PHYSICAL MODEL TESTS ON WAVE OVERTOPPING AND FLOW PROCESSES ON DIKE CRESTS INFLUENCED BY WAVE-CURRENT INTERACTION

PHYSICAL MODEL TESTS ON WAVE OVERTOPPING AND FLOW PROCESSES ON DIKE CRESTS INFLUENCED BY WAVE-CURRENT INTERACTION Stefanie Lorke 1, Babette Scere 1, Holger Scüttrumpf 1, Antje Borncein 2, Reinard Pol 2 Flow procee like flow dept and flow velocitie give important information about eroion and infiltration procee, wic can lead to an untable dike tructure and conequently to dike failure. Up to now everal pyical model tet on wave run-up and wave overtopping are available to adjut and improve deign formula for different dike tructure. Ti kind of pyical model tet ave been performed in te ere preented project FlowDike. It main purpoe i to conider two new apect tat could influence te aement of wave run-up and wave overtopping a well a te flow procee on dike wic ave not been invetigated yet: longore current and wind. Epecially in etuarie and along coat, te effect of tidal and torm induced current combined wit local wind field can influence te incoming wave parameter at te dike toe a well a te wave run-up eigt, te wave overtopping rate and te flow procee on dike. Ti paper will focu on tee flow procee on dike lope and dike cret on an 1:6 loped dike influenced by oblique wave attack and longore current. Keyword: flow procee; layer tickne; dike lope; dike cret; wave overtopping; pyical model tet; wave; current; dike; EurOtop-Manual INTRODUCTION Coatal and etuarine dike are deigned on te bai of deign water level and incoming wave condition. Hig wave combined wit low freeboard eigt can reult in wave overtopping and ubequently in dike failure. Additional factor uc a te angle of wave attack or te rougne of a dike ave to be conidered for wave run-up and wave overtopping (EurOtop-Manual, 2007). Furtermore a longore current in front of te defence tructure, like te tidal current, could ave an influence on wave run-up, wave overtopping and flow procee on dike cret. In order to invetigate tee procee influence of a longore current on wave run-up, wave overtopping and flow procee on dike cret pyical model tet were performed at te Dani Hydraulic Intitute (DHI) in Hørolm (Denmark) in mall cale in 2009 (project FlowDike: Hydralabproject HyIII-DHI-5 and KFKI-project 03KIS075 (RWTH Aacen Univerity) and 03KIS076 (TU Dreden)). Te model et-up and reult on wave run-up and wave overtopping are preented in Lorke et al. (2012). Invetigation on overtopping flow procee for different dike lope and freeboard eigt a well a dike rougnee ave been invetigated in detail by Scüttrumpf & van Gent (2003) and Boman (2007). Te patial effect like te influence of oblique wave attack and/or a longore current on wave overtopping parameter like flow procee on dike cret ave not been invetigated yet. Ti paper will concentrate on te reult of flow dept on te 1:6 loped dike. EXPERIMENTAL SET-UP Te bain of te DHI a a lengt of 35 m and a widt of 25 m. For te model tet te dike out of concrete wit a lengt of 26.5 m wa divided lengtwie into two part: one part wit a cret eigt of 0.60 m, te oter part wit a cret eigt of 0.70 m. Te model tet ave been divided into two tet pae. Te main difference wa te dike lope of 1:3 and 1:6. Te water dept wa 0.50 m during te firt tet pae and 0.55 m during te econd tet pae. Wit a 16 m long multidirectional wave generator irregular long creted wave (Jonwap pectrum) were generated for different angle of wave attack up to 45, tereby perpendicular wave attack i defined a 0. A longore current up to 0.40 m/ wa generated along te dike line. Te wave run-up eigt wa meaured wit a wave run-up board. Te wave overtopping amount wa collected in overtopping tank wic ave been weigted by load cell. Figure 1 give an overall view of te model et-up along te dike line. 1 Intitute for Hydraulic Engineering and Water Reource Management (IWW), RWTH Aacen Univerity, Mie-vander-Roe-Strae 1, 52056 Aacen, Germany; lorke@iww.rwt-aacen.de; babette.cere@rwt-aacen.de; cuettrumpf@iww.rwt-aacen.de 2 Intitute of Hydraulic Engineering and Tecnical Hydromecanic (IWD), TU Dreden, 01062 Dreden, Germany; antje.borncein@tu-dreden.de; Reinard.Pol@tu-dreden.de 1

2 COASTAL ENGINEERING 2012 Figure 1. View along te dike line of te model et-up. Te meaurement of flow procee on dike cret required te following intrument: wave gauge to meaure te flow dept micro propeller to meaure te flow velocity u Eac intrument wa intalled on te eaward and on te landward ide of eac dike cret. Furtermore, a wave gauge wa intalled on te lope during te tet on te 1:6 loped dike. Figure 2 (left) ow an overtopping proce near te inlet to an overtopping tank and te meauring device on te dike cret. Figure 2 (rigt) ow te meauring device on te dike cret in a more detailed perpective. Figure 2. Meaurement on te dike cret. Te poition of meauring device are illutrated cematically in top view in Figure 3a. Te coen intallation permitted to meaure te procee of flow dept and flow velocitie on te dike cret. Te flow velocitie ave been meaured wit micro propeller by Sciltknect (cf. Figure 3b). Tee device ave a vane rotation tat i cloely linear to flow velocity and unaffected by preure, temperature, denity or umidity. Te meauring range of te propeller varie between 0.04 m/ and 5 m/ wit an accuracy of 2 % of te full cale. Flow dept ave been meaured by wave gauge (cf. Figure 3c). A cange of conductivity between two tin, parallel tainle teel electrode of a wave gauge can be detected and converted into flow dept. Te device on te dike cret were ituated 0.03 m from eac cret edge, o a ditance of 0.24 m wa kept between te aligned eaward and landward meaurement. Moreover, te flow dept on te dike lope were meaured by additional wave gauge wic were placed at a orizontal ditance of 0.12 m downtream te cret edge of te two different dike eigt (cf. Figure 3).

COASTAL ENGINEERING 2012 3 a) b) c) Figure 3. a) Meaurement on te dike cret (cematically); b) micro propeller; c) wave gauge. TEST PROGRAMM Te main difference of te two tet pae wa te dike lope of 1:3 and 1:6. During bot tet pae te following boundary condition ave been kept contant: long creted wave under a Jonwap pectrum (one tet included 1 000 wave) wit active wave aborption two freeboard eigt R c [m] (1:3 loped dike: 0.10 m, 0.20 m; 1:6 loped dike: 0.05 m, 0.15 m) dike rougne (concrete) dike geometry During te tet te following boundary condition ave been varied, to determine teir influence on wave run-up, wave overtopping and flow procee: wave parameter (ignificant wave eigt H [m] and peak period T p []) angle of wave attack β [ ] (perpendicular wave attack: β = 0 ; wave attack wit te current: β > 0 ; wave attack againt te current: β < 0 ) longore current velocity v x [m/] wind velocity u [m/] perpendicular to te dike line Eac tet erie contained ix tet wit different ea tate. Werea, angle of wave attack, longore current velocity and wind velocity ave been kept contant. Te approaced wave eigt and wave period are given in Table 1 for bot tet pae. A matrix of te different tet configuration i given in Figure 4. Extenive table wit all tet and teir boundary condition are given in Lorke (2012). In total 119 tet were performed on an 1:3 loped dike and 152 tet were done on an 1:6 loped dike. Table 1. Sea tate applied on te 1:3 and 1:6 loped dike. 1:3 loped dike 1:6 loped dike H [m] T p [] H [m] T p [] ea tate 1 0.07 1.474 0.09 1.670 ea tate 2 0.07 1.045 0.09 1.181 ea tate 3 0.10 1.760 0.12 1.929 ea tate 4 0.10 1.243 0.12 1.364 ea tate 5 0.15 2.156 0.15 2.156 ea tate 6 0.15 1.529 0.15 1.525

4 COASTAL ENGINEERING 2012 1:3 loped dike 1:6 loped dike 0.40 0.40 8 8 Current [m/] 0.30 5 10 5 10 Current [m/] 0.30 8 8 0.15 0.15 8 0.00 5 10 5 10 5 10 0.00 8 8 8-45 -30-15 0 +15 +30-45 -30-15 0 +15 +30 Wave direction [ ] Wave direction [ ] Figure 4. Matrix of te conducted tet erie on te 1:3 loped dike (left) and on te 1:6 loped dike (rigt) (tet regarding te influence of wind are marked by te value of te wind velocity [m/] in te cell; = tet were not carried out, = tet were carried out) (modified according to Lorke (2012)). STATE OF THE ART Flow procee on dike were analyed by Scüttrumpf (2001) and van Gent (2002) in everal model tudie. Terein, different dike geometrie - i. e. a variation of dike lope and cret eigt were invetigated a well a everal rougnee of dike. Bot invetigation ave been brougt togeter (Scüttrumpf & van Gent, 2003). Boman et al. (2008) ued te raw data of Scüttrumpf (2001) and van Gent (2002) and analyed tem uing a new approac. For eac part of te dike (eaward lope, dike cret and landward lope) formulae to decribe te flow dept ave been determined and verified. Scüttrumpf (2001) decribe te flow dept on te eaward lope,lope by te following formula: 0.035 x* (1) lope wit flow dept on dike lope wic i exceeded by 2 % of te incident wave [m] x* geometric parameter: x* = x Z - x A [m] x Z orizontal ditance from till water level (SWL) to run-up [m] x A orizontal ditance from SWL to conidered point on dike lope A [m] Te ued parameter of equation (1) are illutrated in Figure 5. Figure 5. Geometrical parameter on dike lope ued by Scüttrumpf & van Gent (2003). Te flow procee along te dike cret can be decribed by te formula given by Scüttrumpf & van Gent (2003):,ea xc exp c (xc 0),land C, x C B C wit,land flow dept on landward cret wic i exceeded by 2 % of te incident wave [m],ea flow dept on eaward cret wic i exceeded by 2 % of te incident wave [m] x c orizontal ditance from te beginning of cret to conidered location on dike cret [m] B C cret widt [m] c C, empirically determined coefficient [-] In Figure 6 te parameter of te previou equation are illutrated. Te coefficient c C, a to be determined for eac different model et-up. Scüttrumpf (2001) pecified c C, = 0.89 for a 1:6 loped dike and van Gent (2002) c C, = 0.4 for a 1:4 loped dike. (2)

COASTAL ENGINEERING 2012 5 Figure 6. Geometrical parameter ued by Scüttrumpf & van Gent (2003). Boman et al. (2008) defined formulae to decribe te flow procee on dike cret uing te data of Scüttrumpf (2001) and van Gent (2002). Terefore, a furter coefficient c tran, a been introduced. Wit ti coefficient te decrement of flow dept due to te tranition from te outer lope to te orizontal cret i conidered. Anoter difference to te formulae of Scüttrumpf & van Gent (2003) (cf. equation (2)) i te correlation of te orizontal ditance to te eaward cret x C to te wave lengt L 0., land ( xc ) x C c, exp c (3) tran C,, ea( xc 0) f C L0 wit L 0 wave lengt [m] γ f-c friction factor on te cret (= 1 for a moot urface) [-] c tran, empirical determined coefficient to conider te influence due to tranition [-] For te 1:6 loped dike te coefficient c tran, wa determined a 0.81 and c C, a 6 by Boman et al. (2008). EVALUATION OF FLOW PROCESSES ON DIKES Dike lope During Project FlowDike te flow dept on te lope ave been meaured 0.03 m and 0.13 m above till water level on te 1:6 loped dike. Analying tee meaurement, te data i comparable to te recommended formula (1). Figure 7 ow te comparion of te meaured data (red and blue dot) to te grap preented by Scüttrumpf (2001) (orange line). Te meaurement of te wave gauge tat i intalled 0.13 m above SWL correpond well to Scüttrumpf (2001). Te formula by Scüttrumpf (2001) underetimate te flow dept meaured 0.03 m above SWL. Ti lead to te preumption, tat te flow dept of te run-up flow do not follow a linear variation. Figure 7. Flow dept on te dike lope 0.13 m above SWL (left) and 0.03 m above SWL (rigt). Terefore, a non-linear relationip of te flow dept along te dike lope a to be conidered and a new geometric parameter x a been determined. It definition i given in te following formula: wit x Z x A x' R y u A x z x A (4) R u orizontal ditance from SWL to run-up [m] orizontal ditance from SWL to te conidered point A on dike lope [m]

6 COASTAL ENGINEERING 2012 R u flow dept on dike lope wic i exceeded by 2 % of te incident wave [m] y A vertical ditance from SWL to wave gauge on dike lope (cf. point A in Figure 5) [m] A potential function a been derived to decribe te relationip of te flow dept on te dike lope and te geometric parameter x : 2 % 0.058 ' x 0. 721 (5) Figure 8. Flow dept on te dike lope 0.13 m above SWL and 0.03 m above SWL. Dike cret Invetigating te flow dept on dike cret, firt comparion to Scüttrumpf & van Gent (2003) were accomplied. Terefore, te coefficient of equation (2) ave been derived and compared wit previou reult. Figure 9 ow te analyi of te 1:3 loped dike (orange line) and 1:6 loped dike (red line) a well a te reult of Scüttrumpf (2001) and van Gent (2002) wit black broken line. For te 1:3 loped dike a coefficient of 0.35 and for te 1:6 loped dike of 0.49 a been found. Altoug tee value ow a deviation from te coefficient of Scüttrumpf, a tendency witin all invetigation can be recognized. Wit a teeper dike lope te coefficient c decreae and conequently te flow dept abate along te dike cret. A good approximation i given to te coefficient of van Gent for a 1:4 loped dike, wic lie between te coefficient for te 1:3 and 1:6 loped dike. However, a deviation between te coefficient of Scüttrumpf to te oter reult i noticeable, becaue te meaured flow dept by Scüttrumpf i meaured on te dike lope directly at te tranition from lope to cret. Figure 9. Flow dept on te dike cret in comparion to Scüttrumpf & van Gent (2003). Te formula (3) by Boman et al. (2008) amplifie te formula (2) by Scüttrumpf & van Gent (2003) by conidering te wave lengt. For te preented tudy te coefficient c tran a been defined a contant. Te coefficient c C, a been derived for te two invetigated dike lope. Te reult are preented in Figure 10. Te iger te inclination of te dike lope te iger i te coefficient c C,.

COASTAL ENGINEERING 2012 7 Figure 10. Flow dept on te dike cret in comparion to Boman et al. (2008). FLOW PROCESSES ON DIKES RELATED TO MEAN WAVE OVERTOPPINGON RATES Te flow dept ave been meaured at tree poition: on te lope, on te eaward ide and on te landward ide of te dike cret. Figure 11 ow te dimenionle mean wave overtopping rate q* againt te dimenionle flow dept * tat are defined a following for breaking wave condition: * H m1,0 tan (6) * q m1,0 q (7) 3 g H tan wit flow dept on dike exceeded by 2 % of te incoming wave [m] H ignificant wave eigt [m] m-1,0 wave teepne baed on pectral wave parameter H and T m-1,0 [-] tan α dike lope [-] q mean wave overtopping rate [l/(m)] Te iger te overtopping rate i te iger i te flow dept. Te preading in dimenionle flow dept can be explained by detecting not only te wave run-up but alo te run-down event of te overtopping procee. For all poition (lope, eaward, landward) a power function wa applied to decribe te relationip dike lope: 0. 248 2 %* 0.629 q * eaward ide of te cret: 0. 297 (8) 2 %* 0.637 q * landward ide of te cret: 0. 239 (9) 2 %* 0.293 q * (10) Te flow dept on te eaward ide are, depending on te mean dimenionle wave overtopping rate, about 25 % le tan on te lope. Te flow dept on te landward ide decreae in comparion to te flow dept on te eaward ide again by about 30 %.

8 COASTAL ENGINEERING 2012 Figure 11. Dimenionle flow dept againt dimenionle overtopping rate. INFLUENCE OF OBLIQUE WAVE ATTACK ON FLOW PROCESSES ON DIKES Te analyi of te influence of oblique wave attack on flow procee on te eaward ide of te dike cret will be performed by te ame principle ued for analying te wave overtopping rate (cf. EurOtop-Manual 2007, Lorke 2010). Terefore, te dimenionle flow dept * on te dike (cf. formula (6)) and te dimenionle freeboard eigt R c * are determined. Te dimenionle freeboard eigt for breaking wave condition i given a follow: R * c R H c m1,0 tan (11) wit R c freeboard eigt [m] H ignificant wave eigt [m] m-1,0 wave teepne baed on pectral wave parameter [-] tanα dike lope [-] In Figure 12 te relative freeboard eigt i given on te x-axi wile te exponential y-axi ow te relative flow dept * on te eaward ide of te dike cret. Te reult for te 1:3 loped dike (left) and 1:6 loped dike (rigt) are given. Te reference tet i own by te blue data point wit te correponding regreion curve given by te blue grap. Reference tet are carried out and analyed for perpendicular wave attack, witout current and witout wind but wit different wave parameter. Te oter grap ow te reult for tet wit angle of wave attack of 15 (red), 30 (green) and 45 (orange). Te correponding regreion curve can be decribed by exponential function: * * a exp b Rc (12) wit a empirical coefficient [-] b empirical coefficient [-] a i equal to te y-axi intercept of te regreion curve. For wave teepnee m-1,0 of about 0.025 and a dike lope of tanα = 1/6 a freeboard eigt of R c = 0 m lead to a flow dept on eaward ide of and * H tan H m 1,0 (13) 0.025 0.39 1 H 6 b 0 * a exp a (14)

Conequently te flow dept can be given a For a uppoed relation of COASTAL ENGINEERING 2012 9 a H (15) 0.39 0.5 H (16) a contant y-axi intercept a of 0.2 a been derived. Firt of all a decreaing flow dept i noticeable for increaing dimenionle freeboard eigt. Additionally, te iger te angle of wave attack i te lower i te flow dept on te dike cret for uncanged dimenionle freeboard eigt R c *. Ti trend correpond to former invetigation in te influence of te obliquene of te wave in wave run-up and wave overtopping (cf. Borncein 2012, Lorke 2012). Figure 12. Dimenionle flow dept againt dimenionle freeboard eigt for different angle of wave attack; left: 1:3 loped dike; rigt: 1:6 loped dike. Te inclination of te regreion curve i an indication for te quantity of te influence of te angle of wave attack on te flow dept. Te iger te inclination i te iger i te reduction of te flow dept due to te analyed influence factor (ere: angle of wave attack). In order to compare te influence of te angle of wave attack, an influence factor defined a te quotient of te inclination of te grap of te reference tet b ref and te inclination of te grap b β for every invetigated angle of wave attack a been derived: b ref (17) b Tee influence factor are plotted in Figure 13 for flow dept (left) and flow velocitie (rigt) againt te angle of wave attack. Te figure ow te influence factor conidered for calculating te flow dept and flow velocitie on te eaward ide of dike cret. Te influence factor of flow dept for te 1:3 loped dike are lower tan for te 1:6 loped dike. Ti mean tat on te 1:3 loped dike te flow dept decreae more ignificant wile increaing te angle of wave attack tan on te 1:6 loped dike. Inconitent influence factor are given for te tet on 15 degree wave attack. Te formula of te regreion curve i given for an equal y-axi intercept of 1.0 a follow: 1:3 loped dike: 0.011 1. 0 (18) 1:6 loped dike: 0.008 1. 0 (19) wit β angle of wave attack [ ] No clear tendency i noticeable for te influence factor on flow velocitie.

10 COASTAL ENGINEERING 2012 Figure 13. Angle of wave attack againt influence factor on flow dept (left) and flow velocity (rigt) on eaward ide of te dike cret. WAVE-CURRENT INTERACTION A new apect in te introduced tudy wa not only te detailed analyi of flow procee on dike cret influenced by oblique wave attack. Moreover, te influence of a longore current on wave runup and wave overtopping and terefore, on te preented flow procee a been invetigated. A preented in Lorke et al. (2010) an angle of wave energy, wic i a combination of te angle of wave attack and a longore current a been introduced. Figure 14 ow cematically te combination of te two vector for te longore current and te wave direction for negative (left) and poitive (rigt) angle of wave attack. Te daed arrow decribe te relative direction of te wave attack generated by te wave generator and te correponding angle β. Te dotted arrow indicate te direction of te longore current parallel to te dike line. According to Holtuijen (2007) te current doe not cange te angle of wave attack but it energy direction by te combination of te two vector current velocity v x and relative group velocity c g,rel marked wit te correponding arrow. A own in Figure 14, negative angle of wave attack lead to a maller abolute value of te angle of wave energy β e werea poitive angle of wave attack lead to a iger angle of wave energy β e tan te angle of wave attack β. Figure 14. Interaction between wave direction and current (Lorke et al. 2012). INFLUENCE OF SPATIAL EFFECTS ON WAVE OVERTOPPING Correponding to Lorke et al. 2010 te influence factor for oblique wave attack for average wave overtopping rate are plotted in Figure 15. Te black grap i te recommended grap by de Waal & van der Meer (1992) for wave overtopping. Te triangle give te influence factor for tet witout current. Te current influence i given by te circle (0.15 m/), diamond (0.30 m/) and quadrat (0.40 m/). Te grap on te left ow te influence factor againt te angle of wave attack. Adopting te angle of wave energy te data point influenced by a current witc to te rigt and correpond better to te formula by de Waal & van der Meer (1992) (cf. Figure 15, rigt).

COASTAL ENGINEERING 2012 11 Figure 15. Angle of wave attack (left) and angle of wave energy (rigt) againt influence factor for wave overtopping. INFLUENCE OF SPATIAL EFFECTS ON FLOW PROCESSES ON DIKES Correponding to te analyi of te influence of te angle of wave attack on flow procee on dike, te influence of a longore current will be analyed. Figure 16 ow te dimenionle flow dept againt te dimenionle freeboard eigt on te eaward ide of te cret of te 1:6 loped dike for different current velocitie. Te regreion curve of te data point of te different current velocitie wit te ame y-axi intercept ave nearly te ame gradient. Tat allow te aumption tat no ignificant influence i noticeable for te influence of a longore current on te flow dept on te dike cret for perpendicular wave attack. Hence, tere i a good agreement wit te concluion of te reult on wave overtopping (Lorke et al. 2012). A ligtly increaing flow dept i noticeable for a current of 0.40 m/ for mall relative freeboard eigt. Figure 16. Dimenionle flow dept againt dimenionle freeboard eigt for different current velocitie. Moreover, tet wit oblique wave attack and a longore current ave been conducted. Te correponding influence factor, wic ave been determined in relation to te reference tet, are plotted in Figure 17 againt te angle of wave attack (left) and againt te angle of wave energy (rigt). Te regreion of te reult of te reference tet can be decribed by te following formula: 1:6 loped dike: 0.833 co1.111 2 0. 307 (20) wit β angle of wave attack [ ] Te correlation coefficient for te reference tet i R² = 0.951. Conidering te tet wit a longore current a correlation coefficient of R² = 0.453 a been derived. Introducing te angle of wave energy doe not reult in muc better agreement to te regreion curve. Te correlation coefficient a been derived R² = 0.307.

12 COASTAL ENGINEERING 2012 Figure 17. Angle of wave attack (left) and angle of wave energy (rigt) againt influence factor for flow dept on eaward ide of dike cret. CONCLUSIONS Pyical model tet ave been conducted in te allow water wave bain of te DHI (Dani Hydraulic Intitute) in Hørolm, Denmark. Te intention wa to get furter information on wave runup and wave overtopping at dike epecially on te influence of a longore current and wind perpendicular to te dike line. Te angle of wave attack, te current and te wind velocity were varied during te meaurement of wave run-up eigt, wave overtopping rate, flow velocitie and flow dept on dike lope and dike cret. Mainly, ti paper preent te reult on flow dept and flow velocitie on dike lope and dike cret on te 1:6 loped dike. Good agreement to invetigation by Scüttrumpf (2001), van Gent (2002) and Scüttrumpf & Oumeraci (2005) for flow dept on dike lope and dike cret ave been depicted. A potential function decribing te flow dept along dike lope could be derived. Te flow dept on te eaward ide are, depending on te mean dimenionle overtopping rate, about 25 % le tan on te eaward lope. Te flow dept on te landward ide of te dike cret decreae in comparion to te flow dept on te eaward ide again by about 30 %. Te influence of oblique wave attack on flow dept on dike can be conidered by uing an influence factor. Te relationip between te angle of wave attack and te influence factor can be decribed by a linear function. Tereby, te flow dept decreae wile increaing te angle of wave attack, wic i comparable wit reult on invetigation on wave run-up and wave overtopping (de Waal & van der Meer 1992, EurOtop-Manual 2007). Te angle of wave energy a to be ued to conider te influence of a longore current on wave overtopping rate and flow dept on dike cret. To conider ti patial effect te influence factor for oblique wave attack on flow dept on dike a to be adapted by conidering te angle of wave energy. ACKNOWLEDGMENT Project FlowDike-D wa financially upported by te German Minitry of Education and Reearc (BMBF) witin a KFKI-project (German Coatal Engineering Reearc Council - GCERC/KFKI, project-no.: 03KIS075 (RWTH Aacen Univerity) and 03KIS076 (TU Dreden)).). Te autor tank te taff of te Dani Hydraulic Intitute (DHI) in Hørolm (Denmark) for teir cientific upport during te tet pae and for providing acce to te ydraulic laboratory during te Hydralab-project FlowDike (no. HyIII-DHI-5) and te KFKI-project FlowDike-D. REFERENCES Borncein, A.; Pol, R.; Lorke, S. (2012): Wave run-up on dike. In: 5t SCACR 2011 - International Sort Conference on Applied Coatal Reearc: Honouring Prof. Robert A. Dalrymple; 6t to 9t June, 2011, RWTH Aacen Univerity, Germany; proceeding / ed. by H. Scüttrumpf [et al.]. pp. 121-128; ttp://www.iww.rwt-aacen.de/fileadmin/internet/cacr/scacr_2011_proceeding.pdf Boman, G. 2007. Velocity and flow dept variation during wave overtopping, Mater Tei, Delft Univerity of Tecnology. Delft, Te Neterland. Boman, G., van der Meer, J., Hoffman, G., Scüttrumpf, H., Veragen, H. J. 2008. Individual overtopping event at dike. ASCE, 31t International Conference on Coatal Engineering 2008, Proceeding ICCE 2008, Hamburg, Germany, p. 2944-2956.

COASTAL ENGINEERING 2012 13 de Waal, J. P., van der Meer, J. W. 1992. Wave runup and overtopping on coatal tructure. Proceeding of te 23rd International Conference on Coatal Engineering, pp. 1772-1784 EurOtop-Manual. 2007. Pullen, T., Allop, N. W. H., Bruce, T., Kortenau, A., Scüttrumpf, H., van der Meer, J. W. Die Küte EurOtop Wave Overtopping of Sea Defence and Related Structure: Aement Manual, Iue 73, URL: ttp://www.overtopping-manual.com/eurotop.pdf (04-18-12). Holtuijen, L. H. 2007. Wave in oceanic and coatal water. Cambridge Univ. Pre. United Kingdom. Lorke, S., Brüning, A., van der Meer, J., Scüttrumpf, H., Borncein, A., Gilli, S., Pol, R., Sclüter, F., Spano, M., Ria, J., Werk, S. 2010. On te effect of current on wave run-up and wave overtopping. ASCE, 32nd International Conference on Coatal Engineering 2010, Proceeding ICCE 2010. Sangai, Cina. Lorke, S., Borncein, A., Scüttrumpf, H., Pol, R. 2012. Influence of wind and current on wave runup and wave overtopping. Final report 2012. Dreden and Aacen, Germany. Scüttrumpf, H. 2001. Wellenüberlauftrömung bei Seedeicen - Experimentelle und teoretice Unterucungen. Diertation an der TU Brauncweig, Germany. Scüttrumpf, H., Oumeraci, H. 2005. Layer ticknee and velocitie of wave overtopping flow at eadike. Journal of Coatal Engineering Vol. 52, Iue 6. pp. 473-495 Scüttrumpf, H., van Gent, M. R. A. 2003. Wave overtopping at eadike. ASCE, Proceeding Coatal Structure 2003, p. 431-443. Portland, Oregon. van Gent, M. R. A. 2002. Wave overtopping event at dike, Proceeding of te 28t International Conference on Coatal Engineering. pp. 2203-2215. Cardiff, United Kingdom.