An Experimental Study of Beach Evolution with an Artificial Seepage

An Experimental Study of Beach Evolution with an Artiﬁcial Seepage

Paper: An Experimental Study of Beach Evolution with an Artiﬁcial Seepage

Changbo Jiang∗,∗∗, Yizhuang Liu∗,BinDeng∗,∗∗,†,YuYao∗,∗∗, and Qiong Huang∗∗∗

∗School of Hydraulic Engineering, Changsha University of Science and Technology Changsha 410114, P. R. China †Corresponding author, E-mail: [email protected] ∗∗Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha 410114, P. R. China ∗∗∗Guangzhou Zhengjian Construction Engineering Design Co., Ltd., Guangzhou 510220, P. R. China [Received April 10, 2016; accepted September 8, 2016]

Beach erosion caused by extreme wave events (storm face, which has significantly influenced coastal sediment surges) is reported to occur in many coastal areas. transport [4]. Many researchers have suggested that such Artificially lowering the groundwater table effectively erosion could be induced by exfiltration or higher ground- stabilizes sand beaches in an environmentally friendly water table, while infiltration or lower groundwater table way. Mechanisms affecting beach stabilization remain contributes to onshore sediment transport [5–11]. Other unclear, however, due to the complex interaction be- studies suggest that the groundwater table does not sig- tween waves and coastal seepage. This study discusses nificantly change the beach profile [12–13] possibly be- the effects of coastal seepage on beach profile evolu- cause either infiltration increases the effective bed sedi- tion and bed materials sorting based on laboratory ex- ment weight and thus impedes sediment mobility or infil- periments in which seepage is induced artificially by tration tends to increase bed stress, thus enhancing sedi- a drain pipe at three cross-shore locations on a 1:10 ment mobility. The two types of mechanics mutually con- beach. Morphodynamic beach responses with and flict in infiltration and vice versa for the exfiltration [14]. without seepage under a typical cnoidal wave condi- The so-called beach drainage system (BDS) is based tion are reported. Results show that artificial seep- on the concept of lowering the groundwater table to re- age impacts only insignificantly on total upper-beach duce erosion. The BDS consists of a drain pipe parallel to deposition volume but could increase accretion on the the shoreline connected through a blind pipe to a pump- berm’s leeside by reducing seaside sand accumulation. ing station that transports drained water back to the sea or It also induces a steeper berm slope and shoreline re- to another destination [15]. Despite the above two oppo- cession. A drain pipe near the shoreline generated the site effects, many investigators report its positive effect on greatest accretion height on the upper beach. Seep- beach stabilization. Results of the first field survey, con- age location had no significance effect on bed material ducted by Chappell et al. [16] in Australia, showed that sorting, however. sediment accreted on the beach face by artificially lowering the groundwater level. Goler [17], in reviewing the Keywords: beach evolution, coastal seepage, bed sorting, BDS from 1981 to 2004, claimed that the BDS affected cnoidal wave shoreline accretion positively. Law et al. [18] demon- strated that the BDS affects the shore profile little over the long term period, but induced seepage retards erosion 1. Introduction in the first few hours of their laboratory experiment. A full-scale laboratory investigation series on a BDS in the Storm surges are natural phenomena of water rising large wave flume Grosser WellenKanal of the Coastal Re- commonly associated with strong atmospheric distur- search Centre in Hannover, Germany [19–22], indicated bances such as tropical cyclones and strong extratropical that the BDS decreases undertow current and water table cyclones. A large sum of field studies has shown that dev- rise due to wave motion while it increases the reflection astating storm waves mobilize a multitude of coastal sand, coefficient. An increase in bed stabilization is observed significantly eroding the coast in affected areas [1–3]. under low wave energy. Although the BDS is considered Many active engineering solutions to stabilize the shore- a possible “soft” method for reducing beach erosion and line have been attempted, such as spur dikes, breakwa- enhancing sand accretion, however, questions remain con- ters, and seawalls, but these solutions, considered “hard” cerning, e.g., the location effect of the drain pipe on beach engineering, modify original coastal morphology – some- evolution and bed materials sorting. We investigated the times harming near-shore ecology and environment. Sev- response of beach evolution and bed material sorting in eral recent environmentally friendly methods have been the location of seepage under a typical cnoidal wave be- proposed to stabilize beaches by controlling the ground- cause the cnoidal wave most closely resembles the wave water table through infiltration or exfiltration on the beach form seen during a storm or hurricane in rather shallow

Journal of Disaster Research Vol.11 No.5, 2016 973 Jiang, C. et al.

Fig. 1. Experiment setup.

water [23]. flume’s water level, drained water was pumped to the end We describe the beach evolution laboratory setup with of the flume through a discharging pipe and returned to artificial seepage in Section 2. Section 3 presents results the front of the flume via a pipe connecting both ends of and discussion of beach profile variation, berm slope, de- the flume. The infiltration rate was measured by a flow position volume on the upper beach and bed sorting with meter installed near the discharging pipe outlet (Fig. 2c). and without seepage. Section 4 summarizes our study’s We tested the case first without artificial seepage, ob- main conclusions. taining the profile shown in Fig. 3a. A drain pipe was then introduced to induce seepage in each test, with a total of three pipe locations (S1 – S3) selected based on the 2. Experimental Setup obtained profile: S1 was located at the point of maximum erosion depth, S2 was near the shoreline and S3 was at Experiments were conducted at Changsha University the maximum accretion point as detailed in Table 1.The of Science and Technology, P.R., China, in a wave flume pipe was kept 10 cm beneath the beach surface during 0.8 m deep, 0.5 m wide and 40 m long. A flap wave- all tests. To ensure that measured results were replicable, maker was installed at one end of the flume and a sand three runs were conducted for each test. Taking the beach beach with an initial 1:10 slope was constructed in the with drain pipe S1 as an example, we compared beach wave flume. The beach was well-sorted quartz sand with a profile changes after 2-hour wave action among the three characteristic 0.438 mm diameter measured by a Malvern runs as shown in Fig. 4. Mastersizer 2000, D50, as shown in Fig. 1. The typical cnoidal wave condition had an incident Six resistance wave gauges (RBR Co., Ltd., Canada) wave height of 0.09 m, a wave period of 2 s, and a water (WG1∼WG6) and three ultrasonic water gauges (Sin- depth of 40 cm. The wavelength for our wave condition fotek Co., Ltd., China) (UWG1∼UWG3) were used to was 3.69 m, or less than 10% of the total flume length measure wave surface evolution at selected sites. WG1 of 40 m. Before each run, the beach was reestablished was set 14 m away from the beach toe to measure incident with a 1:10 slope and the pump was opened for half an waves. WG2 was placed at the beach toe itself. Shoaling hour to obtain a stable groundwater level. The tested in- waves were monitored by WG3-WG6. Wave breaking, filtration rate from S1 to S3 was 28.15 l/s, 23.00 l/s, and runup and rundown were monitored by UWG1-UWG3. 6.64 l/s. The wavemaker was run for 2 hours in each test Morphological beach measurements were made using and beach profiles were recorded at 0, 0.5, 1 and 2 hours. a URI-III topographic surveying meter system (Electronic We assumed that the wave reflection effect in this study Information Institute, Wuhan University, China), with an was insignificant for three reasons: accuracy of ±1 mm. The URI-III consisted of a URI-III profiler, a measuring bridge controller, a measuring bridge (1) We have divided the 2-h measurement for each case and a PC-based acquisition system. We used the system’s into 40 stages and run the wavemaker only for 3 min- ultrasonic measurement in this study. To reduce measure- utes in each stage, then stopped it until water in the ment error, three cross-shore beach profile sections were flume became calm, thus minimizing multiple reflec- measured along the flume width, each twice. We aver- tion. aged the six measurements and treated the result as the (2) The wavemaker had an active absorbing function final beach profile. found to work well for short waves. To lower the groundwater level, we arranged a PVC drain pipe 25 mm in diameter parallel to the shoreline (3) The sand beach itself was porous thus further absorb with its length equating the flume width (Fig. 2). The reflected wave energy. drain pipe collected infiltrated waters induced by a pumping system during experiments. A series of holes 2 mm in To analyze sediment sorting on the beach under the diameter were drilled along the pipe at 10 mm intervals. seepage effect, sand samples were collected at four cross- To avoid sand blockage during tests, the pipe was covered shore regions in each test: the erosion zone; the near with a geotextile filter sheet (Fig. 2b). To maintain the shoreline; around the berm crest, i.e., the maximum vertical distance between the bed profile after 2-hour wave

974 Journal of Disaster Research Vol.11 No.5, 2016 An Experimental Study of Beach Evolution with an Artiﬁcial Seepage

Fig. 2. The arrangement of drain pipe in the ﬂume.

Fig. 3. Beach proﬁle changes after 0 h, 0.5 h, 1 h and 2 h. (a) No pipe, (b) S1-drain pipe at x = 3.01 m, (c) S2-drain pipe at x = 3.90 m, (d) S3-drain pipe at x = 4.70 m.

Journal of Disaster Research Vol.11 No.5, 2016 975 Jiang, C. et al.

Table 1. Cross-shore drain pipe locations relative to the beach toe (x = 0) and ﬂume bottom (z = 0).

Pipe location x(m) z(m) No pipe NA NA S1 3.01 0.205 S2 3.90 0.300 S3 4.70 0.370

Fig. 4. The comparison of beach proﬁle change among three runs for the beach with drain pipe S1 after 2-hour wave action.

Table 2. Sand sampling horizontal positions relative to the beach toe (x = 0).

Pipe location Erosion zone (m) Shoreline zone (m) Berm crest (m) Backshore region(m) No pipe 3.01∗, 3.15, 3.25, 3.38 3.90 4.69 4.90 S1 3.15, 3.35, 3.53, 3.71∗ 4.08 4.68 5.02 S2 3.19, 3.35, 3.50, 3.68∗ 4.22 4.76 5.12 S3 3.19, 3.30, 3.50, 3.65∗ 4.14 4.70 5.02 ∗the maximum erosion location.

action and the initial bed profile; and the backshore zone, the beach (x = 3.01 m) after the second hour test, while i.e., the shoreward area of the berm crest. Sand was sam- the maximum accretion moved onshore during the entire pled as shown in Table 2. Bed sorting analysis was based test (Fig. 3a). When seepage was induced by S1, the on 2-hour sampling records. maximum bed erosion depth was about 3.6 cm around the breaking point (x = 3.48 m), while the maximum accretion height was 4.0 cm at x = 4.43 m, after 0.5 hours. Af- 3. Results and Discussion ter 1 hour, erosion depth and accretion height increased to 6.0 cm and 7.0 cm, moving onshore by 5.0 cm and 3.1. Beach Profile Variation 14.0 cm. Interestingly, the maximum bed erosion depth To compare seabed morphological change with and decreased to 5.5 cm but it moved onshore by 18 cm af- without seepage, we present beach profile evolution for ter 2 hours, although the upper beach bed variation was all tests as shown in Fig. 3. It appears that sand accreted insignificant (Fig. 3b). In view of S2, the maximum on the upper beach (x > 4.00 m), shoreward sand move- bed erosion depth was about 6.9 cm around the break- ment from the surf zone to the swash zone was found ing point (x = 3.55 m), while the maximum accretion and a berm – the deposition of the beach face formed by height was 5.5 cm at x = 4.71 m after 0.5 hours. After coarse sand subjected to wave action – generally formed 1 hour, the maximum erosion depth and accretion height on the upper beach. Maximum erosion depth and accre- increased to 8.6 cm and 8.4 cm, but their positions moved tion height are given in Tables 3 and 4, together with their slightly toward onshore. After 2 hours, bed variation locations. Without seepage, maximum bed erosion was near breaking point (3.40 m < x < 3.70 m) was insignif- around the surf zone between x = 3.30 m and 3.70 m in icant and the maximum accretion height at x = 4.76 m the first hour test, then moved from the surf zone back to increased to 10.1 cm (Fig. 3c). Regarding S3, the max- the shoaling zone at some locations on the lower part of imum bed erosion depth was about 7.1 cm around the

976 Journal of Disaster Research Vol.11 No.5, 2016 An Experimental Study of Beach Evolution with an Artiﬁcial Seepage

Table 3. Maximum erosion depths and their occurring locations over time.

After 0.5h After 1h After 2h Pipe locations Depth (cm) Location (m) Depth (cm) Location (m) Depth (cm) Location (m) No pipe 5.5 3.51 5.6 3.61 5.3 3.01 S1 3.6 3.48 6.0 3.53 5.5 3.71 S2 6.9 3.55 8.6 3.60 8.8 3.68 S3 7.1 3.53 8.1 3.64 8.0 3.65

Table 4. Maximum accretion heights and their occurring locations over time.

After 0.5h After 1h After 2h Pipe locations Depth (cm) Location (m) Depth (cm) Location (m) Depth (cm) Location (m) No pipe 6.1 4.40 6.6 4.67 7.0 4.69 S1 4.0 4.43 7.0 4.57 7.9 4.68 S2 5.5 4.71 8.4 4.67 10.1 4.76 S3 7.3 4.63 8.9 4.64 9.8 4.70

ing point. The accretion height of 7.9 cm at x = 4.68 m on the upper portion of the beach and the erosion depth of 5.5 cm at x = 3.71 m near the breaking point were found on the beach for S1. The least accretion height and erosion depth were found where there was no pipe, i.e., 7.0 cm at x = 4.69 m on the upper beach and 5.3 cm at x = 3.01 m on the lower part of the beach. The S2 test accretion height was almost 1.5 times larger than that for where there was no pipe. As stated, the shoreline pipe location, S2, influenced beach profile changes the most among the three locations. This was because S2 was closest to the breaking point, where plunging breakers hitting the beach face were enhanced by increased downward drag due to infiltration [22]. More sand was consequently lifted around Fig. 5. Bed elevation after 2 hour wave action related to the breaking point. the initial bed. S1-drain pipe at x = 3.01 m, S2-drain pipe at x = 3.90 m, S3-drain pipe at x = 4.70 m. 3.2. Mean Upper Beach Slope and Shoreline Change breaking point (x = 3.53 m), while maximum accretion The mean upper beach slope in each test, shown in height was 7.3 cm at x = 4.63 m, after 0.5 hour of the run Table 5, was estimated by connecting the berm crest to time. After 1 hour, the maximum erosion depth and ac- the shoreline. Under seepage conditions, the slope was cretion height increased to 8.1 cm and 8.9 cm and their steeper than without seepage. Without considering seep- positions moved slightly toward onshore. After 2 hours, age, the beach slope (β) could be calculated by Eq. (2), as bed variations around the breaking point and on the up- proposed by Inman and Frautschy (1966) [24]: per beach were insignificant except for the maximum ac- 1 − c cretion height, which increased to 9.8 cm at x = 4.70 m β ϕ tan =tan + c ...... (1) (Fig. 3d). For all tests with seepage (S1–S3), maximum 1 erosion was found near the breaking point and maximum β is the beach slope, tanϕ the coefficient of inter fric- accretion on the upper beach. tion for granular shear, and c a coefficient depending on The bed profiles after 2-hour wave action subtracted by the ratio of boundary currents to the orbital velocity of the the initial bed profile for cases with and without seepage waves. They found that a steeper slope may be generated are shown in Fig. 5. Note that S2 promoted the great- because c decreases with increasing energy dissipation est accretion height of 10.1 cm at x = 4.76 m on the up- and boundary current velocity. Seepage induced by the per beach and the greatest erosion depth of 8.8 cm near drain pipe increases percolation into the beach, which dis- the breaking point (x = 3.68 m). S3 promoted relatively sipates more wave energy, and hence larger slope. Some less effect compared to S2 on the beach with an accre- researchers [25–27] have suggested that infiltration could tion height of 9.8 cm at x = 4.70 m on the upper beach also increase near bed velocity, which would result in a and erosion depth of 8.0 cm at x = 3.65 m near the break- steeper slope when seepage is present. Near the shoreline,

Journal of Disaster Research Vol.11 No.5, 2016 977 Jiang, C. et al.

Table 5. Deposition volume around the berm. β is the mean slope of upper beach, Vt is the total sediment volume of the berm, Vf is the seaside sediment volume of the berm, ∗ Vb is the leeside sediment volume of the berm, Δxsm is relative shoreline shift.

V(m3) Pipe location tanβ Δxsm(m) Vt(m3) Vf /Vt (%) Vb/Vt (%) No pipe 0.190 0.025 70.2 29.8 −0.10 S1 0.230 0.023 62.2 37.8 +0.08 S2 0.287 0.028 49.3 50.7 +0.22 S3 0.275 0.026 52.7 47.3 +0.14 ∗:“+” means shoreline moves landward, “–”means shoreline moves seaward

Fig. 6. Berm proﬁle after 2hour wave action related to the initial bed.

relative shoreline shift Δxsm, defined as horizontal shore- 3.4. Cross-Shore Grain Size Distribution line change between the evolutional and initial beds – positive meaning landward movement and negative meaning To analyze bed material sorting with and without seep- seaward movement – is shown in Table 5. Δxsm is pos- age at each sand sampling location, we plotted grain size itive after the 2-hour test for all tests in the presence of distribution in Fig. 7. In the erosion zone, we found seepage, suggesting coastline recession. that the percentage of finer sand (D < 355 μm) exceeded that in the initial bed and decreased slightly in the cross- D > 3.3. Upper Beach Deposition Volume shore direction. The percentage of coarser material ( 632 μm) was less, however, than that in initial bed and in- In this study, we found a berm in all tests due to ac- creased in the cross-shore direction. Interestingly, the per- V cretion on the upper beach. Berm volume ( ) was cal- centage of medium-sized sediment, i.e., 355 μm < D < culated by calculating the area between evolutional and 632 μm, had no notable change and was about 50% at all initial profiles (Fig. 6) based on the following equation: sampling positions in the erosion zone. Near the shore- n line and in the backshore zone, i.e., shoreward of the berm V = D ∑ Δzi • Δx ...... (2) crest, especially for S1 and S3, an obvious increase was i=1 seen for both the medium and coarser sand but finer ma- D is flume width, Δzi the vertical difference between terial decreased to a percentage of less than 10%. Around evolutional and initial beds, Δx the cross-shore sampling the berm crest, grain distribution resembled that in the interval, and i the i-th sampling location. Berm shapes erosion zone, where the percentage of finer material in- were not identical in these tests, so we divided berms into creased but that of coarser sediment decreased. Based on two – seaside and leeside – by a dividing line connecting the above analysis, we reasoned that finer material tended the berm crest and the initial bed (Fig. 6). We then calcu- to be deposited in the erosion zone, whereas coarser sand lated total deposition volume Vt, seaside deposition over tended to accumulate near the shoreline and in the back- the total deposition (Vf /Vt) and leeside deposition over shore zone where deposition occurred, as confirmed in total deposition (Vb/Vt) in each test. Results are shown in Fig. 8 in mean grain size distribution. Two peaks oc- Table 5. Total deposition volume Vt had a slight increase curred in mean grain size distribution along the beach pro- for S2 and S3 compared to that without seepage. Vt de- file for all tests with and without seepage, i.e., mean grain creased slightly for S1, but for Vb/Vt, a notable increase size increased gradually toward the shore, first peaking was observed with seepage, indicating that infiltration in- near the shoreline, and mean grain size decreased near duced by the drain pipe increased accretion on the berm’s the berm crest. In the backshore zone, mean grain size leeside – a leeside accretion assumed contributed by a re- peaked again. Our findings thus differed from those from duction in sand accumulation on the seaside. Celiko˘glu et al. (2006) [28], who found that finer material

978 Journal of Disaster Research Vol.11 No.5, 2016 An Experimental Study of Beach Evolution with an Artiﬁcial Seepage

Fig. 7. Distribution of sediment grain size after 2 hour wave action. (a) No pipe, (b) S1-drain pipe at x = 3.01 m, (c) S2-drain pipe at x = 3.90 m, (d) S3-drain pipe at x = 4.70 m

4. Conclusions

Beach profile changes and bed material sorting with and without seepage under cnoidal wave action were investigated experimentally, with the following results: 1. Seepage induced by a drain pipe placed under the shoreline promoted the greatest accretion height and erosion depth on the beach. 2. The berm slope was steeper under the effect of seepage due to increased percolation into the beach, increasing energy dissipation and boundary current velocity. The shoreline also receded when seepage was present. Fig. 8. Distribution of mean grain size after 2-hour wave 3. Artificial seepage impacted insignificantly on total action. S1-drain pipe at x = 3.01 m, S2-drain pipe at x = deposition volume on the upper beach, but could in- 3.90 m, S3-drain pipe at x = 4.70 m. crease accretion on the leeside by reducing sand accumulation on the seaside of the berm.

accumulated in the accretion area and coarser sand was 4. We found that ﬁner materials accumulated in the ero- deposited in the erosion region. We found no big differ- sion region, while coarser sands tended to settle near ence in bed material sorting in the presence and absence the shoreline and in the backshore zone. The location of seepage in our study. of seepage does not signiﬁcantly affect bed material sorting. Our conclusions thus provide some guidance to build an effective BDS. BDS mechanics in stabilizing a beach

Journal of Disaster Research Vol.11 No.5, 2016 979 Jiang, C. et al.

are very complex and further affected by many other fac- [21] P. Ciavola, P. Contestabile, F. Aristodemo, and D. Vicinanza, “Beach sediment mixing under drained and undrained conditions,” tors, such as pipe parameter – diameter, power and num- J. of Coastal Research, special issue 65, pp. 1503-1508, 2013. ber – and incident wave conditions. Further work is thus [22] P. Nielsen, “Coastal groundwater dynamics,” In: Proc. of Coastal needed on the above factors. Dynamics ’97, ASCE, pp. 546555, 1997. [23] B. R. Seiffert, M. Hayatdavoodi, and R. C. Ertekin.“Experiments and calculations of cnoidal wave loads on a coastal-bridge deck with girders,” European J. of Mechanics B/Fluids, Vol.52, pp. 191-205, Acknowledgements 2015. [24] D. L. Inman and J. D. Frautschy, “Littoral processes and the devel- This study was supported financially by the National Natural opment of shorelines,” Proc. Coastal Engineering Specialty Conf., Science Foundation of China 51239001, 51179015, 51309035, ASCE, pp. 511-536, 1966. and 51509023; the Scientific Research Fund of Hunan Provin- [25] A. G. Maclean, “Open channel velocity profiles over a zone of rapid infiltration,” J. of Hydraulic Research, Vol.29, pp. 15-27, 1991. cial Education Department, China Nos. 14B002 and 14C0024; [26] D.C. Conley and D. Inman, “Ventilated oscillatory boundary lay- the Science Foundation of the Ministry of Transport, China ers,” J. of Fluid Mechanics, Vol.273, pp. 261284, 1994. 2015319825080; and Hunan Provincial Innovation Foundation for [27] X. W. Chen and Y. M. Chiew, “Velocity distribution of turbulent Postgraduate CX2016B391. open channel flow with bed suction,” J. of Hydraulic Research, Vol.130, pp. 140-148, 2004. [28] Y. Celiko˘glu, Y. Yüksel, and M. S. Kabdas¸li, “Cross-shore sorting on a beach under wave action,” J. of Coastal Research, Vol.22, References: pp. 487-501, 2006. [1] G. H. Lee, R. J. Nicholls, and W. A. Birkemeier, “Storm-driven variability of the beach-near shore profile at Duck, North Carolina, USA, 1981-1991,” Marine Geology, Vol.148, pp. 163-177, 1998. [2] H. M. Fritz, C. Blount, R. Sokoloski, J. Singleton, A. Fuggle, Name: B. G. McAdoo et al., “Hurricane Katrina storm surge distribution Changbo Jiang and field observations on the Mississippi Barrier Island,” Estuarine, Coastal and Shelf Science, Vol.74, pp. 12-20, 2007. Affiliation: [3] M. M. Fiore, E. E. D’Onofrio, J. L. Pousa, E. J. Schnack, and G. R. Bértola, “Storm surges and coastal impacts at Mar del Plata, Ar- Professor, Changsha University of Science and gentina,” Continental Shelf Research, Vol.29, pp. 1643-1649, 2009. Technology [4] P. Nielsen, S. Robert, B. Moller-Christiansen, and P. Oliva, “Infiltra- tion effects on sediment mobility under waves,” Coastal Engineer- ing, Vol.42, pp. 105-114, 2001. [5] M. R. A. Bagnoldm, “Beach formation by waves; some model experiments in a wave tank,” J. Institution Civil Engineering, Vol.15, pp. 27-54, 1940. Address: 960, 2nd Section, Wanjiali South RD, Changsha, Hunan, P. R. China [6] W.S. Grant, “Influence of the water table on beach aggradations and degradation,” J. Marine Research, Vol.7, pp. 655-660, 1948. Brief Career: [7] G. Elioti and D. J. Clarke, “Semi diurnal variation in beach faces 2004- Professor, Changsha University of Science and Technology, China aggradations and degradation,” Marine Geology, Vol.79, pp. 1-22, 2006- Visiting Fellow, Cornell University, U.S.A. 1988. 2012- Visiting Professor, Cornell University, U.S.A. [8] L. Li and D. A. Barry, “Wave-induced groundwater flow,” Advances Selected Publications: in Water Resources, Vol.23, pp. 325-337, 2000. • “Study on threshold motion of sediment and bedload transport by [9] G. Masselink and L. Li, “The role of swash infiltration in determin- tsunami waves” Ocean Engineering, Vol.100, pp 97-106, Mar., 2015. ing the beachface gradient: a numerical study,” Marine Geology, • “Numerical Investigation of Solitary Wave Interaction with a Row of Vol.176, pp. 139-156, 2001. Vertical Slotted Piles,” J. of Coastal Research, Vol.31 No.6, pp. 1502-1511, [10] D. C. Conley and J. G. Griffin, “Direct measurements of bed stress Nov., 2015. under swash in the field,” J. of Geophysical Research, Vol.109, C3, Academic Societies & Scientific Organizations: 2004. • Global Water Partnership (GWP) [11] D. P. Horn, “Measurements and modeling of beach groundwater • Int. Association for Hydro-Environment Engineering and Research flow in the swash-zone: a review,” Continental Shelf Research, Vol.26, pp. 622-652, 2006. (IAHR) [12] A. R. Packwood, “The influence of beach porosity on wave uprush and backwash,” Coastal Engineering, Vol.7, pp. 29-40, 1983. [13] M. Sato, “Understand watertable and beach face erosion,” Proc. 22nd Int. Conf. on Coastal Engineering, pp. 2645-2657, 1990. [14] I. L. Turner, G. Masselink, “Swash infiltration – exfiltration and sed- Name: iment transport,” J. of Geophysical Research, Vol.103, pp. 30813– Yizhuang Liu 30824, 1998. [15] J. Chappell, I. G. Eliot, M. P. Bradshaw, and E. Lonsdale, “Exper- imental control of beach face dynamics by water table pumping,” Affiliation: Engineering Geology, Vol.14, pp. 29-41, 1979. Ph.D. Candidate, School of Hydraulic Engineer- [16] G. Goler, “Numerical Modeling of Groundwater Flow Behavior in ing, Changsha University of Science and Tech- Response to Beach Dewatering,” Doctoral dissertation: Middle East nology Technical University, 2004. [17] A. W.-K. Law, S.-Y. Lim, and B.-Y. Liu, “A note on transient beach evolution with artificial seepage in the swash zone,” J. of Coastal Research, Vol.18, pp. 379-387, 2002. [18] L. Damiani, D. Vicinanza, F. Aristodemo, A. Saponieri, and S. Cor- Address: varo, “Experimental investigation on wave set-up and nearshore ve- 960, Section 2nd, South Wanjiali Road, Changsha, Hunan, P. R. China locity field in presence of a BDS,” J. of Coastal Research, special Brief Career: issue 64, pp. 55-59, 2011. 2008-2012 Bachelor, Changsha University of Science and Technology, [19] F. Aristodemo, P. Ciavola, P. Veltri, and A. Saponieri, “The influ- China ence of a Beach Drainage System on wave reflection and surf beat 2012-2015 Master, Changsha University of Science and Technology, China processes,” J. of Coastal Research, special issue 64, pp. 455-459, 2015- Ph.D. Candidate, Changsha University of Science and Technology, 2011. China [20] P. Contestabile, F. Aristodemo, D. Vicinanza, and P. Ciavola, “Lab- oratory study on a beach drainage system,” Coastal Engineering, Vol.66, pp. 50-64. 2012.

980 Journal of Disaster Research Vol.11 No.5, 2016 An Experimental Study of Beach Evolution with an Artiﬁcial Seepage

Name: Bin Deng

Afﬁliation: Supervisor, Lecturer, School of Hydraulic En- gineering, Changsha University of Science and Technology

Address: 960, Section 2nd, South Wanjiali Road, Changsha, Hunan, P. R. China Brief Career: 2010- Ph.D., Changsha University of Science and Technology, China 2011- Visiting Scholar, The City College of New York, U.S.A. Selected Publications: • “Numerical investigation of swash zone hydrodynamics,” Science China Technological Sciences, Vol.56, No12, pp. 3093-3103, 2013. • “PIV measurement of hydrodynamic characteristics of pier with a slot,” Advances in Water Science, Vol.25, pp. 383-391, May, 2014.

Name: Yu Yao

Afﬁliation: Supervisor, Lecturer, School of Hydraulic En- gineering, Changsha University of Science and Technology

Address: 960, Section 2nd, South Wanjiali Road, Changsha, Hunan, P.R. China Brief Career: 2012- Ph.D., Nanyang Technological University, Singapore 2013- Research Fellow, Earth observatory of Singapore 2014- Research Fellow, University of Hawaii at Manoa, U.S.A. Selected Publications: • “Modeling Wave Processes over Fringing Reefs with an Excavation Pit,” Coastal Engineering, Vol.109, pp. 9-19, Jan., 2016. • “haracteristics of monochromatic waves breaking over fringing reefs,” J. of Coastal Research, Vol.29, pp. 94-104, Jan., 2013. • “1DH Boussinesq modeling of wave transformation over fringing reefs,” Ocean Engineering, Vol.47, pp. 30-42, Mar., 2013. Academic Societies & Scientiﬁc Organizations: • Coastal Education and Research Foundation (CERF)

Name: Qiong Huang

Afﬁliation: Engineer, Guangzhou Zhengjian Construction Engineering Design Co., Ltd.

Address: 547, Nanhua East Road, Guangzhou ,Guangdong, P.R. China Brief Career: 2008-2012 Bachelor, Changsha University of Science and Technology, China 2012-2015 Master, Changsha University of Science and Technology, China 2015- Engineer, Guangzhou Zhengjian Construction Engineering Design Co., Ltd., China

Journal of Disaster Research Vol.11 No.5, 2016 981