scholarly journals Predicting site-specific storm wave run-up

2020 ◽  
Vol 104 (1) ◽  
pp. 493-517 ◽  
Author(s):  
Julia W. Fiedler ◽  
Adam P. Young ◽  
Bonnie C. Ludka ◽  
William C. O’Reilly ◽  
Cassandra Henderson ◽  
...  

Abstract Storm wave run-up causes beach erosion, wave overtopping, and street flooding. Extreme runup estimates may be improved, relative to predictions from general empirical formulae with default parameter values, by using historical storm waves and eroded profiles in numerical runup simulations. A climatology of storm wave run-up at Imperial Beach, California is developed using the numerical model SWASH, and over a decade of hindcast spectral waves and observed depth profiles. For use in a local flood warning system, the relationship between incident wave energy spectra E(f) and SWASH-modeled shoreline water levels is approximated with the numerically simple integrated power law approximation (IPA). Broad and multi-peaked E(f) are accommodated by characterizing wave forcing with frequency-weighted integrals of E(f). This integral approach improves runup estimates compared to the more commonly used bulk parameterization using deep water wave height $$H_0$$ H 0 and deep water wavelength $$L_0$$ L 0 Hunt (Trans Am Soc Civ Eng 126(4):542–570, 1961) and Stockdon et al. (Coast Eng 53(7):573–588, 2006. 10.1016/j.coastaleng.2005.12.005). Scaling of energy and frequency contributions in IPA, determined by searching parameter space for the best fit to SWASH, show an $$H_0L_0$$ H 0 L 0 scaling is near optimal. IPA performance is tested with LiDAR observations of storm run-up, which reached 2.5 m above the offshore water level, overtopped backshore riprap, and eroded the foreshore beach slope. Driven with estimates from a regional wave model and observed $$\beta _f$$ β f , the IPA reproduced observed run-up with $$<30\%$$ < 30 % error. However, errors in model physics, depth profile, and incoming wave predictions partially cancelled. IPA (or alternative empirical forms) can be calibrated (using SWASH or similar) for sites where historical waves and eroded bathymetry are available.

2021 ◽  
Vol 14 (12) ◽  
pp. 55-65
Author(s):  
Anant Patel ◽  
Sanjay Yadav

Most of the natural disasters are unpredictable, but the most frequent occurring catastrophic event over the globe is flood. Developing countries are severely affected by the floods because of the high frequencies of floods. The developing countries do not have good forecasting system compared to the developed country. The metro cities are also settled near the coast or river bank which are the most vulnerable places to floods. This study proposes plan for street level flood monitoring and warning system for the Surat city, India. Waterlogging happens in the low lying area of the Surat city due to heavy storm and heavy releases from the Ukai dam. The high releases from upstream Ukai dam and heavy rainfall resulted into flooding in the low lying area of the Surat city. This research proposed a wireless water level sensor network system for the street water level flood monitoring. The system is proposed to monitor the water levels of different areas of city through the wireless water level sensors as well as to capture live photos using CCTV camera. This will help authority not only to issue flood warning but also to plan flood mitigation measures and evacuation of people.


2018 ◽  
Vol 7 (3.7) ◽  
pp. 58
Author(s):  
Mahanijah Md Kamal ◽  
Aqil Muhammad Sabri

Wireless communication for flood monitoring is developed to observe the status of flooding which could alert people who were in the area when it happens. Flood is a very common problem that Malaysian faced every year caused by the change of climate and also due to urbanization. These floods can cause a lot of damages and can even endanger to human lives. The flooding can be caused by the overflowing of rivers or drains in the affected area. Problems in rural areas near the river bank, not all equipped with flood warning system. Flood warning system is usually found in the main streets with limited warning distance. Therefore, it is necessary to put a wireless communication system that can detect the rising water levels during flooding and also gives warn the local residents especially those who live along the river banks. This system can be used as flood monitoring tool as well as for evacuation during save and rescue operation. The purpose of this paper is to propose a wireless communication based on Arduino system that can help the local residents by detecting the water levels and give an early warning when a flood occurs. Basically, there are two part of the system which are the sensor node and the base station that can generate warning signal during flooding to the affected area. 


2011 ◽  
Vol 1 (8) ◽  
pp. 4
Author(s):  
Thorndike Saville

The distribution of wave steepness (H/T ) for fully developed sea is obtained from Bretschneider's joint distribution of wave height and wave period. This steepness distribution is used with standard wave runup curves to develop a frequency curve of wave run-up. Use of this run-up distribution curve will permit more accurate estimation of the variability in wave run-up for design cases, and particularly the percent of time in which run-ups will exceed that predicted for the significant wave. The distribution may also be used with normal overtopping procedures to determine more accurate estimates of overtopping quantities. Wave run-up may be defined as the vertical height above mean water level to which water from a breaking wave will rise on a structure face. Accurate design data on the height of wave run-up is needed for determination of design crest elevations of protective structures subject to wave action such as seawalls, beach fills, surge barriers, and dams. Such structures are normally designed to prevent wave overtopping with consequent flooding on the landward side and, if of an earth type, possible failure by rearface erosion. Because of the importance of wave run-up elevations in determining structure heights and freeboards, a great deal of work has been done in the past six years in an attempt to relate wave run-up to incident wave characteristics, and slope or structure characteristics. Compilations based largely on laboratory experimental work have been made and have fe-?* suited in curves similar to those shown in Figure 1 which is reprinted from the U. S. Beach Erosion Board Technical Report No. 4. Such curves most frequently have related the dimensionless ratio of relative run-up (R/H ) to incident wave steepness in deep water (H /T ), as a function of structure type or slope. (H is the equivalent deep water wave height.) The curves shown in Figure 1 are of this type, and pertain to structures having a depth of water greater than three wave heights at the toe of the structure; this depth limitation in effect means that the wave breaks directly on the structure. The curves shown in Figure 1 are a portion of a set of five separate figures, covering different structure depths (d/H ). All are published in Beach Erosion Board Technical Report Number 4. These curves were derived primarily from small scale laboratory tests. Further laboratory tests with much larger waves (heights two to five feet) have shown that a scale effect exists for some conditions.


2020 ◽  
Vol 4 ◽  
pp. 96-109
Author(s):  
A.V. Romanov ◽  
◽  
M.V. Yachmenova ◽  

Based on the example of flood warning data provided by EFAS for the territory of Northwestern Administration for Hydrometeorology and Environmental Monitoring in 2018-2020, the structure of the systematized issues of the EFAS portal is analyzed. The issues determine a feedback for the year-round monitoring of the accuracy of flood forecasting using the LISFLOOD base model, as well as its calibration. Several most important feedback sections are highlighted, that allow improving significantly a procedure for the quantitative and qualitative differentiated assessment of short- and medium-range flood forecasts. Using the results of the numerical analysis, a general description of the EFAS flood warning system quality and the prospects for the participation of the Russian Federation in it are given. Keywords: flooding, hydrological forecasts, forecast lead time, feedback, forecast accuracy


Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1061
Author(s):  
Thanh Thi Luong ◽  
Judith Pöschmann ◽  
Rico Kronenberg ◽  
Christian Bernhofer

Convective rainfall can cause dangerous flash floods within less than six hours. Thus, simple approaches are required for issuing quick warnings. The flash flood guidance (FFG) approach pre-calculates rainfall levels (thresholds) potentially causing critical water levels for a specific catchment. Afterwards, only rainfall and soil moisture information are required to issue warnings. This study applied the principle of FFG to the Wernersbach Catchment (Germany) with excellent data coverage using the BROOK90 water budget model. The rainfall thresholds were determined for durations of 1 to 24 h, by running BROOK90 in “inverse” mode, identifying rainfall values for each duration that led to exceedance of critical discharge (fixed value). After calibrating the model based on its runoff, we ran it in hourly mode with four precipitation types and various levels of initial soil moisture for the period 1996–2010. The rainfall threshold curves showed a very high probability of detection (POD) of 91% for the 40 extracted flash flood events in the study period, however, the false alarm rate (FAR) of 56% and the critical success index (CSI) of 42% should be improved in further studies. The proposed adjusted FFG approach has the potential to provide reliable support in flash flood forecasting.


Author(s):  
Thomas Nester ◽  
Andreas Schöbel ◽  
Ulrike Drabek ◽  
Christian Rachoy ◽  
Hans Wiesenegger

2018 ◽  
Vol 197 ◽  
pp. 16003
Author(s):  
Aris Haris Rismayana ◽  
Castaka Agus Sugianto ◽  
Ida Bagus Budiyanto

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