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1.
The aim of this study is to promote appropriate land development policies and to improve operations of flood risk in urban areas. This study first illustrated a multi-parameter flood hazard index (FHI) model for assessing potential flood risk areas in the Guanzhong Urban Area (GUA), a large-scale urban area in northwestern China. The FHI model consisted of the following seven parameters: rainfall intensity, flow accumulation, distance from the river network, elevation, land use, surface slope, and geology. The parameter weights were assigned using an analytical hierarchy process and the sum weight of the first three parameters accounted for 71.21% of the total weight and had significant influence on flooding. By combining with population factor, the FHI model was modified to estimate the flood control area in the GUA. The spatial distribution of the flood risk was obviously different in the flood hazard area and flood control area. The very low risk and medium risk area in the flood control area increased by 11.19% and reduced by 9.03% compared to flood hazard area, but there were no obvious differences in other levels of risk areas. The flood control assessment indicated that very high flood risk areas were principally concentrated along river banks (the Weihe River and its tributaries) and in the middle of the Guanzhong Plain. Land use and population distribution are related to flooding. Especially, forestland was located in 84.48% of the very low risk area, while low risk areas were mainly located in 91.49% of high population dispersion area.  相似文献   

2.
The boat‐based, mobile mapping system (BoMMS) with a laser scanner allows the derivation of detailed riverine topographical data for fluvial applications. Combined with data acquisition from static terrestrial LiDAR (light detection and range) or mobile terrestrial LiDAR on the ground, boat‐based laser scanning enables a totally new field mapping approach for fluvial studies. The BoMMS approach is an extremely rapid methodology for surveying riverine topography, taking only 85 min to survey a reach approximately 6 km in length. The BoMMS approach also allowed an effective survey angle for deep river banks, which is difficult to achieve with aerial or static terrestrial LiDAR. Further, this paper demonstrates the three‐dimensional mapping of a point‐bar and its detailed morphology. Compared with the BoMMS surface, approximately, 80% and 96% of the terrestrial LiDAR points showed a height deviation of less than 2 cm and 5 cm, respectively, with an overall standard deviation of ± 2·7 cm. This level of accuracy and rapidity of data capture enables the mapping of post‐flood deposition directly after a flood event without an extensive time lag. Additionally, the improved object characterisation may allow for better 3D mapping of the point bar and other riverrine features. However, the shadow effect of the BoMMS survey in point bar mapping should be removed by additional LiDAR data to acquire entire riverine topography. The approach demonstrated allowed a large reach to be surveyed compared with static terrestrial LiDAR and increased the spatial limit of survey towards aerial LiDAR, but it maintains the same or even better temporal resolution as static terrestrial LiDAR. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

3.
We have developed a flood water level estimation method that only employs satellite images and a DEM. The method involves three steps: (1) discriminating flood areas and identifying clumps of each flood area, (2) extracting the edges of the identified flood area using a buffering technique, and (3) performing spatial interpolation to transform the extracted elevation to flood water levels. We compared the estimated flood water levels with the observed ones. The RMSE using the RADARSAT was 1.99 and 1.30 m at river and floodplain points, respectively, whereas the RMSE using the MODIS was 4.33 and 1.33 m at the river and floodplain points, respectively. Given that most errors are attributed to the DEM, the method exhibited good performance. Furthermore, the method reproduced the flow directions and flood water level changes during the flooding period. Thus, we demonstrated that the characteristics of flood inundation can be understood even when ground observation data cannot be obtained.  相似文献   

4.
This article explores the length scales and statistical characteristics of form roughness along the outer banks of two elongate bends on a large meandering river through investigation of topographic variability of the bank face. The analysis also examines how roughness varies over the vertical height of the banks and when the banks are exposed subaerially and inundated during flood stage. Detailed data on the topography of the outer banks were obtained subaerially using terrestrial LiDAR during low flow conditions and subaqueously using multibeam echo sounding (MBES) during near‐bankfull conditions. The contributions of various length scales of topographic irregularity to roughness for subaerial conditions were evaluated for different elevation contours on the bank faces using Hilbert–Huang Transform (HHT) spectral analysis. Statistical characteristics for discrete areas on the bank faces were determined by calculating the root‐mean‐square of normal distances from a triangulated irregular network (TIN) surface. Results of the HHT analysis show that the characteristics of roughness along bank faces composed primarily of non‐cohesive sediment, and eroding into cropland, vary with bank elevation and exhibit a dominant range of roughness length scales (~15–50 m). However, bank faces composed predominantly of cohesive material and carved into a forested floodplain have relatively uniform topographic roughness characteristics over the vertical extent of the bank face and do not exhibit a dominant roughness length scale or range of length scales. Additionally, comparison between local surface roughness for subaerial versus subaqueous conditions shows that roughness decreases considerably when the banks are submerged, most likely because of the removal of vegetation and eradication of small‐scale erosional features in non‐cohesive bank materials by flow along the bank face. Thus, roughness appears to be linked to the hydraulic conditions affecting the bank, at least relative to conditions that develop when banks are exposed subaerially. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

5.
Upland agricultural land management activities such as grazing, vegetation burning, and bare ground restoration impact hydrological elements of headwater catchments, many of which may be important for downstream flood peaks (e.g., overland flow and soil water storage). However, there is poor understanding of how these management practices affect river flow peaks during high magnitude rainfall events. Using the distributed TOPMODEL, spatial configurations of land management were modelled to predict flood response in an upland catchment, which contains different regions operating subsidized agricultural stewardship schemes. Heavy grazing leading to soil compaction and loss of vegetation cover in stewardship regions covering 79.8% of the catchment gave a 42‐min earlier flow peak, which was 82.2% higher (under a 1‐hr 15‐mm storm) than the current simulated hydrograph. Light grazing over the same regions of the catchment had much less influence on river flow peaks (18 min earlier and 32.9% increase). Rotational burning (covering 8.8% of the catchment), most of which is located in the headwater areas, increased the peak by 3.2% in the same rainfall event. Vegetation restoration with either Eriophorum or Sphagnum (higher density) in bare areas (5.8%) of the catchment provided a reduction of flood peak (3.9% and 5.2% in the 15‐mm storm event), whereas the same total area revegetated with Sphagnum in riparian regions delivered a much larger decrease (15.0%) in river flow peaks. We show that changes of vegetation cover in highly sensitive areas (e.g., near‐stream zones) generate large impacts on flood peaks. Thus, it is possible to design spatially distributed management systems for upland catchments, which reduce flood peaks while at the same time ensuring economic viability for upland farmers.  相似文献   

6.
We propose an improvement of the overland‐flow parameterization in a distributed hydrological model, which uses a constant horizontal grid resolution and employs the kinematic wave approximation for both hillslope and river channel flow. The standard parameterization lacks any channel flow characteristics for rivers, which results in reduced river flow velocities for streams narrower than the horizontal grid resolution. Moreover, the surface areas, through which these wider model rivers may exchange water with the subsurface, are larger than the real river channels potentially leading to unrealistic vertical flows. We propose an approximation of the subscale channel flow by scaling Manning's roughness in the kinematic wave formulation via a relationship between river width and grid cell size, following a simplified version of the Barré de Saint‐Venant equations (Manning–Strickler equations). The too large exchange areas between model rivers and the subsurface are compensated by a grid resolution‐dependent scaling of the infiltration/exfiltration rate across river beds. We test both scaling approaches in the integrated hydrological model ParFlow. An empirical relation is used for estimating the true river width from the mean annual discharge. Our simulations show that the scaling of the roughness coefficient and the hydraulic conductivity effectively corrects overland flow velocities calculated on the coarse grid leading to a better representation of flood waves in the river channels.  相似文献   

7.
Comprehensive flood risk assessment requires enhanced understanding of the coevolution of the river and its floodplain occupation. Paleoflood analysis to determine flood prone areas in combination with numerical simulations to estimate flood hazard and a historical analysis of urban development to consider the evolution of exposure to floods is a possible way forward. The well‐documented 2006 extreme flood in the Biobío River system and the impacted metropolitan area of Concepción, Chile (~1 million inhabitants) was used as a complex scenario to test the reliability of the proposed method. Results showed that flood prone areas determined with hydro‐geomorphological methods are consistent with those computed with numerical models based on detailed digital elevation models. The flood generation via superficial flow pathways resulting in inundated areas could explain that rivers tend to reactivate paleochannels in extreme conditions. Urban development progressively increased the city's exposure to floods from 0 ha in 1,751 to 1,363 ha in 2006 evidencing a lack of appropriate flood risk management. The 100‐year peak discharge resulted in a high flood risk for about 5% of the total urbanized area of Concepción, and higher discharges are likely to reactivate a paleochannel that crosses the current city centre. We conclude that the proposed paleo hydro‐geomorphology, hydraulic, and urban planning multimethod approach is a necessary tool to enhance understanding of flood risk in complex scenarios to improve flood risk management.  相似文献   

8.
Fallout radionuclides (FRNs) 137Cs and 210Pb are well established as tracers of surface and sub‐surface soil erosion contributing sediment to river systems. However, without additional information, it has not been possible to distinguish sub‐surface soil erosion sources. Here, we use the FRN 7Be (half‐life 53 days) in combination with 137Cs and excess 210Pb to trace the form of erosion contributing sediment in three large river catchments in eastern Australia; the Logan River (area 3700 km2), Bowen River (9400 km2) and Mitchell River (4700 km2). We show that the combination of 137Cs, excess 210Pb and 7Be can discriminate horizontally aligned sub‐surface erosion sources (rilled and scalded hillslopes and the floors of incised drainage lines and gully ‘badland’ areas) from vertical erosion sources (channel banks and gully walls). Specifically, sub‐surface sources of sediment eroded during high rainfall and high river flow events have been distinguished by the ability of rainfall‐derived 7Be to label horizontal soil surfaces, but not vertical. Our results indicate that in the two northern catchments, erosion of horizontal sub‐surface soil sources contributed almost as much fine river sediment as vertical channel banks, and several times the contribution of hillslope topsoils. This result improves on source discrimination provided previously and indicates that in some areas erosion of hillslope soils may contribute significantly to sediment yield, but not as topsoil loss. We find that in north‐eastern Australia, scalded areas on hillslopes and incising drainage lines may be sediment sources of comparable importance to vertical channel banks. Previous studies have used the combination of 137Cs, excess 210Pb and 7Be to estimate soils losses at the hillslope scale. Here, we show that with timely and judicious sampling of soil and sediment during and immediately after high flow events 7Be measurements can augment fallout 137Cs and 210Pb to provide important erosion source information over large catchments. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

9.
Sang‐Hyeok Kang 《水文研究》2009,23(11):1642-1649
In urban areas with a high building density, features such as roads, buildings and river dykes significantly affect flow dynamics and flood propagation. This should therefore be accounted for in the model set‐up. While 2D hydraulic models of densely urban areas are at the forefront of current research into flood inundation mechanisms, these models are constrained by inadequate parameters of topography and insufficient data. In order to solve these problems, topographic information obtained from digital elevation model (DEM) is directly programmed into the urban inundation model for a densely urban area, without exchanging the input data. In this paper, the extraction of building area is described using a tight coupling approach within a GIS environment, and its influence on the extent of flood inundation with a high building density is estimated. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

10.
Arctic deltas, such as the Mackenzie Delta, are expected to face major climate change and increased human influence in the near future. Deltas are characterised by highly dynamic fluvial processes, and changing climate will cause considerable evolution of the riverine environment. The changes are difficult to predict with existing knowledge and data. This study quantified channel planform change of the Mackenzie Delta (1983–2013), analysing its temporal and spatial patterns. We addressed the main obstacle of research on large remote areas, the lack of data, by developing a unique work flow that utilised Landsat satellite imagery, hydrological time series, remote sensing‐based change analysis, and automatic vectorisation of channels. Our results indicate that the Mackenzie Delta experienced constant evolution but at a highly varying rate over the 30 years. The study demonstrates that the magnitude and duration of flood peaks and the presence of spring ice breakup floods determine the rate of Arctic delta planform change. Changing winter conditions and spring flood magnitudes may therefore affect the stability of Arctic deltas. However, no clear trends towards decreased recurrence or magnitude of spring floods or increased instability of the delta plain have yet been observed in the Mackenzie Delta. The delta plain was most dynamic at the beginning and at the end of the examined period, corresponding to intense flooding, whereas the rates of change were subtle during the low‐flood period 1994–2007. The largest changes have occurred along the wide Middle Channel and in the outermost delta. Relative to their size, however, smaller meandering channels have been highly dynamic. Hotspots of change in the delta plain are located in anastomosing and braiding channel segments and, at the local scale, in point bars and cut‐banks along meandering channels. Our study describes how Landsat satellite data can be utilised for advancing fluvial geomorphological research in remote areas. However, cloudiness in the delta restricts production of dense time series with simultaneous coverage of the whole area and requires manual preprocessing.  相似文献   

11.
Movies taken by witnesses of extreme flood events are increasingly available on video sharing websites. They potentially provide highly valuable information on flow velocities and hydraulic processes that can help improve the post‐flood determination of discharges in streams and flooded areas. We investigated the troubles and potential of applying the now mature large‐scale particle image velocimetry (LSPIV) technique to such flood movies that are recorded under non‐ideal conditions. Processing was performed using user‐friendly, free software only, such as Fudaa‐LSPIV. Typical issues related to the image processing and to the hydrological analysis are illustrated using a selected example of a pulsed flash‐flood flow filmed in a mountainous torrent. Simple corrections for lens distortion (fisheye) and limited incoherent camera movement (shake) were successfully applied, and the related errors were reduced to a few percents. Testing the different image resolution levels offered by YouTube showed that the difference in time‐averaged longitudinal velocity was less than 5% compared with full resolution. A limited number of GRPs, typically 10, is required, but they must be adequately distributed around the area of interest. The indirect determination of the water level is the main source of uncertainty in the results, usually much more than errors because of the longitudinal slope and waviness of the free‐surface of the flow. The image‐based method yielded direct discharge estimates of the base flow between pulses, of the pulse waves, and of the time‐averaged flow over a movie sequence including a series of five pulses. A comparison with traditional indirect determination methods showed that the critical‐depth method may produce significantly biassed results for such a fast, unsteady flow, while the slope‐area method seems to be more robust but would overestimate the time‐averaged flow rate if applied to the high‐water marks of a pulsed flow. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

12.
Spatially distributed hydrologic models can be effectively utilized for flood event simulation over basins where a complex system of reservoirs affecting the natural flow regime is present. Flood peak attenuation through mountain reservoirs can, in fact, mitigate the impact of major floods in flood‐prone areas of the lower river valley. Assessment of this effect for a complex reservoir system is performed with a spatially distributed hydrologic model where the surface runoff formation and the hydraulic routing through each reservoir and the river system are performed at a fine spatial and time resolution. The Toce River basin is presented as a case study, because of the presence of 14 active hydroelectric dams that affect the natural flow regime. A recent extreme flood event is simulated using a multi‐realization kriging method for modelling the spatial distribution of rainfall. A sensitivity analysis of the key elements of the distributed hydrologic model is also performed. The flood hydrograph attenuation is assessed. Several possible reservoir storage conditions are used to characterize the initial condition of each reservoir. The results demonstrate how a distributed hydrologic model can contribute to defining strategies for reservoir management in flood mitigation. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

13.
LAURENCE C. SMITH 《水文研究》1997,11(10):1427-1439
The growing availability of multi-temporal satellite data has increased opportunities for monitoring large rivers from space. A variety of passive and active sensors operating in the visible and microwave range are currently operating, or planned, which can estimate inundation area and delineate flood boundaries. Radar altimeters show great promise for directly measuring stage variation in large rivers. It also appears to be possible to obtain estimates of river discharge from space, using ground measurements and satellite data to construct empirical curves that relate water surface area to discharge. Extrapolation of these curves to ungauged sites may be possible for the special case of braided rivers. Where clouds, trees and floating vegetation do not obscure the water surface, high-resolution visible/infrared sensors provide good delineation of inundated areas. Synthetic aperture radar (SAR) sensors can penetrate clouds and can also detect standing water through emergent aquatic plants and forest canopies. However, multiple frequencies and polarizations are required for optimal discrimination of various inundated vegetation cover types. Existing single-polarization, fixed-frequency SARs are not sufficient for mapping inundation area in all riverine environments. In the absence of a space-borne multi-parameter SAR, a synergistic approach using single-frequency, fixed-polarization SAR and visible/infrared data will provide the best results over densely vegetated river floodplains. © 1997 John Wiley & Sons, Ltd.  相似文献   

14.
A rising exposure to flood risk is a predicted consequence of increased development in vulnerable areas and an increase in the frequency of extreme weather events due to climate change. In the face of this challenge, a continued reliance on engineered at‐a‐point flood defences is seen as both unrealistic and undesirable. The contribution of ‘soft engineering’ solutions (e.g. riparian forests, wood in rivers) to integrated, catchment scale flood risk management has been demonstrated at small scales but not larger ones. In this study we use reduced complexity hydrological modelling to analyse the effects of land use and channel changes resulting from river restoration upon flood flows at the catchment scale. Results show short sections of river‐floodplain restoration using engineered logjams, typical of many current restoration schemes, have highly variable impacts on catchment‐scale flood peak magnitude and so need to be used with caution as a flood management solution. Forested floodplains have a more general impact upon flood hydrology, with areas in the middle and upper catchment tending to show reductions in peak magnitude at the catchment outflow. The most promising restoration scenarios for flood risk management are for riparian forest restoration at the sub‐catchment scale, representing 20–40% of the total catchment area, where reductions in peak magnitude of up to 19% are observed through de‐synchronization of the timings of sub‐catchment flood waves. Sub‐catchment floodplain forest restoration over 10–15% of total catchment area can lead to reductions in peak magnitude of 6% at 25 years post‐restoration. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

15.
For 2 years, water flow‐patterns in the Garonne floodplain of south‐western France were studied in the field and through hydrodynamic modelling (MARTHE Hydrodynamic Software developed by BRGM). Water flow‐paths and the transport of dissolved elements between river and aquifer have been investigated and modelled. In order to quantify the buffer function of the alluvial floodplain, we focused our work on the effect of a major flood on the water flow‐direction, and on nitrate transport. Thus, we showed that the effect of a large flood in the river was rapidly lost with increasing distance from the river. During the observation period, a hydrologically active strip only 300 m wide on either side of the riverbed played a buffering role in absorbing the flood crest. It was also found that meanders favour the exchange between river and alluvial aquifer, shown by the creation of bypasses between the upstream and downstream parts of meanders. This, in turn, contributes to a dilution of nitrates in the phreatic aquifer, which here has higher nitrate content than the surface water; such dilution may result in an overestimation of the denitrification process in the wooded riverbanks. The coupling of chemical measurements—especially of chlorides and nitrate—with modelling of the dissolved‐element transport allows us to establish the water balance for the riparian wetland, and to separate the effect of dilution and denitrification on nitrate concentration. This indicated the existence of areas in the riparian wetlands where denitrification is particularly strong, leading to reductions in nitrate concentrations of 10 to 30 mg/l NO3? during the flood. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

16.
In the last few years, the scientific community has developed several hydrological models aimed at the simulation of hydrological processes acting at the basin scale. In this context, the portion of peak runoff contributing areas represents a critical variable for a correct estimate of surface runoff. Such areas are strongly influenced by the saturated portion of a river basin (influenced by antecedent conditions) but may also evolve during a specific rainfall event. In the recent years, we have developed 2 theoretically derived probability distributions that attempt to interpret these 2 processes adopting daily runoff and flood‐peak time series. The probability density functions (PDFs) obtained by these 2 schematisations were compared for humid river basins in southern Italy. Results highlighted that the PDFs of the peak runoff contributing areas can be interpreted by a gamma distribution and that the PDF of the relative saturated area provides a good interpretation of such process that can be used for flood prediction.  相似文献   

17.
The transition area between rivers and their adjacent riparian aquifers, which may comprise the hyporheic zone, hosts important biochemical reactions, which control water quality. The rates of these reactions and metabolic processes are temperature dependent. Yet the thermal dynamics of riparian aquifers, especially during flooding and dynamic groundwater flow conditions, has seldom been studied. Thus, we investigated heat transport in riparian aquifers during 3 flood events of different magnitudes at 2 sites along the same river. River and riparian aquifer temperature and water‐level data along the Lower Colorado River in Central Texas, USA, were monitored across 2‐dimensional vertical sections perpendicular to the bank. At the downstream site, preflood temperature penetration distance into the bank suggested that advective heat transport from lateral hyporheic exchange of river water into the riparian aquifer was occurring during relatively steady low‐flow river conditions. Although a small (20‐cm stage increase) dam‐controlled flood pulse had no observable influence on groundwater temperature, larger floods (40‐cm and >3‐m stage increases) caused lateral movement of distinct heat plumes away from the river during flood stage, which then retreated back towards the river after flood recession. These plumes result from advective heat transport caused by flood waters being forced into the riparian aquifer. These flood‐induced temperature responses were controlled by the size of the flood, river water temperature during the flood, and local factors at the study sites, such as topography and local ambient water table configuration. For the intermediate and large floods, the thermal disturbance in the riparian aquifer lasted days after flood waters receded. Large floods therefore have impacts on the temperature regime of riparian aquifers lasting long beyond the flood's timescale. These persistent thermal disturbances may have a significant impact on biochemical reaction rates, nutrient cycling, and ecological niches in the river corridor.  相似文献   

18.
Recognizing the underlying mechanisms of bank storage and return flow is important for understanding streamflow hydrographs. Analytical models have been widely used to estimate the impacts of bank storage, but are often based on assumptions of conditions that are rarely found in the field, such as vertical river banks and saturated flow. Numerical simulations of bank storage and return flow in river-aquifer cross sections with vertical and sloping banks were undertaken using a fully-coupled, surface-subsurface flow model. Sloping river banks were found to increase the bank infiltration rates by 98% and storage volume by 40% for a bank slope of 3.4° from horizontal, and for a slope of 8.5°, delay bank return flow by more than four times compared with vertical river banks and saturated flow. The results suggested that conventional analytical approximations cannot adequately be used to quantify bank storage when bank slope is less than 60° from horizontal. Additionally, in the unconfined aquifers modeled, the analytical solutions did not accurately model bank storage and return flow even in rivers with vertical banks due to a violation of the dupuit assumption. Bank storage and return flow were also modeled for more realistic cross sections and river hydrograph from the Fitzroy River, Western Australia, to indicate the importance of accurately modeling sloping river banks at a field scale. Following a single wet season flood event of 12 m, results showed that it may take over 3.5 years for 50% of the bank storage volume to return to the river.  相似文献   

19.
Data concerning grain-size distribution, mineralogy, geochemistry, and chlorinated hydrocarbon concentrations, obtained from 246 surface sediment samples collected in the Northern Adriatic sea (Italian area), provide the basis for a multivariate statistical analysis which evaluates the influence of riverine inputs, the differences among various depositional environments and the presence of polluted zones.Cluster analysis applied to grain size has identified nine groups of lithotypes associated with the morphology and the hydrology of the basin.In the Gulf of Venice, principal component analysis on clay minerals and carbonates has permitted recognition of two main areas located north and south of the Brenta river. More subareas correspond to other lithological types.Principal component analysis of nine metal (Hg, Cd, Cu, Pb, Cr, Zn, Fe, Ni, and Co) concentrations reveals that the studied sea area is more complex from the geochemical point of view. Three geochemical zones related to riverine inputs, different lithotypes and specific forms of contamination are identified. High pollution of both halocarbons and heavy metals is associated with fine grain size.  相似文献   

20.
Flood inundation models have been recognized to be a valuable tool to reproduce flow dynamics in a given area and support decision‐making processes on flood management measures. In many cases, in the simulation of flood events, only the main river channel and the associated structures are represented within the model. However, during flood events involving lowland areas, the minor drainage network – and the associated hydraulic structures – may have an important role in conveying flow and determining which areas will be flooded. The objective of this study is to investigate whether – and to what extent – small hydraulic structures in drainage networks have an influence in flooding on lowland areas. The case study for this research is the 1990 flood event which occurred in the lowland plain of the Reno River, in Northern Italy. The study area is mainly used for agricultural purposes and has a drainage system with several small bridges and culverts. The influence of the minor hydraulic structures on flood dynamics was analyzed through a combined use of one‐dimensional (1D) and two‐dimensional (2D) hydraulic models. First, a number of detailed and simplified approaches to represent hydraulic structures in the computational grids were analyzed by means of the HECRAS 1D model. Second, these approaches were implemented and tested in several 2D simulations of the flood event. The simulated inundation extents and flood levels were then compared with the observed data and with each other. The analysis of results showed that simplified schematizations were sufficient to obtain good model predictions of peak inundation extent and flood levels, at least for the present case study. Moreover, the influence of the structures on the peak flood inundation extent and flood levels was found to be limited, whereas it showed to be more significant during the drainage phase of the flood. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

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