scholarly journals An early warning system for wave-driven coastal flooding at Imperial Beach, CA

2021 ◽  
Author(s):  
Mark A. Merrifield ◽  
Mele Johnson ◽  
R. T. Guza ◽  
Julia W. Fiedler ◽  
Adam P. Young ◽  
...  
Keyword(s):  
Water Level ◽  
Sea Level ◽  
Incident Wave ◽  
High Tide ◽  
Warning System ◽  
Model Errors ◽  
Wave Runup ◽  
Peak Period ◽  
Beach Morphology ◽  
Wave Forecast

AbstractWaves overtop berms and seawalls along the shoreline of Imperial Beach (IB), CA when energetic winter swell and high tide coincide. These intermittent, few-hour long events flood low-lying areas and pose a growing inundation risk as sea levels rise. To support city flood response and management, an IB flood warning system was developed. Total water level (TWL) forecasts combine predictions of tides and sea-level anomalies with wave runup estimates based on incident wave forecasts and the nonlinear wave model SWASH. In contrast to widely used empirical runup formulas that rely on significant wave height and peak period, and use only a foreshore slope for bathymetry, the SWASH model incorporates spectral incident wave forcing and uses the cross-shore depth profile. TWL forecasts using a SWASH emulator demonstrate skill several days in advance. Observations set TWL thresholds for minor and moderate flooding. The specific wave and water level conditions that lead to flooding, and key contributors to TWL uncertainty, are identified. TWL forecast skill is reduced by errors in the incident wave forecast and the one-dimensional runup model, and lack of information of variable beach morphology (e.g., protective sand berms can erode during storms). Model errors are largest for the most extreme events. Without mitigation, projected sea-level rise will substantially increase the duration and severity of street flooding. Application of the warning system approach to other locations requires incident wave hindcasts and forecasts, numerical simulation of the runup associated with local storms and beach morphology, and model calibration with flood observations.

scholarly journals Decadal trends in beach morphology on the east coast of South Africa and likely causative factors

2012 ◽  
Vol 12 (8) ◽  
pp. 2515-2527 ◽  
Author(s):  
S. Corbella ◽  
D. D. Stretch
Keyword(s):  
South Africa ◽  
Sea Level Rise ◽  
Sea Level ◽  
East Coast ◽  
Storm Event ◽  
Wave Direction ◽  
Peak Period ◽  
Beach Morphology ◽  
Shoreline Changes ◽  
Causative Factors

Abstract. Sandy shorelines are dynamic with constant changes that can cause hazards in developed areas. The causes of change may be either natural or anthropogenic. This paper evaluates evidence for shoreline changes and their causative factors using a case study on the east coast of South Africa. Beach morphology trends were found to be location-specific, but overall the beaches show a receding trend. It was hypothesized that wave, tide, sea level and wind trends as well as anthropogenic influences are causative factors, and their contributions to shoreline changes were evaluated. Maximum significant wave heights, average wave direction, peak period and storm event frequencies all show weak increasing trends, but only the increases in peak period and wave direction are statistically significant. The chronic beach erosion cannot be attributed to wave climate changes since they are still too small to explain the observations. Instead, the impacts of sea level rise and reductions in the supply of beach sediments are suggested as the main causative factors. The analysis also identifies a trend in the frequency of severe erosion events due to storms that coincide with a 4.5-yr extreme tide cycle, which demonstrates the potential impact of future sea level rise.

scholarly journals The Role of Beach Morphology and Mid-Century Climate Change Effects on Wave Runup and Storm Impact on the Northern Yucatan Coast

2021 ◽  
Vol 9 (5) ◽  
pp. 518
Author(s):  
Gabriela Medellín ◽  
Martí Mayor ◽  
Christian M. Appendini ◽  
Ruth Cerezo-Mota ◽  
José A. Jiménez
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Water Levels ◽  
Transformation Model ◽  
Wave Runup ◽  
Beach Morphology ◽  
Extreme Water Levels ◽  
Storm Impact ◽  
Wave Conditions

Wave runup is a relevant parameter to determine the storm impact on barrier islands. Here, the role of the beach morphology on wave runup and storm impact was investigated at four coastal communities located on the northern Yucatan coast. Current wave conditions based on regional wind simulations, topo-bathymetric transects measured at each location, and a nonlinear wave transformation model were employed to reconstruct multi-year runup time series. Dune morphology features and extreme water levels (excluding storm surge contributions) were further employed to determine the storm impact at each site for different return periods. Despite the similar offshore conditions along the coast, extreme water levels (i.e., runup and setup) showed intersite differences that were mainly ascribed to subaerial and submerged morphological features. Numerical results showed that the average surf zone beach slope, sandbars, berm, and dune elevation played an important role in controlling extreme water levels and storm impact at the study sites under the present climate. Moreover, in order to assess the potential effect of climate change on coastal flooding, we analyzed wave runup and storm impact in the best-preserved site by considering wave conditions and sea level rise (SLR) projections under the RCP 8.5 scenario. Modelling results suggest no significant increase in the storm impact regime between the present and future conditions in the study area unless SLR is considered. It was found that to accurately estimate SLR contribution, it should be incorporated into mean sea level prior to performing numerical wave runup simulations, rather than simply adding it to the resulting wave-induced water levels.

scholarly journals Inundation due to the tide in the context of sea level rise and the role of Can-Gio forest in the reduction of inundation

2018 ◽  
Vol 20 (K7) ◽  
pp. 76-85
Author(s):  
Hoa Thi Le ◽  
Hoa Tang My Son ◽  
Hong Thi My Tran ◽  
Giang Song Le
Keyword(s):  
Sea Level Rise ◽  
Water Level ◽  
Sea Level ◽  
High Tide ◽  
High Water ◽  
High Water Level ◽  
Maximum Water Level ◽  
Level Increase ◽  
The Future ◽  
Calculation Results

Lower basin of Sai Gon – Dong Nai river is lowland. It’s inundated at high tide. Using mathematical model method with the integrated 1D2D model, the inundation hazard due to the high tide in this region has been evaluated through the inundated area. The calculation results also showed that in the case when the damping ability of Can Gio forest is disabled high water level at Nha Be and Phu An can be increased about 2 – 3 cm and the effect will be stronger in the future following the sea level rise. In the case the Can Gio forest is diked to create a reservoir with reasonable in- and outflow directions, the high water level at Nha Be and Phu An can be decreased about 10 - 11 cm and the effect will be stronger in the future following the sea level rise. This water level decrease effect almost compensates the water level increase due to the sea level rise and keeps the maximum water level at Phu An not exceed actual one until 2050 regardless the sea level rise.

scholarly journals The role of tidal modulation in coastal flooding on a micro-tidal coast during Central American Cold Surge events

2017 ◽  
Author(s):  
Wilmer Rey ◽  
Paulo Salles ◽  
E. Tonatiuh Mendoza ◽  
Alec Torres-Freyermuth ◽  
Christian M. Appendini
Keyword(s):  
Water Level ◽  
Sea Level ◽  
High Tide ◽  
Coastal Flooding ◽  
Numerical Results ◽  
Water Levels ◽  
Flood Hazards ◽  
Wave Setup ◽  
Set Up

Abstract. Coastal flooding in the Yucatan Peninsula is mainly associated with storm surge events triggered by high-pressure cold fronts systems passing through the Gulf of Mexico. To assess coastal flood hazards, this study uses a thirty-year water level hindcast, and considers the contribution of wave setup and the role of tidal hydrodynamics. To diagnose the mechanisms controlling the water levels, extreme sea level occurrence probability at Progreso Port was performed to identify the two worst storms in terms of maximum residual tide (Event A), and maximum water level (Event B). Numerical results suggest that during Event A the wave setup contribution reaches 0.35 m at the coast and 0.17 m inside the back-barrier lagoon, while these values are smaller for Event B (0.30 m and 0.14 m, respectively). Besides, numerical results of the effect of the astronomical tidal phase on the wave set-up and the residual sea level show that: (i) the wave set-up is tidally modulated and contributes up to 14 % to the extreme water levels at the inlet, (ii) the residual tide is larger (smaller) during near-low (high) or receding (rising) tide, and (iii) maximum flooding occurs when the storm peak coincides with rising or high tide, despite micro-tidal conditions.

scholarly journals Highwater Mark Collection after Post Tropical Storm Dorian and Implications for Prince Edward Island, Canada

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3201
Author(s):  
Donald E. Jardine ◽  
Xiuquan Wang ◽  
Adam L. Fenech
Keyword(s):  
Sea Level ◽  
Prince Edward Island ◽  
Tide Gauge ◽  
Sand Dunes ◽  
Warning System ◽  
Coastal Areas ◽  
Tropical Storm ◽  
Public Understanding ◽  
Wave Runup ◽  
Rising Sea Level

Prince Edward Island (PEI), Canada has been experiencing the consequences of a rising sea level and intense storms on its coasts in recent years. The most recent severe event, Post Tropical Storm Dorian (Dorian), began impacting Prince Edward Island on 7 September 2019 and lasted for over 20 h until the morning of 8 September 2019. The measurement of highwater marks (HWM) from the storm was conducted between 25 September and 25 October 2019 using a high precision, survey grade methodology. The HWM measured included vegetation lines, wrack lines, beach, cliff, and dune morphological features, and tide gauge data at 53 locations in the Province along coastal areas that are exposed to high tides, storm surge, high winds, and wave runup. Photos were taken to provide evidence on the nature of the HWM data locations. The data reveal that Dorian caused extensive coastal floods in many areas along the North and South Coast of Prince, Queens and Western Kings Counties of Prince Edward Island. The floods reached elevations in excess of 3.4 m at some locations, posing threats to local infrastructure and causing damage to natural features such as sand dunes in these areas. The HWM data can provide useful information for community and emergency response organizations as plans are developed to cope with the rising sea level and increased frequency of highwater events as predicted by researchers. As Dorian has caused significant damage in several coastal areas in PEI, better planning using an enhanced storm forecasting and coastal flood warning system, in conjunction with flood stage values, could possibly have reduced the impacts of the storm in the impacted areas. This could help enhance public understanding of the potential impacts in local areas and how they can prepare and adapt for these events in the future.

scholarly journals Description of a coastal impact event in Basque Country: the 9 February 2016 case

2018 ◽  
Vol 15 ◽  
pp. 137-143
Author(s):  
Santiago Gaztelumendi ◽  
Joseba Egaña ◽  
Pedro Liria ◽  
José A. Aranda
Keyword(s):  
Basque Country ◽  
High Tide ◽  
Warning System ◽  
Impact Event ◽  
Wave Impact ◽  
Peak Period ◽  
Wave Characteristics ◽  
Westerly Winds ◽  
Points Of View ◽  
Basque Coast

Abstract. In this work we analysed a case from 9 February 2016 from two points of view, the meteorological–ocean characteristics of the event and the damage produced during the episode in the Basque coastal area. On 7 and 8 February 2016 an intense zonal circulation was established in the Atlantic, with very strong westerly winds (over 100 km h−1) and high fetch (more than 2000 km). As a consequence a strong swell (over 7 m) arrived on the Basque coast affecting littoral areas. The wave characteristics are particularly energetic during the morning of the 9 February, which had a significant wave of 9.5 m and a peak period of 20 s in deep water (Donostia buoy). The arrival of these energetic waves coincides with high tide during spring when the sea level reaches 4.69 m in the Port of Bilbao. Overtopping indexes exceeded red-level thresholds established within the Euskalmet coastal warning system and the wave impact resulted in relevant damage (more than EUR 3 million) in different littoral areas. This event is the first red-level case since the new Euskalmet warning procedure became operational at the beginning of 2015.

scholarly journals Spatial distribution of water level impact to back-barrier bays

2018 ◽  
Author(s):  
Alfredo L. Aretxabaleta ◽  
Neil K. Ganju ◽  
Zafer Defne ◽  
Richard P. Signell
Keyword(s):  
Water Level ◽  
Sea Level ◽  
Water Levels ◽  
Analytical Models ◽  
Barnegat Bay ◽  
Sea Level Fluctuations ◽  
Flooding Hazard ◽  
Short Period ◽  
Inlet Geometry ◽  
Spatial Estimates

Abstract. Water level in semi-enclosed bays, landward of barrier islands, is mainly driven by offshore sea level fluctuations that are modulated by bay geometry and bathymetry, causing spatial variability in the ensuing response (transfer). Local wind setup can have a secondary role that depends on wind speed, fetch, and relative orientation of the wind direction and the bay. Inlet geometry and bathymetry primarily regulate the magnitude of the transfer between open ocean and bay. Tides and short-period offshore oscillations are more damped in the bays than longer-lasting offshore fluctuations, such as storm surge and sea level rise. We compare observed and modeled water levels at stations in a mid-Atlantic bay (Barnegat Bay) with offshore water level proxies. Observed water levels in Barnegat Bay are compared and combined with model results from the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) modeling system to evaluate the spatial structure of the water level transfer. Analytical models based on the dimensional characteristics of the bay are used to combine the observed data and the numerical model results in a physically consistent approach. Model water level transfers match observed values at locations inside the Bay in the storm frequency band (transfers ranging from 70–100 %) and tidal frequencies (10–55 %). The contribution of frequency-dependent local setup caused by wind acting along the bay is also considered. The approach provides transfer estimates for locations inside the Bay where observations were not available resulting in a complete spatial characterization. The approach allows for the study of the Bay response to alternative forcing scenarios (landscape changes, future storms, and rising sea level). Detailed spatial estimates of water level transfer can inform decisions on inlet management and contribute to the assessment of current and future flooding hazard in back-barrier bays and along mainland shorelines.

scholarly journals Environmental controls on surf zone injuries on high-energy beaches

2019 ◽  
Vol 19 (10) ◽  
pp. 2183-2205 ◽  
Author(s):  
Bruno Castelle ◽  
Tim Scott ◽  
Rob Brander ◽  
Jak McCarroll ◽  
Arthur Robinet ◽  
...  
Keyword(s):  
Wave Height ◽  
Surf Zone ◽  
High Tide ◽  
High Energy ◽  
Water Levels ◽  
Small Scale ◽  
Beach Morphology ◽  
Environmental Controls ◽  
Flow Activity ◽  
Incident Waves

Abstract. The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and bodyboarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso–macro-tidal surf beach coast of southwestern France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide, and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind, likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore-break- and rip-related SZIs and weakest for surfing-related SZIs, the latter being also unaffected by tidal stage or range. Therefore, the analysis focused on bathers. More shore-break-related SZIs occur during shore-normal incident waves with average to below-average wave height (significant wave height, Hs = 0.75–1.5 m) and around higher water levels and large tide ranges when waves break on the steepest section of the beach. In contrast, more rip-related drownings occur near neap low tide, coinciding with maximised channel rip flow activity, under shore-normal incident waves with Hs >1.25 m and mean wave periods longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is interannually highly variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break-related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip-related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks or months in advance is therefore of paramount importance for predicting the primary surf zone life risks along this coast.

scholarly journals Prototyping of Flooding Early Warning System using Internet of Things Technology and Social Media

2018 ◽  
Vol 197 ◽  
pp. 16003
Author(s):  
Aris Haris Rismayana ◽  
Castaka Agus Sugianto ◽  
Ida Bagus Budiyanto
Keyword(s):  
Social Media ◽  
Internet Of Things ◽  
Water Level ◽  
Water Distribution ◽  
Warning System ◽  
Integrated System ◽  
Water Levels ◽  
Prototype System ◽  
The Status ◽  
Internet Of Things Technology

When the rainy season arrives, flooding is a common phenomenon. Almost every street, housing, village, river, even in the city center, wherever floods can occur. One effort to prevent the flooding is to create a floodgate on reservoirs or dams that are used to control the water distribution. The water level at this dam must be checked frequently to anticipate if the water level is at a dangerous level. The inspection of water levels will be very difficult if it must be conducted by humans who must be available in the field at any time. This research aims to create a prototype system that can replace the human role in monitoring the dam water level condition at any time by developing an integrated system between hardware and software using IoT (Internet of Things) technology approach and social media (twitter and telegram). The developed system consists of the height sensor (distance), microcontroller and wifi module, which is placed on the water gate. This system serves to measure the water level at any time and send data in real time to the server. The results of system testing performed shows that when the system is in normal circumstances, the system sends data to the server every minute, and updates the status of water level in twitter every 5 minutes. In case the water level has exceeded a predetermined limit, the system sends data to the server every 5 seconds and passes the warning message to all registered telegram contacts.

Sign in / Sign up

Export Citation Format

Share Document