In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and property.Rapid and accura...In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and property.Rapid and accurate flash flood inundation modelling is an essential foundational research area,which can aid in the reduction of casualties and the minimization of disaster losses;however,this modelling is also very difficult,and models need to be urgently developed to address flash flood forecasting and warnings.The objective of this study is to construct a numerical modelling method for flash floods in drylands.Based on a 2D high-resolution flood numerical model(Flood Map-Hydro Inundation2D),we hindcasted the dynamic process of flash flooding and show the spatio-temporal characteristics of flash flood inundation for the“8·18”flash flood disaster that occurred in Datong county,Qinghai province.The results showed that the model output effectively agreed with the observed inundation after the event in terms of both spatial extent and temporal process.Extensive flooding mainly occurred between 00:00 and 01:00 on August 18,2022.Qingshan,Hejiazhuang and Longwo villages were affected most heavily.We further conducted model sensitivity analysis and found that the model was highly sensitive to both roughness and hydraulic conductivity in drylands,and the effect of hydraulic conductivity was more pronounced.Our study confirmed the good performance of our model for the simulation of flash flooding in arid areas and provides a potential method for flash flood assessment and management in arid areas.展开更多
Dam-break flows pose significant threats to urban areas due to their potential for causing rapid and extensive flooding. Traditional numerical methods for simulating these events struggle with complex urban landscapes...Dam-break flows pose significant threats to urban areas due to their potential for causing rapid and extensive flooding. Traditional numerical methods for simulating these events struggle with complex urban landscapes. This paper presents an alternative approach using Radial Basis Functions to simulate dam-break flows and their impact on urban flood inundation. The proposed method adapts a new strategy based on Particle Swarm Optimization for variable shape parameter selection on meshfree formulation to enhance the numerical stability and convergence of the simulation. The method’s accuracy and efficiency are demonstrated through numerical experiments, including well-known partial and circular dam-break problems and an idealized city with a single building, highlighting its potential as a valuable tool for urban flood risk management.展开更多
Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2oo8. Debris flow mitigation and risk assessment is a key issue for reconstruc...Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2oo8. Debris flow mitigation and risk assessment is a key issue for reconstruction. The existing methods of inundation simulation are based on historical disasters and have no power of prediction. The rain- flood method can not yield detailed flow hydrograph and does not meet the need of inundation simulation. In this paper, the process of water flow was studied by using the Arc-SCS model combined with hydraulic method, and then the debris flow runoff process was calculated using the empirical formula combining the result from Arc-SCS. The peak discharge and runoff duration served as input of inundation simulation. Then, the dangerous area is predicted using kinematic wave method and Manning equation. Taking the debris flow in Huashiban gully in Beichuan County, Sichuan Province, China on 24 Sep. 2oo8 as example, the peak discharge of water flow and debris flow were calculated as 35.52 m3·s-1 and 215.66 m3·s-, with error of 4.15% compared to the measured values. The simulated area of debris-flow deposition was 161,500 m2, vs. the measured area of 144,097 m2, in error of 81.75%. The simulated maximum depth was 12.3 m, consistent with the real maximum depth between lO and 15 m according to the field survey. The minor error is mainly due to the flow impact on buildings and variations in cross-section configuration. The present methodology can be applied to predict debrisflow magnitude and evaluate its risk in other watersheds inthe earthquake area.展开更多
Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore ...Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore model)was used to investigate the storm surge inundation in the southwestern Hangzhou Bay region during Typhoon Chan-hom in 2015.The simulated hydrodynamic processes(sea surface wave and storm tide)were validated with measured data from wave buoys and tide gauges,indicating that the overall performance of the model was satisfactory.The storm surge inundation in the coastal area was simulated for several idealized control experiments,including different wave effects(wave-enhanced wind stress,wave-enhanced bottom stress,and wave radiation stress).Dike overflowing cases with different dike heights and dike breaking cases with different dike breach lengths were considered in the simulation.The results highlight the necessity of incorporating wave effects in the accurate simulation of storm surge inundation.Dike height significantly influences the magnitude and phase of the maximum inundation area in the dike overflowing cases,and dike breach length is an important factor impacting the magnitude of the maximum inundation area in the dike breaking cases.This study may serve as a useful reference for accurate coastal inundation simulation and risk assessment.展开更多
A two-dimensional hydrodynamic model, Floodarea was applied to simulate the flood inundation area and flood depth in Manas basin, China. Two scenes of Landsat TM images were also used in this research. One image was u...A two-dimensional hydrodynamic model, Floodarea was applied to simulate the flood inundation area and flood depth in Manas basin, China. Two scenes of Landsat TM images were also used in this research. One image was used to produce the spatial distributed manning roughness to feed the model, the other one was used to delineate the actual inundated area by a modified NDWI method. The model and the manning roughness were validated by the comparison of simulated flood inundation extent and the corresponding actual inundated area obtained from Landsat image. The results show that the actual inundation extent obtained from Landsat image was 240.45 km2, and the modeled inundation area was276.15 km2. It indicates that manning roughness ranging from 0.025 to 0.833 is appropriate in the basin. In addition, the modeled flood depth varied from 0 to7.77 m. Taking land use into account, five hazard zones were identified in the study area. This study would be beneficial to flood control and disaster reduction.展开更多
Coastal flooding caused by tropical cyclones has long been a major threat to life,property,and infrastructure in coastal zones.This study assessed the risk of flooding in Chittagong,southeastern Bangladesh,under extre...Coastal flooding caused by tropical cyclones has long been a major threat to life,property,and infrastructure in coastal zones.This study assessed the risk of flooding in Chittagong,southeastern Bangladesh,under extreme sea level scenarios caused by high astronomical tides and storm surges.The Jelesnianski typhoon model and the ADvanced CIRCulation hydrodynamic model were used to simulate 91 typhoons that occurred in the Bay of Bengal between 1981 and 2017,and observational data were used for model validation.The inundation model was based on a digital elevation model and a seed spread algorithm,and a geographical information system was used to visualize the flood risk.Under four scenarios,the changes in flood levels caused by sea level rise had no signifi-cant influence on the extent of flooding in Chittagong.At flood levels of 8.82m(50-year storm surge without sea level rise)and 8.89 m(50-year storm surge with sea level rise),the maximum estimated area of inundation was 11.35 km^(2).The western coastal and southeastern river coastal plain areas of Chittagong have the highest risk of inundation due to their low-lying terrain.At flood levels of 9.83m(100-year storm surge without sea level rise)and 9.97m(100-year storm surge with sea level rise),the maximum simulated flood extent was 36.44km^(2).Simulated floodwaters propagated in a south–north direction,and most of the northern areas of the city are at risk of inundation under these scenarios.展开更多
In order to forecast storm surge inundation, a two-dimensional model is established. In the model, an alternating computation sequence method is used to solve the governing equations, and the dry and wet method is int...In order to forecast storm surge inundation, a two-dimensional model is established. In the model, an alternating computation sequence method is used to solve the governing equations, and the dry and wet method is introduced to treat the moving boundary. This model is easy to use. It has a friendly input interface and Arcview GIS is used as the output interface. The model is applied to the Shantou area to simulate the storm surge elevations and inundations caused by Typhoons 6903 ane 0104 using the same relevant parameters. The calculated results agree well with the observations.展开更多
Coastal inundation results in many human casualties and significant economic losses.In this study,an inundation model with an unstructured mesh was developed using the ADvanced CIRCulation(ADCIRC)and Simulating WAves ...Coastal inundation results in many human casualties and significant economic losses.In this study,an inundation model with an unstructured mesh was developed using the ADvanced CIRCulation(ADCIRC)and Simulating WAves Nearshore(SWAN)models to simulate 43 inundation events from 1998 to 2018.A combined wind-pressure field derived from the assimilation windpressure model was used to drive the coupled ADCIRC-SWAN model.On the basis of the model results,a sensitivity study of the influence of land reclamation on coastal inundation was conducted.The results of the study showed that coastline changes caused by reclamation significantly influence the distribution of coastal inundation,particularly in areas where narrow waterways,bays,and peninsulas are newly formed.Combining the extreme inundation events calculated using the Gumbel and Weibull distributions,the 10-year,50-year,100-year,and 200-year return coastal inundations were obtained for the Pearl River Estuary in China.The risk of coastal inundation was analyzed according to the probability of the inundation depth exceeding 1 m.A hazard grade zoning map was drawn to guide disaster relief and mitigation in the reclamation area.展开更多
A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations. The model included two sections, one was for the simulation of s...A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations. The model included two sections, one was for the simulation of storm surge tidal level and the other for the simulation of storm surge inundation in the coastal area. While simulating the storm surge tidal level, the alternating direction implicit (ADI) method was applied to dispersing and solving 2D storm surge equations. In the simulation of storm surge inundation, the 2D unsteady flow equations were dispersed and solved using the structureless grids of finite volume method (FVM). A coupling calculation mode of the process of inundation and storm surge tidal level variation was proposed, therefore the storm surge inundation process and area could be calculated while simulating and forecasting the process of storm surge tidal setup. Furthermore, an extratropical storm surge and inundation in Bohai Bay were simulated using this numerical model. Simulation results are in good agreement with the measured data, which shows that this numerical model provides a new method of simulating and forecasting storm surge and inundation in Bohai Bay.展开更多
In recent studies, the effects of complex costal topography on tsunami run-up has sparked heated discussion. This study mainly aims at investigating the effects of complex costal topography on the tsunami inundation d...In recent studies, the effects of complex costal topography on tsunami run-up has sparked heated discussion. This study mainly aims at investigating the effects of complex costal topography on the tsunami inundation distance and the effectiveness of sand dunes in dissipating tsunami wave energy. The experiments were carried out in a wave flume to investigate the potential reduction effects of wave run-up by non erodible sand dune like features. The results show that increasing dunes spacing could not significantly affect inundation distance. However, if the height of sand dunes is of the same order of magnitude as the incoming tsunami wave and the gaps between the dunes are large enough, successful tsunami mitigation could also be possible.展开更多
The Sumatra-Andaman arc is an active subduction zone and had generated several destructive Tsunamis in the past.In this paper we have analyzed two historical Tsunamigenic earthquakes from this region. One of the histo...The Sumatra-Andaman arc is an active subduction zone and had generated several destructive Tsunamis in the past.In this paper we have analyzed two historical Tsunamigenic earthquakes from this region. One of the historical earthquake is the earthquake of 26th June 1941 in the North Andaman region,which was one of the strongest in the Andaman Sea and Bay of Bengal of magnitude M_w=7.7.This earthquake had triggered tsunami which affected the east coast of India.The other is the earthquake in Car Nicobar region on 31 st December 1881 of magnitude M_w=7.9. This submarine earthquake beneath the展开更多
Mapping floods is important for policy makers to make timely decisions in regards to emergency responses and future planning.It is therefore crucial to develop a rapid inundation modelling framework to map flood inund...Mapping floods is important for policy makers to make timely decisions in regards to emergency responses and future planning.It is therefore crucial to develop a rapid inundation modelling framework to map flood inundation.This study develops an airborne scanning laser altimetry(LiDAR)digital elevation model(DEM)based Rapid flood Inundation Modelling framework(LiDAR-RIM)for assessment of inundation extent,depth,volume and duration for flood events.The modelling framework has been applied to the mid-Murrumbidgee region in the southeast Murray-Darling Basin,Australia for two flood events occurred in December 2010 and March 2012.The inundation extents estimated using this methodology compared well to those obtained from two Landsat ETM+images,demonstrating suitability and applicability of this method.For testing possibility of larger area application,the framework also uses 30-m resolution shuttle radar topography mission(SRTM)-DEM to replace Li DAR-DEM for the same modelling.The inundation extents obtained by using the SRTM-DEM are smaller than those obtained using the Li DAR-DEM,especially for large flood events.A possible reason is that the river cross sections obtained from the SRTM-DEM are not accurate enough for inundation modelling.The Li DAR-RIM has an advantage for process modelling and scenario modelling under future climatic conditions.展开更多
Four typical cases of storm tide inundation at one of the typical storm surge prone areas in China and worldwide,i.e.Southeast China coast,are presented to demostrate the impact of climate change.It is relied on the s...Four typical cases of storm tide inundation at one of the typical storm surge prone areas in China and worldwide,i.e.Southeast China coast,are presented to demostrate the impact of climate change.It is relied on the statistical trend analysis of tropical cyclone intensification(TCI)and sea level rise(SLR)considering temporally non-stationary and spatially non-uniform effects,numerical analysis taking into account the tide-surge-wave coupling effect and GIS-based analysis for inundation evaluation.The results show that the high sea surface elevation tends to occur in the bays and around the estuaries.The maximal sea surface elevations of the worst situation at present without considering TCI and SLR(i.e.scenario S2)are 6.06 m,5.82 m and 5.67 m around Aojiang,Feiyunjiang and Oujiang river estuaries,respectively.Whereas,the maximal sea surface elevations for the three estuaries would increase to 7.02 m,6.67 m and 6.44 m,respectively,when the non-stationary extreme wind speed of 100-year recurrence period and SLR equivalent to the situation of 2100s(i.e.scenario S4)are taking into account.The potential inundation area of scenario S4 would expand by 108%to about 798 km^(2) compared with scenario S2.In addition,the remotely sensed maps and inundation durations of the hardest hit regions are provided,which will aid the prevention and mitigation of storm tide inundation hazard and future coastal management there.展开更多
An integrated hydrological model has been applied for a rural-urban catchment of the Szamos-Kraszna interfluve geographic area, using the WateRisk integrated hydrological model system. The aim of the hydrological simu...An integrated hydrological model has been applied for a rural-urban catchment of the Szamos-Kraszna interfluve geographic area, using the WateRisk integrated hydrological model system. The aim of the hydrological simulations was to identify the role that the relief plays in the water coverage formation process, and to highlight the possible consequences of it on phosphorus transport processes. To support this aim, the rainfall-runoff and the one-dimensional flow routing modules have been modelled, and maximal water cover has been calculated. Measured water coverage data by remote sensing have been compared to calculated maximum water cover in several ways. Results support the existing perspective on excess water formation namely that the process is very complex, therefore, the coincidence of the locations of measured water cover with calculated maximum water cover based on the DEM （digital elevation model） and the river network is low. Analysis shows that as far as the larger depressions of the area are concerned, the error of the DEM is not high, but it is likely that at locations with small altitude differences, the error of DEM can cause larger errors. The results foreshadow the importance of the micro relief of the area on phosphorus transport.展开更多
In the context of current climate change, an abnormality of flooding is a common form of disaster in Vietnam. Hanh Stream reservoir has occurred great flood in 1986, 2010. In the future, the risk of flooding is possib...In the context of current climate change, an abnormality of flooding is a common form of disaster in Vietnam. Hanh Stream reservoir has occurred great flood in 1986, 2010. In the future, the risk of flooding is possible to happen again. In view of management of the risk of natural disasters： large flooding situation downstream is one of the most dangerous risks for the reservoir. Due to downstream of Hanh Stream reservoir is a narrow coastal plains, quick infrastructure development, especially interwoven road and railway systems, so that flood drainage ability will be affected greatly. The consciousness of risks that may be occurred in the future in order to propose preventive measures and proactive response to minimize damages always is the requirement for all projects. The hydrodynamic calculation, flooding maps, emergency plan to prevent flooding downstream of Hanh Stream reservoir is also needed. The article is raised the issue of requirements to calculate coastal narrow delta strip flooding in the Central of Vietnam when impacted by the upstream reservoir of flood discharge in terms of extreme heavy rain and flooding and presented computational methods of Mike software package for case flooded plain of Cam Ranh Bay in downstream reservoirs of Hanh Stream, Khanh Hoa Province, Vietnam.展开更多
An investigation has been carried out in the vicinity of the coastal villages of Kanyakumari District,India to decode the influence of coastal geomorphology on inundation degree and run-up level.Even though the tsunam...An investigation has been carried out in the vicinity of the coastal villages of Kanyakumari District,India to decode the influence of coastal geomorphology on inundation degree and run-up level.Even though the tsunami waves approach the study area in different patterns,the consequences are found to be mainly dependent upon the coastal configuration and local geographic setting,the study area are considered to be of three types based upon the geomorphic arrangement,namely shallow coast,elevated coast and estuarine coast.The inundation and run-up level vary from coast to coast even though there is no remarkable variation in the intensity of the approaching tsunami surge.The inundation extent ranges from to 54 m to 413 m with maximum along estuarine coast and minimum along elevated coast.Estuarine coast recorded the maximum run-up level of about 6 m and the minimum of about 1 m along the elevated coast.The percentage of inundated area in the total coastal area varies between 19% to 10% along estuarine coast and elevated coast respectively.Inundation and run-up level cannot be appreciable in the inland along the elevated coast.The beaches of elevated coast are less affected whereas those of estuarine coast are highly affected.Inundation is limited in the elevated beaches along the study area.展开更多
As part of a broad assessment of climate change impacts in Morocco,an assessment of vulnerability and adaptation of coastal zones to sea-level rise was conducted.The Kenitra coast is socio-economically vulnerable to a...As part of a broad assessment of climate change impacts in Morocco,an assessment of vulnerability and adaptation of coastal zones to sea-level rise was conducted.The Kenitra coast is socio-economically vulnerable to accelerated sea-level rise,due to its low topography and its high ecological and touristic value.In this study,the effects of future relative sea-level were evaluated for the low alluvial plain Atlantic(Kenitra coastal).展开更多
Coastal inundation along the northeast coast of the United States is usually caused by strong winter storms(WS).However,the accurate prediction of coastal inundation due to the WS is challenging.Therefore,our study ai...Coastal inundation along the northeast coast of the United States is usually caused by strong winter storms(WS).However,the accurate prediction of coastal inundation due to the WS is challenging.Therefore,our study aims to develop a unique high-resolution modeling system to accurately predict the coastal inundation in the ungauged coastal areas of Saco-Casco Bays and map the flood risk zones to potential sea level rise due to these storms.Hindcasts of five classic WS in 2014-2015 were studied.The inundation models are based on FVCOM that uses unstructured grid to capture the minor to significant flooding near the shallow areas of the bays,harbor entrance and river banks.In this study,topography has been generated from the NOAA’s integrated dataset of Portland,ME 1/3 arc-second MHW digital elevation model.The model runs were driven by two different sets of meteorological(NECOFS WRF and NOAA’s NAM WRF)forcing to examine the effect of spatial resolution on the predicted inundation.The study reveals that among the five storm surge cases,WS-III produces a maximum surge of 0.7 m and WS-II cause a minimum surge of 0.3 m.In all scenarios,southward wind-driven coastal current flowing towards Biddeford Pool,Pine Point and Camp Ellis forms a small-scale eddy which causes significant inundation however strength of the current varies accordingly.Sensitivity experiments have been carried out using NECOFS WRF simulation products with varying parameters of marshland elevation and bottom friction to understand the influence of intertidal storage on the predicted flooding.展开更多
Groundwater inundation occurs when rivers with high water levels are hydraulically connected to the adjacent riversides.Huge barrages constructed in South Korea have caused the river water levels and groundwater level...Groundwater inundation occurs when rivers with high water levels are hydraulically connected to the adjacent riversides.Huge barrages constructed in South Korea have caused the river water levels and groundwater levels in the riversides to increase.We used a discriminant model with seven input variables,namely the sediment thickness,difference between the land elevation and river water level,difference between the groundwater and river water levels,soil drainage type,topsoil texture,subsoil texture,and hydrological soil feature classification,to develop a map of the groundwater inundation vulnerability along the basins of the Nakdong River.We estimated the groundwater levels in unmonitored areas with a linear regression model developed from the relationship between the distance from the river and the depth to the groundwater in 91 monitoring wells.We produced a grid map for the vulnerability with an optimum grid size of 100 m.We validated the groundwater inundation vulnerability map by comparing highly susceptible areas with swampy fields observed in a field survey.This result indicates that the vulnerability map will be helpful to forecast and prepare inundation in the riversides during the rainy season when the river water levels are inevitably high.展开更多
Urban inundation has become a growing concern for many coastal cities around the world.Tam Ky City,located downstream of Ban Thach and Tam Ky rivers in central Vietnam,is no exception.According to annual statistics,th...Urban inundation has become a growing concern for many coastal cities around the world.Tam Ky City,located downstream of Ban Thach and Tam Ky rivers in central Vietnam,is no exception.According to annual statistics,the city frequently experiences heavy rainfall from tropical storms and monsoons,making inundation a recurring issue.In response to this challenge,this study developed a flood forecasting model specifically tailored for Tam Ky City,based on forecast rainfall and tidal levels.A key strength of the flood forecasting model lies in its integration of rainfall‐runoff processes,effectively connecting the river basin and the city.To ensure the model's accuracy and reliability,the parameters of the flood forecasting model were meticulously calibrated and verified for floods occurred on rivers as well as in urban areas.An experimental flood forecast was performed during Typhoon Nuru on September 28,2022,and the forecast results of inundation locations and depths in the city well reflected the actual observations.展开更多
基金National Natural Science Foundation of China,No.41871164。
文摘In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and property.Rapid and accurate flash flood inundation modelling is an essential foundational research area,which can aid in the reduction of casualties and the minimization of disaster losses;however,this modelling is also very difficult,and models need to be urgently developed to address flash flood forecasting and warnings.The objective of this study is to construct a numerical modelling method for flash floods in drylands.Based on a 2D high-resolution flood numerical model(Flood Map-Hydro Inundation2D),we hindcasted the dynamic process of flash flooding and show the spatio-temporal characteristics of flash flood inundation for the“8·18”flash flood disaster that occurred in Datong county,Qinghai province.The results showed that the model output effectively agreed with the observed inundation after the event in terms of both spatial extent and temporal process.Extensive flooding mainly occurred between 00:00 and 01:00 on August 18,2022.Qingshan,Hejiazhuang and Longwo villages were affected most heavily.We further conducted model sensitivity analysis and found that the model was highly sensitive to both roughness and hydraulic conductivity in drylands,and the effect of hydraulic conductivity was more pronounced.Our study confirmed the good performance of our model for the simulation of flash flooding in arid areas and provides a potential method for flash flood assessment and management in arid areas.
文摘Dam-break flows pose significant threats to urban areas due to their potential for causing rapid and extensive flooding. Traditional numerical methods for simulating these events struggle with complex urban landscapes. This paper presents an alternative approach using Radial Basis Functions to simulate dam-break flows and their impact on urban flood inundation. The proposed method adapts a new strategy based on Particle Swarm Optimization for variable shape parameter selection on meshfree formulation to enhance the numerical stability and convergence of the simulation. The method’s accuracy and efficiency are demonstrated through numerical experiments, including well-known partial and circular dam-break problems and an idealized city with a single building, highlighting its potential as a valuable tool for urban flood risk management.
基金supported by the National Basic Research Program of China(973 Program)(Grant No.2011CB409902)the National Natural Sciences Foundation of China(Grant No. 40671025)
文摘Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2oo8. Debris flow mitigation and risk assessment is a key issue for reconstruction. The existing methods of inundation simulation are based on historical disasters and have no power of prediction. The rain- flood method can not yield detailed flow hydrograph and does not meet the need of inundation simulation. In this paper, the process of water flow was studied by using the Arc-SCS model combined with hydraulic method, and then the debris flow runoff process was calculated using the empirical formula combining the result from Arc-SCS. The peak discharge and runoff duration served as input of inundation simulation. Then, the dangerous area is predicted using kinematic wave method and Manning equation. Taking the debris flow in Huashiban gully in Beichuan County, Sichuan Province, China on 24 Sep. 2oo8 as example, the peak discharge of water flow and debris flow were calculated as 35.52 m3·s-1 and 215.66 m3·s-, with error of 4.15% compared to the measured values. The simulated area of debris-flow deposition was 161,500 m2, vs. the measured area of 144,097 m2, in error of 81.75%. The simulated maximum depth was 12.3 m, consistent with the real maximum depth between lO and 15 m according to the field survey. The minor error is mainly due to the flow impact on buildings and variations in cross-section configuration. The present methodology can be applied to predict debrisflow magnitude and evaluate its risk in other watersheds inthe earthquake area.
基金supported by the National Key Research and Development Program of China(Nos.2016YFC140 2000,2016YFC1401002,and 2018YFC1407003)the National Natural Science Foundation of China(NSFC)(NosU1706216,41606024,and 41506023)+3 种基金the CAS(Chinese Academy of Sciences)Strategic Priority Project(No.XDA 19060202)the CAS Innovative Foundation(No.CXJJ-16M111)the NSFC Innovative Group(No.41421005)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1406402)
文摘Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore model)was used to investigate the storm surge inundation in the southwestern Hangzhou Bay region during Typhoon Chan-hom in 2015.The simulated hydrodynamic processes(sea surface wave and storm tide)were validated with measured data from wave buoys and tide gauges,indicating that the overall performance of the model was satisfactory.The storm surge inundation in the coastal area was simulated for several idealized control experiments,including different wave effects(wave-enhanced wind stress,wave-enhanced bottom stress,and wave radiation stress).Dike overflowing cases with different dike heights and dike breaking cases with different dike breach lengths were considered in the simulation.The results highlight the necessity of incorporating wave effects in the accurate simulation of storm surge inundation.Dike height significantly influences the magnitude and phase of the maximum inundation area in the dike overflowing cases,and dike breach length is an important factor impacting the magnitude of the maximum inundation area in the dike breaking cases.This study may serve as a useful reference for accurate coastal inundation simulation and risk assessment.
文摘A two-dimensional hydrodynamic model, Floodarea was applied to simulate the flood inundation area and flood depth in Manas basin, China. Two scenes of Landsat TM images were also used in this research. One image was used to produce the spatial distributed manning roughness to feed the model, the other one was used to delineate the actual inundated area by a modified NDWI method. The model and the manning roughness were validated by the comparison of simulated flood inundation extent and the corresponding actual inundated area obtained from Landsat image. The results show that the actual inundation extent obtained from Landsat image was 240.45 km2, and the modeled inundation area was276.15 km2. It indicates that manning roughness ranging from 0.025 to 0.833 is appropriate in the basin. In addition, the modeled flood depth varied from 0 to7.77 m. Taking land use into account, five hazard zones were identified in the study area. This study would be beneficial to flood control and disaster reduction.
基金funded by the National Key Research and Development Program of China(No.2016YFC1401103)Funds for the Central Universities(No.202165003)the Open Fund of Shandong Province Key Laboratory of Ocean Engineering,Ocean University of China(No.kloe201903).
文摘Coastal flooding caused by tropical cyclones has long been a major threat to life,property,and infrastructure in coastal zones.This study assessed the risk of flooding in Chittagong,southeastern Bangladesh,under extreme sea level scenarios caused by high astronomical tides and storm surges.The Jelesnianski typhoon model and the ADvanced CIRCulation hydrodynamic model were used to simulate 91 typhoons that occurred in the Bay of Bengal between 1981 and 2017,and observational data were used for model validation.The inundation model was based on a digital elevation model and a seed spread algorithm,and a geographical information system was used to visualize the flood risk.Under four scenarios,the changes in flood levels caused by sea level rise had no signifi-cant influence on the extent of flooding in Chittagong.At flood levels of 8.82m(50-year storm surge without sea level rise)and 8.89 m(50-year storm surge with sea level rise),the maximum estimated area of inundation was 11.35 km^(2).The western coastal and southeastern river coastal plain areas of Chittagong have the highest risk of inundation due to their low-lying terrain.At flood levels of 9.83m(100-year storm surge without sea level rise)and 9.97m(100-year storm surge with sea level rise),the maximum simulated flood extent was 36.44km^(2).Simulated floodwaters propagated in a south–north direction,and most of the northern areas of the city are at risk of inundation under these scenarios.
基金supported by the Key Projects of the 10^th Five-Year Plan,Operational Storm Surge Numerical Forecast Model and Hazard Reduction Techniques
文摘In order to forecast storm surge inundation, a two-dimensional model is established. In the model, an alternating computation sequence method is used to solve the governing equations, and the dry and wet method is introduced to treat the moving boundary. This model is easy to use. It has a friendly input interface and Arcview GIS is used as the output interface. The model is applied to the Shantou area to simulate the storm surge elevations and inundations caused by Typhoons 6903 ane 0104 using the same relevant parameters. The calculated results agree well with the observations.
基金Data listed in Section 2 are available from the public platforms.The authors are thankful to those public platforms for providing the data.This work is supported by the National Key Research and Development Program of China(No.2016YFC1402000).The numerical work is supported by the High-Performance Computing Center,Institution of Oceanology,CAS.
文摘Coastal inundation results in many human casualties and significant economic losses.In this study,an inundation model with an unstructured mesh was developed using the ADvanced CIRCulation(ADCIRC)and Simulating WAves Nearshore(SWAN)models to simulate 43 inundation events from 1998 to 2018.A combined wind-pressure field derived from the assimilation windpressure model was used to drive the coupled ADCIRC-SWAN model.On the basis of the model results,a sensitivity study of the influence of land reclamation on coastal inundation was conducted.The results of the study showed that coastline changes caused by reclamation significantly influence the distribution of coastal inundation,particularly in areas where narrow waterways,bays,and peninsulas are newly formed.Combining the extreme inundation events calculated using the Gumbel and Weibull distributions,the 10-year,50-year,100-year,and 200-year return coastal inundations were obtained for the Pearl River Estuary in China.The risk of coastal inundation was analyzed according to the probability of the inundation depth exceeding 1 m.A hazard grade zoning map was drawn to guide disaster relief and mitigation in the reclamation area.
基金Supported by Meteorological New Technology Promotion Project of China Meteorological Administration (No. CMATG2006M22)
文摘A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations. The model included two sections, one was for the simulation of storm surge tidal level and the other for the simulation of storm surge inundation in the coastal area. While simulating the storm surge tidal level, the alternating direction implicit (ADI) method was applied to dispersing and solving 2D storm surge equations. In the simulation of storm surge inundation, the 2D unsteady flow equations were dispersed and solved using the structureless grids of finite volume method (FVM). A coupling calculation mode of the process of inundation and storm surge tidal level variation was proposed, therefore the storm surge inundation process and area could be calculated while simulating and forecasting the process of storm surge tidal setup. Furthermore, an extratropical storm surge and inundation in Bohai Bay were simulated using this numerical model. Simulation results are in good agreement with the measured data, which shows that this numerical model provides a new method of simulating and forecasting storm surge and inundation in Bohai Bay.
文摘In recent studies, the effects of complex costal topography on tsunami run-up has sparked heated discussion. This study mainly aims at investigating the effects of complex costal topography on the tsunami inundation distance and the effectiveness of sand dunes in dissipating tsunami wave energy. The experiments were carried out in a wave flume to investigate the potential reduction effects of wave run-up by non erodible sand dune like features. The results show that increasing dunes spacing could not significantly affect inundation distance. However, if the height of sand dunes is of the same order of magnitude as the incoming tsunami wave and the gaps between the dunes are large enough, successful tsunami mitigation could also be possible.
文摘The Sumatra-Andaman arc is an active subduction zone and had generated several destructive Tsunamis in the past.In this paper we have analyzed two historical Tsunamigenic earthquakes from this region. One of the historical earthquake is the earthquake of 26th June 1941 in the North Andaman region,which was one of the strongest in the Andaman Sea and Bay of Bengal of magnitude M_w=7.7.This earthquake had triggered tsunami which affected the east coast of India.The other is the earthquake in Car Nicobar region on 31 st December 1881 of magnitude M_w=7.9. This submarine earthquake beneath the
基金CAS Talents Program and IGSNRR Supporting Fund,No.YJRCPT2019-101。
文摘Mapping floods is important for policy makers to make timely decisions in regards to emergency responses and future planning.It is therefore crucial to develop a rapid inundation modelling framework to map flood inundation.This study develops an airborne scanning laser altimetry(LiDAR)digital elevation model(DEM)based Rapid flood Inundation Modelling framework(LiDAR-RIM)for assessment of inundation extent,depth,volume and duration for flood events.The modelling framework has been applied to the mid-Murrumbidgee region in the southeast Murray-Darling Basin,Australia for two flood events occurred in December 2010 and March 2012.The inundation extents estimated using this methodology compared well to those obtained from two Landsat ETM+images,demonstrating suitability and applicability of this method.For testing possibility of larger area application,the framework also uses 30-m resolution shuttle radar topography mission(SRTM)-DEM to replace Li DAR-DEM for the same modelling.The inundation extents obtained by using the SRTM-DEM are smaller than those obtained using the Li DAR-DEM,especially for large flood events.A possible reason is that the river cross sections obtained from the SRTM-DEM are not accurate enough for inundation modelling.The Li DAR-RIM has an advantage for process modelling and scenario modelling under future climatic conditions.
基金supported by the National Natural Science Foundation of China(Grant 11902024)the National Key R&D Program of China(Grant 2017YFC1404202)the Strategic Priority Research Programs(Category B)of the Chinese Academy of Sciences(Grant XDB22040203).
文摘Four typical cases of storm tide inundation at one of the typical storm surge prone areas in China and worldwide,i.e.Southeast China coast,are presented to demostrate the impact of climate change.It is relied on the statistical trend analysis of tropical cyclone intensification(TCI)and sea level rise(SLR)considering temporally non-stationary and spatially non-uniform effects,numerical analysis taking into account the tide-surge-wave coupling effect and GIS-based analysis for inundation evaluation.The results show that the high sea surface elevation tends to occur in the bays and around the estuaries.The maximal sea surface elevations of the worst situation at present without considering TCI and SLR(i.e.scenario S2)are 6.06 m,5.82 m and 5.67 m around Aojiang,Feiyunjiang and Oujiang river estuaries,respectively.Whereas,the maximal sea surface elevations for the three estuaries would increase to 7.02 m,6.67 m and 6.44 m,respectively,when the non-stationary extreme wind speed of 100-year recurrence period and SLR equivalent to the situation of 2100s(i.e.scenario S4)are taking into account.The potential inundation area of scenario S4 would expand by 108%to about 798 km^(2) compared with scenario S2.In addition,the remotely sensed maps and inundation durations of the hardest hit regions are provided,which will aid the prevention and mitigation of storm tide inundation hazard and future coastal management there.
文摘An integrated hydrological model has been applied for a rural-urban catchment of the Szamos-Kraszna interfluve geographic area, using the WateRisk integrated hydrological model system. The aim of the hydrological simulations was to identify the role that the relief plays in the water coverage formation process, and to highlight the possible consequences of it on phosphorus transport processes. To support this aim, the rainfall-runoff and the one-dimensional flow routing modules have been modelled, and maximal water cover has been calculated. Measured water coverage data by remote sensing have been compared to calculated maximum water cover in several ways. Results support the existing perspective on excess water formation namely that the process is very complex, therefore, the coincidence of the locations of measured water cover with calculated maximum water cover based on the DEM （digital elevation model） and the river network is low. Analysis shows that as far as the larger depressions of the area are concerned, the error of the DEM is not high, but it is likely that at locations with small altitude differences, the error of DEM can cause larger errors. The results foreshadow the importance of the micro relief of the area on phosphorus transport.
文摘In the context of current climate change, an abnormality of flooding is a common form of disaster in Vietnam. Hanh Stream reservoir has occurred great flood in 1986, 2010. In the future, the risk of flooding is possible to happen again. In view of management of the risk of natural disasters： large flooding situation downstream is one of the most dangerous risks for the reservoir. Due to downstream of Hanh Stream reservoir is a narrow coastal plains, quick infrastructure development, especially interwoven road and railway systems, so that flood drainage ability will be affected greatly. The consciousness of risks that may be occurred in the future in order to propose preventive measures and proactive response to minimize damages always is the requirement for all projects. The hydrodynamic calculation, flooding maps, emergency plan to prevent flooding downstream of Hanh Stream reservoir is also needed. The article is raised the issue of requirements to calculate coastal narrow delta strip flooding in the Central of Vietnam when impacted by the upstream reservoir of flood discharge in terms of extreme heavy rain and flooding and presented computational methods of Mike software package for case flooded plain of Cam Ranh Bay in downstream reservoirs of Hanh Stream, Khanh Hoa Province, Vietnam.
基金the National Resource Data Management System (NRDMS) Division of the Department of Science and Technology (DST)Government of India for supplying the necessary equipment and financial assistance
文摘An investigation has been carried out in the vicinity of the coastal villages of Kanyakumari District,India to decode the influence of coastal geomorphology on inundation degree and run-up level.Even though the tsunami waves approach the study area in different patterns,the consequences are found to be mainly dependent upon the coastal configuration and local geographic setting,the study area are considered to be of three types based upon the geomorphic arrangement,namely shallow coast,elevated coast and estuarine coast.The inundation and run-up level vary from coast to coast even though there is no remarkable variation in the intensity of the approaching tsunami surge.The inundation extent ranges from to 54 m to 413 m with maximum along estuarine coast and minimum along elevated coast.Estuarine coast recorded the maximum run-up level of about 6 m and the minimum of about 1 m along the elevated coast.The percentage of inundated area in the total coastal area varies between 19% to 10% along estuarine coast and elevated coast respectively.Inundation and run-up level cannot be appreciable in the inland along the elevated coast.The beaches of elevated coast are less affected whereas those of estuarine coast are highly affected.Inundation is limited in the elevated beaches along the study area.
文摘As part of a broad assessment of climate change impacts in Morocco,an assessment of vulnerability and adaptation of coastal zones to sea-level rise was conducted.The Kenitra coast is socio-economically vulnerable to accelerated sea-level rise,due to its low topography and its high ecological and touristic value.In this study,the effects of future relative sea-level were evaluated for the low alluvial plain Atlantic(Kenitra coastal).
文摘Coastal inundation along the northeast coast of the United States is usually caused by strong winter storms(WS).However,the accurate prediction of coastal inundation due to the WS is challenging.Therefore,our study aims to develop a unique high-resolution modeling system to accurately predict the coastal inundation in the ungauged coastal areas of Saco-Casco Bays and map the flood risk zones to potential sea level rise due to these storms.Hindcasts of five classic WS in 2014-2015 were studied.The inundation models are based on FVCOM that uses unstructured grid to capture the minor to significant flooding near the shallow areas of the bays,harbor entrance and river banks.In this study,topography has been generated from the NOAA’s integrated dataset of Portland,ME 1/3 arc-second MHW digital elevation model.The model runs were driven by two different sets of meteorological(NECOFS WRF and NOAA’s NAM WRF)forcing to examine the effect of spatial resolution on the predicted inundation.The study reveals that among the five storm surge cases,WS-III produces a maximum surge of 0.7 m and WS-II cause a minimum surge of 0.3 m.In all scenarios,southward wind-driven coastal current flowing towards Biddeford Pool,Pine Point and Camp Ellis forms a small-scale eddy which causes significant inundation however strength of the current varies accordingly.Sensitivity experiments have been carried out using NECOFS WRF simulation products with varying parameters of marshland elevation and bottom friction to understand the influence of intertidal storage on the predicted flooding.
基金supported by the Daejeon University Research Grants(2016)scheme.
文摘Groundwater inundation occurs when rivers with high water levels are hydraulically connected to the adjacent riversides.Huge barrages constructed in South Korea have caused the river water levels and groundwater levels in the riversides to increase.We used a discriminant model with seven input variables,namely the sediment thickness,difference between the land elevation and river water level,difference between the groundwater and river water levels,soil drainage type,topsoil texture,subsoil texture,and hydrological soil feature classification,to develop a map of the groundwater inundation vulnerability along the basins of the Nakdong River.We estimated the groundwater levels in unmonitored areas with a linear regression model developed from the relationship between the distance from the river and the depth to the groundwater in 91 monitoring wells.We produced a grid map for the vulnerability with an optimum grid size of 100 m.We validated the groundwater inundation vulnerability map by comparing highly susceptible areas with swampy fields observed in a field survey.This result indicates that the vulnerability map will be helpful to forecast and prepare inundation in the riversides during the rainy season when the river water levels are inevitably high.
基金Science and Technology Fund of Quang Nam Province,Grant/Award Number:32/HD-SKHCN。
文摘Urban inundation has become a growing concern for many coastal cities around the world.Tam Ky City,located downstream of Ban Thach and Tam Ky rivers in central Vietnam,is no exception.According to annual statistics,the city frequently experiences heavy rainfall from tropical storms and monsoons,making inundation a recurring issue.In response to this challenge,this study developed a flood forecasting model specifically tailored for Tam Ky City,based on forecast rainfall and tidal levels.A key strength of the flood forecasting model lies in its integration of rainfall‐runoff processes,effectively connecting the river basin and the city.To ensure the model's accuracy and reliability,the parameters of the flood forecasting model were meticulously calibrated and verified for floods occurred on rivers as well as in urban areas.An experimental flood forecast was performed during Typhoon Nuru on September 28,2022,and the forecast results of inundation locations and depths in the city well reflected the actual observations.
