

Fig. 10: concrete slabs to temporarily close the openings until the new levee is operational

Fig. 11: a stilling basin in construction

Fusion of information from geophysical and geotechnical investigations for levee assessment

The identification of levees constitutive materials, as well as the detection of possible interfaces and anomalies, are crucial for site characterization. During investigation campaigns, complementary geophysical and geotechnical methods are usually used. These two sets of methods yield data with very different spatial scales and different levels of incompleteness, uncertainty and inaccuracy. On the one hand, geophysical methods are generally non-intrusive and provide physical information on large volumes of soils but with significant potential uncertainties. These uncertainties are due in particular to the integrative and indirect aspects (relative to the parameters related to failure modes limit state equations) of the methods as well as to the resolution of the inverse problems. On the other hand, geotechnical investigation methods are intrusive and provide more local information but also more accurate and very often directly related to parameters related to failure modes limit state equations. An important issue to improve the characterization of subsoils and existing levees is to be able to combine acquired geophysical and geotechnical data, while taking into account their respective uncertainties, inaccuracies and spatial distributions. The complementarity of these two sets of methods is often underused since the uncertainty and inaccuracy associated with each method are rarely considered. Furthermore, results are usually only graphically superimposed and considered with an expert opinion instead of being mathematically merged. These works propose a specific methodology in order to manage conflictual information and different levels of uncertainties and inaccuracies from different investigation methods, expanding geotechnical information between borehole positions. It presents a new way of mathematically combining data from these two types of information sources, taking into account the specificities of each kind of method. This new methodology considers the framework fixed by the theory of belief masses and improves the characterization of lithological sets within levees and their foundation. It provides information on the level of conflict between information sources while proposing a confidence index associated with the results.

By: Théo Dezert

Figure 1: Section of a levee with representation of lithological materials having the highest belief mass values after fusion process between electrical resistivity, granulometry and CPT data (left) and their associated belief mass values (right).

Figure 2: Levee modeled resistivity longitudinal section obtained by inverting Wenner-Schlumberger apparent resistivity data
Figure 3 : ISBT vertical profiles for each CPT test and associated soil classes
Figure 4 : Representation of the levee section displaying borehole positions in dashed lines and associated ISBT (white dotted line) and particle size distribution (white solid line) corresponding classes

 

References :

Journal articles:
  • Dezert, T., Fargier, Y., Lopes, S. P., & Côte, P. (2019). Geophysical and geotechnical methods for fluvial levee investigation: A review. Engineering Geology, 105206.
  • Dezert, T., Lopes, S. P., Fargier, Y., & Côte, P. (2019). Combination of geophysical and geotechnical data using belief functions: Assessment with numerical and laboratory data. Journal of Applied Geophysics, 170, 103824.
Conference papers:
  • Dezert, T., Fargier, Y., Palma-Lopes, S., & Côte, P. (2019, September). Levee Characterization by Means of Data Fusion of In-Situ Geophysical and Geotechnical Information. In 25th European Meeting of Environmental and Engineering Geophysics (Vol. 2019, No. 1, pp. 1-5). European Association of Geoscientists & Engineers.
  • Dezert, T., Fargier, Y., Palma-Lopes, S., & Cote, P. (2018, September). Application of Belief Functions to Levee Assessment: chapter X in: Belief Functions: Theory and Applications.

https://hal.archives-ouvertes.fr/hal-01891806/

  • Dezert, T., Lopes, S. P., Fargier, Y., & Cote, P. (2018, September). Geophysical and Geotechnical Data Fusion for Levee Assessment-Interface Detection with Biased Geophysical Data. In 2nd Conference on Geophysics for Mineral Exploration and Mining (Vol. 2018, No. 1, pp. cp-566). European Association of Geoscientists & Engineers.

https://www.earthdoc.org/content/papers/10.3997/2214-4609.201802536

ICOLD Meeting 2020 New Delhi

UPDATE (4 March) : the meeting has been postponed due to the Coronavirus epidemic. The new dates are: Sat. 26 Sept. – Th. 01 Oct. 2020.
The dates for the WG workshop and meeting are on Sunday 27th and Monday 28th respectively.


The 2020 ICOLD meeting will be in New Delhi, India, from 4 to 10 April. Registration is now open and the early bird rate ends at the end of January, so hurry if you want to benefit from this reduced rate. Information and registration here : https://www.icold2020.org  The third bulletin is available on line on the same web site.

The Levees Technical Committee of ICOLD (ICOLD LE TC)  will hold a workshop on Monday  6 and a meeting on Tuesday 7. During registration attendees have to indicate which TC workshop and meeting they plan to attend. We invite all our levees community members to register for these TC events, wether a member of the LE TC, of  the EUCOLD LFD WG or simply interested in levees, and to encourage your colleagues and relations to do the same. It is important that we have a large attendance for a wide exchange of information and knowledge, and it is also important to register for logistic reasons (room size).

NB: LE TC members not able to attend are strongly advised to have a colleague from their national dam committee to attend the TC workshop and meeting on their behalf.

new geotechnical software

Rijkswaterstaat has launched new geotechnical software for slope stability on November 28th

This was developed together with Deltares and our dike reinforcement program HWBP (The Slope Stability Project / POV Macrostabiliteit).

Raymond van der Meij from Deltares was the main driving force behind the development. Meindert Van was one of the initiators.

We have merged the knowledge from five different initiatives in the Netherlands on slope stability in the new software.

 

It will be available on the Deltares and on the Rijkswaterstaat website (Helpdeskwater.nl)

It will be in the English language. The software is available to everyone (free of charge). Support for users who assess or design flood defenses in the Netherlands is covered by Rijkswaterstaat. Support for user in other countries will go through Deltares (this is not free of charge).

 

The user manual is available on

https://www.helpdeskwater.nl/publish/pages/169760/user_manual_d-stability_v20_1.pdf

 

Request: information on drought effects (e.g., cracks) in levees

Dear all,

During last month’s EURCOLD Symposium I presented a paper on drought effects on levees; see https://www.researchgate.net/publication/336641742_Mitigating_drought_risk_for_levees_Mitigating_drought_risk_for_levees . For the Sept2020 Floodrisk Symposium, I wish to extend this work and include some more experiences regarding drought effects on levees. However, it turned out to be quite hard to find publications and data (such as drought crack dimensions+position and other properties, drought crack development and recovery, best practices on remedial measures, etc.). Who can help me out, and send me some useful weblinks/publications and/or [summarized] data?

Thanks in advance!

Marcel Bottema

ECMSGE 2019

The XVIIth ECSMGE conference, held in Reykjavik  with the theme “Geotechnical Engineering, ​foundation of the future” on September 1-6, had a lot of content related to levees and also to dams.
​ISSMGE TC201 on “Geotechnical aspects of Dykes and Levees” has some members in common with ICOLD LE TC and EUCOLD LFD WG.  We will in the future continue to exchange information between our ICOLD groups and TC201, as well as encourage actual collaboration (see report).
With the help of Meindert Van for review and of Cor Zwanenburg for a list of levee papers, we produced a report on the conference with links to additional information, that we encourage you to read.

The report is available for download from our “Members only” menu in the web site.

FLOODrisk2020 : last week to submit an abstract

FLOODrisk 2020

Attention – 1 week left to end of abstract submission

We would like to remind you all that the call for abstracts for the 4th European Conference on Flood Risk Management, that will take place in Budapest will close on 16th September 2019.

FLOODrisk2020 is committed to attract, coach and listen to the next generation of scientists and practitioners who will future-proof our research methods and help to improve our flood risk management practice in order to better cope with deep uncertainty and therefore the 4th conference will focus on the issue of Science and practice for an uncertain future.

YOU NOW HAVE LESS THAN 1 WEEK LEFT TO SUBMIT YOUR ABSTRACT on https://floodrisk2020.net/authors-area/

New issue of our LFD WG newsletter

Hello

we have  issued a new issue of our Levees and Flood Defences  Working Group  newsletter. You can find it available for download on our website.

It concentrates on the different levees related conferences of this year: the ICOLD annual meeting, the ECSMGE conference, and the EUCOLD symposium. It also includes a special feature presenting the extreme flood events on the Missouri in the USA.

Thanks to all the contributors, particularly Noah Vroman from USA for the long paper, and Sam Leonard from UK for the editorial task.

I hope you enjoy it.

Rémy

EUCOLD 2019 Symposium

We encourage all our members to attend the EUCOLD Symposium on October 2-4  (https://www.eurcold2019.com) and particularly the two days organized  by our WG (https://www.eurcold2019.com/eucold-wg-lfd) on Sept. 30 and Oct. 1

Please also disseminate this information among your contacts interested in levees and flood defences.

FLOODrisk2020

 

The deadline for submitting abstracts to the next FLOODrisk conference has been extended to the 16th September : https://floodrisk2020.net/news/abstract-submission-deadline-extension/

Levees and Flood Defences are definitely a topic and I encourage every EUCOLD LFD WG and/or ICOLD LE TC to submit an abstract.

Call for contributions for the 4th Edition of the Levee Working Group Newsletter!

We are looking for articles relating to the engineering, operation, maintenance of Levees… and anything else Levee related that you think will be of interest, for the 4th edition of the Levee Working Group Newsletter.

Article length should be around 500 words or less, and include a photo, map or diagram.

The Newsletter will be published soon, so please can you send contributions by  5th of July,.

Please send any articles to the editor – Sam Leonard (sam.leonard@environment-agency.gov.uk)

Thanks 🙂

Call for newsletter articles

Issue 3 of the Newsletter has recently been published. The EUCOLD Levee Working Group Newsletter is now looking for article contributions for the 4th issue which will be published later in summer of 2019.

We will be looking for articles relating to the engineering, operation, maintenance of Levees… and anything else Levee related that you think will be of interest.

Please send any articles onto the editor – Sam Leonard (sam.leonard@environment-agency.gov.uk)

 

Newsletter issue 03 (April 2019)

A new issue of our LFD WG newsletter is available on the dedicated page of our web site : https://lfd-eurcold.inrae.fr/index.php/wg-newsletter/

Thanks to the editorial team, particularly Sam Leonard and Adrian Rushworth of the UK Environment Agency and also

to to all contributors.

Digues 2019 conference : success and deliverables

The third French Conference on Levees (“Digues 2019”) was held in Aix en Provence on 20-21 March 2019 with technical visits on the Rhône levees on the 22.

It was a success with 100 abstracts submission, 300 participants, 77 final papers, 50 oral presentations and 26 posters.

The book of abstracts is available, with English abstracts, in the “Levee related documents” page of our web site. Full text papers are available online on zenodo.org.

Deadline to submit abstracts for EUCOLD symposium

Last days to send an abstract for the 11th ICOLD European Club Symposium. Deadline is Monday 18th February 2019. All topics refer to all dams – large and small, reservoirs, levees and flood defenses.

Important Dates

Abstracts Submission (300 words max)Monday 18th February 2019
Abstracts AcceptanceFriday 15th March 2019
Full Paper Submission (10 pages max)Monday 30th of April 2019
Full Paper AcceptanceFriday 31st of May 2019

New Year newsletter

Now it is 2019 it is time to think of the next group newsletter. A lot is happening in the world of Levees and it will be good to share what you have been doing. As a guide articles between a quarter and a whole page work well. Photographs and pictures are useful to bring an article to life.

So, please send your articles by the 27 January to Sam Leonard (Sam.Leonard@environment-agency.gov.uk) or Justin Watts (Justin.Watts@environment-agency.gov.uk)

Assessing and managing the risks of transitions in flood defence infrastructure

 

Workshop on  “Assessing and managing the risks of transitions in flood defence infrastructure”

The Environment Agency has teamed up with international experts to help risk management authorities to consider the risks associated with transitions in flood defence structures. The international consortium, made up of HR Wallingford, Royal HaskoningDHV, Deltares, IRSTEA and USACE, integrates current international knowledge and practice on transitions combined with working UK knowledge and practice on risk based tools for asset inspection and management. The project aims to:
• consider the presence of transitions during flood defence condition assessment
• quantify the effects of transitions on flood defence performance and flood risk
• manage the risk of transitions with improved design and retrofit solutions.


Credit: Royal HaskoningDHV

Credit: Royal HaskoningDHV

On 9 October a stakeholder meeting was hold in London to provide the opportunity to influence the direction of the project and to benefit from stakeholder’s experience managing flood defences. The animated discussion focused on specific reliability methods for transitions and the approaches for inspecting them. The workshop also provided the opportunity to hear about the management strategies being employed in the US, France and the Netherland to mitigate the risks associated with transitions.

More information about the project here: http://www.hrwallingford.com/projects/assessing-and-managing-risks-with-transitions-in-flood-defence-infrastructure

Photo OwenTarrantPhoto Owen TarrantPhoto Owen Tarrant

Thoughts on ICOLD Congress, Vienna

 

photo by Ilze Plomp – van der Sar

This was my first ICOLD meeting and was the first formal ICOLD Technical Committee on Levees (TC LE) after it had been setup at the meeting in Prague. Here are a few of my thoughts.

Not only was this the first formal meeting of the LE TC the Congress was also important because Q103 for the congress was on the subject of small dams and levees. Rémy Tourment from France was the general reporter for this question who is also the chairman of the ICOLD TC LE. An interesting range of Reports were presented in four sessions with worthwhile discussion at the end of each session.

ICOLD TC LE also held a workshop on Monday 2 July. Other than providing an opportunity for presentations from new member countries, a significant amount of time was spent in gathering ideas for the dams and levees intercomparison report, using a facilitated brainstorming process. By the end we had a wall of Post It notes with very useful material. One point for the future is to use stickier notes as several did not stay on the wall. This material will be used by a small team from the Committee to further develop the report.

Adrian Rushworth (with thanks to Jonathan Simm for material)

 

Artifical rain showers on levees to prevent flooding

Sprinkler Irrigation (picture by Colette Fatou, Irstea)

While some countries like Japan and some Balkan countries have suffered from severe floods during the spring and early summer of 2018, The Netherlands and England are suffering from severe drought.

In both England and The Netherlands, June 2018 ranks along the 6 warmest and driest June months of the last century and has been record setting in places, with locally just a few millimeters of rain in six weeks’ time. In the Netherlands, the precipitation deficit (precipitation minus evaporation) since the 1st of April is now reaching 200 mm, twice the long-term average for mid-July.

 

The drought has led to a remarkable situation, which has not gone unnoticed amongst the news media: Some of the levee managing organizations in the Netherlands have now started to irrigate their levees. A remarkable situation indeed, because not only too much water turns out to pose a danger for levees, but also a shortage of water. This applies especially to levees consisting of peat. These are quite common for the peaty and low-lying Northwestern half of The Netherlands, and are especially used as embankments for the raised canals that are used to drain the polders in this area. After desiccation, the peat in such levees becomes a very light material which might practically float away (or experience uplift) if too much pressure is exerted on such a levee. This was by and large the reason for a peat levee breach after a similar drought in the hot summer of 2003, near the Dutch village of Wilnis.

 

After the above levee breach, the Dutch Foundation STOWA (www.stowa.nl) has initiated a fair amount of research on peat levees and other small levees, and has come up with guidance for their management during drought. As a result, there is now a protocol, which recommends that from a certain drought level on, levee managers start spraying or irrigating their peat levees, together with intensified inspections. In this way, the risk of cracks and setting of peat (and clay) levees is significantly reduced, as is the risk of sudden failure like in the 2003 case of Wilnis.

 

Further information can be found on:

Research in the Netherlands for Flood Defenses

May, 24th, 2018

Robert Slomp, Robert.slomp@rws.nl

Marcel Bottema,

Introduction

In the newsletter we have given an abstract of the relevant research for Flood Defenses. The present overview covers the research in somewhat more detail. First some general principles are highlighted:

  • Flood-defense research is polydisciplinary, including several scientific disciplines relating to various loads and strength aspects of flood defenses, as well as probabilistics and statistics and governance.
  • Most of the applied research on flood-defense related topics consists of contract research, which is commissioned by the government, and carried out at research institutes like for example Deltares. Besides this, some research is carried out by consultancies.
  • Fundamental research is mainly carried out at universities, especially those of Delft, Wageningen, Utrecht and Twente. There are three main funding sources: the universities themselves, the National Research Council (NWO), and funding by third parties. NWO-funded research is increasingly linked to the National Research Agenda of NWO, and to the research theme ‘Water’ of NWO. Third parties can include the EU.
  • Research is more and more linked to research agenda’s. Besides the National Research Agenda of NWO, there is also a National Knowledge agenda on Water and Climate (NKWK), which combines various agendas of the Ministry of Infrastructure and Water Management, of Rijkswaterstaat, of Water Boards and their Foundation for Applied Water Research (STOWA), the national Levee Reinforcement Program HWBP, as well as various consultancies and research institutes and universities.
  • The flood risk management policy in the Netherland is covered by the following document

https://www.enwinfo.nl/images/pdf/Grondslagen/GrondslagenEN-lowresspread3-v.3.pdf

  • Information on the current flood defense assessment and design tools can be found here.

https://www.helpdeskwater.nl/publish/pages/132671/24_04_2016_implementing_risk_based_flood_defence_standards.pdf

https://www.helpdeskwater.nl/publish/pages/132671/20160423_probabilistic_flood_defence_assessment_tools.pdf

https://www.helpdeskwater.nl/publish/pages/132671/2017_07_16_calibration_report.pdf

The itemized list below highlights some key research activities of The Netherlands on Flood Defenses, even though it is not necessarily complete. The scope is limited to levee-related issues, which implies that research on hydraulic structures is not mentioned.

  • Research at universities, with some participation/contribution of Rijkswaterstaat
    • SafeLevee project (lead partner university of Delft

International Levee Performance Database (http://leveefailures.tudelft.nl)  to facilitate sharing of data on breach formation and breach initiation, to facilitate three work packages with the following objectives

  • to analyze data of levee performance and failure at a macro-scale, to identify system failure patterns and its most important causal factors (e.g. type and shape of a levee, etc.). This requires an innovative combination of techniques and data sources from hydraulic and geotechnical engineering and remote sensing.
  • to a) improve our understanding of the physical processes involved in levee failures; b) improve and/or develop computational models that can be used in safety assessment and design of levees. The focus will thereby be on geotechnical failure mechanisms.
  • to develop more accurate models and theories of breach initiation and formation using available datasets for calibration and validation
  • link

https://www.tudelft.nl/citg/over-faculteit/afdelingen/hydraulic-engineering/sections/hydraulic-structures-and-flood-risk/research/safelevee-project/

  • Flood Risk – All Risk project, lead partner is the university of Delft, other partners are the universities of Utrecht, Wageningen, Twente, Nijmegen, Houston, Tokyo and Berlin
  1. Aim if to facilitate implementation of new risk standards in the flood protection program
  2. The ambition is also to reduce flood risk by a factor 10 in some parts of the Netherlands. Improving the reliability of flood defenses is the main objective. Understanding failure modes is an essential element of this study.
  3. This study has just started.

http://www.taskforcedeltatechnologie.nl/wp-content/uploads/2017/05/Presentation-AllRisk_Taskforce.pdf

See also: https://ncr-web.org/projects/all-risk/

  • Coastal Genesis/Coastal Systems,” Kust Genese”, lead partner Rijkswaterstaat
  1. The Netherlands carries out a lot of beach nourishments to reduce flood risk and for recreation. Understanding the effects of these nourishments is essential.
  2. The project has a number of work packages
  • Long term trends in coastal developments. Exchange of sand between barrier islands.
  • A pilot nourishment on a barrier island (Ameland) to monitor the exchange of sand with the wadden sea area behind the islands.
  • Ecology, effect of the nourishment on the ecology

It wants to be flexible and adaptive program. A lot of data is being generated from the monitoring, making this available for researchers essential.publications are on the website: https://waterenklimaat.nl/research-tracks/coastal-genesis/?lang=en

Kust Genese is part of the Interreg project Building with Nature  http://www.northsearegion.eu/building-with-nature

  • River Care, lead partner university of Twente
  1. The main goal is to understand processes in the river. Some of these processes e.g. long term morphology are linked to flood risk management and changes in the hydraulic boundary conditions (on the water levels)
  2. To improve the fundamental understanding of the behaviour of rivers, and to map the consequences of the measures for hydraulics, morphology and ecology and to improve the current models. The data, knowledge and models will be used to improve the design and maintenance of measures and cut costs of river management.
  3. publications are on the website
  4. See also: https://ncr-web.org/projects/rivercare/
  • Applied contract research on the national level

2.1 Hydraulic Boundary Conditions

Research commissioned by Rijkswaterstaat(the national water authority) with the meteorological office KNMI and Deltares being the main research institutes involved

2.1.1 Research on the wind climate on the North Sea and in the Netherlands,

  1. A better set-up of hydraulic boundary conditions (water levels and waves) for design and assessment on the coast, lakes and estuaries, reducing statistical extrapolation errors, and including more information on physics and physical maxima in extreme event estimates.
  2. There are three main research subjects
    1. to determine the statistics for extreme wind speeds and wind events
    2. to determine whether or not a two-way coupling between wind models and hydraulic models (in particular wave models) is necessary
    3. Establish a dataset with 50 000 years of climate data above the North Sea area for calculation of storm surges, precipitation, extreme discharges and the correlations between the rivers, the rivers and the sea, for the current and for a future climate. We currently have 6500 years.
  3. This is a long term project, with deliverables every year
  4. All documentation will be published in English on the KNMI website, seehttps://www.knmi.nl/research/weather-climate-models/publications#

2.1.2 Research on sea level scenario’s which influence the North Sea Area

  1. There is currently a methodological mismatch between the probabilistic approach for design and safety assessment of flood defenses, and the qualitative scenario approach for climate and sea level rise. The aim of the research is to move towards probabilistic climate projections that are more suitable for risk-based designs.
  2. Ice melt on Antarctica influences the sea levels more than the melt on Greenland. We have to know if our long term scenario’s for the year 2100 and onwards have to be changed.
  3. This is a long term project, with deliverables every year
  4. All documentation will be published on the KNMI website in English.

2.1.3 Research on discharge scenario’s for the Rhine, Meuse and its tributaries, The GRADE project. A resampling technique (GRADE) of rainfall data to construct large artificial time series, e.g. 50 000 years.

  1. A better set op hydraulic boundary conditions (water levels and waves) for assessment and  design on the rivers and estuaries.
  2. There are two main objectives
    1. an update of climate change scenario’s for the Rhine and Meuse river discharges
    2. information for the tributaries for the Rhine branches and the Meuse (e.g. the Vecht river)
  3. In the long run, the aforementioned 50000 years of climate data could be used to validate the GRADE resampling approach.

This is a long term project, with deliverables every year

All documentation will be published n English,  on the KNMI (see above), the Rijkswaterstaat and Deltares websites.

2.1.4 Research on wave action on rivers

  1. A better set-up of hydraulic boundary conditions (water levels and waves) for assessment and  design on the rivers and narrow estuaries.
  2. There are two main objectives
    1. Feasibility study, to check whether the spectral model is a suitable tool to replace the current approach based on the Bretschneider parametric formulas.
    2. measuring wind waves and currents on rivers, measuring the interaction between river flow and the wave action, in order to validate SWAN and Bretschneider and provide suitable model bias corrections.
  3. This is a long term project, with deliverables every year
    1. In 2018 the best method to measure wind waves will be determined.
  4. All documentation will be published in English, on the KNMI, the Rijkswaterstaat and Deltares websites.

2.1.5 Wind, Wave and Run-up measurements on large lakes, between barrier islands in the Waddenzee

  1. These activities are crucial for validation of hydraulic (wave) models, and to provide uncertainty bands and bias corrections. They supplement the permanent water level measurements of the RWS national monitoring network.
  2. There are three main objectives
    • measuring wind and wind-generated waves in the Wadden Sea (tidal inlets and tidal flats) and on large lakes like Lake IJssel. This project started in 1997 for lakes and in 2006 for coastal areas.
    • using this data to calibrate and validate our wind and wave models
    • combining this data with run-up data on two locations in the Wadden sea area

(the last project is formally more a project of TU delft, Rijkswaterstaat is involved in the measurement strategy.

  1. This is a long term permanent project, with deliverables 5 or up to 10 years, after the data has been processed and evaluated.
    • In 2018 the best method to measure wave action will be determined.
    • The run-up study will start in 2018
  2. All documentation will be published in English, on the Rijkswaterstaat and TU websites. Most of the data can be accessed through rws.nl/water.

2.2 Research of Geotechnics

Piping (internal erosion) and slope instability

  1. A more precise description of the failure mechanism of piping so design and assessment of flood defenses is less conservative. This should include (three-dimensional) heterogeneity effects and time-dependence.
  2. The Sellmeijer model currently describes the capacity of sand transport in the pipe. We should try to describe the rate in which the particles are loosened from the soil or we should return to empiric rules (e.g. Bligh and Lane).
  3. Slope instability research will also continue, with a focus on facilitating the recent implementation of the Critical State Soil Model CSSM (also known as undrained approach).
  4. Further slope-instability related research topics are related to pore pressure and infiltration modelling, the strength of the unsaturated zone, and the effect of wave overtopping on slope instability

These are long term projects, with deliverables every year. All documentation will be published on the Rijkswaterstaat and Deltares website in English.

2.3 Revetment failure

  1. A more precise description of the failure mechanism of revetment failure (stone, asphalt and grass) including the subsoil, and a better description of time-dependent effects. This should lead to a less conservative method for design and assessment of flood defenses…
  2. This is a long term project, with deliverables every year. It will start in 2019.
  3. All documentation will be published on the Rijkswaterstaat and Deltares website in English

2.4 Failure path research

  1. Little is known about the levee failure process beyond initial failure of for example a revetment (i.e. beyond the first asphalt crack, or first uplifted stone or grass sod). This is still far from the ultimate limit state and actual levee failure to be considered in the safety assessment.
  2. The failure path approach is inspired on the USACE safety assessment approach and can be used to estimate (using expert judgement) the contribution of this residual strength between initial and total levee failure. It can also be used to identify and prioritize knowledge gaps, also on the interaction of different failure mechanisms
  3. Research is now being carried out to explore the potential of this approach.

3.0 Applied research initiated by STOWA, for regional flood defenses

Research for regional flood defenses have little or no risk for life loss. There are about 15000 km of regional flood defenses in the Netherlands, mainly managed by regional Water Boards. STOWA is the research institute for the regional managers of flood defenses in the Netherlands.

  1. Managing flood defenses poses a lot of practical problems
  2. Research subjects cover inspection and management of levees, including how to deal with trees, animal burrowing, setting of safety standards, providing safety assessment methods, dealing with drought and peat levees, etc.

Projects with the Delta program: e.g. multifunctional use of levees, professionalizing inspection of flood defenses,

  1. for publications see the website (note most are in Dutch).
  2. http://www.stowa.nl/projecten/?projectTask=2. Research subjects in Dutch

4.0 Applied research initiated by the national program for the reinforcement of flood defenses “HWBP”.

Some projects of interest are listed below.

4.1       Influence of sandy and vegetated foreshores on Hydraulic Boundary conditions,

  1. Wave damping by tidal marsh vegetation has been investigated within the NOW BE SAFE project, and will continue to be investigated within the ALL-RISK project described above. See for example DOI 10.1016/j.coastaleng.2016.06.001
  2. The present 2-year project is about the application of these results to design of Wadden Sea levees, and will finish soon.
  3. Despite all efforts and all new insights, there is still a lack of empirical data in extreme conditions, so that uncertainties when accounting for tidal marsh wave damping are large.
  4. Pilot experiments have also been done on sandy foreshore solutions (in order to reduce the amount of levee reinforcement), for example near the Houtribdijk separating Lake Marken and Lake IJssel. See https://www.ecoshape.org/en/projects/hybrid-flood-defence-houtribdijk-sandy-foreshore/

4.2       a review of the method for calculating Hydraulic Boundary conditions

  1. a review of the current way hydraulic boundary conditions are calculated in the Wadden Sea area and suggestions for improvements for design, assessment and forecasting.
  2. A reduction of hydraulic boundary conditions to be used in current dike design.
  3. This is a two-year project which started in 2017, with deliverables in 2018 and 2019
  4. All documentation will be published on the Rijkswaterstaat and Deltares website in Dutch,

4.3 Piping / internal erosion

  1. research on the piping process and experiments with drainage systems (large sand filters) to reduce piping
  2.  finding affordable measures to tackle piping
  3. This is a long term project which started a few years ago and deliverables in 2018 and 2019
  4.  All documentation will be published on the Rijkswaterstaat and Deltares website in Dutch,

4.4 Slope stability

Real life experiments with and without reinforcement using sheet piling

– see the article by Meindert Van, in the mid-2018 Newsletter

4.5 stone revetments

  1. A more precise description of the failure mechanism for certain type of stone revetments used in the Wadden sea so design and assessment of flood defenses is possible.
  2. The objective is to determine a new rule and to implemented it in the current safety assessment software.
  3. This is a long term project, with deliverables at the end of the project in 2019
  4. All documentation will be published on the HWBP website in Dutch

4.6 Asphalt revetments

Many asphalt revetments were constructed in the seventies and are approaching the end of their technical lifetime.

  1. A more precise description of the ageing of asphalt revetment used in the Wadden Sea
  2. The objective is to determine when to intervene.
  3. This is a long term project, with deliverables at the end of the project in 2019
  4. All documentation will be published on the HWBP website in Dutch

Research funded by HWBP, the national reinforcement program

4.7 Managing cables, pipelines crossing levees or near levees A failure of pipeline in or near a levee can cause failure of the levee.Safety assessment rules for cables and especially pipelines near and within levees need a risk-based update.

  1. Managing cables and pipelines near an crossing levees is covered by formal rules. With the implementation of risk based standards for flood defenses some levees now have lower standards. The NEN standards have become more important for those levees.
  2.  This project just started in 2018
  3.  rules covering cables and pipelines are published by NEN: https://www.nen.nl/. The HWBP website will publish the results, probably only in Dutch.

 

Closure of Dutch storm surge barriers

On the 3rd of January 2018, all Dutch storm surge barriers had to close.

For details, see the news item https://www.i-storm.org/news.html on the site of I-storm, the International Network for Storm Surge Barriers.

Closed Maeslant Barrier

The closed Maeslant storm surge barrier (archive photo)

New book on floods and flood risk management

A new book (in two volumes) on flood risk and flood risk management is available at ISTE editions

 

 

 

 

 

 

 

 

 

 

Volume 1  risk knowledge: http://www.iste.co.uk/book.php?id=1210

Volume 2 risk management: http://www.iste.co.uk/book.php?id=1257

A new issue of our Newsletter

A new issue of our newsletter is available here : https://lfd-eurcold.inrae.fr/index.php/wg-newsletter/

I want to thank all the editorial team and the contributors. I hope you will find reading it interesting.

Don’t hesitate to disseminate it to all your contacts (inside and outside of ICOLD) who are interested in levees and flood defences.

Please send us contributions for our next issue and also for the web site (see the last page of the newsletter for what we are looking for).

Photos from ICOLD Prague meeting

 

Many pictures from the Prague ICOLD meeting are on ICOLD’s facebook page (click here).

NB : the link is not active on the home page. When on the home page, click on “View full post” or “Read more” button first

3rd International Conference on Protection against Overtopping 6-8 June 2018, UK

Only a few days left to submit an abstract to this interesting conference (deadline 13 September 2017).

See web site http://www.protections2018.org/ for details. Extract from the homepage:

The increasing demand for dam, levee and seawall safety and flood protection has motivated new research and advancements and a greater need for cost-effective measures in overtopping protection as a solution for overtopping concerns at levees, dams and seawalls. This conference will bring together leading experts from practice, research, development, and implementation for two days of knowledge exchange followed by a technical tour of the Lake District including some of the impressive dams which can be found there. This conference will focus on:

  • Critical issues related to levees, dams and seawalls
  • New developments and advanced tools
  • Overtopping protection systems
  • Overtopping simulators / test facilities
  • Overtopping failure mechanisms
  • System design and performance
  • Applications and innovative solutions
  • Case histories of overtopping events
  • Physical modelling techniques and recent studies
  • Numerical modelling methods.

A new Technical Committe in ICOLD : “Levees”

Dear Colleagues,

I am pleased to inform you of the creation of a Technical Committee “Levees” within ICOLD.

The General Assembly of ICOLD voted and approved this creation during its meeting last Friday (07/07) in Prague, at the 2017 annual meeting.

This excellent news for the international Levees and Flood Defences community is the result of many years of work and actions that have demonstrated to the Large Dams community the interest of working on Levees as well:
– the International Levee Handbook (2009-2013),
– inclusion of the topic by many National Committees, including CFBR (France), NETHCOLD (NL), USSD (USA), BDS (UK) and many more,
– creation in 2015 of our Working Group under the European Club of ICOLD on “Levees and Flood Defences”,
– recognition by the European Club and ICOLD Boards of our WG activity,
– of course, the vast amount of research and guidance from many recent national and international projects (including National Committees products),
– the active support of the National Committees from France, Netherlands and USA and the receptivity of the ICOLD Central Office and Board,
– finally, the vote of the member countries representatives in the General Assembly.

The creation of this Technical Committee (which I hope will have a fruitful production), coupled with Question 103 (Small dams and levees) of the next ICOLD Congress in Vienna in 2018, makes it possible to consider that these particular structures definitively join dams, large and small, among the topics of this major international organization in the field of Hydraulic Works: ICOLD; even if we are not yet ready (joke) to change its-laws or to rename ICOLD as the International Commission on Levees and Dams.

Next year will be essential in terms of activity. We will have to work hard in the EurCOLD LFD WG to present final deliverables to the European Club. The new TC will have to produce draft Terms of Reference and prepare its first Meeting and Workshop in 2018 ICOLD Congress in Vienna, where its ToR will be finalized. The transition between the two groups will need to be as smooth as possible.

Finally, I was chosen as Chairman of this new Technical Committee, which must eventually succeed and replace our European Club WG. I thank all the colleagues, within and without our WG, and from many countries and National Committees, too many to name them, who made all this possible. This is just a beginning!

During the General Assembly: introduction of the proposition by ICOLD President, Mr Anton Schleiss
Picture by Eija Isomäki

During the General Assembly: defending the cause of Levees
Picture by Cees Henk Oostinga

Prague WG Meeting and Workshop

A meeting and a workshop of our Working Group on Levees and Flood Defences will take place during the ICOLD meeting in Prague on July 7, 2017 (see details in the agenda).
WG members are all invited to attend the meeting. ICOLD National Committees have been informed of the event and are invited to send a representative to join us during the meeting. The workshop, as such, is open to all ICOLD meeting participants.

WG meeting in Prague (07/07/2017)

Our Working Group will hold its meeting on Friday, July 7, during the ICOLD Meeting and in the same venue thanks to the help of the local organizing committee. Apologies to members not being able to attend the meting at this date.
The formal meeting will be held during the morning (9:00-12:30), the afternoon (13:30-17:00) will be a workshop type meeting.
Attendance by non-members is possible if place permits, registration in advance.
Our members are welcome to fill (or update)) the following doodle poll in order for us to know who will be present.