Nourishment and disaster mitigation efficiency of feeding sand on the dry section of a dissipative beach

To explore the nourishment effect and disaster reduction efficiency of a fully dissipative dry beach under the impact of storms,this paper uses the measured topography and hydrodynamic data to establish a one-dimensional numerical model of the XBeach beach profile.By numerically modeling the change in the nourished profile for different dry beach widths under normal waves and storm conditions and the recovery process of the profile after the storm,the degree of response in dry beach nourishment for the fully dissipative beach is analyzed.The results show that under normal wave conditions,the response of the nourished dry beach is obvious.Sediment on the dry beach erodes heavily,and the shoreline moves landward over a long distance.With the increase in the width and size of the dry beach,the wave height at the bottom of the backshore profile decreases,the wave height attenuation rate increases continuously,and the wave elimination effect is remarkable.When the storm incident wave intensifies,the wave height attenuation rate of the nourished dry beach decreases,indicating that the smaller the storm intensity is,the more significant the wave reduction effect of the nourished dry beach is.At the same time,different profile arrangements of nourished dry beaches suffer from different degrees of erosion under storm conditions,with significant changes in profile morphology.With intensified storm action,the intensity of sediment erosion in the nourished dry beach increases,the nourishment is weakened,and the recovery effect of the profile after the storm is not obvious.The results of the numerical modeling highlight that the dry beach nourishment method can resist storms to a certain extent,but the overall effect is relatively limited.

Integrated Debris Flow Disaster Mitigation—A Comprehensive Method for Debris Flow Disaster Mitigation

Integrated disaster mitigation needs interpreting torrent catchment areas as complex landscape systems. The history of valley-evolution shows the influence of climate and vegetation on the valley-evolution. The energy-concept (energy dissipation concept including the idea of the energy-line) is used for a simple explanation of debris flow. Examples of heavy debris flow disasters in controlled torrents in the Alps and Pyrenees give hints, which expanding the time scale can show that side-effects restrict or counteract the mitigation measures. A pallet of different mitigation measures to avoid or to reduce some of the side-effects is shown. The comprehensive method of disaster mitigation also includes the effect of vegetation. The pallet includes: avoiding hazards (hazard mapping, warning and alarming), appropriate land use and avoiding disaster-enhancing measures in the landscape and technical measures, which take into account their side-effects. The energy line is used as simple design theory. The Jiu-Jitsu Principle is explained too. With this comprehensive method a more sustainable reduction of disasters seems possible.

Overview of Earthquake Preparedness and Disaster Mitigation in China1

As an earthquake-prone country, China has made sustained efforts in the study of earthquakes and disaster mitigation during the past several decades, with China Seismological Bureau (CSB) as the backbone of these efforts. Working towards this purpose, a series of key projects were implemented in the “Ninth Five-Year Plan” (1995-2000) to upgrade earthquake monitoring systems and to improve the supporting infrastructure, significant results in earthquake science were achieved. In the new century, we have worked out a blueprint for earthquake preparedness and disaster mitigation in the “Tenth Five-Year Plan”, which emphases 3 systems (i.e. Seismic Monitoring & Prediction, Seismic Hazards Prevention, Emergency Response), and 10 key projects in earthquake science and technology.

Overview on Mangrove Forest Disaster Prevention and Mitigation Functions

This paper provides a comprehensive overview on coastal protection and hazard mitigation by mangroves.Previous stud-ies have made great strides to understand the mechanisms and influencing factors of mangroves’protection function,including wave energy dissipation,storm surge damping,tsunami mitigation,adjustment to sea level rise and wind speed reduction,which are sys-tematically summarized in this study.Moreover,the study analyzes the extensive physical models,based on indoor flume experi-ments and numerical models,that consider the interaction between mangroves and hydrodynamics,to help our understanding of mangrove-hydrodynamic interactions.Additionally,quantitative approaches for valuing coastal protection services provided by man-groves,including index-based and process-resolving approaches,are introduced in detail.Finally,we point out the limitations of previous studies,indicating that efforts are still required for obtaining more long-term field observations during extreme weather events,to create more real mangrove models for physical experiments,and to develop numerical models that consider the flexible properties of mangroves to better predict wave propagation in mangroves having complex morphology and structures.

Reflection on China's Disaster Prevention and Mitigation Construction after Rainstorm and Snowstorm

On July 10,2004,Beijing was hit by the rainstorm that has not been seen for many years,which caused water accumulation in many places of the urban area,power supply interruption in many places,and traffic paralysis for nearly 5 h. On July 12,2004,the rainstorm in Shanghai lasted less than 1 h,but it caused 7 deaths,more than 20 injuries,extensive power outages and traffic paralysis. At the end of 2005,the continuous snowfall in Weihai City of Shandong Province for half a month caused direct economic losses of over 200 million yuan,and the continuous heavy snowfall had a serious impact on people’s lives. From July 17 to 23,2021,Henan Province suffered a rare extremely heavy rainstorm in history,with a direct economic loss of 120.6 billion yuan. Faced with such urban meteorological disasters and other types of urban disasters,combined with the current situation of disaster prevention and reduction in China,what will managers,decision-makers,and experts and scholars think about from them.

A support tool incorporating a district disaster mitigation performance evaluation method for the examination of improvement plans in built-up areas

Approximately 20,000 ha of densely built-up areas still remain in Japan. However, the advance of improvements in these areas has been very slow. Thus, making draft improvement plans through citizen-administration partnerships is indispensable to promote improvements. The planning support tool proposed in this study supports a consensus-building process during the creation of draft improvement plans. We develop a disaster mitigation performance evaluation method （DMPEM） for built-up areas at the district level and incorporate this method into a disaster mitigation support Web-GIS. However, DMPEM requires lengthy calculation time because it uses the probabilistic Monte Carlo computation method. Using this tool in realime planning is therefore difficult. In this study, we first develop a system that reduces the calculation time required by DMPEM. Second, the support tool is used to make draft plans through citizen-administration partnerships in districts where residents are conducting various disaster mitigation activities. Finally, we investigate the usefulness of the tool for consensus building through the promotion of lively discussions among residents and clarify the issues associated with practical use of the tool.

Implementation issues of the planning support tool in Japan:Focusing on urban disaster mitigation

This study determined the issues of Planning Support System(PSS)implementation in the field of urban disaster mitigation in Japan by understanding its analytical perspective through a review of Western literature,a questionnaire survey of urban planning consultant companies,and PSS implementation for a practical project in a municipality.Regarding the instrum ental perspective,there was difficulty in conducting the simulationbased PSS due to the enormous simulation time required.Regarding the transfer perspective,the importance of the municipality^decision of adopting the PSS to a project,securing the budget and continuous running costs,track record of the practical project,and lack of human resource for the PSS use were clarified.Regarding the user perspective,the difficulty in data collection and update as well as im portance of the cooperative system/support from the developer in the initial period were clarified.Especially,considering the low number of implementations,a platform may be important for the promotion of PSS awareness.This may be also useful for the diffusion of PSS.It is necessary for the developers to fully comm unicate the benefits of PSS adoption.It is thought that a close cooperative system and support are required in the initial stage.For prom oting and understanding the benefits of PSS adoption,a guideline or manual seems to be useful.This is effective for ensuring the budget and providing an explanation to high-level members of the organizations about the effect of utilizing these tools.For the final implementation,the possibility of installation,maintenance,and operation of the PSS by the municipality was discussed.

Near Range Radar and Its Application to Near Surface Geophysics and Disaster Mitigation

In this paper, we discuss about the near range radar applied to various environmental applications and disaster mitigation issues. Synthetic aperture radar（SAR） processing or migration is the key technology in near range radar imaging, which can be used in ground penetrating radar（GPR） and ground-based synthetic aperture radar（GB-SAR）. We demonstrate some applications which include GPR for humanitarian demining, GPR for archaeological survey, GB-SAR for landslide monitoring and nondestructive inspection of wooden buildings. We also demonstrate a new array GPR system “Yakumo”, which was used for archaeological survey for demonstration of advanced multi-static radar signal processing for better radar imaging.

The Characteristics of Earthquake Disasters and Countermeasures for Their Mitigation in Metropolitans

Metropolitans are a result of fast economic development in China. Many metropolitans have emerged in the eastern part of China. Earthquake disasters in metropolitans are more complicated and serious than those in a smaller city, and the impact of earthquake disaster on the economy and society is large. The characteristics of earthquake disasters and countermeasures to protect against and mitigate disaster in the metropolitan, as well as some key research fields in the earthquake disaster protection and mitigation, are discussed.

Disaster Mitigation Theory and Practice in China

During recent ten years, many serious disasters were prevented and reduced by Chinese people and Government. The mechanism of Chinese disaster prevention and reduction was summarized in this paper. 24 years ago, author presented modern theory of disaster prevention and reduction in China firstly. A lot of work was done by Chinese people and scientists. For example, presented strategic suggestion; promoted "China Center of Disaster Reduction"; finished "National Report" and "China Plan on Disaster Reduction" and "China Decade Report" etc. As other part of practice, a series of modern scientific and technologic systems or setup were established or developed. For example, "Synthetic Scientific System of Atmosphere Hydrosphere Disaster Reduction" (SSSAHDR) obtained greatly successes reducing losses about 200 million US$; and it promotes to establish "China Center of Disaster Reduction" and larger step of "China Modern Setup of Disaster Prevention and Reduction" was presented and so on. It is very clear that above theory and practice of disaster prevention and reduction are important and useful for Chinese works on disaster reduction; and it may be a reference for other countries, specially for developing countries. China is in the crossing region of two great hazard belts in the world, and it’s natural hazards frequently strike and cause heavy damage. So, China is one of the few countries where natural hazards strike frequently and make serious damage. During recent ten years (1989-1998), the middle value of all direct economic losses of natural disasters in China are 157.8 billion yuan RMB a year. It is about 2.6%～6.1% General National Production (GNP) of China, the middle loss value of GNP is 3.8% which is very high, it is about ten times than advancing countries. The maximum of economic losses is 300.7 billion yuan RMB in 1998, because great flood struck our country in this year. So, disaster prevention and reduction are very important task in China which is in relation closely with national economic development.

Study on Risk Assessment of Summer Rainstorm Disaster and Countermeasures for Disaster Prevention and Mitigation in Shaoyang City

Using summer(June-August)precipitation observation data in 10 representative stations of Shaoyang City during 1971-2021 and disaster data caused by summer rainstorm in nine counties(cities)and four districts of Shaoyang during 1981-2021,statistical analysis on summer rainstorm and its caused disaster in Shaoyang was conducted,and spatial and temporal characteristics of summer rainstorm and spatial distribution rule of disaster were found out.The results showed that(1)the rainstorm disaster in Shaoyang City occurs almost every year and is highly seasonal.(2)Rainstorm disaster loss is the first of other meteorological disasters.(3)The summer rainstorm disaster has the characteristics of sudden and destructive.On this basis,the relative grades of rainstorm disaster risk degree and disaster loss degree were divided,and the risk assessment of rainstorm and flood disaster in Shaoyang City was made,and the disaster prevention and mitigation measures and countermeasures were put forward.The research could provide scientific decision basis for party and government departments guiding flood fighting and disaster relief.

Valuation of debris flow mitigation measures in tourist towns:a case study on Hongchun gully in southwest China

The estimation of the value on the engineering project in tourist towns is usually very challenging and controversial. In this study, an attempt has been made to evaluate the economic value of the debris flow control engineering in tourist towns by integrating both welfare and disaster economics. The total value of debris flow prevention and control engineering in tourist towns(VDFE) includes investment cost(IC), disaster mitigation benefit(DMB), and loss of brand value(LBV). Here DMB is assessed by the cost-benefit method. The LBV is estimated by incorporating brand equity and costbenefit methods. The engineering for debris flow control in the Hongchun Gully of southwest China was built to protect Yingxiu tourist town and was assessed as an example. The IC for the engineering is180 million RMB, however, the VDFE reaches as high as 3401 million RMB, of which the LBV is 169 million RMB, and the input-output ratio is 1:18. Thus, the LBV cannot be neglected in case of VDFE estimation process. The more developed the tourism in one town or city is, the greater the LBV and the higher the VDFE are.

Networking Observation and Applications of Chinese Ocean Satellites

This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource development.Since the inaugural launch in 2002,China has achieved substantial advancements in ocean satellite technology,forming an observation system composed of the HY-1,HY-2,and HY-3 series satellites.These satellites are integral to global ocean environmental monitoring due to their high resolution,extensive coverage,and frequent observations.Looking forward,China aims to further enhance and expand its ocean satellite capabilities through ongoing projects to support global environmental protection and sustainable development.

Analysis on the Influence of Meteorological Disasters on China Tourism Industry

Main meteorological disasters and their destruction on tourism landscape (including natural landscape and human landscape) were analyzed by using the methods of statistical analysis and cited examples, the impact of meteorological disasters on tourism brand, tourism decision, tourism transport, peak tourist season and the threat on tourism industry chain were studied, the main tourism meteorological disasters in North China, East China, Central China, Northeast Region, Southeast Region and Southwest Region were summarized, and some comprehensive measures of meteorological disaster for prevention and mitigation were put forward.

Research on the Prevention and Control Methods for Forest Disasters in China's Forestry Ecological Environment Construction

With the development of economy,China has gradually begun to pay attention to the protection of the natural environment.Under the concept of"lucid waters and lush mountains are invaluable assets",importance has been attached to the development of forestry economy.The protection of forest resources and the prevention and control of disasters are important contents and necessary components in the construction of China's forestry ecological environment.Through the analysis and research on the types of forest disasters(forest fires,biological disasters,meteorological disasters,geological disasters,deforestation)and disaster-causing factors,some basic countermeasures were put forward with the aim to enhance the production capacity of forest resources,improve the ecological environment of forest resources and prevent forest resource disasters.

Study on Risk Prevention of Rainstorm Disaster in the Jinji River of Guilin

The research aimed to prevent and reduce rainstorm disaster in the Jinji River of Yongfu County,Guilin City.Distribution of population,cultivated land and GDP in the Jinji River were analyzed,and the influence of historical rainstorm process was studied.Moreover,high risk area of meteorological disasters and the region not suitable for constructing residential areas,development zones and projects were distinguished,and its influence on agriculture and forestry was analyzed.If it was necessary to build residential areas,development zones and projects or the human society has already been in the high-risk area of meteorological disasters and it was difficult to move,what engineering measures should be taken to prevent the occurrence of risks.The research could provide scientific basis for design standard of disaster prevention engineering,to prevent the occurrence of disaster risk.

Research on Risk Assessment of City Natural Disaster based on Neural Network

Aiming at the selection of fuzzy AHP and fuzzy DH methods in the previous studies, this paper evaluate the qualitative index system using expert questionnaire, the self-learning BP neural network model to construct the index of system, and complete the establishment of model, in order to avoid the serious subjectivity, and using statistical and measurement methods test the reliability index, analyze the validity of the evaluation index system and completeness. Finally, the paper validate the practicability of the model.

Mitigating Disaster Impacts in Africa

The financial cost of disasters in Africa is estimated by the AU to run between 3 and 15 percent of the continent＇s GDR High vulnerability to disaster risk is thus a major challenge undermining Africa＇s accelerated and sustainable structural transformation efforts. But there is a plan in place to build resilience to disasters and reduce the risk impact,

Extracting water body data based on SDWI and threshold segmentation:A case study in permafrost area surrounding Salt Lake in Hoh Xil,Qinghai-Tibet Plateau,China

There are a large number of lakes,rivers,and other natural water bodies distributed in the permafrost area of the Qinghai-Tibet Plateau(QTP).The changes in water bodies will affect the distribution of water resources in sur-rounding areas and downstream areas,resulting in environmental impact and bringing potential flood disasters,which will induce more serious issues and problems in alpine and high-altitude areas with a fragile habitat(such as the QTP in China).Generally,effective,reasonable,and scientific monitoring of large-scale water bodies can not only document the changes in water bodies intuitively,but also provide important theoretical reference for subsequent environmental impact prediction,and disaster prevention and mitigation in due course of time.The large-scale water extraction technology derived from the optical remote sensing(RS)image is seriously affected by clouds,bringing about large differences among the extracted water result products.Synthetic aperture radar(SAR)RS technology has the unique advantage characteristics of all-weather,all-day,strong penetration,and not being affected by clouds,which is hopeful in extracting water body data,especially for days with cloudy weather.The data extraction of large-scale water bodies based on SAR images can effectively avoid the errors caused by clouds that become prevalent at present.In this paper,the Hoh Xil Salt Lake on the QTP and its surrounding five lakes are taken as the research objects.The 2-scene Sentinel-1 SAR image data covering the whole area on 22 August 2022 was used to verify the feasibility of extracting water body data in permafrost zones.Furthermore,on 22 August 2022,the wealth here was cloudy,which made the optical RS images,e.g.,Sentinel-2 images full of clouds.The results show that:using the Sentinel-1 image and threshold segmentation method to extract water body data is efficient and effective with excellent results in permafrost areas.Concretely,the Sentinel-1 dual-polarized water index(SDWI),calculated by combining dual vertical–vertical(VV)polarized and verti-cal–horizontal(VH)polarized data is a useful index for water extraction and the result is better than each of the VV or VH polarized images.

Fast and robust inversion of earthquake source rupture process and its application to earthquake emergency response

Fast inversion of source rupture process for significant earthquake is introduced and applied to earthquake emergency response. We retrieve and use the apparent source time functions （ASTFs） to stabilize the rupture process inversion, aiming to get the rupture process results correctly and quickly. The applications to 22 significant earthquakes occurred between January 2009 and July 2011 show an average inversion time consumed of about four hours, suggesting a high efficiency of this method, which much improves the inversion speed of the rupture process and is helpful in earthquake disaster mitigation and relief.