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.

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.

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.

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.

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.

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.

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.

An Introductory Overview of Earthquake Early Warning

Earthquake early warning(EEW)is discriminated from earthquake prediction by using initial seismic waves to predict the severity of ground motion and issue the warning information to potential affected area.The warning information is useful to mitigate the disaster and decrease the losses of life and economy.We reviewed the development history of EEW worldwide and summarized the methodologies using in different systems.Some new sensors came and are coming into EEW giving more developing potential to future implementation.The success of earthquake disaster mitigation relies on the cooperation of the whole society.

Large, moderate, small earthquakes and seismic fortification criterion

This paper discusses the relation between two-step seismic design and the standard of probability of exceedance, and the relation of three-levels seismic ground motion parameters given by probability method and comprehensive probability method. The relative size relations of the ground motions with 2%, 10%, 63% probability of exceedance in 50 years, namely large earthquake, moderate earthquake, and small earthquake, are discussed through a practical example of seismic hazard analysis. The methods to determine seismic fortification criterion are discussed.

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.

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.

Current Situation and Countermeasures of Weather Modification Ground Operation in Heilongjiang Province

Heilongjiang Province is the granary of China,which plays a key role in ensuring the national food security.The total grain output of Heilongjiang Province has ranked first in China for 12 consecutive years.In the past four years,it has been stable at more than 75 billion kg,a record high.One bowl of rice in every nine bowls in China comes from Heilongjiang.The work of weather modification and disaster prevention and reduction is an important measure to ensure the development of agricultural production,and is the key of meteorological services for agriculture.Based on the actual work of artificial weather modification in Heilongjiang Province,this paper analyzes the current situation of ground operation in Heilongjiang Province,studies and judges the safety production,and puts forward reasonable countermeasures.The purpose is to improve the ground operation ability of artificial weather modification and provide safe and scientific services for agricultural production.

持续强降雨影响下黄土高原地形变化分布特征——以延安市顾屯流域为例

As China's Loess Plateau has lately witnessed increasingly extreme precipitation events,it is important to analyze the impact of extreme precipitation and identify the conditions for the occurrence of geological disasters.Field surveys can provide detailed geological information in this regard but are time consuming and labor intensive.In this paper,we provide a case study on the Gutun catchment of Yan'an,which was affected by prolonged heavy rainfall in July 2013.We used Digital Elevation Model(DEM)data obtained by processing ZY-03 stereo-pair images before and after the rainy season,including the period of prolonged heavy rainfall mentioned above,to analyze the topographical changes triggered by the rainfall.The results showed the following:(1)The rainy season reduced the elevation of the catchment by about 1.7 cm.The major change in its elevation ranged from-0.5 to 0 m,accounting for 38.41%of the overall area of change and dominating above 70 m of slope height.(2)The rainy season increased the average inclination of the slopes in the area from 28.81°to 28.95°,while the range of their peak inclination was mainly distributed in the range of 24°-36°.(3)Sunny and half-sunny slopes exhibited a greater loss in elevation,while shady and half-shady slopes exhibited an increase in elevation.More drastic topographical changes were observed in the shady and half-shady slopes.(4)The morphology of the area that had undergone a reduction in elevation was characterized by concave slopes,while convex slopes abounded in the area with increased elevation.(5)The sunny or shady properties of the slope aspect constituted the key factor influencing the topographical changes,followed by the height,inclination,and shape of the slopes.The work here can provide guidance for measures related to disaster prevention and mitigation.

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.

Satellite Image Classification Using a Hybrid Manta Ray Foraging Optimization Neural Network

A semi supervised image classification method for satellite images is proposed in this paper.The satellite images contain enormous data that can be used in various applications.The analysis of the data is a tedious task due to the amount of data and the heterogeneity of the data.Thus,in this paper,a Radial Basis Function Neural Network(RBFNN)trained using Manta Ray Foraging Optimization algorithm(MRFO)is proposed.RBFNN is a three-layer network comprising of input,output,and hidden layers that can process large amounts.The trained network can discover hidden data patterns in unseen data.The learning algorithm and seed selection play a vital role in the performance of the network.The seed selection is done using the spectral indices to further improve the performance of the network.The manta ray foraging optimization algorithm is inspired by the intelligent behaviour of manta rays.It emulates three unique foraging behaviours namelys chain,cyclone,and somersault foraging.The satellite images contain enormous amount of data and thus require exploration in large search space.The spiral movement of the MRFO algorithm enables it to explore large search spaces effectively.The proposed method is applied on pre and post flooding Landsat 8 Operational Land Imager(OLI)images of New Brunswick area.The method was applied to identify and classify the land cover changes in the area induced by flooding.The images are classified using the proposed method and a change map is developed using post classification comparison.The change map shows that a large amount of agricultural area was washed away due to flooding.The measurement of the affected area in square kilometres is also performed for mitigation activities.The results show that post flooding the area covered by water is increased whereas the vegetated area is decreased.The performance of the proposed method is done with existing state-of-the-art methods.

Dynamic analysis of the Wenchuan Earthquake disaster and reconstruction with 3-year remote sensing data

Earth observation is an effective technique that plays an important role in earthquake damage reduction and reconstruction.This paper introduces the results of dynamic analysis on monitoring and assessing heavily impacted areas affected by the Wenchuan Earthquake using remote sensing data acquired in the past 3 years from 2008 to 2010.Immediately after the disaster on 12 May 2008,the Chinese Academy of Sciences launched a project entitled‘Wenchuan Earthquake Disasters Monitoring and Assessment Using Remote Sensing Technology.’More than 400 images from 17 satellites and 20.2TB airborne remote sensing data were acquired to facilitate quick monitoring and evaluation of severely damaged areas in 14 counties.Results of the image analyses were forwarded on a timely basis to assist with consultative service and decisionmaking support.In subsequent years,in order to monitor the process of environmental restoration and reconstruction,airborne optical remote sensing images covering most of the severely damaged areas were again acquired in May 2009 and April 2010.These images were analyzed and compared along with images from 2008.Results were useful in support of further work on environmental protection and reconstruction in earthquake-damaged areas.Three typical areas were selected for illustrative purposes including Tangjiashan Barrier Lake,Beichuan County,and counties of Yingxiu and the new Beichuan.These results well demonstrate the importance and effectiveness of the utility of earth observation for disaster mitigation and reconstruction.

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.