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1.
Makkah city, Saudi Arabia, is periodically exposed to flash floods that result in major human and economical damages. That is due to several factors including its rugged topography and geological structures. Hence, precise assessment of floods becomes a more vital demand in development planning. A GIS-based methodology has been developed for quantifying and spatially mapping the flood characteristics. The core of this new approach is integrating several topographic, metrological, geological, and land use data sets in a geographic information system (GIS) environment that utilizes the curve number method of flood modelling for ungauged arid catchments. Based on the estimated flood volume of sub-basins, a hazard factor has been developed to quantify the expected hazard level for each road. Applying this proposed approach reveals that 21?% of the road network in Makkah city is subjected to low flood hazards, 29?% is facing medium hazards, and 50?% of roads are exposed to harsh flood impacts. The developed approach may be considered a digital precise method that can be easily re-run, in other situations or regions, to estimate flood hazards on roads.  相似文献   

2.
Systematic natural hazard mapping in Japan was started after WW II using aerial photographs. Analysing the interaction between disaster occurrence and land conditions is the most useful method for establishing the disaster prediction system for three types of disaster, flood disaster, mass-movement disaster, and earthquake disaster, which are strongly related to land conditions. A series of maps on natural hazards were established based on the results analysed. In our opinion, the following problems of natural hazard mappings remain so far unsolved:
  1. No clear distinction is made between natural hazard mapping and land classification.
  2. Organization of information for natural hazard prevention is not yet established.
  3. There is no established earthquake disaster prevention map.
  4. Utilization of new machines and tools is inadequate.
  5. Effect of human activity is not estimated.
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3.
开展1∶1万地质灾害易发区图编制工作,可为地质灾害防治规划、土地利用总体规划、地质灾害危险性评估、建设工程选址等提供可靠的资料,对做好地质灾害防治工作具有重要意义。本文以泰顺县为例,采用地质灾害综合危险性指数法划分地质灾害易发区,总结分析地质灾害易发程度分区评价的经验,为大比例尺易发区图编制作一些有益的探讨。  相似文献   

4.
Economic risk maps of floods and earthquakes for European regions   总被引:2,自引:0,他引:2  
Europe experiences different natural hazards and subsequent risks that have various effects on the development of its regions. The spatial significance of hazards can be expressed as an economic risk when combining hazard potential with vulnerability data. Two examples of European natural hazard maps on floods and earthquakes, as well as the resulting risk profiles of regions (combination of hazard potential and vulnerability) give a first impression on the spatial characters of hazards in Europe and their potential impact on further spatial development. The economic risk maps enable a view on the spatial dimension of the economic damage potential of flood and earthquakes, pointing out comparable situations across Europe with the aim to facilitate targeted responses and policies. The spatial character of a hazard is either defined by spatial effects that might occur in case of a disaster or by the possibility of spatial planning responses. The integration of the economic vulnerability of a region (regional GDP per capita, population density) leads to a classification of areas according to their economic risk or damage potential towards hazards. These synthetic risk profiles are presented as risk maps of European regions in administrative boundaries. Obtained information can be of interest for spatial planning and development strategies, e.g. economic risk profile of regions can influence the targets of investments and could thus be an important background for structural funding.  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.
Using detailed field mapping, an analysis of landslide risk has been undertaken in the flysch highlands of the Outer Western Carpathians. The standardized Czech methodology of expert derived susceptibility zonation widely used for land development planning purposes and deterministic modeling of shallow landslides was used to separately assess the susceptibility of different landslide types. The two susceptibility zonation maps were used to define landslide hazard using information about landslide reactivation and the return periods of precipitation that triggered the respective landslide types. A risk matrix was then used to qualitatively analyze the landslide risk to selected assets. The monetary value of these assets, according to actual market prices, was calculated and analyzed with respect to the risk classification. Since the study area is an important residential and recreational area, the practical application of the derived results was checked through a series of interviews conducted with personnel of the local government planning and construction office. This demonstrated a willingness to apply the landslide hazard maps as well as restraints of its successful application. The main one is the absence of legally binding regulations to enforce the spatial planers to use this information.  相似文献   

7.
Tsunamis are among the most destructive and lethal of coastal hazards. These are time-specific events, and despite directly affecting a narrow strip of coastline, a single occurrence can have devastating effects and cause massive loss of life, especially in urbanized coastal areas. In this work, in order to consider the time dependence of population exposure to tsunami threat, the variation of spatio-temporal population distribution in the daily cycle is mapped and analyzed in the Lisbon Metropolitan Area. High-resolution daytime and nighttime population distribution maps are developed using ‘intelligent dasymetric mapping,’ that is, applying areal interpolation to combine best-available census data and statistics with land use and land cover data. Workplace information and mobility statistics are considered for mapping daytime distribution. In combination with a tsunami hazard map, information on infrastructure, land use and terrain slope, the modeled population distribution is used to assess people’s evacuation speed, applying a geospatial evacuation modeling approach to the city of Lisbon. The detailed dynamic population exposure assessment allows producing both daytime and nighttime evacuation time maps, which provide valuable input for evacuation planning and management. Results show that a significant amount of population is at risk, and its numbers increase dramatically from nighttime to daytime, especially in the zones of high tsunami flooding susceptibility. Also, full evacuation can be problematic in the daytime period, even if initiated immediately after a major tsunami-triggering earthquake. The presented approach greatly improves tsunami risk assessment and can benefit all phases of the disaster management process.  相似文献   

8.
For risk analyses not only knowledge about the impact of different types of hazards, but also information about the elements and values at risk is necessary. This article introduces a methodology for a countrywide estimation of asset values for commercial and industrial properties using Germany as an example. It consists of a financial appraisal of asset values on the municipal level and a further disaggregation by means of land use data. Novelties are the distinction of 60 economic activities, the consideration of production site sizes and the application of a dasymetric mapping technique for a sector-specific estimation and disaggregation of asset values. A validation with empirical data confirms the feasibility of the calculation. The resulting maps can be used for loss estimations e.g. in the framework of cost–benefit analyses that aim to evaluate hazard mitigation measures or for portfolio analyses by banks and insurance companies. The approach can be used for other countries if the necessary data is available (mainly in industrialized countries). In any case, it reveals the critical points when estimating commercial and industrial asset values.  相似文献   

9.
The Yangtze River Delta region is an area highly vulnerable to flooding. As the population density is rising concomitantly with high economic growth, this region is becoming more vulnerable to natural hazards. We conducted a survey to investigate the individual risk perception of both the local authorities and the general community, analyze the current situation regarding risk management and identify problems in the current risk management scheme. Data were collected through questionnaires distributed to some members of the community and interviews with representatives of the local authorities. The primary findings are as follows: (1) risk and disaster multipliers perceived by lay people show the stigma effect of the Wenchuan earthquake; (2) the responses of college students illustrate that the stigma effect has less influence on people who have more knowledge about hazards; (3) differences exist in comparative groups (China and USA), which shows that the society and culture influence people’s perception of risk; and (4) economic activities have complicated flood risk management such as land shortage, ground subsidence and flood diversion. Accordingly, the following measures should be taken: (1) the government should improve the risk communication and education of lay people; (2) the government must also control unsuitable land use and balance economic development and risk management; (3) flood diversion areas should be compensated through special funds collected from other cities; and (4) local governments should provide more support for hazard mitigation.  相似文献   

10.
杨益国 《吉林地质》2006,25(1):82-84
文章详细地介绍了公路工程建设用地地质灾害危险性评估工作一些常见的基本工作方法,包括野外图件的选用,地质灾害危险性评估区范围的确定,各类地质灾害的测绘、描述、记录以及评估报告编写应注意的几个问题。  相似文献   

11.
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   

12.
Luino  F.  Belloni  A.  Turconi  L.  Faccini  F.  Mantovani  A.  Fassi  P.  Marincioni  F.  Caldiroli  G. 《Natural Hazards》2018,94(1):471-488

A project to develop a flood hazard management plan along the east shore of Lago Maggiore was carried out. Several municipal territories along a coastal stretch have been analysed, identifying the rate of water rise and the limits of the submerged areas. This study discusses the overall methodological approach and presents the results for Porto Valtravaglia, as a significant case study. The first step was a detailed analysis of historical events to locate the most frequently damaged sites. Thousands of historical documents on past floods were collected, selected and validated, to map the most vulnerable sites. The second step was a morphological analysis of the studied coastal stretch. Multi-temporal aerial snap-shots were used and field surveys were conducted to verify the reliability of the historical data and to identify the critical hydraulic conditions along the shore. The third step was a review of the general urban development plans of the 17 studied municipalities. Aerophotogrammetric and cadastral maps were used to evidence and define the eight classes of land use destinations. In addition, the floodable areas were divided into three vulnerability and exposure categories considering different peculiarities of social and working life. Finally, using GIS spatial analysis tools, these data were compiled into risk maps and wielded as the municipal emergency plans’ baseline scenarios. For each studied municipality was hypothesised the alarm thresholds upon which were activated the flood emergency procedures.

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13.
Microzonation is an effort to evaluate and map potential hazards found in an area, urban area in particular, that could be induced by strong ground shaking during an earthquake. These hazards include: ground motion amplification, liquefaction, and slope failure. The microzonation maps, depicting ground-motion amplification, liquefaction, and landslide potentials, can be produced if the ground motion on bedrock (input) and the site conditions are known. These maps, in combination with ground-motion hazard maps (on bedrock), can be used to develop a variety of hazard mitigation strategies such as seismic risk assessment, emergency response and preparedness, and land-use planning. However, these maps have certain limitations that result from the nature of regional mapping, data limitations, generalization, and computer modeling. These microzonations show that when strong ground shaking occurs, damage is more likely to occur, or be more severe, in the higher hazard areas. The zones shown on the hazard maps should not serve as a substitute for site-specific evaluations.  相似文献   

14.
Makkah City, west of the Kingdom of Saudi Arabia, is considered the third main highly populated metropolitan area in the Kingdom of Saudi Arabia. It exhibits two unique features that increase the hazardous flood consequences: (1) its topography is very complex and (2) about three million Muslims are gathered annually in Makkah to perform Hajj over a 2-week period. Floods are natural returning hydrological phenomena that have been affecting human lives. The objectives of the current study are: (1) identification of land use types and road networks in Makkah, (2) hydrological modeling of flood characteristics in Makkah based on precise up-to-date databases, (3) examination of the relationship between land use, land cover changes, transportation network expansion, and the floods' prosperities and hazards, and (4) development of digital hydrological maps for present and near future flood hazards in Makkah. The attained results show that the mean runoff depth and the total flood volume are significantly increased from 2010 to 2030. Additionally, it has been found that a great part of the road network in Makkah City is subjected to high dangerous flood impacts. The overall length of flood danger-factor roads is increased from 481 km (with almost 37 %) to 1,398 km (with 74 % approximately) between 2010 and 2030. Thus, it is concluded that urbanization has a direct strong relationship with flood hazards. Consequently, it is recommended that the attained results should be taken into account by decision makers in implementing new development planning of the Makkah metropolitan area.  相似文献   

15.
Japanese local governments consist of about 3,380 municipalities in 2000. The total survey undertaken in 1997 says that GIS was implemented in 455 (14.3%) out of 3,182 municipalities that answered to the survey. This paper considers GIS utilization, especially focusing on urban planning and management in Japanese local government. Typical GIS applications in the urban planning and management are divided into three businesses: inquiry on the content of urban plan decision, register management, and planning. The most successful GIS application in the local government is an inquiry system on the content of urban plan decision. ‘Mappy’, Urban Plan Information Inquiry System developed by Yokohama City, is introduced as an example. The register management treats the registers for urban planned road, urban park, and urban open space, and the receipt book for development permission application. GIS can systematize their management based on maps. District diagnosis system using GIS performed two analyses in Ichikawa City. One is the calculation of area and ratio for land-use. The other is the measurement of land-use purity. GIS can calculate the degree of purity (namely occupancy rate) of specified land-use in the land-use zoning system. Most of Japanese local governments implement GIS and obtain moderate results. However, it is reported that some municipalities that paid huge amount of budget to implement GIS hardly used them. The final section will consider various issues in the use of administrative GIS. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
Flooding in urban area is a major natural hazard causing loss of life and damage to property and infrastructure. The major causes of urban floods include increase in precipitation due to climate change effect, drastic change in land use–land cover (LULC) and related hydrological impacts. In this study, the change in LULC between the years 1966 and 2009 is estimated from the toposheets and satellite images for the catchment of Poisar River in Mumbai, India. The delineated catchment area of the Poisar River is 20.19 km2. For the study area, there is an increase in built-up area from 16.64 to 44.08% and reduction in open space from 43.09 to 7.38% with reference to total catchment area between the years 1966 and 2009. For the flood assessment, an integrated approach of Hydrological Engineering Centre-Hydrological Modeling System (HEC-HMS), HEC-GeoHMS and HEC-River analysis system (HEC-RAS) with HEC-GeoRAS has been used. These models are integrated with geographic information system (GIS) and remote sensing data to develop a regional model for the estimation of flood plain extent and flood hazard analysis. The impact of LULC change and effects of detention ponds on surface runoff as well as flood plain extent for different return periods have been analyzed, and flood plain maps are developed. From the analysis, it is observed that there is an increase in peak discharge from 2.6 to 20.9% for LULC change between the years 1966 and 2009 for the return periods of 200, 100, 50, 25, 10 and 2 years. For the LULC of year 2009, there is a decrease in peak discharge from 10.7% for 2-year return period to 34.5% for 200-year return period due to provision of detention ponds. There is also an increase in flood plain extent from 14.22 to 42.5% for return periods of 10, 25, 50 and 100 years for LULC change between the year 1966 and year 2009. There is decrease in flood extent from 4.5% for 25-year return period to 7.7% for 100-year return period and decrease in total flood hazard area by 14.9% due to provisions of detention pond for LULC of year 2009. The results indicate that for low return period rainfall events, the hydrological impacts are higher due to geographic characteristics of the region. The provision of detention ponds reduces the peak discharge as well as the extent of the flooded area, flood depth and flood hazard considerably. The flood plain maps and flood hazard maps generated in this study can be used by the Municipal Corporation for flood disaster and mitigation planning. The integration of available software models with GIS and remote sensing proves to be very effective for flood disaster and mitigation management planning and measures.  相似文献   

17.
Landslides are one of the most frequent and common natural hazards in many parts of Himalaya. To reduce the potential risk, the landslide susceptibility maps are one of the first and most important steps in the landslide hazard mitigation. Earth observation satellite and geographical information system-based techniques have been used to derive and analyse various geo-environmental parameters significant to landslide hazards. In this study, a bivariate statistics method was used for spatial modelling of landslide susceptibility zones. For this purpose, thematic layers including landslide inventory, geology, slope angle, slope aspect, geomorphology, slope morphology, drainage density, lineament and land use/land cover were used. A large number of landslide occurrences have been observed in the upper Tons river valley area of Western Himalaya. The result has been used to spatially classify the study area into zones of very high, high, moderate, low and very low landslide susceptibility zones. About 72% of active landslides have been observed to occur in very high and high hazard zones. The result of the analysis was verified using the landslide location data. The validation result shows significant agreement between the susceptibility map and landslide location. The result can be used to reduce landslide hazards by proper planning.  相似文献   

18.
This paper presents a method for transforming the information of an engineering geological map into useful information for non-specialists involved in land-use planning. The method consists of classifying the engineering geological units in terms of land use capability and identifying the legal and the geologic restrictions that apply in the study area. Both informations are then superimposed over the land use and a conflict areas map is created. The analysis of these data leads to the identification of existing and forthcoming land use conflicts and enables the proposal of planning measures on a regional and local scale. The map for the regional planning was compiled at a 1:50,000 scale and encompasses the whole municipal land area where uses are mainly rural. The map for the local planning was compiled at a 1:10,000 scale and encompasses the urban area. Most of the classification and operations on maps used spatial analyst tools available in the Geographical Information System. The regional studies showed that the greater part of Analandia’s territory presents appropriate land uses. The local-scale studies indicate that the majority of the densely occupied urban areas are in suitable land. Although the situation is in general positive, municipal policies should address the identified and expected land use conflicts, so that it can be further improved.  相似文献   

19.
Bangladesh is one of the most natural hazard-prone countries in the world with the greatest negative consequences being associated with cyclones, devastating floods, riverbank erosion, drought, earthquake, and arsenic contamination, etc. One way or other, these natural hazards engulfed every corner of Bangladesh. The main aim of this research paper is to carry out a multi-hazards risk and vulnerability assessment for the coastal Matlab municipality in Bangladesh and to recommend possible mitigation measures. To this aim, hazards are prioritized by integrating SMUG and FEMA models, and a participation process is implemented so as to involve community both in the risk assessment and in the identification of adaptation strategies. The Matlab municipality is highly vulnerable to several natural hazards such as cyclones, floods, and riverbank erosion. The SMUG is a qualitative assessment, while FEMA is a quantitative assessment of hazards. The FEMA model suggests a threshold of highest 100 points. All hazards that total more than 100 points may receive higher priority in emergency preparedness and mitigation measures. The FEMA model, because it judges each hazard individually in a numerical manner, may provide more satisfying results than the SMUG system. The spatial distributions of hazard, risk, social institutions, land use, and other resources indicate that the flood disaster is the top environmental problem of Matlab municipality. Hazard-specific probable mitigation measures are recommended with the discussion of local community. Finally, this study tries to provide insights into the way field research combining scientific assessments tools such as SMUG and FEMA could feed evidence-based decision-making processes for mitigation in vulnerable communities.  相似文献   

20.
Natural hazards in Central Java Province,Indonesia: an overview   总被引:2,自引:0,他引:2  
Central Java Province, Indonesia, suffers from natural hazard processes such as land subsidence, coastal inundation, flood, volcanic eruption, earthquake, tsunami, and landslide. The occurrence of each kind of natural hazard is varied according to the intensity of geo-processes. It is necessary to learn from the historical record of coastal inundation, flood, volcanic eruption, earthquake, tsunami, and landslide hazards in Central Java Province to address issues of comprehensive hazard mitigation and management action. Through the understanding about the nature and spatial distribution of natural hazards, treatments can be done to reduce the risks. This paper presents the natural hazard phenomena in Central Java Province and provides critical information for hazard mitigation and reduction.  相似文献   

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