首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
This work focuses on the exploitation of very high-resolution (VHR) satellite imagery coupled with multi-criteria analysis (MCA) to produce flood hazard maps. The methodology was tested over a portion of the Yialias river watershed basin (Nicosia, Cyprus). The MCA methodology was performed selecting five flood-conditioning factors: slope, distance to channels, drainage texture, geology and land cover. Among MCA methods, the analytic hierarchy process technique was chosen to derive the weight of each criterion in the computation of the flood hazard index (FHI). The required information layers were obtained by processing a VHR GeoEye-1 image and a digital elevation model. The satellite image was classified using an object-based technique to extract land use/cover data, while GIS geoprocessing of the DEM provided slope, stream network and drainage texture data. Using the FHI, the study area was finally classified into seven hazard categories ranging from very low to very high in order to generate an easily readable map. The hazard seems to be severe, in particular, in some urban areas, where extensive anthropogenic interventions can be observed. This work confirms the benefits of using remote sensing data coupled with MCA approach to provide fast and cost-effective information concerning the hazard assessment, especially when reliable data are not available.  相似文献   

2.
Flash floods are considered to be one of the worst weather-related natural disasters. They are dangerous because they are sudden and are highly unpredictable following brief spells of heavy rain. Several qualitative methods exist in the literature for the estimations of the risk level of flash flood hazard within a watershed. This paper presents the utilization of remote sensing data such as enhanced Thematic Mapper Plus (ETM+), Shuttle Radar Topography Mission (SRTM), coupled with geological, geomorphological, and field data in a GIS environment for the estimation of the flash flood risk along the Feiran–Katherine road, southern Sinai, Egypt. This road is a vital corridor for the tourists visiting here for religious purposes (St. Katherine monastery) and is subjected to frequent flash floods, causing heavy damage to man-made features. In this paper, morphometric analyses have been used to estimate the flash flood risk levels of sub-watersheds within the Wadi Feiran basin. First, drainage characteristics are captured by a set of parameters relevant to the flash flood risk. Further, comparison between the effectiveness of the sub-basins has been performed in order to understand the active ones. A detailed geomorphological map for the most hazardous sub-basins is presented. In addition, a map identifying sensitive sections is constructed for the Feiran–Katherine road. Finally, the most influenced factors for both flash flood hazard and critical sensitive zones have been discussed. The results of this study can initiate appropriate measures to mitigate the probable hazards in the area.  相似文献   

3.
Floods are regular feature in rapidly urbanizing Dhaka, the capital city of Bangladesh. It is observed that about 60% of the eastern Dhaka regularly goes under water every year in monsoon due to lack of flood protection. Experience gathered from past devastating floods shows that, besides structural approach, non-structural approach such as flood hazard map and risk map is effective tools for reducing flood damages. In this paper, assessment of flood hazard by developing a flood hazard map for mid-eastern Dhaka (37.16 km2) was carried out by 1D hydrodynamic simulation on the basis of digital elevation model (DEM) data from Shuttle Radar Topography Mission and the hydrologic field-observed data for 32 years (1972–2004). As the topography of the area has been considerably changed due to rapid land-filling by land developers which was observed in recent satellite image (DigitalGlobe image; Date of imagery: 7th March 2007), the acquired DEM data were modified to represent the current topography. The inundation simulation was conducted using hydrodynamic program HEC-RAS for flood of 100-year return period. The simulation has revealed that the maximum depth is 7.55 m at the southeastern part of that area and affected area is more than 50%. A flood hazard map was prepared according to the simulation result using the software ArcGIS. Finally, to assess the flood risk of that area, a risk map was prepared where risk was defined as the product of hazard (i.e., depth of inundation) and vulnerability (i.e., the exposure of people or assets to flood). These two maps should be helpful in raising awareness of inhabitants and in assigning priority for land development and for emergency preparedness including aid and relief operations in high-risk areas in the future.  相似文献   

4.
Probabilistic landslide hazards and risk mapping on Penang Island, Malaysia   总被引:15,自引:0,他引:15  
This paper deals with landslide hazards and risk analysis of Penang Island, Malaysia using Geographic Information System (GIS) and remote sensing data. Landslide locations in the study area were identified from interpretations of aerial photographs and field surveys. Topographical/geological data and satellite images were collected and processed using GIS and image processing tools. There are ten landslide inducing parameters which are considered for landslide hazard analysis. These parameters are topographic slope, aspect, curvature and distance from drainage, all derived from the topographic database; geology and distance from lineament, derived from the geologic database; landuse from Landsat satellite images; soil from the soil database; precipitation amount, derived from the rainfall database; and the vegetation index value from SPOT satellite images. Landslide susceptibility was analyzed using landslide-occurrence factors employing the probability-frequency ratio model. The results of the analysis were verified using the landslide location data and compared with the probabilistic model. The accuracy observed was 80.03%. The qualitative landslide hazard analysis was carried out using the frequency ratio model through the map overlay analysis in GIS environment. The accuracy of hazard map was 86.41%. Further, risk analysis was done by studying the landslide hazard map and damageable objects at risk. This information could be used to estimate the risk to population, property and existing infrastructure like transportation network.  相似文献   

5.
The production of flood hazard assessment maps is an important component of flood risk assessment. This study analyses flood hazard using flood mark data. The chosen case study is the 2013 flood event in Quang Nam, Vietnam. The impacts of this event included 17 deaths, 230 injuries, 91,739 flooded properties, 11,530 ha of submerged and damaged agricultural land, 85,080 animals killed and widespread damage to roads, canals, dykes and embankments. The flood mark data include flood depth and flood duration. Analytic hierarchy process method is used to assess the criteria and sub-criteria of the flood hazard. The weights of criteria and sub-criteria are generated based on the judgements of decision-makers using this method. This assessment is combined into a single map using weighted linear combination, integrated with GIS to produce a flood hazard map. Previous research has usually not considered flood duration in flood hazard assessment maps. This factor has a rather strong influence on the livelihood of local communities in Quang Nam, with most agricultural land within the floodplain. A more comprehensive flood hazard assessment mapping process, with the additional consideration of flood duration, can make a significant contribution to flood risk management activities in Vietnam.  相似文献   

6.
The study proposes an original methodology for producing probability-weighted hazard maps based on an ensemble of numerical simulations. These maps enable one to compare different strategies for flood risk management. The methodology was applied over a 270-km2 flood-prone area close to the left levee system of a 28-km reach of the river Reno (Northern Central Italy). This reach is characterised by the presence of a weir that allows controlled flooding of a large flood-prone area during major events. The proposed probability-weighted hazard maps can be used to evaluate how a structural measure such as the mentioned weir alters the spatial variability of flood hazard in the study area. This article shows an application by constructing two different flood hazard maps: a first one which neglects the presence of the weir using a regular levee system instead, and a second one that reflects the actual geometry with the weir. Flood hazard maps were generated by combining the results of several inundation scenarios, simulated by coupling 1D- and 2D-hydrodynamic models.  相似文献   

7.
Geomorphological zoning for flood inundation using satellite data   总被引:3,自引:0,他引:3  
The authors investigated geomorphological features on the central plain of Thailand utilizing satellite remote sensing data and made geomorphological land classification map showing flood-stricken area. Land classification maps showing flood-striken area tell us former flood inundation area, such as inundation depth, inundation width, flood flow course and flood direction, as well as estimating of the features of flooding. Thus map is useful for planning of flood control works.We classified land form units in the central plain of Thailand as following; delta, tidal flat, lagoon, mud spit, back marsh, natural levee, fan and former river course and so on. After that, the principal component analysis is applied to Landsat TM data and gives good results for photo interpretation of land form units and we transfer geomorphological land classification map to make zoning map of flood risk for the purpose of evaluating the flood damages.  相似文献   

8.
绘制直观与可靠的城市洪涝灾害风险区划图,为城市防洪排涝相关部门决策提供参考依据。以广州市东濠涌流域为研究区域,综合考虑城市降雨、径流、地形和排水系统特性,构建基于InfoWorks ICM的一维-二维耦合城市洪涝仿真模型,模拟暴雨重现期为1年、5年、50年情景下的洪涝过程并获取致灾因子数据。调研分析区域的孕灾环境、承灾体和防灾减灾能力概况,结合层次分析法、评价等级和阈值划分等进行洪涝灾害风险评估。结果表明:城市洪涝仿真模型在一维排水系统和二维地面淹没模拟上均有较好的精度和可靠性,保证了致灾因子数据的可靠性;风险区划图能较好地反映流域的风险分布;随着重现期增大,较高、高风险区的面积显著增加,为防洪排涝重点关注区域。  相似文献   

9.
Hydrogeomorphic methods for the regional evaluation of flood hazards   总被引:1,自引:0,他引:1  
The “upstream” approach to flood hazard evaluation involves the estimation of hydrologic response in small drainage basins. This study demonstrates the application of geomorphology to such studies in a region of unusually intense flooding in central Texas. One approach to flood hazard evaluation in this area is a parametric model relating flood hydrograph characteristics to quantitative geomorphic properties of the drainage basins. A preliminary model uses multiple regression techniques to predict potential peak flood discharge from basin magnitude, drainage density, and ruggedness number. After mapping small catchment networks (4 to 20 km2) from remote sensing imagery, input data for the model are generated by network digitization and analysis by a computer-assisted routine of watershed analysis. The study evaluated the network resolution capabilities of the following data formats: (1) large-scale (1:24,000) topographic maps, employing Strahler's “method of v's”, (2) low altitude black-and-white aerial photography (1:13,000 and 1:20,000 scales), (3) NASA-generated aerial infrared photography at scales ranging from 1:48,000 to 1:123,000, and (4) Skylab Earth Resources Experiment Package S-190A and S-190B sensors (1:750,000 and 1:500,000 respectively). Measured as the number of first order streams or as the total channel length identified in small drainage areas, resolution is strongly dependent on basin relief. High-density basins on the Edwards Plateau were poorly depicted on orbital imagery. However, the orbital network definition of low-relief basins on the inner Texas Coastal Plain is nearly as accurate as results from large-scale topographic maps. Geomorphic methods are also useful for flood hazard zonation in “downstream” flood plain areas. Studies of the Colorado River valley near Austin, Texas, easily distinguished infrequent (100- to 500-year recurrence interval), intermediate (10- to 30-year), and frequent (1- to 4-year) hazard zones. These mapping techniques are especially applicable to the rapid regional evaluation of flood hazards in areas for which there is a lack of time and money to generate more accurate engineering-hydraulic flood hazard maps.  相似文献   

10.
Existing methods of evaluating the hazard posed by moraine-dammed lakes are unsystematic, subjective, and depend on the expertise and biases of the geoscientist. In this paper, we provide a framework for making objective preliminary assessments of outburst flood hazard in southwestern British Columbia. Our procedure relies on remote sensing methods and requires only limited knowledge of glacial processes so that evaluations of outburst flood hazard can be incorporated into routine hazard assessments of glaciated regions. We describe objective approaches, which incorporate existing empirical relations applicable to the study region, for estimating outburst peak discharge, maximum volume, maximum travel distance, maximum area of inundation, and probability. Outburst flood hazard is greatest for moderately large lakes that are impounded by large, narrow, ice-free moraine dams composed of sedimentary rock debris and drain into steep, sediment-filled gullies above major river valleys. We demonstrate the application of the procedure using three case studies and show that flood hazard varies, especially with major changes in lake level. Our assessment scheme yields reproducible results and enables engineers and geoscientists to prioritize potentially hazardous lakes for more detailed field investigation.  相似文献   

11.
This paper presents a methodology for developing a landslide hazard zonation map by integration of global positioning system (GPS), geographic information system (GIS), and remote sensing (RS) for Western Himalayan Kaghan Valley of Pakistan. The landslides in the study area have been located and mapped by using GPS. Eleven causative factors such as landuse, elevation, geology, rainfall intensity, slope inclination, soil, slope aspect, distances from main road, distances from secondary roads, and distances from main river and those from trunk streams were analyzed for occurrence of landslides. These factors were used with a modified form of pixel-based information value model to obtain landslide hazard zones. The matrix analysis was performed in remote sensing to produce a landslide hazard zonation map. The causative factors with the highest effect of landslide occurrence were landuse, rainfall intensity, distances from main road, distances from secondary roads, and distances from main river and those from trunk streams. In conclusion, we found that landslide occurrence was only in moderate, high, or very high hazard zones, and no landslides were in low or very low hazard zones showing 100% accuracy of our results. The landslide hazard zonation map showed that the current main road of the valley was in the zones of high or very high hazard. Two new safe road routes were suggested by using the GIS technology.  相似文献   

12.
Debris flows, debris floods and floods in mountainous areas are responsible for loss of life and damage to infrastructure, making it important to recognize these hazards in the early stage of planning land developments. Detailed terrain information is seldom available and basic watershed morphometrics must be used for hazard identification. An existing model uses watershed area and relief (the Melton ratio) to differentiate watersheds prone to flooding from those subject to debris flows and debris floods. However, the hazards related to debris flows and debris floods are not the same, requiring further differentiation. Here, we demonstrate that a model using watershed length combined with the Melton ratio can be used to differentiate debris-flow and debris-flood prone watersheds. This model was tested on 65 alluvial and colluvial fans in west central British Columbia, Canada, that were examined in the field. The model correctly identified 92% of the debris-flow, 83% of the debris-flood, and 88% of the flood watersheds. With adaptation for different regional conditions, the use of basic watershed morphometrics could assist land managers, scientists, and engineers with the identification of hydrogeomorphic hazards on fans elsewhere.  相似文献   

13.
Flood hazard evaluation is an important input for Nuclear Power Plants external events safety studies. In the present study, flood hazard at various nuclear sites in India due to rainfall has been evaluated. Hazard estimation is a statistical procedure by which rainfall intensity versus occurrence frequency is estimated from historical records of rainfall data and extrapolated with asymptotic extreme value distribution. Rainfall data needed for flood hazard assessment are daily annual maximum rainfall (24?h data). The observed data points have been fitted using Gumbel, power law and exponential distribution, and return period has been estimated. To study the stationarity of rainfall data, a moving window estimate of the parameters has been performed. The rainfall pattern is stationary in both coastal and inland regions over the period of observation. The coastal regions show intense rainfall and higher variability than inland regions. Based on the plant layout, catchment area and drainage capacity, the prototype fast breeder reactor (PFBR) site is unlikely to be flooded.  相似文献   

14.
An attempt to carry out morphometric, statistical, and hazard analyses using ASTER data and GIS technique of Wadi El-Mathula watershed, Central Eastern Desert, Egypt. Morphometric analysis with application of GIS technique is essential to delineate drainage networks; basin geometry, drainage texture, and relief characteristics, through detect forty morphometric parameters of the study watershed and its sub-basins. Extract new drainage network map with DEM, sub-basin boundaries, stream orders, drainage networks, slope, drainage density, flow direction maps with more details is very necessary to analyze different morphometric and hydrologic applications for the study basin. Statistical analysis of morphometric parameters was done through cluster analysis, regression equations, and correlation coefficient matrix. Clusters analyses detect three independents variables which are stream number, basin area, and stream length have a very low linkage distance of 0.001 (at very high similarity of 99.95%) in a cluster with the basin width. Main channel length and basin perimeter (at very high similarity of 99.83%) are in a cluster with basin length. Using the regression equations and graphical correlation matrix indicates the mathematical relationships and helps to predict the behavior between any two variables. Hazard analysis and hazard degree assessment for each sub-basin were performed. The hazardous factors were detected and concluded that most of sub-basins are classified as moderately to highly hazardous. Finally, we recommended that the flood possibilities should be taken in consideration during future development of these areas.  相似文献   

15.
对地观测卫星遥感能够提供广泛可靠的空间信息,是洪水风险识别与动态模拟的重要支撑技术之一。为阐明卫星遥感技术对洪水研究的推动作用,回顾了洪水风险识别与动态模拟研究的发展历程及技术需求,以对地观测卫星遥感三大阶段的发展轨迹为主线,分析了遥感空间信息在洪水研究中的历史性贡献和阶段性效用,讨论总结了危险分区法、水文模型和微波遥感监测等3种洪水研究典型方法的应用进展。提出未来洪水风险识别与动态模拟研究的重点:遥感空间信息与模型算法的深度结合,遥感反演算法与系统的开发及应用,典型洪水研究方法集成系统的开发与应用,大数据方法与手段的应用。以期为提升洪水应急响应能力与灾害风险管理水平提供有效参考。  相似文献   

16.
对地观测卫星遥感能够提供广泛可靠的空间信息,是洪水风险识别与动态模拟的重要支撑技术之一。为阐明卫星遥感技术对洪水研究的推动作用,回顾了洪水风险识别与动态模拟研究的发展历程及技术需求,以对地观测卫星遥感三大阶段的发展轨迹为主线,分析了遥感空间信息在洪水研究中的历史性贡献和阶段性效用,讨论总结了危险分区法、水文模型和微波遥感监测等3种洪水研究典型方法的应用进展。提出未来洪水风险识别与动态模拟研究的重点:遥感空间信息与模型算法的深度结合,遥感反演算法与系统的开发及应用,典型洪水研究方法集成系统的开发与应用,大数据方法与手段的应用。以期为提升洪水应急响应能力与灾害风险管理水平提供有效参考。  相似文献   

17.
Application of geographic information systems and remote sensing are a powerful tool for the assessment of risk and management of flood hazards. By using these techniques to extract new drainage network with more details to prepare natural hazard maps which may help decision makers and planners to put suitable solutions reducing the impact of these hazards. Ras Sudr city and surrounding area had been attacked by flash floods of Wadi Sudr and Wadi Wardan which are nearly perpendicular to the eastern side of the Gulf of Suez, Egypt, and many infrastructures had destroyed. GIS techniques and remote sensing are used to find the interrelation between the morphometric parameters by using statistical correlation to determine the area under varying flood conditions. The results of morphometric parameters and the new data of last flood which occurred on 17-18th January 2010 indicate that the two basins are threatened by the risk of flash floods and Wadi Wardan is more risky than Wadi Sudr.  相似文献   

18.
Lixin  Yi  Ke  Cheng  Xiaoying  Cao  Yueling  Sun  Xiaoqing  Cheng  Ye  He 《Natural Hazards》2017,85(2):1223-1248

Flood management consists many aspects such as hazard assessment, vulnerability assessment, exposure assessment, risk assessment, early warning system, damage assessment as well as risk mitigation planning. Conventional flood management are depending on the ground based monitoring of rainfall and river discharge. Many parts of the world are not covered by these sensor networks in one hand and these ground based systems are costly. Most of the tropical countries have high flood risk and low financial and institutional capacity to afford ground based system. While conventional flood management is time and cost intensive, spaceborne remote sensing provides timely and low-cost data in comparison to field observation, and is the obvious choice for most developing countries affected by flooding. Many aspects of flood management are being aided with the advancement of remote sensing technology. More precise and near real time flood detection, lead time in flood early warning system, accurate and advance inputs of hydrological models are now blessed by space technology. Many methods and approaches have been developed to overcome the constrains in the application of spaceborne remote sensing in flood management. Application of satellite remote sensing in flood hazard assessment is well documented, however, the application of space technology in other aspects of the flood management is also promising. Therefore, this review paper focuses on the applicability of spaceborne remote sensing and in most of the aspects in flood management.

  相似文献   

19.
用光学遥感数据和地理信息系统(GIS)分析了马来西亚Selangor地区的滑坡灾害。通过遥感图像解译和野外调查,在研究区内确定出滑坡发生区。通过GIS和图像处理,建立了一个集地形、地质和遥感图像等多种信息的空间数据库。滑坡发生的因素主要为:地形坡度、地形方位、地形曲率及与排水设备距离;岩性及与线性构造距离;TM图像解译得到的植被覆盖情况;Landsat图像解译得到的植被指数;降水量。通过建立人工神经网络模型对这些因素进行分析后得到滑坡灾害图:由反向传播训练方法确定每个因素的权重值,然后用该权重值计算出滑坡灾害指数,最后用GIS工具生成滑坡灾害图。用遥感解译和野外观测确定出的滑坡位置资料验证了滑坡灾害图,准确率为82.92%。结果表明推测的滑坡灾害图与滑坡实际发生区域足够吻合。  相似文献   

20.
Flooding is one of the most destructive natural hazards that cause damage to both life and property every year, and therefore the development of flood model to determine inundation area in watersheds is important for decision makers. In recent years, data mining approaches such as artificial neural network (ANN) techniques are being increasingly used for flood modeling. Previously, this ANN method was frequently used for hydrological and flood modeling by taking rainfall as input and runoff data as output, usually without taking into consideration of other flood causative factors. The specific objective of this study is to develop a flood model using various flood causative factors using ANN techniques and geographic information system (GIS) to modeling and simulate flood-prone areas in the southern part of Peninsular Malaysia. The ANN model for this study was developed in MATLAB using seven flood causative factors. Relevant thematic layers (including rainfall, slope, elevation, flow accumulation, soil, land use, and geology) are generated using GIS, remote sensing data, and field surveys. In the context of objective weight assignments, the ANN is used to directly produce water levels and then the flood map is constructed in GIS. To measure the performance of the model, four criteria performances, including a coefficient of determination (R 2), the sum squared error, the mean square error, and the root mean square error are used. The verification results showed satisfactory agreement between the predicted and the real hydrological records. The results of this study could be used to help local and national government plan for the future and develop appropriate (to the local environmental conditions) new infrastructure to protect the lives and property of the people of Johor.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号