共查询到20条相似文献，搜索用时 15 毫秒
1.
The identification of potential coastal inundation caused by future sea level rise requires not only time series records from tide gauges, but also high-quality digital elevation models (DEMs). This study assesses the importance of DEM vertical accuracy in predicting inundation by sea level rise along the Valdelagrana beach and marshes of the Bay of Cádiz (SW Spain). A present-day (2000) and a projected (2100) high tide have been spatialized over a traditional (aerial photogrammetry) regional DEM of Andalusia with a horizontal spatial resolution of 10 m and a vertical accuracy of 0.68 m RMSE (root mean square error), and a LIDAR-derived DEM of the Valdelagrana study site with the same spatial resolution but a vertical accuracy of 0.205 m RMSE. The simulations are based on a bathtub model, which accounts for the effect of vertical barriers. The results reveal that the presence of infrastructures such as roads and salterns is the key to delimit the extent of water penetration during high tides in an otherwise homogeneously flat area comprising the beach and marshes of Valdelagrana. Moreover, in comparison with the highly accurate LIDAR DEM, the inundation areas derived from the lower-resolution DEM are overestimated by 72 % and 26 % for the present-day and future scenarios respectively. These findings demonstrate that DEM vertical accuracy is a critical variable in meaningfully gauging the impacts of sea level rise. 相似文献
2.
《Coastal Engineering》2005,52(9):793-810
In this paper we outline the development and application of a simple two-dimensional hydraulic model for use in assessments of coastal flood risk. Such probabilistic assessments typically need evaluation of many thousands of model simulations and hence computationally efficient codes of the type described here are required. The code, LISFLOOD-FP, uses a storage cell approach discretized as a regular grid and calculates the flux between cells explicitly using analytical relationships derived from uniform flow theory. The resulting saving in computational cost allows fine spatial resolution simulations of regional scale flooding problems within minutes or a few hours on a standard desktop PC. The development of the code for coastal applications is described, followed by an evaluation of its performance against four test cases representing a variety of flooding problems at different scales. For three of these cases an observed flood extent is available to compare to model predictions. In each case the model is able to match the observed shoreline to within the error of the of the observed flow, topography and validation data and outperforms a non-model flood extent prediction made using a simple Geographical Information System (GIS) technique. 相似文献
3.
The numerical modeling of coastal inundation from severe cyclones is a challenging area for coastal hazard mapping, emergency planning and evacuation measures. There is a need for realistic estimate of onshore coastal inundation by the operational weather centers for precise warnings to minimize loss of life and property. At present, there is no modeling effort to evaluate the extent of coastal inundation for any coastal state in India. The operational center disseminates information only on peak surge and its location just before cyclone landfall, with no prior information about onshore inundation. To bridge this gap, the present study applies the state-of-art ADCIRC hydrodynamic model to evaluate peak surge and onshore inundation along coastal Tamil Nadu for the December 2011 Thane cyclone event. Post-storm analysis and field reconnaissance survey report from IMD and ICMAM were available for the Thane cyclone to skill assess model computation. The model that computed peak surge and onshore inundation is in good concurrence with field measurements. The study signifies that near-shore beach slope has a direct bearing on onshore inundation, and its importance in numerical modeling is highlighted. This study being first of its kind for Indian coast, emphasized that coastal inundation modeling should form an integral part in a storm surge prediction system for operational needs. 相似文献
4.
Visualising coastal zone inundation is crucial for both a quick assessment of coastal vulnerability and a full understanding of possible implications to population, infrastructure and environment. This study presents a simple but effective method of assessing the spatial extent of coastal zone inundation due to predicted sea level rise using commonly available elevation and image data as well as GIS software. The method is based on the geometrical principle of matching the raised sea level with the corresponding elevation contour line on land. Results for a test area along the south-west coast of Western Australia (∼200 km of coast line) show that a sea level rise of less than 0.5 m over the 21st century will have only minor impact but will become important when added to an extreme sea level event (e.g. storm surge). Both century-scale (∼0.5 m) based on tide gauge records and larger (>few metres) longer-term sea level rise predictions based on the melt of ice covered areas show essentially the same areas that are most vulnerable. Furthermore, the effectiveness of the method is demonstrated by the detection of areas that can be protected by relatively small flood protective structures at river and estuary entrances, thus providing valuable information for policy makers and local councils. 相似文献
5.
If the rising sea level due to climate change proceeds in the future with the rate observed in the past four decades, it could inundate some coastal lowlands. The aim of this paper is to assess future risk of sea-level rise (SLR) on the Nile delta of Egypt located along the Mediterranean Sea. Digital Elevation Models (DEMs) are verified, against ground control points, and used to identify areas susceptible to inundation due to future SLR. Analysis of DEMs maps and cross-shore profiles has identified locations that are vulnerable to SLR including coastal wetlands, agriculture areas, and urban neighborhoods. The results have revealed that about 7% of the Nile delta area is at risk of inundation due to future SLR. This information could be used by coastal zone managers in planning and protection of coastal areas. 相似文献
6.
Coastal topography is the principal variable that affects the movement of the tsunami wave on land. Therefore, land surface elevation data are critical to a tsunami model for computing extent of inundation. Elevation data from India's remote sensing satellite CARTOSAT-1 are available for the entire Indian coastline, while elevation data collected using Airborne Laser Terrain Mapper (ALTM) are only available for selected sections of the coastline. This study was carried out to evaluate the suitability of CARTOSAT-1 and ALTM elevation data sets in the tsunami inundation modeling. Two areas of the coastal Tamil Nadu that were severely affected during the December 2004 tsunami and surveyed extensively for mapping the extent of inundation were selected as the study areas. Elevation data sets from ALTM, CARTOSAT-1 and field measurement collected using Real-time Kinematic GPS (RTK-GPS) were compared for these areas. The accuracy of ALTM and CARTOSAT-1 data, the significance of interpolation methods and data used on model outputs were studied. The analysis clearly revealed that the elevation accuracy of CARTOSAT-1 data (+/?2m) was much lower than ALTM data (+/?0.6m). However, it was found that despite the differing elevation accuracy, both ALTM and CARTOSAT-1 can be used to produce tsunami inundation maps for open coasts with an accuracy of 185 m (2 grid cells) at 75% and 50% confidence level, respectively. 相似文献
7.
《Estuarine, Coastal and Shelf Science》2006,66(1-2):240-254
The seaward extent of New Zealand's coastal zone (defined here in a biophysical sense as the area of terrigenous influence) was determined from remotely sensed ocean colour and turbidity data. The cross-shore behavior of the colour and turbidity fields were quantified at a number of transects around the coastline and the locations where these fields changed from coastal to oceanic signatures were identified. Results from these analyses suggest that the coastal zone can extend several hundreds of kilometers offshore. Furthermore, the seaward extent determined from these analyses was not correlated to the underlying bathymetry of the continental shelf and slope; features commonly used to define the offshore extent of coastal zones. The estimated seaward limits determined from the analyses of the remotely sensed data were compared to limited available in situ data and predictions from a numerical circulation model. Observations of coastal zooplankton species several hundreds of kilometers offshore suggest good agreement with the predicted seaward extent of coastal zones determined from the remotely sensed data. Offshore transport of surface particles predicted by the circulation model also suggested that pelagic organisms and suspended inorganic particles may be advected offshore at least several hundreds of kilometers. 相似文献
8.
《Ocean Modelling》2008,20(3):252-269
The effects of wave–current interactions on the storm surge and inundation induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal regions are examined by using a three-dimensional (3-D) wave–current coupled modeling system. The 3-D storm surge and inundation modeling component of the coupled system is based on the Princeton ocean model (POM), whereas the wave modeling component is based on the third-generation wave model, simulating waves nearshore (SWAN). The results indicate that the effects of wave-induced surface, bottom, and radiation stresses can separately or in combination produce significant changes in storm surge and inundation. The effects of waves vary spatially. In some areas, the contribution of waves to peak storm surge during Hurricane Hugo reached as high as 0.76 m which led to substantial changes in the inundation and drying areas simulated by the storm surge model. 相似文献
9.
D. C. Mason I. J. Davenport R. A. Flather C. Gurney G. J. Robinson J. A. Smith 《Estuarine, Coastal and Shelf Science》2001,53(6):759
A sensitivity analysis of the waterline method of constructing a Digital Elevation Model (DEM) of an intertidal zone using remote sensing and hydrodynamic modelling is described. Variation in vertical height accuracy as a function of beach slope is investigated using a set of nine ERS Synthetic Aperture Radar (SAR) images of the Humber/Wash area on the English east coast acquired between 1992 and 1994. Waterlines from these images are heighted using a hydrodynamic tide-surge model and interpolated using block kriging. On 1:500 slope beaches, an average block height estimation standard deviation of 18–22 cm is achieved. This rises to 27 cm on 1:100 slope beaches, and 32 cm on 1:30 slope beaches. The average heighting error at different slopes is decomposed into components due to waterline heighting error, inadequate sensor resolution and interpolation inaccuracy. It is shown that, at 1:500 slope, waterline heighting error and interpolation inaccuracy are the main error sources, whilst at 1:30 slope, errors due to inadequate sensor resolution become dominant. The ability of the technique to generate intertidal DEMs for almost the entire coastal zone in a complete ERS SAR scene covering 100×100 km is demonstrated. 相似文献
10.
The aim was to explore the use of Light Detection and Ranging (LiDAR) data to map the micro-topography of an intertidal wetland in southeast Queensland Australia. The driver for this was the need to identify and map the habitats of the immature stages of an aedine disease vector mosquito (Aedes vigilax (Skuse)). We derived a high resolution digital elevation model (DEM) data set at a vertical resolution of 0.05 m from LiDAR data. The relative accuracy of the DEM across the site was tested by comparing water depth predictions derived from the DEM against in-situ water depth readings from pressure sensors over a 10-day tidal cycle, which included high spring tides. We found that the field observations of micro-topographic units important for mosquito management matched those delineated from the DEM. The micro-topography included a low berm or central ridge that was more or less continuous across the site, a shallow back basin and fringing mangroves. The fringing mangroves had unimpeded connection to the tidal source, however the central ridge blocked tidal water from the back basin for all but the highest tides. Eggshell survey indicated that the back basin was the area suitable for immature mosquitoes. We conclude that LiDAR data has application for understanding and mapping the structure of mangrove wetlands. We have also demonstrated (in a small area) that LiDAR is useful for modelling the effect of sea level changes on the coastal fringe. LiDAR may be the only method to inform research on changes to land use and ecosystems caused by sea level change. 相似文献
11.
Assessment and management of coastal multi-hazard vulnerability along the Cuddalore-Villupuram, east coast of India using geospatial techniques 总被引：3，自引：0，他引：3
The current study area is coastal zone of Cuddalore, Pondicherry and Villupuram districts of the Tamil Nadu along the southeast coast of India. This area is experiencing threat from many disasters such as storm, cyclone, flood, tsunami and erosion. This was one of the worst affected area during 2004 Indian Ocean tsunami and during 2008 Nisha cyclone. The multi-hazard vulnerability maps prepared here are a blended and combined overlay of multiple hazards those affecting the coastal zone. The present study aims to develop a methodology for coastal multi-hazard vulnerability assessment. This study was carried out using parameters probability of maximum storm surge height during the return period (mean recurrence interval), future sea level rise, coastal erosion and high resolution coastal topography with the aid of the Remote Sensing and GIS tools. The assessment results were threatening 3.46 million inhabitants from 129 villages covering a coastal area 360 km2 under the multi-hazard zone. In general river systems act as the flooding corridors which carrying larger and longer hinterland inundation. Multi-hazard Vulnerability maps were further reproduced as risk maps with the land use information. These risk caused due to multi-hazards were assessed up to building levels. The decision-making tools presented here can aid as critical information during a disaster for the evacuation process and to evolve a management strategy. These Multi-hazard vulnerability maps can also be used as a tool in planning a new facility and for insurance purpose. 相似文献
12.
Hermann M. Fritz Christopher D. Blount Fawzi B. Albusaidi Ahmed Hamoud Mohammed Al-Harthy 《Estuarine, Coastal and Shelf Science》2010
Super Cyclone Gonu is the strongest tropical cyclone on record in the Arabian Sea. Gonu caused coastal damage due to storm surge and storm wave impact as well as wadi flooding. High water marks, overland flow depths, and inundation distances were measured in the coastal flood zones along the Gulf of Oman from 1 to 4 August 2007. The high water marks peaked at Ras al-Hadd at the eastern tip of Oman exceeding 5 m. The storm surge of Gonu is modeled using the Advanced Circulation Model (ADCIRC). The multi-hazard aspect is analyzed by comparing observations from Cyclone Gonu with the 2004 Indian Ocean Tsunami. 相似文献
13.
Prediction of coastal hazards due to climate change is fraught with uncertainty that stems from complexity of coastal systems, estimation of sea level rise, and limitation of available data. In-depth research on coastal modeling is hampered by lack of techniques for handling uncertainty, and the available commercial geographical information systems (GIS) packages have only limited capability of handling uncertain information. Therefore, integrating uncertainty theory with GIS is of practical and theoretical significance. This article presents a GIS-based model that integrates an existing predictive model using a differential approach, random simulation, and fuzzy set theory for predicting geomorphic hazards subject to uncertainty. Coastal hazard is modeled as the combined effects of sea-level induced recession and storm erosion, using grid modeling techniques. The method is described with a case study of Fingal Bay Beach, SE Australia, for which predicted responses to an IPCC standard sea-level rise of 0.86 m and superimposed storm erosion averaged 12 m and 90 m, respectively, with analysis of uncertainty yielding maximum of 52 m and 120 m, respectively. Paradoxically, output uncertainty reduces slightly with simulated increase in random error in the digital elevation model (DEM). This trend implies that the magnitude of modeled uncertainty is not necessarily increased with the uncertainties in the input parameters. Built as a generic tool, the model can be used not only to predict different scenarios of coastal hazard under uncertainties for coastal management, but is also applicable to other fields that involve predictive modeling under uncertainty. 相似文献
14.
Prediction of coastal hazards due to climate change is fraught with uncertainty that stems from complexity of coastal systems, estimation of sea level rise, and limitation of available data. In-depth research on coastal modeling is hampered by lack of techniques for handling uncertainty, and the available commercial geographical information systems (GIS) packages have only limited capability of handling uncertain information. Therefore, integrating uncertainty theory with GIS is of practical and theoretical significance. This article presents a GIS-based model that integrates an existing predictive model using a differential approach, random simulation, and fuzzy set theory for predicting geomorphic hazards subject to uncertainty. Coastal hazard is modeled as the combined effects of sea-level induced recession and storm erosion, using grid modeling techniques. The method is described with a case study of Fingal Bay Beach, SE Australia, for which predicted responses to an IPCC standard sea-level rise of 0.86 m and superimposed storm erosion averaged 12 m and 90 m, respectively, with analysis of uncertainty yielding maximum of 52 m and 120 m, respectively. Paradoxically, output uncertainty reduces slightly with simulated increase in random error in the digital elevation model (DEM). This trend implies that the magnitude of modeled uncertainty is not necessarily increased with the uncertainties in the input parameters. Built as a generic tool, the model can be used not only to predict different scenarios of coastal hazard under uncertainties for coastal management, but is also applicable to other fields that involve predictive modeling under uncertainty. 相似文献
15.
Uncertainty in the behaviour of future storm events and extreme water levels means that the introduction of Early Warning Systems for coastal inundation risk at vulnerable local sites becomes increasing paramount. In this study the coupled hydro-morphodynamic model XBeach is used at two sites along the Emilia-Romagna coastline in northern Italy to predict coastal inundation risk in the presence of coastal structures and temporary artificial dunes. These dunes are typically formed by beach scraping and are used on this coastline to protect beach-front infrastructure during the winter period. Coastal inundation risk is defined by the cross-shore distance between the seaward edge of the building and the time-varying waterline predicted by XBeach. A series of synthetic storm events as well as a real-world scenario that caused dune failure at one of the sites are tested. Comparisons between XBeach results and the Van Der Meer empirical formula for wave transmission behind offshore structures show a very strong agreement, while the real-world scenario indicates promising model prediction performance of dune failure at least one day in advance. A new model tool known as DuneMaker is developed that modifies XBeach model grids to simulate the impacts of scraped/placed artificial dunes of varying size, shape and configuration. The use of this tool is demonstrated on the same model test runs, where it is shown that improved dune design can reduce the predicted coastal inundation risk at critical points of vulnerability identified by the model. 相似文献
16.
A change in the elevation of bare tidal flats outside a mangrove area is an indispensable factor for the sustainable development of mangroves. Waterline extraction, as an effective and economical tool used in reconstructing the terrain of an intertidal zone, has been widely applied to open-coast tidal flats by constructing a digital elevation model (DEM). However, mangrove wetlands are usually located in wave-sheltered sites, such as estuaries and bays that have narrow tidal channels flanked by tidal flats. Changes in water level are affected by the dry-wet processes of complex landforms caused by tides. This article takes as a study case the area of Yingluo Bay, which covers the core region of the Zhanjiang and Shankou National Mangrove National Nature Reserve in southwestern China. Waterline extraction based on seventeen multisource and multispectral satellite images obtained from December 2014 to April 2015, combining the finite-volume coastal ocean model (FVCOM) hydrodynamic model in an iterative process, was used to generate a topographical map of the bare tidal flat outside the mangrove area in Yingluo Bay. The quality of the iterative DEMs was evaluated via six transects of a ground-based survey using Real - time kinematic (RKT) GPS in May 2015. The mean absolute error (MAE) and root mean square error (RMSE) of the DEM decreased with an increase in the number of iterations. In this study, the DEM in the third iteration was used as the final output because the difference from the previous iterative DEM satisfied an inversion-stopping criterion. The MAE and RMSE of the final DEM with the measured data were 0.072 and 0.09?m, respectively, without considering small tidal creeks. The method used in this study can be an effective and highly precise approach for detecting and reconstructing the historical terrain of a bare tidal flat outside a mangrove area. This work also has great importance regarding intertidal resource management and the sustainable development of mangroves facing the vulnerable coastal ecological environment. 相似文献
17.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
18.
Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding. 相似文献
19.
An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the GeoClaw framework and compared to ADCIRC for Hurricane Ike along with observed tide gauge data and the computational cost of each model run. 相似文献
20.
Numerous urbanized embayments in California are at risk of flooding during extreme high tides caused by a combination of astronomical, meteorologic and climatic factors (e.g., El Niño), and the risk will increase as sea levels rise and storminess intensifies. Across California, the potential exists for billions of dollars in losses by 2100 and predictive inundation models will be relied upon at the local level to plan adaptation strategies and forecast localized flood impacts to support emergency management. However, the predictive skill of urban inundation models for extreme tide events has not been critically examined particularly in relation to data quality and flood mapping methodologies. With a case study of Newport Beach, California, we show that tidal flooding can be resolved along streets and at individual parcels using a 2D hydraulic inundation model that captures embayment amplification of the tide, overtopping of flood defenses, and overland flow along streets and into parcels. Furthermore, hydraulic models outperform equilibrium flood mapping methodologies which ignore hydraulic connectivity and are strongly biased towards over-prediction of flood extent. However, infrastructure geometry data including flood barriers, street and parcel elevations are crucial to accurate flood prediction. A real time kinematic (RTK) survey instrument with an error of approximately 1 cm (RMSE) is found to be suitable for barrier height measurement, but an error of approximately15 cm (RMSE) typical of aerial laser scanning or LiDAR is found to be inadequate. Finally, we note that the harbor waterfront in Newport Beach is lined by a patchwork of public and private parcels and flood barriers of varied designs and integrity. Careful attention to hydraulic connectivity (e.g., low points and gaps in barriers) is needed for successful flood prediction. 相似文献