Relationship between Regional Rainstorm Index and Flood Disaster Ratio of Crop

According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the determination method of extreme climate event index recommended by IPCC. Based on rainstorm weather index,rainstorm climate index and national rainstorm standard,the number of rainstorm days and rainfall amount in past years were calculated,and the correlation of annual number of rainy days,rainstorm days,precipitation and rainstorm amount with the flood disaster ratio of crop was analyzed,and the results showed that annual number of rainy days and rainstorm days couldn＇t reflect flood disaster ratio of crop truly,while annual precipitation and rainstorm amount had obvious linear positive correlation with the flood disaster ratio of crop. In addition,the correlation degree between rainstorm amount calculated by regional climate index and flood disaster ratio of crop was the highest,so it was suggested that rainstorm amount calculated by regional rainstorm climate index could be used to predict and evaluate flood disaster.

Risk assessment of coastal flooding disaster by storm surge based on Elevation-Area method and hydrodynamic models:Taking Bohai Bay as an example

The future inundation by storm surge on coastal areas are currently ill-defined.With increasing global sealevel due to climate change,the coastal flooding by storm surge is more and more frequently,especially in coastal lowland with land subsidence.Therefore,the risk assessment of such inundation for these areas is of great significance for the sustainable socio-economic development.In this paper,the authors use Elevation-Area method and Regional Ocean Model System(ROMS)model to assess the risk of the inundation of Bohai Bay by storm surge.The simulation results of Elevation-Area method show that either a 50-year or 100-year storm surge can inundate coastal areas exceeding 8000 km^(2);the numerical simulation results based on hydrodynamics,considering ground friction and duration of the storm surge high water,show that a 50-year or 100-year storm surge can only inundate an area of over 2000 km^(2),which is far less than 8000 km^(2);while,when taking into account the land subsidence and sea level rise,the very inundation range will rapidly increase by 2050 and 2100.The storm surge will greatly impact the coastal area within about 10-30 km of the Bohai Bay,in where almost all major coastal projects are located.The prompt response to flood disaster due to storm surge is urgently needed,for which five suggestions have been proposed based on the geological background of Bohai Bay.This study may offer insight into the development of the response and adaptive plans for flooding disasters caused by storm surge.

A catastrophic natural disaster chain of typhoon-rainstorm-landslide-barrier lake-flooding in Zhejiang Province, China

On August 10,2019,due to the effect of a rainstorm caused by Super Typhoon Lekima,a landslide occurred in Shanzao Village,China.It blocked the Shanzao stream,forming a barrier lake,and then the barrier lake burst.This is a rare natural disaster chain of typhoon-rainstorm-landslide-barrier lake-flooding.This study was built on field surveys,satellite image interpretation,the digital elevation model(DEM),engineering geological analysis and empirical regression.The purpose was to reveal the characteristics and causes of the landslide,the features and formation process of the barrier lake and the dam break flooding discharge.The results show that the volume of the landslide deposit is approximately 2.4×105 m3.The burst mode of the landslide dam is overtopping,which took only 22 minutes from the formation of the landslide dam to its overtopping.The dam-break peak flow was 1353 m3/s,and the average velocity was 2.8–3.0 m/s.This study shows that the strongly weathered rock and soil slope has low strength and high permeability under the condition of heavy rainfall,which reminds us the high risk of landslides and the importance of accurate early warning of landslides under heavy rainfalls in densely populated areas of Southeast China,as well as the severity of the disaster chain of typhoon-rainstorm-landslide-barrier lake-flooding.

Damage of Flood-causing Rainstorm to Towns in Zhumadian City and Its Countermeasures for Disaster Reduction

Based on meteorological data of Zhumadian City in the past 56 years, the damage of flood-causing rainstorm to towns in Zhumadian City as well as its cataclysm form, influencing system, cataclysm characteristics and action mechanism were analyzed to discuss the characteristics and rules of damage caused by flood-causing rainstorm. Meanwhile, countermeasures against flood-causing rainstorm cataclysm in Zhumadian City were proposed to provide scientific references for early warning and monitoring of flood-causing rainstorm as well as flood control and disaster mitigation.

Characteristics of Rainstorm and Flood Disaster in Shaoyang City and Flood Protection Countermeasures

Based on ground meteorological observation data at 10 representative stations of Shaoyang City during 1951-2017 and rainfall data at over 220 automatic weather stations during 2005-2017,statistical analysis on rainstorm and flood disaster in Shaoyang was conducted. Occurrence characteristics and rule of rainstorm and flood disaster were found,and disaster situation was evaluated and analyzed. The results showed that（ 1）there was almost local rainstorm and flood in Shaoyang City every year,with strong seasonal characteristic.（ 2） The loss caused by rainstorm and flood disaster was the most serious in various meteorological disasters.（ 3） Rainstorm and flood disaster generally had the sudden and devastating characteristics. Via the analysis and research on rainstorm and flood disaster,defense measure and countermeasure of rainstorm and flood were proposed,which could provide scientific decision basis for party and government leading flood relief,and had important guidance significance for preventing and mitigating disasters by government agencies.

Analysis and Zoning of Rainstorm Flood Disaster Risk in Huaihe River Basin

Taking the rainstorm flood disaster of Huaihe River basin as the research object,according to the principles of risk assessment for natural disasters,starting from the fatalness of inducing factors and the vulnerability of hazard bearing body,the weight of each impact factor was calculated by using AHP. By using spatial analysis and statistical function of GIS,the integrated risk chart of rainstorm flood disaster in Huaihe River basin was obtained. The results showed that the high risk areas of rainstorm flood disaster in Huaihe River basin mainly distributed in the southern part of Henan,the central northern part of Anhui and eastern part of Jiangsu Province. Due to higher fatalness of inducing factors in southern Henan,there was high risk in the region. Central Anhui and east Jiangsu were not only high-fatalness zones but also high vulnerability zones of population and economy.

Research on Model of Flood Disaster's Monitoring and Its Application Based on DEM

In order to assess the flood damage rapidly and accurately,this paper proposed a practical method of flood disaster monitoring based on meso-scale automatic weather stations rainfall data and 1:5 million high-precision DEM (digital elevation model) data.It can predict roughly areas by the automatic weather station rainfall analysis and processing when the floods happen.Using partitions 'horizontal' approximation methods,the model of DEM flooding disaster's monitoring has been constructed based on 1:5 million high-precision DEM.And the technical methods applied to the analysis of experimental area.The result of flood disaster's monitoring is carried on comparison and the analysis through the verification by CBERS-02B.It finds that the area of floods is very consistent by the model of DEM and CBERS-02B flooding disaster's monitoring.So the method of flood disaster's motoring based on DEM can be real-time,dynamic,and can monitor the flood zone accurately and effectively.It also can provide the decision making department with present and assisting scheme of policy making.

Analysis on A Rainstorm Type Landslide Disaster in Wanning

Due to the common influence of tropical depression,the low pressure trough and the cold air,the strong precipitation synoptic process occurred in Hainan Island on October 22,2009.It caused that the landslide geological disaster happened in several spots in the eastern line highway.By analyzing on the generation reason of landslide,it gained that the landslide which happened in several spots in the eastern line highway was caused by the common effect of special topographical condition,strong wind and rainstorm.The strong precipitation and strong wind which were generated by the tropical depression were the direct reasons which induced the rainstorm type landslide in the eastern line highway.

Characters and Impacts Evaluation of Rainstorms and Floods from July 8 to 13,2010 in Zunyi City

A strong rainfall during June 8-13,2010 in Zunyi City is comprehensively analyzed by several diagnosis methods,including space location,maximum value,history comparison,maximum value assumption and disaster influence analysis.Results show that this time the successive heavy precipitation fall in the northeastern area of Zunyi City,which are Zheng’an,Daozheng and Wuchuan etc..There are in total of 4 times of heavy rainstorms,8 times of rainstorms and 8 times of heavy rains in 14 meteorological observatories of the entire city.In the whole 215 towns,the daily precipitation in 162 stations reaches rainstorm scale,of which 45 stations reaches heavy rainstorm scale.The 24 hours rainfall of the heavy rain in Wuchuan Maotian town reaches 288.6 mm and the maximum rainfall intensity is 90.2 mm.The total precipitation from 22:00 on 7th to 05:00 on 10th in Fenshui,Wuchuan reaches 423.0 mm.The 1 h maximum precipitation,daily maximum precipitation and the maximum precipitation in any 3 days all surpasses the rainstorm which occurs once in a hundred years.The heavy precipitation results in large range of water-logging and flooding;the water level of several rivers passes the dangerous or warning line.The damages and impacts of the disaster are also put forward in this paper.

Spatial diversion and coordination of flood water for an urban flood control project in Suzhou, China

Suzhou City,located in the Yangtze River Delta in China,is prone to flooding due to a complex combination of natural factors,including its monsoon climate,low elevation,and tidally influenced position,as well as intensive human activities.The Large Encirclement Flood Control Project(LEFCP)was launched to cope with serious floods in the urban area.This project changed the spatiotemporal pattern of flood processes and caused spatial diversion of floods from the urban area to the outskirts of the city.Therefore,this study developed a distributed flood simulation model in order to understand this transition of flood processes.The results revealed that the LEFCP effectively protected the urban areas from floods,but the present scheduling schemes resulted in the spatial diversion of floods to the outskirts of the city.With rainstorm frequencies of 10.0%to 0.5%,the water level differences between two representative water level stations(Miduqiao(MDQ)and Fengqiao(FQ))located inside and outside the LEFCP area,ranged from 0.75 m to 0.24 m and from 1.80 m to 1.58 m,respectively.In addition,the flood safety margin at MDQ and the duration with the water level exceeding the warning water level at FQ ranged from 0.95 m to 0.43 m and from 4 h to 22 h,respectively.Rational scheduling schemes for the hydraulic facilities of the LEFCP in extreme precipitation cases were developed ac-cording to food simulations under seven scheduling scenarios.This helps to regulate the spatial flood diversion caused by the LEFCP during extreme precipitation.

The Research Framework Model of Rapid Assessment and Emergency Plan Selection for Urban Flood Disaster

Given that it is difficult to assess the harmfulness and make emergency response timely in the early stage when flood disasters happen in cities for that the data are complex and rapidly changing, this article constructs a rapid assessment model, namely Simple Simos Procedure and PROMTHEE II Model (SSPPM), to assess the severity of flood disaster occurring in cities at the early stage based on a view of the rapid flood disaster assessment. On this basis, the fuzzy VIKOR method is applied to choose a scientific emergency plan. This article aims to construct a research framework model, which can provide some practice implications to reduce the losses caused by flood disaster.

DISTRIBUTIONS AND HYDROLOGICAL CHARACTERISTICS OF TROPICAL CYCLONE RAINSTORMS AND FLOODS IN CHINA

Regional distribution of the rainstorms and floods caused and affected by tropical cyclones are described and the geographicla divisions of China are also given in this paper. The hydrological characteristics of tropical cyclone rainstorms and floods are discussed and compared with that on non-tropical cyclones.

The influences of the tectonic subsidence and the siltation on the situation of preventing flood disasters in the Dongting Lake area

With the long-term data of the geodetic sea level measurements undertaken in the Dongting Basin and the recent sediment data of Dongting Lake, we analyze the tectonic subsidence rate of the Dongting Basin and the sedimentary rate of Dongting Lake. From the point of view of geomorphology and hydrogeology, we distinguish the two different spatial concepts between 'the basin of Dongting Lake' and 'the Dongting Basin'. Then, we discuss the influences of the tectonic subsidence and the siltation on the levees and the space of storing flood. The better quality of levees is required due to the tectonic subsidence and the siltation, and the difficulties of preventing flood disasters are increasing. The space of storing flood is not affected by the tectonic subsidence, but by the siltation. At present, the sedimentary rate of Dongting Lake is higher than the tectonic subsidence rate of the Dongting Basin. The tectonic subsidence capacity of the Dongting Basin counteracts a part of sedimentary capacity, and the shrinking tendency of Dongting Lake is restrained to a certain extent, but the tectonic subsidence is harmful to the situation of preventing flood disasters in the Dongting Lake area.

Dryness-wetness change and regional differentiation of flood-drought disasters in Guangdong during 1480-1940AD

Based on the historical records of the drought and flood disasters during 1480-1940AD, this paper reconstructs the sequences of wetness index （WI） and drought and flood disasters. We find a good identical relationship between the fluctuation of WI sequence and the δ^18O record of the GISP2 ice core in Greenland, which shows an apparent monsoonal disposal pattern of moisture and temperature. By applying the Morlet Wavelet Transform Method to deal with the data, several apparent periodicities, such as 7-8a, 11-15a, 20-23a and ca 50a, are revealed, among which some can be attributed to the solar forcing. Based on results of Cluster Analysis of dry-wet changes, we resume the regional differentiation pattern of flood-drought disasters all over Guangdong during different climatic intervals in the LIA and, find the western and northern parts of Guangdong have undergone drastic changes in drought-flood regional differentiation, but the eastern part is relatively stable, and the area of the Pearl River Delta shows stable condition of more flood disasters.

Community-Based Approach in the Prevention and Management of Flood Disasters in Babessi Sub-Division (Ndop Plain, North West Cameroon)

Flood is a recurrent natural disaster that has caused enormous human and material damage in many places and continues to hit local committees at an alarming rate. The need to setup permanent committees to prevent and manage flood disasters by local communities is therefore indispensable. In rural areas, the creation of such a structure is always a welcome relief to flood victims but it is often marred by numerous management problems. This study aimed to analyze the community-based approach in the prevention and management of flood disasters in Babessi Subdivision (North West Cameroon), to identify the causes of flood disasters and the preventive strategies used by this local community. A total number of 300 questionnaires as well as structured interviews were used to collect data in the field and the data were analyzed by simple descriptive statistics. The main results revealed that the main cause of flood disasters is heavy and consistent rainfall. Also, poor refuse disposal and drainage system management contribute to floods. The identification of areas likely to be affected by floods and preventing the riparian population from constructing houses along these areas especially beside the main rivers are the flood preventive measures adopted by the local flood management committee. The flood victims are reluctant to relocate to the settlement site earmarked by the Government, meanwhile, the local flood committee do not have the legal tools to forcefully relocate them. The population of Babessi needs to be sensitized on the impending dangers of flood hazard and be encouraged to participate in implementing the adopted strategies to prevent and manage subsequent flood disasters.

An AMSR-E Data Unmixing Method for Monitoring Flood and Waterlogging Disaster

Spectral remote sensing technique is usually used to monitor flood and waterlogging disaster.Although spectral remote sensing data have many advantages for ground information observation,such as real time and high spatial resolution,they are often interfered by clouds,haze and rain.As a result,it is very difficult to retrieve ground information from spectral remote sensing data under those conditions.Compared with spectral remote sensing tech-nique,passive microwave remote sensing technique has obvious superiority in most weather conditions.However,the main drawback of passive microwave remote sensing is the extreme low spatial resolution.Considering the wide ap-plication of the Advanced Microwave Scanning Radiometer-Earth Observing System(AMSR-E) data,an AMSR-E data unmixing method was proposed in this paper based on Bellerby's algorithm.By utilizing the surface type classifi-cation results with high spatial resolution,the proposed unmixing method can obtain the component brightness tem-perature and corresponding spatial position distribution,which effectively improve the spatial resolution of passive microwave remote sensing data.Through researching the AMSR-E unmixed data of Yongji County,Jilin Provinc,Northeast China after the worst flood and waterlogging disaster occurred on July 28,2010,the experimental results demonstrated that the AMSR-E unmixed data could effectively evaluate the flood and waterlogging disaster.

The Impacts of Flood and Local Communities’ Coping Strategies along the River Gambia

Flood disasters as Climate change hazards are common in developing countries, particularly in communities along the river Gambia. Local communities, for instance, had their local coping strategies that enabled them to stay in their communities even amid these ordeals, and climate change disaster threats. This work strives to understand flood impacts and the local peoples’ adaptation or coping strategies along the River Gambia basin. A community-based cross-sectional research study of 422 research participants of which 294 are males (69.7%) and females 128 (30.3%), and a focus group discussion of 10 groups which comprised 5 female groups and 5 male groups respectively found that 98.6% of the households experienced floods in their community, and 70.6% experienced flood in their houses, 2.1% have impending flood information and 88.4% do not know evacuation centres. The majority of the households had some local coping strategies, but they acknowledged their insufficient effectiveness. The result also shows that the impact of floods on farmlands, roads, buildings, and livestock was greatly felt. Coping strategies such as sandbags, raised elevations, contour bonds, dikes, and buildings on highlands were all found to be common mechanisms the local people used. The study opines that floods affect communities, but the effects vary depending on individual assets.

The Spatial and Temporal Distribution Characteristics of Rainstorm Disaster in Sichuan Province over the Past Decade

The spatial and temporal distribution characteristics of rainstorm disaster in Sichuan Province were investigated by statistical analysis method based on 2002-2015 rainstorm disaster data of Sichuan Province. As shown by the results, the rainstorm disaster in Sichuan Province was distributed mainly in four regions including Liangshan Prefecture and Sichuan Basin during 2002-2015, and the rainstorm disaster distribution had a good corresponding relationship with the rainstorm center regions;in terms of annual variation trend, the variation of rainstorm disaster frequency showed a significant quasi-2-3-year oscillation period;in terms of monthly distribution, June, July and August saw the heaviest rainstorms;the high death toll from rainstorms was attributed to not only routine rainfall, occurrence time and terrain feature, but also the populace’s awareness of disaster prevention and the disaster prevention measures they adopted. The research result has important significance to improve the pertinence and practicability of decision-making meteorological services.

Constrction of watershed flood disastermanagement information system and its application to the catastrophic flood of theYangtze River in 1998

This paper introduces a general method of establishing Watershed Flooding Disaster Management Information System (WFDMIS). The functions, database, models, user interface, software and hardware are considered. An application example in Poyang Lake Basin was given.

Use of GIS and Remote Sensing Technology as a Decision Support Tool in Flood Disaster Management: The Case of Southeast Louisiana, USA

The primary objective of this paper was to identify flood-prone areas in Southeast of Louisiana to help decision-makers to develop appropriate adaptation strategies and flood prediction, and mitigation of the effects on the community. In doing so, the paper uses satellite remote sensing and Geographic Information System (GIS) data for this purpose. Elevation data was obtained from the National Elevation Dataset (NED) produced by the United States Geological Survey (USGS) seamless data warehouse. Satellite data was also acquired from USGS Earth explorer website. Topographical information on runoff characteristics such as slope, aspect and the digital elevation model was generated. Grid interpolation TIN (triangulated irregular network) was carried from the digital elevation model (DEM) to create slope map. Image Drape was performed using ERDAS IMAGINE Virtual GIS. The output image was then draped over the NED elevation data for visualization purposes with vertical exaggeration of 16 feet. Results of the study revealed that majority of the study area lies in low-lying and very low-lying terrain below sea level. Policy recommendation in the form of the need to design and build a comprehensive Regional Information Systems (RIS) in the form of periodic inventorying, monitoring and evaluation with full support of the governments was made for the study area.