ADCIRC Model Research Articles

Research on numerical simulation of typhoon waves with different return periods in nearshore areas: case study of Guishan island Waters in Guangdong province, China

China is one of the countries that are most severely affected by typhoon waves. Typhoon waves often cause catastrophic economic losses and human casualties in the nearshore and offshore areas of China. Risk assessments of nearshore typhoon wave disasters are of great practical significance for the prevention and mitigation of typhoon wave disasters in coastal areas. This study proposes a method of assessing the risks of typhoon wave disasters. The coupled ADCIRC and SWAN model is employed to establish a high-precision numerical model for the study area, which is then used to simulate the process of historical typhoon wave disasters, followed by a statistical analysis of the risk of disasters at the grid scale using the frequency analysis method. The modelling method is empirically analysed, taking the coastal waters from Guishan Island to Zhuhai City, Guangdong Province, as the study area. The processes of 249 typhoon wave disasters in this area were simulated, and the wave height distribution in the 100 m grid of the study area with different return periods calculated. The obtained results can serve as a basis for the development of a methodology for the assessment of typhoon wave disaster risk in coastal areas and could provide a basis for research on disaster-causing mechanisms associated with nearshore waves on the hazard-bearing body. The method proposed in this study can also be applied to other nearshore coastal waters.

Численное моделирование сгонно-нагонных колебаний в заливе Донузлав (Черное море)

Surge oscillations in the coastal zone of the seas can have a significant impact on the infrastructure and safety of navigation in bays and bays. The purpose of this work is to study the surge oscillations in the Donuzlav Bay located on the western coast of the Crimean Peninsula and connected to the sea by a narrow strait. The Advanced Circulation Model for Shelves Coasts and Estuaries (ADCIRC) is used for this. The numerical algorithm of the model is based on the finite element method using triangular elements and linear basis functions. The input data of the ADCIRC model were the surface wind velocity and atmospheric pressure fields over the Black Sea. Numerical modeling was performed on two nested unstructured grids. The first grid included the entire Black Sea, the second grid included the bay and the adjacent sea area. To graphically display the simulation results, the Generic Mapping Tools (GMT) mapping package was used. Analysis of the simulation results for different wind directions showed that when the wind acts on the water area of the Donuzlav Bay, seiche-like oscillations occur in the fields of sea level and currents. The intensity of these fluctuations is determined by how quickly the wind speed reaches its maximum value. Owing to the narrowness of the strait outside the bay, fluctuations do not appear. Modeling of an extreme storm situation that occurred in the Black Sea on November 11, 2007 was carried out. During the storm, a rapid change in wind direction from southeast to west occurred with a simultaneous increase in wind speed to 15–21 m/s. This caused a rise in sea level at the top of the bay to 0.5 m and an increase in the current velocity in the strait to 0.6 m/s.

MATAGORDA SHIP CHANNEL AND ITS ENTRANCE'S NAVIGATION EFFICIENCY AND SAFETY IMPROVEMENT VIA ADCIRC AND CMS MODEL SIMULATION

The present study investigated alternatives including deepening/widening of Matagorda Ship Channel in the south central coast of Texas to improve navigation safety through entrance inlet channel by using ADCIRC and CMS numerical models. The alternatives modify bayside channel depths from 38 ft to 50 ft, referenced to Mean Lower Low Water (MLLW), and widths from 200 ft to 600 ft, and deepen the entrance channel from 38 ft to 55 ft MLLW and widen the channel from 300 ft to 600 ft. The alternatives include seven new dredged material placement areas along the ship channel. Model results show the proposed ship channel dimensions will slightly increase flow efficiency and current magnitude in Matagorda Bay. Current velocities in and around ship channel tend to increase with alternatives, large river input and future sea level rise in the region. However, the current effect becomes more pronounced during tropical storms.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/YAugdJe9dIw

Внутри- и межгодовая изменчивость сгонно-нагонных колебаний уровня моря в Северном Каспии

The article presents the results of hydrodynamic modeling of sea level fluctuations in the Caspian Sea using the ADCIRC model for the period from 1979 to 2017. Surges are simulated using an irregular triangulation computational grid with a changing cell size, that easily adapts to changes in shoreline and depth and, therefore, more accurately describes coastal zones. It is found that the seasonal variability of surges is characterized by a maximum in winter and spring and by a minimum in summer. On the western coast of the North Caspian Sea, the maximum sea-level fluctuations are observed in December-February, and on the northern and eastern coasts – in February and March. The areas of inundation of the coastal territory of the Russian sector of the sea are identified. For the surge on March 12–16, 1995, that was one of the most catastrophic ones in terms of its consequences, the inundation area made up 53% of the possible flooded area, and the inundation area for the surge registered on March 27–April 1, 2015 made up 71 %. The more severe consequences of the surge in 1995 are associated with the fact that the mean annual sea level, that determines the possible flooded area, in 1995 was much higher than in 2015. Keywords: ADCIRC, Caspian Sea, unstructured grid, storm surge, sea level, numerical modeling Fig. 11. Ref. 15.

Osobennosti gidrodinamicheskikh protsessov v rayone Bakal'skoy kosy po dannym chislennogo modelirovaniya

Hydrodynamic processes have a decisive influence on morphodynamics of the coastal area of seas. This paper studies, using computational modeling, characteristics of currents, sea level and wind waves in the Bakalskaya Spit area at storm situations of various types. For computational modeling the joined model ADCIRC+SWAN was used, which includes the barotropic hydrostatic model of currents ADCIRC and spectral wave model SWAN. The joined model uses an unstructured grid with a high spatial resolution. Calculations for a storm situation in the Black Sea (20–27 March, 2013) showed that the current field in the Bakalskaya Spit area varies greatly in terms of time and space. The greatest current velocities (up to 0.9 m/s) emerge between the island and the spit tip. Surges in the spit area reach up to 0.3 m. In the variation of sea level, oscillations with a period of ~ 10.5 h prevail. This period is close to that of the lowest mode of seiche oscillations in the Karkinitsky Bay. The wind waves are the most intensive at the western side of the spit, and during the storm peak, the height of significant waves hs reaches 2–2.5 m. The eastern side of the spit is less exposed to the waves. Here, the hs values are half as big. Between the spit tip and the island the maxima hs are 1 m. Matching calculations of waves performed using the joined model ADCIRC+SWAN and using the model SWAN showed that the joined model provides higher waves. At the western side of the spit, this increase in hs reaches 0.5 m

Characteristic of Wave-induced Setup in Yangtze Estuary during Typhoon Processes

Zhang, Z.; Pan, Y.; Yu, P.B., Chen, Y.P. and Yang, Y.Z., 2020. Characteristic of wave-induced setup in Yangtze Estuary during typhoon processes, In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1563-1568. Coconut Creek (Florida), ISSN 0749-0208.Yangtze River delta is one of the most economically developed and densely populated regions of China, and it is often affected by the storm surge and large waves induced by Typhoons. The terrain in Yangtze Estuary is complex with four branches entering the ocean and many underwater ridges, making the tide-wave interaction complicated. A well understanding of the tide-wave interaction during typhoon processes is important for the disaster prevention and mitigation. In this study, a coupled storm surge and typhoon wave model was setup based on ADCIRC and SWAN model. The computation domain extends from Datong station to the sea outside Yangtze Estuary. The model was verified by simulating the storm surge process during 7 Typhoon processes. After model verification, storm surge and typhoon wave processes during typical typhoon processes that affects Yangtze Estuary were simulated with the model. The characteristic of tide-wave interaction during the typical typhoon processes were analyzed by comparison between the simulated results obtained from the coupled model and uncoupled models. The effects of the terrain on the tide-wave interaction were discussed. A general portray of the tide-wave interaction in Yangtze Estuary during typhoon processes was given.

Simulation of Environmental Changes Consdering Sea-level Rise Near a Mega-scale Coastal Dike (Saemangeum [SMG] Dike, Korea)

Yoo, S.-C. and Suh, S.-W., 2020. Simulation of environmental changes considering sea-level rise near a mega-scale coastal dike (Saemangeum [SMG] dike, Korea). In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 309–314. Coconut Creek (Florida), ISSN 0749-0208.The construction of one of the biggest coastal dikes in Korea, the 33-km long Saemangeum (SMG) dike, was completed in 2006. Coastal environmental changes resulted in tidal asymmetry in the near field (i.e., adjacent to the dike) and the far field (i.e., up to opposite part of the Yellow Sea). Coastal hydrodynamic variations and engineering developments for gate operations (to maintain inner reservoir water quality (WQ) standards) rapidly alter coastal environments. The sea level is expected to rise by 80 cm by the end of this century, and an additional 21.4 cm of seasonal local summer sea level jump will serve as a reversing factor of WQ. This study applied the ADCIRC and EFDC models to simulate regional and local hydrodynamic and WQ changes. The far-field impacts of the SMG will occur continuously till year 2100 along the Chinese coast with M2 mordulation. The target water management level was set to elevation with respect to mean sea level (EL) as -1.5 m, which is very limited in terms of free discharge time for gate operation. According to the tidal excursion and residence time simulations, only 14% of gate operations in a month will be possible compared to the existing all-year-round condition, and only 4% will be exchangeable in summer. It is found that SMG yields alteration of tidal hydrodynamics showing overall de-amplification of ∼10 cm in the Yellow Sea (YS), especially along the west coast of Korea (WCK), as well as a slight amplification of ∼10 cm on the eastern coast of China. In addition, reducing the time for inner discharge because of the rising outer sea level directly influences WQ both in the areas near the gates and the inner water due to the increased residence time. Intensive study including long-term variations in tidal asymmetry and associated morphologies is needed to manage the hydrodynamic and/or WQ changes associated with such mega-scale coastal constructions.

The Study of a New Tidal Power for a Practical Use

Park, Y.H. and Youn, D., 2020. The study of a new tidal power for a practical use. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1500–1504. Coconut Creek (Florida), ISSN 0749-0208.Dynamic Tidal Power (DTP), a kind of tidal power was first developed 20 years ago but it has never been actually built. Because DTP generates power using the diffraction effect of tides, it requires very long and large structures considering tidal period. Economic feasibility is most demanded for a practical use and various studies have been conducted to increase its output. Different shape and length DTPs had been tested in a previous study but they were not economical. For this reason, other ways were simulated to increase power generation in the study. Multiple and slit-type DTPs were chosen. It was found that the proper spacing between DTP structures was necessary for efficient power generation considering tidal diffraction effect. Because the intensity of light is varied as it passes through a single slit, a slit-type DTP was analyzed. The result from a slit-type DTP was failed to improve capacity but it was similar to those of a straight DTP. Because a slit-type DTP required less structure, it would be more economical and environmentally friendly. The study area was located in the west central coast of Korea where the tidal range was the largest and water depth was shallow. The simulations were conducted by the two dimensional numerical model ADCIRC.

A comparative study of storm surge and wave setup in the East China Sea between two severe weather events

The coastal regions of the East China Sea are frequently threatened by the increased sea level induced by intense tropical cyclones. In this study, a coupled wave-circulation model ADCIRC + SWAN is used to investigate the spatial and temporal characteristics of storm surges and wave setup heights in the southeastern coastal area of China during two severe weather events with different tracks: Typhoon Saomai, which made direct landfall, and the bypassing Typhoon Chan-hom. By definition, the storm surge is attributable to the wind forcing, while the wave setup results from the wave radiation stress. The simulated sea levels agree well with the observations, with improved results when the wave setup was considered. The simulation results showed clearly different spatial patterns depending on the track type. The maximum storm surge resulted from the cumulative effect of the local onshore wind forcing, occurring on the right side of the Typhoon Saomai track and the left side of the Typhoon Chan-hom track. Significant surge levels along the coast on the left side of the typhoon track were well observed in both cases, resulting from the coastal-trapped shelf waves. The Saomai track type is more likely to cause extremely high storm surges along the coast due to the stronger cumulative effect of the onshore wind forcing. The maximum wave setup was governed by the swell and slope of the sea floor. The locations of the maximum wave setup and surge level were spatially close during Typhoon Saomai, but they were separated during Typhoon Chan-hom.

High resolution modeling of western Alaskan tides and storm surge under varying sea ice conditions

A depth-integrated high resolution (down to 25–50 m) tide and storm surge model has been developed for the Alaska region with a focus on the coasts of western Alaska. The model uses the ADCIRC basin-to-channel scale unstructured grid circulation code forced with Climate Forecast System version 2 reanalysis meteorology. The tidal solution has been validated at 121 shelf and nearshore stations, with lower overall errors than a data assimilated tidal model (FES2012). The ADCIRC model shows considerable skill at simulating tide and coastal surge, and resulting overland flooding on the Yukon–Kuskokwim Delta, during both summer and winter storms. The root-mean-square-error of the model does not exceed 20 cm at any station, outperforming the Global Ocean Forecasting System (GOFS 3.1), a 1/12∘ data assimilated ocean general circulation model which is coupled to sea ice physics. The ADCIRC model incorporates the effect of sea ice through parameterizations of the wind drag coefficient, modifying the air–sea momentum transfer under ice coverage. Three large winter storms with distinctly different ice coverages along the coasts of western Alaska were chosen to exhibit the variable effect of sea ice on the resulting storm surge. Under forming coastal ice coverage, local increases in water levels due to ice is seen in coastal areas, and under predominantly dense pack ice, an increase in momentum transfer in the marginal sea ice at the shelf break leads to an increase in sea levels across the entire Bering Sea, both commensurate with observations. Under the most variable ice fields, results are mixed, in part due to uncertainties in the air–sea–ice drag parameterization such as related to the assumption that sea ice drift and wind velocities are always well correlated. Including a description of sea ice drift and current speeds explicitly in the air–sea–ice drag formulation and considering wave–surge–ice interaction should improve the description of momentum transferred to the water column and resulting simulation of surge.

Preliminary Estimation of Tidal Current Energy for Three Straits in the Vicinity of Bali and Lombok Islands

Indonesia is an archipelago country which has a great potential of ocean energy resources including tidal current and wave power. In this present work, tidal power in three different straits, namely Alas strait, Bali strait and Lombok strait will be estimated. In order to achieve our goal, a two-dimensional, depth-integrated Advanced Circulation (ADCIRC-2DDI) model was employed. Eight tidal constituents were imposed along the ocean open boundaries. Two different sources of tidal constituents namely Le Provost and OTIS (OSU Tidal Inversion Software) were used. Tidal elevations have been validated and calibrated against tide gauge data in which at least six tide gauges are available in the study location. We found that, tidal constituents from high resolution database that is OTIS give better results. Open boundary conditions have been improved using Green’s function approach. As a result, significant reduction of the root-mean-square error (RMSE) has been obtained. This indicates that the method is powerful.  Furthermore, tidal current energy was estimated. Since there is no tidal current observation available in the area, tidal velocities were compared with the tidal current obtained from finite element solutions 2014 (FES2014). We found that tidal current obtained from ADCIRC model has a very good agreement with FES2014. Moreover, tidal current speed in the vicinity of Bali and Lombok islands could reach up to 3.8 m/s. As a consequence, tidal current power could exceed 10.98 kW / m 2 with assuming that turbine efficiency is about 0.39.

The Application of Dynamic Tidal Power in Korea

Park, Y.H., 2018. The Application of Dynamic Tidal Power in Korea In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1306–1310. Coconut Creek (Florida), ISSN 0749-0208.Tidal power is attractive as a predictable renewable energy, but it requires a high tidal range. The west coast of Korea is a place where the extreme tidal range is observed, so various studies have been conducted. The largest tidal power, Sihwa Tidal Power Station was successfully built and operated there. However, subsequent projects have been postponed or cancelled due to environmental issues. Dynamic Tidal power (DTP) is an alternative way to a conventional tidal barrage system. Because DTP has to be a huge structure to produce diffraction of tides, it was tested by a numerical model. The 2D numerical model ADCIRC was used in the simulation. DTP was simulated in the largest tidal range of the Korean coast and it was examined in various ways. DTP generates power by the phase difference of tide and it is available even in a small tidal range. The tidal difference between the front and back of DTP becomes maximized on 180 degrees out of phase theoretically. Though the phase difference also increased with the length of DTP structure, it could not reach 180 degrees out of phase even at the DTP length of 50 km. Because the length of DTP structure should be longer than tens of kilometers considering the length of tide, it may cause economic and environmental issues. The phase difference was varied along DTP and it was increasing as the location of measurement moved closer to the coast. When the required length of DTP is optimized, it would be more practical. The study focused on the reduction of the DTP length and some shapes were suggested finally.

Simulation of Wave Overtopping and Inundation over a Dike Caused by Typhoon Chaba at Marine City, Busan, Korea

Suh, S.-W. and Kim, H.-J., 2018. Simulation of wave overtopping and inundation over a dike caused by Typhoon Chaba at Marine city, Busan, Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 711–715. Coconut Creek (Florida), ISSN 0749-0208.This study follows up previous research on simulating the wave-induced overtopping of coastal dikes by incorporating the empirical formulas of EurOtop version 2007 into the storm surge model ADCIRC SWAN. Hindcasting simulations were performed for the wave overtopping and inundation induced by Typhoon Chaba along the dike of Marine City, South Korea, in 2016. The simulation results showed that the wave overtopping and inundation lasted for at least three hours and were spread over the dike. Normal storm surge inundation was not seen because the dike crest height of 4.40 m was higher than the peak water surface elevation (WSE) of 1.13 m and significant wave height of 3.09 m. Near the dike, the wave overtopped maximum inundation height was ~0.7 m and decreased along the overland road to the upper zone, which agrees with the field survey results. This tendency was almost the same as that reported previously regardless of the dike dimensions and incoming wave heights. The reduction factor in EurOtop is an important influence in generating the inundation. Sensitivity tests indicated that a value of 0.63 is appropriate for combining a rising WSE with storm waves and filling gap effects on two-layer tetrapod slopes. This kind of approach to inundation vulnerability is more applicable than the prevailing storm surge inundation for natural or low-lying coastal areas because more than 50% of the South Korean coast is artificial and should help in developing early warning systems and/or vulnerability analyses of mitigation projects at other artificial coasts.

Chrystal and Proudman resonances simulated with three numerical models

The aim of this work was to study Chrystal and Proudman resonances in a simple closed basin and to explore and compare how well the two resonant mechanisms are reproduced with different, nowadays widely used, numerical ocean models. The test case was based on air pressure disturbances of two commonly used shapes (a sinusoidal and a boxcar), having various wave lengths, and propagating at different speeds. Our test domain was a closed rectangular basin, 300 km long with a uniform depth of 50 m, with the theoretical analytical solution available for benchmark. In total, 2250 simulations were performed for each of the three different numerical models: ADCIRC, SCHISM and ROMS. During each of the simulations, we recorded water level anomalies and computed the integral of the energy density spectrum for a number of points distributed along the basin. We have successfully documented the transition from Proudman to Chrystal resonance that occurs for a sinusoidal air pressure disturbance having a wavelength between one and two basin lengths. An inter-model comparison of the results shows that different models represent the two resonant phenomena in a slightly different way. For Chrystal resonance, all the models showed similar behavior; however, ADCIRC model providing slightly higher values of the mean resonant period than the other two models. In the case of Proudman resonance, the most consistent results, closest to the analytical solution, were obtained using ROMS model, which reproduced the mean resonant speed equal to 22.00 m/s— i.e., close to the theoretical value of 22.15 m/s. ADCIRC and SCHISM models showed small deviations from that value, with the mean speed being slightly lower—21.97 m/s (ADCIRC) and 21.93 m/s (SCHISM). The findings may seem small but could play an important role when resonance is a crucial process producing enhancing effects by two orders of magnitude (i.e., meteotsunamis).

Role of continental shelf on non-linear interaction of storm surges, tides and wind waves: An idealized study representing the west coast of India

The study reports role and dependence of continental shelf geometry on the non-linear interaction of storm surges, tides, and wind waves. As a case study, the shelf geometry representing the west coast of India is considered and numerical simulations are executed using the standard representation of a tropical cyclone. The idealized experiments assume the west coast of India as a straight coastline with varying continental shelf width ranging from 35 km in the south to 330 km in the north. For the experiments, ADCIRC model in standalone mode and coupled ADCIRC+SWAN are used by considering 13 idealized cyclone tracks covering the study domain. It is noticed that an amplification of peak storm surge of ∼12 cm for every 10 km increase in the shelf width. During different phases of the tide, the surge-wave interaction modifies the water level elevation and its occurrence as the tidal range increases towards north. The interaction of tides on surges and wind waves is observed maximum at low-tide and minimum at flood tide over the wide shelf regions. In general, the non-linear interaction is found to be 15%–20% for any cyclone track or tidal phase. The wave setup caused by wind waves is marginally varies with change of amplitude and phase of the tide, however, its profile is significantly modified, particularly over the wider shelf widths.

Storm Surge along the Yellow River Delta under Directional Extreme Wind Conditions

ABSTRACT Wang, Z.; Zhou, L.; Li, Q., and Sun, X., 2017. Storm surge along the Yellow River Delta under directional extreme wind conditions. In: Zhi, Y. and Guido Aldana, P.A. (eds.), Sustainability of Water Resources and the Development of Coastal Environments: Select Proceedings from the 2016 International Conference on Water Resource and Environment (WRE2016). Journal of Coastal Research, Special Issue No. 80, pp. 86–91. Coconut Creek (Florida), ISSN 0749-0208. The storm surge model ADCIRC is applied to simulate storm surges along the Yellow River Delta. The wind force applied in this study was simulated by meteorological model MM5. Wind speed in storm surges among simulations and station observations were compared to verify consistency between simulations and real storm surges. The directional extreme wind parameters were studied in areas near the Yellow River Delta and determined by Pearson-III distribution. From these parameters, three typical storm surges forced by relative directional extreme wind ...

Effects of sea level rise and typhoon intensity on storm surge and waves in Pearl River Estuary

Climate changes, including sea level rise (SLR) and typhoon intensification (TI), have had widespread impacts on natural systems. Through the use of coupled ADCIRC+SWAN models, this study investigates the effects of potential SLR as well as TI on storm surges and waves in Pearl River Estuary, China. Meanwhile, examination of how SLR and TI impact seawalls has been conducted. Results demonstrated that TI has a greater impact on storm surge, whereas SLR has a greater impact on wave heights in the estuary. There is no substantial difference of peak surge height (referring to the mean sea level of the corresponding SLR scenarios) in response to the increase of sea level in the study area. However, by combining the sea level rises of 0.5–1.0m, the surface elevations of peak storm surge increased under SLR conditions. Besides, enhanced typhoon intensity was found to cause the increase of peak surge height as well as wave height in some shallow areas. Furthermore, the combination of those two factors also increased peak surge height and greatly increased wave height. By running the coupled ADCIRC and SWAN models, the simulated results can be employed in flood mitigation and design of seawalls in Pearl River Estuary.

Interaction between storm surge and typhoon waves in the radial sandy ridge area during Typhoon Damery

The radial sandy ridge area along the Jiangsu coast has a complex topography with many tidal creeks and emerged ridges, which may induce a significant interaction between surge and waves when a typhoon is passing through this area. In this study, the ADCIRC and SWAN models are used to simulate the storm surge and typhoon waves during the period of Typhoon Damery which occurred in 2010. The interaction between the surge and waves is studied by comparing the simulated results obtained from the coupled ADCRIC+SWAN and uncoupled ADCIRC and SWAN models. A cyclic increase-and-decrease of significant wave height is found near the typhoon landing area, with the maximum change in the order of 1m, due to the tide and surge effect. A notable increase in the surge level is found on the nearshore emerged ridges as the typhoon passing by, with the maximum change in the order of 0.1m, due to the wave effect. It is also found that the interaction between the storm surge and typhoon waves is less significant in tidal creeks due to their relatively large water depth.

Storm surge disaster risk assessment and zoning, taking Cangnan County for instance

The storm surge and inundation simulation using the shallow-water circulation model ADCIRC has been implemented for the Cangnan County of Zhejiang Province. The main purpose is using this model to estimate the coastal storm surge disaster risk and zoning. The hindcast experiments indicate that the model system has good performance in capturing the changes of storm surge caused by tropical cyclones. Compared to the observations, the average deviation of the peak value of water level is less than 10%. We used the hypothetical tropical cyclones and the 19a of June-October mean high astronomical tide, and combined the geographic elevation and land description to assess the inundation hazard. It shows that the inundation hazard is high in the coastal region of Jinxiang Town and the south bank area of Aojiang River, but is relatively low in the Jiangnan Inning and the high altitude inland areas. The risk assessment that integrates the inundation hazard and the structure vulnerability is also conducted to zone the county into the different storm surge disaster risk levels, which can give support to the effective prevention of various tropical cyclone storm surge in the future.

Effect of Coastal Erosion on Storm Surge: A Case Study in the Southern Coast of Rhode Island

The objective of this study was to assess the effect of shoreline retreat and dune erosion on coastal flooding in a case study located in the southern coast of Rhode Island, USA. Using an extensive dataset collected during 2011, an ADCIRC model was developed to simulate the propagation of storm surge in the coastal areas, including coastal inlets and ponds. A simplified methodology, based on the geological assessment of historical trends of the shoreline retreat and dune erosion in this area, was incorporated in the model to represent coastal erosion. The results showed that for extreme storms (e.g., a 100-year event), where coastal dunes are overtopped and low-lying areas are flooded, the flooding extent is not significantly sensitive to coastal erosion. However, failure of the dunes leads to a significant increase of the flooding extent for smaller storms. Substantial dampening of the storm surge elevation in coastal ponds for moderate and small storms was associated with coastal inlets connecting to coastal ponds which are often not resolved in regional surge models. The shoreline change did not significantly affect the extent of flooding. It was also shown that the accuracy of a storm surge model highly depends on its ability to resolve coastal inlets, which is critical for reliable storm surge predictions in areas with inlet-basin systems.