"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:80be8bd0-b8fe-4b7c-9700-c32a3a644d73","http://resolver.tudelft.nl/uuid:80be8bd0-b8fe-4b7c-9700-c32a3a644d73","Field experiment on alternate bar development in a straight sand-bed stream","Eekhout, J.P.C.; Hoitink, A.J.F.; Mosselman, E.","","2013","Alternate bars in rivers and streams develop as a result of differences in length scales involved in the adjustment of flow and sediment transport to irregularities of the bed. The amount of field evidence supporting theoretical insights is highly limited. Here, we present results from a large-scale field experiment in a 600 m long straight reach. Over a period of almost 3 years, the channel was allowed to evolve autogenously from initially flat bed conditions, subject to discharge variation. Alternate bars developed within 8 months from the start of the experiment. The initial stages of bar development included bar growth, both in wavelength and amplitude, and bar migration. The latter was too limited to classify the bars as being migrating bars; therefore, we classify the bars as nonmigrating bars. Toward the end of the experiment, the regular alternate bar pattern evolved into an irregular pattern and bar amplitude started to decrease. From the start of the experiment we observed a declining channel slope, from 1.8 m km?1 initially to 0.9 m km?1 halfway the experiment, after which it stabilized. We applied two bar theories to establish their predictive capacity. Both bar theories predicted the development of alternate bars under the constructed channel conditions. In response to the declining channel slope, both theories predicted a decreasing likelihood for the development of alternate bars. Our study shows that under field conditions, the applied bar theories may predict the initial stages of bed development.","river morphology; alternate bars; bar theory; field experiment; stream restoration","en","journal article","American Geophysical Union","","","","","","","2014-06-13","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:37a2b1c3-43d2-4446-8a61-0c4cf56da4f3","http://resolver.tudelft.nl/uuid:37a2b1c3-43d2-4446-8a61-0c4cf56da4f3","Erosion of river banks along the Paraná de las Palmas River, Argentina","Den Bieman, J.; Van den Koppel, M.; Van Velzen, G.; Verbruggen, W.","","2010","One of the branches of the Paraná delta is the Paraná de las Palmas River. This branch doesn’t have the biggest discharge but has the most navigation. The situation in the Paraná de las Palmas isn’t without problems though; the river banks show erosion over the whole length of the branch. This erosion has been investigated by the following research questions: - What are the contributions of the different erosion agents to the total erosion rate of the river banks along the Paraná de las Palmas River? - What kind of measures can be taken to decrease the erosion rate, and what are the effects of the different measures? Although the bank erosion occurs in the whole river branch, in answering the research questions, a smaller study area is defined between km 81 and km 90 of the river branch (measured from Buenos Aires), close to the city of Campana. This study area contains one bend and one straight river section.","Parana; river bend erosion; river morphology; revetment; shore protection","en","student report","TU Delft - Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:fc471d22-7d80-48aa-a3c9-de936d2bf6cc","http://resolver.tudelft.nl/uuid:fc471d22-7d80-48aa-a3c9-de936d2bf6cc","Experimental research on the effects of surface screens on a mobile bed","Troost, S.T.","De Vriend, H.J. (mentor); Uijttewaal, W.S.J. (mentor); Mosselman, E. (mentor); Sloff, C.J. (mentor); Havinga, H. (mentor)","2010","In 2000 the Dutch government chose a new point of view for the Dutch rivers: “Room for the River”. This viewpoint is the basis for a new approach of high water protection in the Netherlands. Instead of strengthening and raising the dikes, solutions must be based on space and spatial quality. One of the suggested measures is the addition of secondary channels. The purpose of these channels is enlarging the conveyance area and the ecological role of the river. Maintaining the profile of these channels involves substantial financial consequences. Finding a sustainable solution for undesired erosion or sedimentation is the main focus of this study. The research question is stated as follows: “How can the undesired erosion or sedimentation in secondary channels be corrected with a temporary but sustainable solution in the form of surface screens?”. The main part of this study is an experimental study on the effects of surface screens on a mobile bed. The design of the physical experiments requires choices about the geometry of the flume. The experiments were carried out with a straight flume and with a dividing wall. Preparing the experiments requires information about the flume facility. The experiments have been carried out in the Environmental Fluid Mechanics Laboratory of DUT. The upstream boundary conditions are discharge and velocity distribution. The downstream boundary condition consisted of a fixed water level. The water level was kept constant along the natural slope of the surface. The experiments consist of taking velocity and bed level. The angle of attack and the penetration depth were chosen to be variable. The angle of attack was varied between 15 and 25 degrees. With these relatively small angles the screen acts as guidance for the flow, instead of an obstruction. The penetration depth was varied between 20% and 60% of the water column. The initial test run determined the optimal measurement duration and the initial equilibrium. Four representative cases have been described in detail, giving support to the general conclusions. The flow pattern changes under influence of the surface screen. The main flow direction is guided by the screen, introducing a transverse velocity at the surface. As flow continuity in the flume has to be maintained, the water near the bottom is forced to have a transverse velocity in opposite direction. Redistribution of the suspended transport and the bottom transport was induced. This generated locations were the actual transport did not meet the transport capacity, which gives rise to morphological changes. Next to the spiral motion the screen had an effect on the longitudinal flow velocities. The attacked side of the flume experiences a higher velocity, thereby having a higher transport capacity. This higher capacity gives rise to local erosion of the bed. At the unattacked side, sedimentation occurs, thereby rising the bed level. In the B-series of the experiment a dividing wall was added. The screen in front of the bifurcation gave rise to the same two processes, but the wall introduced an extra effect. The screen influenced the bifurcation relationship. The bed level adapted to the new conditions. The upstream effect of the bifurcation is explained by changes in water level topography, thereby influencing the backwater curve. In general the wall amplified the morphological development of the bed. Finally some suggestions have been made for the practical application of surface screens. In general the screens can be applied in a (secondary) channel or in front of a bifurcation. The use of a screen inside a channel has an advantage not to interfere with the navigation channel. The advantage of a screen in front of a bifurcation is influencing two channels simultaneously. One of the main disadvantages of the latter is the possibility of disturbing the delicate bifurcation relationship. When carefully implemented this effect can simultaneously be the main advantage of this screen layout, as the morphological response increases.","surface screen; surface screens; morphology; river training; spiral flow; river engineering; river morphology; experimental research; morphological response; sediment management; secondary channel; river maintenance; bifurcation","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:baf1b98c-6613-4a0e-9e4d-c065730c4a57","http://resolver.tudelft.nl/uuid:baf1b98c-6613-4a0e-9e4d-c065730c4a57","The design and application of scour anticipated designs in river related and coastal structures in various countries and their effectiveness","Van Duivendijk, J.","","2006","Keynote lecture at the ICSE2006. Various types of scour can confront the engineer, who has to design and construct a hydraulic structure in a marine environment. The engineer is interested in the magnitude of the scour to be expected and its development in time. He hopes that such information, if at all available, is accurate and that he can base his design and construction method on such information without meeting any unexpected hydraulic response. In principle the engineer can react differently, according to the situation: 1 he accepts that scour will develop after completion of the structure and, given its extent and rate of development, he takes measures to prevent (or limit) damage to the structure and loss of stability; 2 he tries to prevent the scour or, in any case, takes measures to keep it away from the structure; 3 he is aware of the possibility that the works will be only exposed to scour during construction and he takes temporary measures to limit the damage; 4 he completely under-estimates or is not aware of any danger of scour and must repair the damage afterwards against high cost. In the paper is elaborated the said situations, as encountered by my colleagues and myself, by presenting five case histories. They will be presented in chronological order as one learns always from mistakes. Moreover, one starts usually by having responsibility for small projects and ends up doing large projects","scour; river morphology","en","conference paper","CUR","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:1107be41-27fb-430c-a63c-09fe839fc928","http://resolver.tudelft.nl/uuid:1107be41-27fb-430c-a63c-09fe839fc928","Sediment exchange between the main channel and the groyne fields of a river","Yossef, M.F.M.","","2003","Report on a physical scale model test in the Fluid Mechanics lab on the effect of groynes on the bed and sediment transport in rivers.","groynes; rivers; river morphology; sediment transport; Delft Cluster; DC 03.03.04","en","report","Delft Cluster","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4c4a5a36-aeda-4b46-a1eb-b500b739268f","http://resolver.tudelft.nl/uuid:4c4a5a36-aeda-4b46-a1eb-b500b739268f","Grensmaasproject: Veiligheid, natuurontwikkeling en delfstoffen","Spaargaren, G.R.","Olthof, J. (mentor); Havinga, H. (mentor); De Ridder, H.A.J. (mentor); Stive, M.J.F. (mentor)","2002","Sinds begin jaren negentig wordt gewerkt aan plannen voor het Grensmaasgebied. Het Grensmaasgebied wordt gevormd door een gedeelte van de rivier de Maas, namelijk vanaf Maastricht tot aan Maaseik. Een van de maatregelen die voortkomt uit de Grensmaasplannen is rivierverruiming. Bij deze verruimingswerken komen grote hoeveelheden delfstoffen vrij, die voomamelijk bestaan uit zand en grind. De korreldiameter van het grind loopt uiteen van 30 mm tot wel 600 mm. Op 12 locaties in het Grensmaasgebied worden diverse constructies aangelegd, waaronder overlaten en bochtbeschermingen. Traditioneel worden deze constructies uitgevoerd in breuksteen of beton. Wellicht is het mogelijk, zowel technisch als economisch, om de constructies uit te voeren in grof grind in plaats van in de traditionele materialen. Bij projectlocatie Visserweert dient er, voor de gegraven nevengeul, een overlaatconstructie te worden aangelegd. Op deze manier kan voorkomen worden dat in de toekomst de nevengeul hoofdgeul gaat worden. Bochtbescherming is nodig om ervoor te zorgen dat de rivierloop vast blijft liggen tegen Visserweert aan. Voor het bepalen van de steendiameter, vereist voor de geplande constructies, wordt onder andere gebruik gemaakt van de parameters voor mobiliteit en transport. De mobiliteitsparameter (\}') is een maat voor de hydraulische belasting en de sterkte eigenschappen van het bodemmateriaal. De transportparameter, qs*, is een maat voor de hoeveelheid transport van bodemmateriaal. De transportformule van Paintal, gecorrigeerd door het Waterloopkundig Laboratorium, is tot op heden de meest geschikte voor grind. Het blijft echter moeilijk om het transport te bepalen bij lagere mobiliteitsparameters, omdat bij die waarden de huidige transportformules vooral betrekking hebben op breuksteen. Uit computersimulaties kon niet met zekerheid worden vastgesteld dat bij de ontwerp-overstromingsfrequentie van 1:250 jaar de maatgevende omstandigheden optreden. De omstandigheden die gebruikt zijn voor het ontwerp komen voort uit de overstromingsfrequentie van 1:50 jaar. Voor de overlaatconstructie is, bij de overstromingsfrequentie van 1:50 jaar, grind nodig met een dso van 0,08 m. De vereiste steengrootte van het grind voor de bochtbeschermingsconstructie heeft een dso van 0,10 m. Op basis van kosten is de constructie uitgevoerd in breuksteen het goedkoopst. Ten opzichte van breuksteen zijn grind en beton 8% respectievelijk 24% duurder. Verschillende groepen uit de samenleving, te weten beleidsmakers, gebruikers en natuurbeheerders, beoordelen grind als het meest geschikte uitvoeringsmateriaal voor de overlaatconstructie. Deze beoordeling is gebaseerd op de maatschappelijke waarde van het uitvoeringsmateriaal gecombineerd met de kosten van het materiaal. Ten opzichte van het meest geschikt bevonden uitvoeringsmateriaal grind kost de uitvoering in breuksteen 60% meer en is de prijs van de betonvariant 106% hoger. Maatschappelijk gezien wordt grind als beste oplossing gevonden, ook al is deze optie duurder. Uiteindelijk zal de keuze voor het uitvoeringsmateriaal afhangen van overleg tussen de verschillende belangengroepen.","Maas river; river restauration; flood wave flooding; river morphology","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:84a60af7-bd53-4a5c-b9b9-1f67f905d26b","http://resolver.tudelft.nl/uuid:84a60af7-bd53-4a5c-b9b9-1f67f905d26b","Migrating Pools in Yangtze River","Li, Y.","","2002","The severity and location of bank erosion and bed scour changes with the variation of water level. At low flows, the main flow thread tends to follow the concave bank. As the discharge increases, the flow tends to cut across the convex bar, to concentrate against concave bank only downstream the bend apex. This change of flow pattern is important when predicting the magnitude and position of river bed scour during floods. Local scour hole may have a significant effect on the macroscale river morphology (Mossleman et al,2001). Local scour can affect the stability of man-made structures, such as riprap revetments, and lead failure if no counter-measures are against the scour. The migrations of pools may jeopardises the safety of the river dikes; dike collapse events due to this phenomenon are still common in China.","scour; Yangtze river; river morphology; Delft Cluster; DC 03.03.04","en","report","Delft Cluster","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:41ae9273-0819-4bc5-80f3-c44f73a56d9e","http://resolver.tudelft.nl/uuid:41ae9273-0819-4bc5-80f3-c44f73a56d9e","Onderzoek naar de afmetingen van een overlaat langs de Waal","Vermeij, M.","Battjes, J.A. (mentor); Visser, P.J. (mentor); Voortman, H.G. (mentor); Vrijling, J.K. (mentor)","2001","Van oudsher heeft Nederland te maken met rivieroverstromingen. Door de eeuwen heen werd er voortdurend strijd tegen het water gevoerd. Bedijkingen moesten de bedreiging van overstromingen beheersbaar maken met als gevolg dat sedimentatie en dus ophoging van het land nu plaats vindt in het winterbed van de rivieren. De rivieren komen hierdoor steeds hoger te liggen ten opzichte van het te beschermen land en de dijken moeten steeds verder worden opgehoogd. Bovendien zal de verwachte maximum afvoer van de rivieren de komende decennia toenemen als gevolg van klimaatsveranderingen (RIZA, WL-Delft en KNMI, 2000). De hogere dijken, hoger liggende rivieren en het dalende land leiden tot steeds grotere gevolgen voor de veiligheid, de economie en de maatschappij bij een dijkdoorbraak. Naar aanleiding van de hoogwaters van 1993 en 1995 heeft de regering in 1996 de beleidslijn ""Ruimte voor de Rivier"" vastgesteld. Een van de hieruit voortkomende acties is het onderzoeken of een hogere rivierafvoer veilig kan warden opgevangen met rivierverruimende maatregelen in plaats van met een nieuwe ronde van dijkversterking. Het project ""Ruimte voor Rijntakken"" onderzoekt maatregelen waarmee de stijging van de maatgevende afvoer bij Lobith van 15.000m3/s naar 16.000m3/s veilig kan worden afgevoerd. Een mogelijke maatregel is het aanleggen van een retentiepolder. Voor nog hogere afvoeren kunnen noodoverloopgebieden worden aangewezen die dienst moeten doen als binnendijks bergingsgebied. De Commissie Noodoverloopgebieden, ook wel Commissie Luteijn genoemd, werd april 2001 ingesteld om hiernaar onderzoek te doen. Medio mei 2002 zal de Commissie advies uitbrengen over de mogelijkheden en consequenties van noodoverloopgebieden. Het principe van retentiepolders en noodoverloopgebieden is in technisch opzicht hetzelfde. Het zijn beide gebieden die bij extreme afvoeren tijdelijk worden gebruikt voor de opvang van rivierwater. Het verschil is dat retentiepolders onderdeel uitmaken van de maatregelen om de rivierwaterstand beneden de maatgevende waterstand te houden, noodoverloopgebieden worden pas ingezet als de waterstand boven de maatgevende waterstand dreigt uit te komen. Doel van beide maatregelen is rivierwater zijdelings af te voeren in daarvoor aangewezen gebieden om hoge waterstanden benedenstrooms te voorkomen. Hierdoor neemt de kans op overstroming verder benedenstrooms af en kan schade in bijvoorbeeld stedelijke gebieden worden voorkomen. Dit onderzoek concentreert zich op onderstaande drie aspecten met betrekking tot noodoverloopgebieden en retentiepolders. De nadruk ligt op het onderzoeken van mogelijke afmetingen van de overlaat, de verlaging in de waterkering waarover het rivierwater zijdelings wordt afgevoerd naar de retentiepolder of noodoverloopgebied. - Hoe kunnen de benodigde afmetingen van een overlaat worden bepaald? - Wat zijn de voor- en nadelen van de mogelijke alternatieven voor de afmetingen van de overlaat? - Hoe groot is het effect van de overlaat, de waterstandsdaling, langs de rivieras?","river morphology; emergency weir; flooding","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:71074f88-77b2-4d0f-8d29-3e4fc350ea0f","http://resolver.tudelft.nl/uuid:71074f88-77b2-4d0f-8d29-3e4fc350ea0f","Morphologische Reaktion der Waal auf Baggermaßnahmen","Siegfried, A.","Klaassen, G.J. (mentor); Taal, M. (mentor); De Vriend, M. (mentor)","2000","Veldonderzoek naar het effect van baggermaatregelen (zowel baggeren als storten) in de Waal op de morfologie van de rivier.","river morphology; dredging; river bed; riviermorfologie; waal","de","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Socrates (jointly with Karlsruhe University)","",""
"uuid:57369598-9309-4685-aebf-9f759d857710","http://resolver.tudelft.nl/uuid:57369598-9309-4685-aebf-9f759d857710","Experimenteel onderzoek naar waterbeweging in een rivier met kribvak en uiterwaard","Bos, R.M.; Havinga, F.J.","Uijttewaal, W. (mentor); Booij, R. (mentor)","2000","Bij overstroomde kribben in een rivier met uiterwaard zijn grootschalige horizontale wervels te verwachten. Het tijdsgemiddelde langssnelheidsprofiel in dwarsrichting is bepalend voor het ontstaan van grootschalige wervels. In het kribvak vindt een grote richtingsvariatie in ruimte en tijd plaats. Deze variatie zorgt voor een grote uitwisseling van impuls, wat in de praktijk kan leiden tot uitwisseling van stoffen en fijn sediment. Benedenstrooms van de krib is een verticale neer aanwezig. In het kribvak is geen horizontale neervorming geconstateerd. Wel zijn de snelheden daar zeer laag. Achterloopsheid is te verklaren door een slingering van de kroming om de wortel van de krib heen. Bij relatief lage snelheden in de uiterwaard zijn de wervels vanuit de hoofdgeul dominant en zorgen die ervoor dat er een sterke stroming vanuit de hoofdgeul op de wortel van de krib gericht staat. De turbulente intensiteit op de dwarsraai midden in het kribvak heeft een lokaal en een absoluut maximum op de buigpunten van het horizontale snelheidsprofiel. De locatie van de maxima komt overeen met de theorie betreffende Kelvin-Helmholtz instabiliteiten. De grootte van de maxima kan echter niet gerelateerd worden aan de grootte van de gradiënt van de langssnelheid; de grootste fluctuaties vinden plaats op de overgang, daar waar de gradiënt significant kleiner is dan in de hoofdgeul. De kribben forceren in de hoofdgeul een grote gradiënt van de langssnelheid. Hierdoor worden horizontale wervels gevormd. Door de grote weerstand van de benedenstrooms kribben, vindt advectie plaats van de wervels naar de uiterwaard, wat grote snelheidsfluctuaties op de overgang tot gevolg heeft. Zo ontstaat er een grote impulsoverdracht van de hoofdgeul naar kribvak en uiterwaard.","river morphology; kribvakken; river groynes; flood plain; uiterwaard","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:a91affdd-1808-458b-a253-86a3e581519c","http://resolver.tudelft.nl/uuid:a91affdd-1808-458b-a253-86a3e581519c","One and two dimensional effects of floods on river morphology: A SOBEK model for River Waal","Franca, M.","Havinga, F. (mentor); Sloff, C.J. (mentor); De Vriend, H.J. (mentor)","1998","The importance of the Rhine and its branches is unquestionable. It has an important role as an attraction point to human activities and as a navigation channel from the North Sea into Europe. The present report is one of the numerous studies made for the Rhine branches, in this case the River Waal. The main ""tool"" used during this work is SOBEK, a software package developed by Delft Hydraulics and the Institute of Inland Water Management and Waste Water Treatment (RIZA) of the Dutch government. In this report, a one-dimensional model for the river Waal is presented, see Chapter 3. This model was used for several simulations that led to the following conclusions. By means of the 1D model SOBEK it was possible to conclude that the dominant discharge can be used to predict riverbed changes without losing accuracy, see Chapter 6. When using a variable discharge for river simulations a simplification can be made by averaging the peaks, see Chapter 6. With the results from the 1D model some parameters of the Waal were computed as relaxation, wave and damping lengths, see Chapter 6. In the present work an attempt was made to use the quasi two-dimensional option of SOBEK (Sedredge) to model the interaction between the floodplains and the main channel during periods of high water periods, see Chapter 4. A two-dimensional model was built with this propose. This model was based on two parallel and laterally coupled channels, one simulating the main channel and the other the flood plains. Unfortunately the simulations showed the impossibility of doing this. SOBEK didn't compute any sediment exchange between both channels probably due to the large difference of levels between them. Another incapacity of SOBEK is related with the fact that it doesn't work when one of the channels is not inundated, see Chapter 7. With a one-dimensional model and with a two-dimensional model (2 parallel channels) for the main channel, it was possible to make conclusions about the relative importance of the bends and of the floodplains in the Waal, see Chapter 8. Definitely the influence of the floodplains on the river morphology is minor when compared with the influence of the bends. The difference of levels between the two channels in the two-dimensional model is considerable. When neglecting them, this will have large morphological consequences. Hence it is suggested that any future study about this Rhine branch should include the bends. In Chapter 9 one simulation is presented to study river behaviour when there is a narrowing in a channel. For this simulation an academic model was built based on characteristics of the Waal. The simulations were made for a permanent constriction and for a temporary one. July/98 In the case of a permanent constriction the evolution of the riverbed to its equilibrium state can be seen. The local perturbation creates a sand wave, which propagates downstream before the river reaches the equilibrium. Upstream the river doesn't show any kind of perturbation. After removing the obstacle after 3 years, the perturbation starts migrating downstream, damping as it proceeds. The riverbed takes a long time to re-establish the equilibrium bed along 15 km. An important fact to remind is that the consequences of making the constriction are not only felt locally, but have a large influence downstream.","river morphology; Sobek; Waal","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:2815827d-031f-4b9d-955d-edb6b86eb2a6","http://resolver.tudelft.nl/uuid:2815827d-031f-4b9d-955d-edb6b86eb2a6","De morfologische effecten van de baggergeulen in de Zandmaas","Balsters, A.","Ribberink, J.S. (mentor); Havinga, H. (mentor); Van Velzen, E. (mentor); De Vriend, H. (mentor)","1998","Naar aanleiding van de hoogwatergolf op de Maas in 1993 werd door de Minister van Verkeer en Waterstaat de Commissie Boertien 11 ingesteld, met als opdracht te adviseren op welke wijze de hoogwateroverlast in het Maasdal in de toekomst beperkt kan worden. Het advies luidde in hoofdzaak een verbreding van de Grensmaas en een verdieping van de Zandmaas. De verdieping van de Zandmaas zou ongeveer drie meter moeten bedragen over het traject Linne(km 68)-Megen(km191). Omdat er in Nederland geen ervaring is met rivierverdiepingen op dergelijke schaal, heeft men in eerste instantie twee proefbaggergeulen op het traject Gennep(km 155)-Grave(km 175) gecreeerd. Bij deze geulen voert men een monitoringsonderzoek uit. Geul 1 loopt van km 155-km 164 en geul 2 loopt van km 166-km 174. Bij Mook (km 165) is een spoorbrug aanwezig en lopen veelleidingen onder de rivier. Omdat men wilde voorkomen dat deze constructies gevaar zouden lopen, heeft men de rivier onverdiept gelaten van km 164 tot km 166. Bij het monitoren kwam naar voren dat bij km 156 veel erosie optrad als gevolg van het blootleggen van een fijne laag. Zijn functie als rivierbeheerder brengt voor RWS o.a. de plicht met zich mee de hoogwateroverlast te beperken. Hiervoor is inzicht nodig in de toekomstige veranderingen in een rivier en inzicht in extreme situaties die zich in de rivier voordoen. Voor het debiet bij maatgevend hoogwater geldt QMHW = 3826 m3/s. Door de rivierverdieping is een waterstandsdaling bewerkstelligd. Als gevolg van de ingreep treden morfologische veranderingen op, zoals de sterke erosie bij de blootgelegde fijne laag. Door de morfologische veranderingen, warden de waterstanden be'invloed. Met het oog op het beperken van de hoogwateroverlast is het van belang te weten hoe dit zich in de toekomst ontwikkelt. Verder is het, LV.m. de veiligheid van de aanwezige spoorbrug en de onder de rivier lopende leidingen bij km 165 van belang te weten wat voor bodemveranderingen optreden. T.a.v. de spoorbrug had men de eis van een toelaatbare erosie van nul meter gesteld. In het afstudeerwerk is aandacht besteedt aan het verwerven van inzicht in de optredende morfologische veranderingen met het oog op de veiligheid van de constructies en de gevolgen van deze veranderingen op de waterstand bij QMHW. Gekeken is aan de hand van het 1D-programma SOBEK, met een versie die rekent met uniform sediment, hoe de situatie verandert in de periode 1997-2017. De gevoeligheid van het model is ook onderzocht. Alvorens het model kon worden gecreeerd, moesten eerst de monitoringsgegevens worden geanalyseerd om de benodigde parameters en de optredende bodemveranderingen te bepalen. Onderscheid is daarom gemaakt in een deel monitoringsgegevens en modeliering van het gebied.","Maas; river morphology; sediment transport","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:cfb067db-510a-43f8-aa51-9baf94a28c5e","http://resolver.tudelft.nl/uuid:cfb067db-510a-43f8-aa51-9baf94a28c5e","Het morfologische effect van bochtverbeteringen in een rivier","Siers, J.","Havinga, H. (mentor); Wang, Z.B. (mentor); Stelling, G.S. (mentor); De Vriend, H.J. (mentor)","1997","In een rivierbocht treedt een zogenaamde spiraalstroming op, waardoor het typische dwarsprofiel van een rivierbocht ontstaat: diep in de buitenbocht en ondiep in de binnenbocht. Hierdoor is slechts over een kleine breedte voldoende vaardiepte aanwezig en vormen bochten in de Waal een knelpunt in de rivier voor de scheepvaart. In het Waalproject worden onder andere deze knelpunten aangepakt. Daarbij wordt gezocht naar nieuwe, kleinschalige maatregelen, omdat de traditionele rivierverbeteringen te grote gevolgen hebben voor zowel de rivier als voor de ecologie en het landschap. Doordat deze maatregelen innovatief van karakter zijn, zijn de effecten ervan nog onvoldoende bekend. In dit afstudeerproject zijn met behulp van het ID-programma SOBEK de grootschalige morfologische effecten van een vaste laag, bodemkribben en bodemschermen bepaald. Deze bochtmaatregelen vergroten de weerstand van de rivier, waardoor de waterstanden bovenstrooms worden opgestuwd. Dit heeft zowel boven- als benedenstrooms van de bochtmaatregel morfologische gevolgen. Voor het bepalen van die morfologische gevolgen is van het rivierensysteem Rijn, Waal en Pannerdens Kanaal een 'gladde' schematisatie gemaakt, dat wil zeggen dat zo weinig mogelijk discontinutteiten in geometrie en ruwheid op een riviertak voorkomen. Met deze schematisatie wordt bereikt, dat de bodemontwikkeling in langsrichting van de rivier geen zeer grote schommelingen vertoont, zoals dat in het door Rijkswaterstaat gebruikte Rijntakken-model het geval is en waardoor de morfologische gevolgen van bochtverbeteringen moeilijk te onderscheiden zijn van de overige morfologische veranderingen. Het model is geijkt op waterbeweging, sedimentbeweging en morfologie. Daarbij is er van uitgegaan, dat het uiteindelijke doel van het model het voorspellen van grootschalige morfologische ontwikkelingen ten gevolge van zomerbed ingrepen op met name de Waal is. Dit betekent dat, hoewel de waterbeweging redelijk goed is geijkt, het model niet geschikt is voor het voorspellen van locale waterstanden, omdat locale kenmerken in de geometrie van de rivier hierop veel invloed kunnen hebben en deze niet in het model zijn meegenomen. Om dezelfde reden is het model ook niet geschikt voor de voorspelling van zeer locale bodemontwikkelingen. De door SOBEK berekende sedimenttransporten komen goed overeen met de sedimenttransporten waarvan in het IVR project ( Rijkswaterstaat) wordt uitgegaan. De autonome bodemdaling in het ontwikkelde SOBEK-model is over het algemeen te klein. Benedenstrooms van een overgang van rivierbocht naar rechtstand treden oscillaties in de bodemligging op. De oscillaties benedenstrooms van een Waalbocht zijn analytisch benaderd met behulp van het twee-kanalen model. Benedenstrooms van een bocht waar een een vaste laag of bodemkribben zijn aangelegd, zijn de oscillaties sterker dan in de oorspronkelijke situatie. Dit wordt veroorzaakt door de erosiekuil die benedenstrooms van de bochtmaatregel ontstaat. Bij bodemschermen ontstaat geen erosiekuil en zijn de bodemoscillaties kleiner dan in de oorspronkelijke situatie.","river bend; river morphology; river training","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:d67d1c10-cde9-498e-8e0a-e38d3634d787","http://resolver.tudelft.nl/uuid:d67d1c10-cde9-498e-8e0a-e38d3634d787","Three-dimensional modelling of secondary flow in river bends","Jongbloed, J.W.","Stelling, G.S. (mentor); Battjes, J.A. (mentor); Di Silvio, G. (mentor); Wang, Z.B. (mentor); Booij, R. (mentor)","1996","The flow in a river bend has a large influence on the cross-sectional profile of the bend. Due to the curvature of the bend a secondary flow, which is perpendicular to the main flow, occurs. The secondary flow is directed outwards in the upper part of the cross-section and inwards in the lower part of the cross-section. It causes by means of the transverse transport of main flow momentum a redistribution of the main flow. This redistribution of the main flow and the sediment transport by the secondary flow cause a typical river bend profile, a steep sloping bank in correspondence with a large depth near the outer wall and a smoothly sloping bank in correspondence with a small depth near the inner wall. To be able to predict (the changes of) the profile and the position of a river bend one must understand the flow pattern and the related sediment transport. To account for the flow pattern several numerical simulation programs have been developed. Since, nowadays, it is impossible to calculate the flow exactly, due to the turbulence, it has to be modelled and some assumptions and approximations have to be made. At Delft Hydraulics a program package (Delft3D) has been developed to simulate these flow cases and their sediment transports. In this thesis research has been done to what extent Trisula, the part that accounts for the prediction of the fluid movement, is capable of predicting the flow in river bends. At first a description of the flow pattern in river bends and a summary of the possibilities of the turbulence modelling are given as well as an abstract of the previous research, both numerically and experimentally, to gain insight in the phenomenon. To verify Trisula an experiment in an 'infinite river bend' has been done at the University of Padua at the Institute of Hydraulics 'G Poleni'. Due to the sensitivity of the boundary conditions this experiment gave not satisfying results so the program had to be checked with other measurement. The measurements of De Vriend were used to verify the computational results of a strongly curved bend and the measurements of Booij were used to verify the computational results of a smoothly curved bend. From the research to the simulation of the flow in river bends, it appeared that Trisula is able to predict the main features that occur in a river bend although the magnitude, especially of the radial velocities, is sometimes too small. The velocity distributions over the vertical and the development and decay of the secondary flow throughout a river bend are predicted rather well. One of the most striking features is the impossibility of trisula to predict the counterrotating secondary flow near the outer wall at sufficiently large Dean numbers due to the incorrect modelling of the turbulence","river morphology; river bend; secondary flow","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:85a99745-565e-42f2-bd16-9eb328ed27de","http://resolver.tudelft.nl/uuid:85a99745-565e-42f2-bd16-9eb328ed27de","Characterization of the non-uniform geometry of mountain rivers","Hoeboer, R.M.","De Vries, M. (mentor); Wang, Z.B. (mentor)","1996","The objective of the study is the characterization of the non-uniform geometry of a mountain river and the development of a method that identifies this geometry. Identification of the geometry enables simplification of a certain river section in modelling, which can be applied in a wide range of applications, for example the prediction of water levels. Identification is based on the tracer methodology, which means that a non-disintegrating substance is released upstream of a river reach and water levels and concentrations are continuously measured. Therefore attention has been paid to the flow and transport processes in a mountain stream with irregular geometry. The non-uniformity of the geometry of a mountain river affects the flow and transport processes. In the study the non-uniformity is modelled by the use of correction coefficients in the hydraulic model and the application of the stagnant zone concept in the transport model. The coefficients represent corrections for the influence of the non-uniformity of the depth and velocity profiles over the crosssection. The stagnant zone concept is based on the assumption of mass exchange between a zone with no net flow besides a main stream. A coupling can be found between the two concepts, which enables rewriting of the identified correction coefficients in a percentage of stagnant zones, relative to the total cross-section. Based on those principles, a flow and transport simulating numerical model is developed. The applicability of the identification system is limited to streams with moderate Froude numbers. The determination of the parameters in a system, in this study the geometrical and hydraulic coefficients, is an identification problem. Integration of the numerical model with the parameter identification procedure DUD results in a system that identifies a geometry for which the produced observations of water levels and concentrations coincide with the measurements. An additional result is the reconstruction of the upstream, unsteady, discharge.","mountain river; river morphology","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:9beec608-e19a-436a-a468-f09d68f9da05","http://resolver.tudelft.nl/uuid:9beec608-e19a-436a-a468-f09d68f9da05","Longitudinal profiles of rivers with a composite cross-section","Eerkens, J.W.","De Vries, M. (mentor); Wang, Z.B. (mentor); Fokkink, R.J. (mentor)","1996","In one-dimensional river modelling it is common to schematise the cross-section into a rectangular cross-section with a constant width. If a quasi-steady flow is assumed, the equilibrium longitudinal profile is known and unique: the bottom slope is constant and equals the water surface slope. However, numerical calculations at DELFT HYDRAULICS suggest that for rivers with a composite cross-section more equilibrium longitudinal profiles can exist. In addition, it appears that a stable curved equilibrium can exist. As an example, a river with floodplains can be mentioned to have a composite crosssection. This report contains a study on the equilibrium longitudinal profiles of rivers with a composite cross-section. In order to calculate these profiles, and their stability, three different models are applied to a schematised river. Calculations are done both analytically and numerically, and all results are visualized in phase diagrams.","river morphology; river bed; sediment transport","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:5d7f96bf-a43d-4dc6-86e7-2e210941eb2a","http://resolver.tudelft.nl/uuid:5d7f96bf-a43d-4dc6-86e7-2e210941eb2a","1-D morphological river models: Schematisation and interpretation","Van Liebergen, J.C.G.","De Vries, M. (mentor); Wang, Z.B. (mentor); Fokkink, R.J. (mentor)","1995","This study contains two topics which are important for the use of a one-dimensional computer model, calculating morphological changes in time. Firstly, for a good prediction of the morphological changes by the model a good reproduction of the water movement and the sediment movement is necessary. One of the conditions for a good reproduction of the process is a good schematisation of the river cross-section in the model. In the river cross-section, a good reproduction of all the parameters playing a role in the morphological process is required. Several schematisation-methods are treated, considering a fluctuation in the discharge and irregularly shaped cross-sections. The second topic of this study considers the interpretation of the calculated morphological change to the real cross-section. The calculated morphological change is distributed over the width of the cross-section in several ways, each distribution with his own physical background. The results show an influence of the distribution-option on some practical parameters. For both topics data are used of the Da River in Vietnam and of the River Waal in the Netherlands.","river morphology; river model","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:df54737a-4d14-4dae-ad1d-59cc9b6fbfb4","http://resolver.tudelft.nl/uuid:df54737a-4d14-4dae-ad1d-59cc9b6fbfb4","Research on bifurcations in rivers","Roosjen, R.; Zwanenburg, C.","De Vries, M. (mentor); Wang, Z.B. (mentor); Fontijn, H.L. (mentor); Fokkink, R.J. (mentor); Van Zomeren, B.C. (mentor)","1995","One of the unsolved problems in the water resource engineering is the morphological behaviour of bifurcations in rivers. Bifurcations can be found in deltas, in estuaries and in braided rivers. When modelling river reaches which contain a bifurcation, a nodal point relation is needed. The problem is to determine this nodal point relation. The distribution of sediment over the two branches is determined by local three-dimensional phenomena and it has to be specified explicitly at every bifurcation that is modelled. Nowadays nodal point relations are used, which are not based on thorough (experimental) research. In this report the search on the distribution of the sediment as a function of the discharge distribution is described. An experimental model of a bifurcation in a river is designed and constructed. This experimental model is used to do experiments which lead to a better insight in the behaviour of the bifurcation. Before starting the experiments, all parts of the test rig were tested. Then several experiments have been designed and carried out with the test rig. The measurement errors, made during the experiments, are described, which gives a good view of the quality of the experiments. Since it was time-consuming to obtain data from the experiments, a thorough statistical analysis of the found data is carried out. Several statistical techniques were used to obtain as much information as possible from the data. With the use of this statistical analysis, nodal point relations were found for the specific types of bifurcations in the test rig, for three different upstream discharges and two different shapes of the bifurcation. It appeared that the general nodal-point relation proposed by Wang et al (1993) was appropriate. The unknown parameters of this relation were found for the circumstances of the experiments; Three relations are found for the first shape of the bifurcation, with a respective upstream discharge of 20 1/s, 30 1/s and 40 1/s. Two relations are found for the second shape of the bifurcation, with a respective upstream discharge of 30 1/s and 40 1/s. It is statisticaly proven that some of the coefficients in these relations are comparable for the different circumstances, but others are not. In order to see whether it is possible to carry out numerical simulations of a bifurcating river, the configuration of the experimental model and the found nodal point relations were used as input for simulations with WENDY. Thus, simulations were carried out of some of the experiments. It appeared that the results of these simulations were comparable to the measured data from the experiments. Therefore it is proven that if a good nodal-point relation is known, a good simulation of a bifurcating river can be carried out. Recommendations are given how to continue this research project in the future. The relations that are found here are only valueable for the given circumstances of the experiments. The final goal, however, of this research is to get a relation of the distribution of the sediment over the two downstream branches which can be used in all circumstances. More research has to be done to obtain this.","bifurcation; river morphology; river hydraulics","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:6c360049-e34d-4feb-ad83-e0e8636d0880","http://resolver.tudelft.nl/uuid:6c360049-e34d-4feb-ad83-e0e8636d0880","On the morphology of rivers on volcano slopes","Sloff, C.J.","De Vries, M. (mentor); Mosselman, E. (mentor); Stelling, G.S. (mentor)","1990","The rivers on the slopes of the Kelud volcano in Indonesia are marked by steep slopes and fine sediment. Therefore often supercritical flow and large sediment transports occur. In this exploratory study a mathematical model has been developed for this type of rivers. The properties of this model are examined with an analysis of the characteristics and with numerical computations. The results show rapid bed variations propagating upstream, which agrees with observations in the rivers on the Kelud volcano.","mountain river; river morphology; volcano; sediment transport","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:943ca4ff-1ea8-46dc-9b36-649e07b9f2a6","http://resolver.tudelft.nl/uuid:943ca4ff-1ea8-46dc-9b36-649e07b9f2a6","Morphological reaction of rivers due to sediment mining","Hendrickx, P.H.A.","De Vries, M. (mentor)","1988","In many rivers sediment is mined at same distance from the river mouth. Examples are the Brantas river at Java, Indonesia and the Mekong river, Thailand. This study contains the research of sediment mining in general. The sediment mining has its consequences on the river morphology: The bedlevel and the waterlevel decrease downstream as weIl as upstream from the point of mining. The waterdepth varies toa along the river. Figure 1.1 shows the changes of waterdepth, waterlevel and bedlevel in a new equilibrium situation, which can be determined in a theoritical way. This will be done in chapter 2. The changes along the river are of great importance for several hydraulic engineering structures: - With decreasing bedlevel bank protections may loose their stability; - Water inlets for irrigation works dry up when the waterlevel falls; - Navigation may become impossible when the waterdepth decreases.","sediment mining; river morphology; bedlevel; waterlevel","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:da3b785f-cc6b-489c-8a7e-849f60d27885","http://resolver.tudelft.nl/uuid:da3b785f-cc6b-489c-8a7e-849f60d27885","Odirmo, A One Dimensional model for River Morphology","Vermeer, K.","Booy, N. (mentor); Ribberink, J. (mentor)","1985","This report consists of five major parts. In Part I agiobal description of the project is given. In Part 11 the results of the definition study are presented and in Part 111 the results of the functional and technical design. Part IV gives a description of the two developed computer programs (ODIRMO and CREADATA). In Part V the test cases for the model are discussed and the results of the tests are given. Part VI is a user guide for the model. In chapter 2 of this part the reader is introduced to the basic equations of river morphology. In chapter 3 the proceeding5 in the project are treated; a short description is given of the System Development Methodology~ the .Definition Study and the Functional and Technical Design. Chapter 3 is concluded with some remarks on both computer programs ODIRMO (One Dimensional River Morphology) for the morphological computations and CREADATA for the preparation of input data and on the test cases used. In chapter 4 some conclusions and recommendations are given and the usefulness of the SDM method for technical problems is discussed. In chapter 5 some references are given.","river morphology","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:94b02c43-421c-4ba6-ac0c-19aa4d59b2a4","http://resolver.tudelft.nl/uuid:94b02c43-421c-4ba6-ac0c-19aa4d59b2a4","A mathematical model of the flow and bed topography in curved channels","Olesen, K.W.","","1985","A two-dimensional horizontal mathematical model of the flow and bed topography in alluvial channel bends is presented. The applicability of the model is restricted to channels of which the width-depth ratio is large, the Froude number is small, bed load is dominant and grain sorting effects are negligible. First order analyses of the mathematical model, using both steady and unsteady perturbations, are carried out, and an integration procedure based on a CSFT finite difference approximation of the mathematical model is outlined. Stability and accuracy of the numerical model are investigated. Computational results are compared with data from two laboratory flumes and with data from a small natural river. The computed bed topographies and flow distributions agree rather well with the measured data, if the model is properly calibrated.","bend flow; river bend; curved channel; annular flume; river morphology","en","report","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4e95ddfd-6ee8-4fe6-8eed-0b3b07c0c757","http://resolver.tudelft.nl/uuid:4e95ddfd-6ee8-4fe6-8eed-0b3b07c0c757","Engineering potamology","De Vries, M.","","1985","Lecture notes on river engineering and river morphology.","river morphology; river engineering","en","lecture notes","TU Delft, Department Hydraulic Engineering and IHE Delft","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:02591ea1-fdfe-4fce-bd6e-2da367a8bc85","http://resolver.tudelft.nl/uuid:02591ea1-fdfe-4fce-bd6e-2da367a8bc85","A sensitivity analysis applied to morphological computations","De Vries, M.","","1985","In river engineering morphological predictions have to be made to study the implications of changes in a river system due to natural causes or human interference. It regards here time-depending processes. Characteristic parameters of the river have to be forecasted both in time and space. The morphological processes, however, are extremely complex and therefore a substantial degree of schematization is required before e.g. mathematical models can be applied to obtain the predictions wanted. Information about available mathematical models can e.g. be obtained from Jansen (1979) and Klaassen et al (1982). The present physical-mathematical formulation of the morphological problems involved is incomplete. For instance the variation of the width B(x,t) cannot yet be predicted. Therefore in this paper the restriction is made that (relatively) unerodible banks are present. The description of the problem in two (horizontal) space dimensions has not yet led to mathematical models that are used on a routine basis. During the last two decades or so, however, one-dimensional models have been developed gradually to useful tools for practical problems. In these models average values across the width of the river are predicted for the waterlevel h(x,t), the bedlevel z(x,t) and consequently for the water depth a(x,t). There is concern, however, regarding the accuracy of these predictions. Very few possibilities exist to calibrate and verify the mathematical models for a particular river. There are a large number of error sources of which here basicly two will be discussed. Sediment transport s(x,t) has to be predicted from the local hydraulic conditions. Alluvial roughness, for instance expressed in the Chezy coefficient C(x,t), also has to be forecast locally. The available transport predictors and roughness predictors are based on the presence of steady uniform flow. Hence there is already a potential source of errors in applying these predictions in a mathematical model with nonsteady and non-uniform flow. The two types of predictions are linked. In many transport predictors (transport formulae) the alluvial roughness has to be known. As future conditions are considered, this roughness also has to be predicted.","river dynamics; river morphology; morphological computations; bed roughness","en","report","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4952bdb8-ad0b-46c7-bdeb-9d3a9f132510","http://resolver.tudelft.nl/uuid:4952bdb8-ad0b-46c7-bdeb-9d3a9f132510","Watermovement over a horizontal bed and solitary sanddune","Termes, A.P.P.","De Vries, M. (mentor); Vreugdenhil, C.B. (mentor); Ribberink, J.S. (mentor); Ooms, G. (mentor)","1984","In order to predict waterlevel changes in rivers due to floodwaves and local bedshapes for navigation, the local behaviour of the riverbed should be known. In many cases the bed of a river ~onsists of dunes, which propagate downstraam due to the sediment transport along the dunes. In this report mainly the watermovement but also the sediment transport along a dune is studied. The investigation consists of a theoretica! and an experimental part. In the theoretica! part a calculation of the flowfield above a dune is carried out using a computer model for the watermovement (ODYSSEE computer program of the Delft Hydraulica Laboratory, DHL). In the experimental part the mechanism of the local sediment transport along the dune is studied. The experimental set up consists of a solitary sanddune on a conveyor belt in a flume. The position of the dune is constant due to: conveyor belt velocity = - propagationvelocity of the dune. In this situation the flowfield above the duneis measured using a Laser Doppier Anemometer (LDA), which is tested first in a uniform flow situation. The local sediment transport, which is known along the steady dune, is related to the local bedshearstress.","river dune; bedform; river morphology","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:9a481fb2-51b6-4f8c-9989-6301b9682c0c","http://resolver.tudelft.nl/uuid:9a481fb2-51b6-4f8c-9989-6301b9682c0c","Alternate bars in and meandering of alluvial rivers","Olesen, K.W.","","1983","The paper presents a linear perturbation analysis of a horizontal two-dimensional mathematical model for the flow and bed topography in straight alluvial rivers with dominant bed-load. A sediment transport model including effects of transverse bed slope, secondary (helical) flow and secondary flow inertia is employed. The stability and the propagation velocity of an unsteady perturbation is investigated. This stability analysis predicts wave lengths which are in good agreement with the wave lengths of alternate bars in straight laboratory flumes. The analysis predicts rather large propagation velocities of the perturbations. Several investigations have assumed the instability to cause meandering and braiding of rivers. However, in view of the corresponding large propagation velocity of the perturbation and the generally low erodibility of the banks, a non-propagating perturbation offers a more adequate explanation of the initiation of meanders and braids. In order to investigate this hypothesis a linear steady state perturbation analysis is carried out. The results of this analysis are compared with meander lengths measured in small meandering channels (laboratory experiments) and with data from large natural rivers. The agreement is good.","river dynamics; meandering; river morphology","en","report","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:d42e1810-6657-4941-9703-a2c08a6550f1","http://resolver.tudelft.nl/uuid:d42e1810-6657-4941-9703-a2c08a6550f1","Steady flow in shallow channel bends","De Vriend, H.J.","Kalkwijk, J.P.T. (promotor)","1981","Making use of a mathematical model solving the complete NavierStokes equations for steady flow in coiled rectangular pipes, fully-developed laminar flow in shallow curved channels is analysed physically and mathematically. Transverse convection of momentum by the secondary flow is shown to cause important deformations of the main velocity distribution. The model is also used to investigate simplified computation methods for shallow channels. The usual 'shallow water approximation' is shown to fail here, but a method starting from similarity hypotheses for the main and the secondary flow works well. On the basis of this method, a simplified mathematical model of steady turbulent flow in river bends is developed and verified using the results of laboratory experiments and fully three-dimensional flow computations. This model works well for shallow and mildly curved channels, but it shows important shortcomings if the channel is less shallow or sharplier curved.","River bend; river flow; river morphology","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:4c18e2d5-5792-420a-abba-565127bc1f46","http://resolver.tudelft.nl/uuid:4c18e2d5-5792-420a-abba-565127bc1f46","A numerical model for morphological computations in rivers with non-uniform sediment","Olesen, K.W.","De Vries, M. (mentor); Engelund, F. (mentor)","1981","l model whithout this restriction this has been done by taking more grain fractions into consideration. (Model for non - uniform or graded sediment). This extension of the mathematical model for uniform sediment is described in chapter 1, where the basic equations of the model for uniform as well as for non - uniform sediment are derived. The main assumptions in the deductions are that the flow can be considered quasi - steady and that the sediment transport is a function of the local hydraulic conditions. The characteristic directions in the model for non - uniform sediment are derived, in case of two grain fractions, and will be briefly analysed. In chapter 2 the basic equations will be discussed and some models for the component parts of the mathematical models will be suggested. Here also some of the general limitations for the morphological computation will be mentioned. An extensive numerical analysis of some finite difference methods for a linear hyperbolic equation is given in chapter 3. A predictor - corrector method is preferred for the solution of the model for non - uniform sediment, and the method is tested on the model for uniform sediment in order to check the applicability to a non -linear hyperbolic system. Finally the predictor - corrector method will be applied to the model for non - uniform sediment after a schematization of the vertical grain size distribution is carried out. The computational results from the numerical model for nonuniform sediment will be compared with solutions obtained from the characteristic method.","rivers; morphological computations; river morphology","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:58bc70ac-2d16-4d9b-907d-b397a3c2544c","http://resolver.tudelft.nl/uuid:58bc70ac-2d16-4d9b-907d-b397a3c2544c","Morphological modelling for rivers with non-uniform flow","Ribberink, J.S.","","1980","In Chapter I a derivation of the equations and an extension of the mathematical model will be carried out. The sediment-mixture is separated in a number of fractions - each with a representative grain size - and the equations describing the sediment-movement are split up for every fraction separately. In order to get some insight in the new model in Chapter 2 a restriction will take place to sediment-mixtures consisting of only two sediment-fractions. As a result only one extra dependent variable viz. the probability of one of the fractions, comes into the equations. Moreover the characteristic directions and relations belonging to the set of partial differential equations will be derived mainly in order to obtain information concerning the time-scales of changes in bedlevel and bedcomposition; also the interaction between these changes and the influence of some determining parameters will be studied. In Chapter 3 specific calculations will be carried out of the characteristic directions and relations and the influence of two possible concepts for a transportformula per fraction is studied. In Chapter 4 four simple applications of the mathematical model for two sedimentfractions are treated. The watermotion is simplified in order to be able to carry out the calculations partly by hand. In Chapter 5 a summary and conclusions are given.","rivers; sedimenttransport; river morphology; non-uniform sand","en","report","TU Delft, Department Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:2b62ccd2-cf9b-471e-bd0f-0d888d53822b","http://resolver.tudelft.nl/uuid:2b62ccd2-cf9b-471e-bd0f-0d888d53822b","Modelling of sediment transport: Link in a chain","De Vries, M.","","1977","Rather than reporting on a specific topic of current research in the broad field of sediment transport and river morphology, the writer will give a general contemplation on the state of the art. This will not be a review in the usual sense. The alloted space would then be filled easily with references. References will only be made here if it cannot be avoided. Moreover only sediment transport due to currents will be treated. To avoid confusion it is necessary to indicate that modelling of sediment transport is used at present (1977) in at least three meanings: (i) A theoretical framework for sediment transport proper. This mainly implies a relation between hydraulic parameters and the amount of sediment transport. This framework will have to be supplemented with experimental data before a useful transport predictor is attained. (ii) A mathematical framework for morphological processes in rivers, used to forecast morphological changes in rivers e.g. due to human interference (morphological computations). (iii) A scale model with mobile bed of a river in order to carry out similar predictions as under (ii) (mobile-bed scale models). In which follows the vague term ""modelling of sediment transport"" will be avoided if confusion may be introduced.","sediment transport; river morphology","en","report","TU Delft","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:ed331010-c8e8-4f42-9396-9ade25ce17ae","http://resolver.tudelft.nl/uuid:ed331010-c8e8-4f42-9396-9ade25ce17ae","Morphological computations","De Vries, M.","","1976","Lecture notes sediment transport in rivers, formulas and numerical models.","sediment transport; river morphology; bedload transport; river dunes; lecture note f10a","en","lecture notes","TU Delft, Section Hydraulic Engineering","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:ac4ccf4f-9d1b-4592-9a46-7f17621b4649","http://resolver.tudelft.nl/uuid:ac4ccf4f-9d1b-4592-9a46-7f17621b4649","A mathematical model of steady flow in curved shallow channels","De Vriend, H.J.","","1976","Uitgaande van de Reynoldsvergelijkingen met de bijbehorende randvoorwaarden wordt een vereenvoudigd wiskundig model afgeleid voor ondiepe bochtige rivieren. met als voornaamste uitgangspunten: - de vertikale afgeleiden van de snelheden zijn groot t.o.v. de horizontale - de schuifspanningseffekten overheersen de traagheids- (advectieve) effekten. Dit lijkt juist voor het geval dat de waterdiepte klein is t.o.v. de breedte en de representatieve bochtstraal. terwijl niet te sterke variaties in de geometrie mogen optreden. Het aldus verkregen stelsel differentiaalvergelijkingen met randvoorwaarden is in twee stappen oplosbaar. Eerst wordt (analytisch) de vertikale verdeling van de snelheidscomponenten en de totale druk bepaald. d.w.z. de vorm van de krommen maar nog niet de numerieke waarden. Met gebruikmaking van deze informatie worden vervolgens de vergelijkingen geIntegreerd over de waterdiepte. waarna de over de diepte gemiddelde waarden van snelheden en druk berekend worden door het geintegreerde stelsel numeriek op te lossen. Bij vergelijking van de resultaten met metingen blijkt het gebruikte model goed te voldoen voor wat betreft de verdelingen in de vertikaal. maar minder goed waar het gaat om de verdeling van de gemiddelde grootheden. vooral bij vlakke bodem. Dit is kwalitatief te verklaren uit het feit dat het advectieve effekt van de secundaire stroming op de hoofdstroom en de invloed van de oevers niet in het model zijn opgenomen.","bend flow; river morphology; annular flume; curved channels","en","report","Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:66b299fb-d0f5-438b-bd02-0dd7b4d06c61","http://resolver.tudelft.nl/uuid:66b299fb-d0f5-438b-bd02-0dd7b4d06c61","Analytical and experimental study of bed load distribution at alluvial diversions","Riad, K.","Thijsse, J.T. (promotor)","1961","It has long been observed that at most canal bifurcations the water diverted to the branch does not carry sediment in direct proportion to the rate of flow. Usually, the major part of sediment reaching a bifurcation is diverted into the small branches. This phenomenon has always bothered engineers responsible for the maintenance of irrigation and navigation canals which branch off relatively large alluvial streams. Experimental studies of this problem have usually been limited to the use of fixed bed flumes in which the velocity of flow was measured at different sections in the vicinity of the bifurcation. The distribution of the velocity both vertically and horizontally were then determined and considered as the basis of comparison between different cases. Some investigators studied the pattern of flow near the bed either by the introduction of sediment particles or pottasium permanganate crystals. In the present experimental study, sand was used as bed material and measurements in any run were only taken after the sand movement had reached equilibrium, when the rate of sediment feeding was equal to the sum of the rates of sediment being trapped at the end of main and branch channels. The experimental set-up consisted of a straight flume 20 m long and 0.80 m wide which represented the main canal and a lO m. X 0.50 m flume which branched off the main flume at 45 degrees, 8.20 m. from the upstream end and which represented the branch canal. At first a series of tests was carried out without a sand bed in order to study the wall roughness. Then the sand bed was introduced and a series of tests was carried out to determine the effect of the ratio between branch and main canal discharges upon the sediment behaviour at the bifurcation. In order to control the rate of sediment diversion into a branch, some artificial means have to be applied. In this respect the writer has experimented with the application of dividing walls which direct the bottom flow and guide vanes which direct the surface flow. In general and within the scope of the experiments, the guide vanes gave the better results. Hence, tests were concentrated on the determination of the best location and direction for such vanes, and the results of these experiments led to the recommendations described on fig. 50.","sediment transport; bed load; river diversion; river morphology","en","doctoral thesis","Waltman Delft","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""