Factor analysis of earthquake-induced geological disasters of the M7.0 Lushan earthquake in China

The seismic intensities, lithologic characteristics and terrain features from a 3000 km2-region near the epicenter of the Lushan earthquake are used to analyze earthquake-induced geological disaster. The preliminary results indicate that secondary effects of the earthquake will affect specific areas, including those with glutenite and carbonate bedrock, a seismic intensity of IX, slopes between 40° and 50°, elevations of less than 2500 m, slope change rates between 20° and 30°, slope curvatures from - 1 to -0.5 and 0. 5 to 1, and relief between 50 and 100 m. Regions with susceptibility indices greater than 0.71 are prone to landslides and collapses. The secondary features are mainly distributed on both sides of the ridges that extend from Baosheng to Shuangshi and from Baosheng to Longxing. Other features are scattered on both sides of the ridges that extend from Qishuping to Baosheng and from Masangping to Lingguan. The distribution of the earthquake-related features trends in the NE direction, and the area that was most affected by the Lushan earthquake covers approximately 52.4 km^2.

Coupling Mechanism of Rural Settlements and Mountain Disasters in the Upper Reaches of Min River

Human settlements are the place where human beings live,among which the rural settlements can be regarded as a reflection of human-land relationship in mountain areas because their vertical distribution is greatly influenced by the specific geographical environment and ecological conditions of mountains.Based on field investigation,this paper uses physical,geographical,and ecological theories to make a comprehensive study of rural settlements and mountain disasters in the upper Min River,which is an ecologically fragile area with high-frequency disasters(collapse,landslide,debris flow,etc.) and a minority inhabit district.By applying these modern scientific theories,this paper attempts to shed some light on the relationship between rural settlements and mountain disasters.Consequently,an in-depth understanding of this relationship was achieved as follows:(1) Rural settlements and mountain disasters are mainly distributed in the intercepted flows of water and soil; and both quantity and quality of arable lands in mountains are important indicators of these flows.(2) The Small Watershed Management Project is a complex system of rural settlements and mountain disasters that interacts with and constrains the ecological system.By this project,the human survival will be better guaranteed.Being fundamental for the ecological reconstruction,the coupling mechanism of rural settlements and mountain disasters is not only an engine to promote harmonious development between human and nature,but also a bridge to link them.

Close Relationship between the Frangibility of Mountain Eco-Environment and Mountain Disasters:A Case Study of Dongchuan,Kunming in Yunnan Province

Anatomical details are given in this article, which is performed by investigating the relationship between through the frangibility of mountain eco-environment and the status of irrational land-use in typical region of debris flow in Dongchuan district, Kunming city, yunnan Province. This analysis is extended to the relationship between vicissitude of mountain disasters and the frangibility of mountain environment. The relatively coupling action of a vicious circle is a evolving characteristic by debris flow sand-gravel there. The eco-security is being faced with serious challenge. The tactics of eco-security has been constructed since 1980s. Thus, the eco-environrnent can gradually be repaired and optimized to achieve a fine circle.

THE CHARACTERISTICS AND VERTICAL ZONE SPECTRUM OF NATURAL DISASTERS IN THE TIANSHAN MOUNTAINS, XINJIANG

With the mountain elevation increasing and climate condition change, the laws of formation, distribution and development of the various natural disasters, which are caused by the climate, change correspondingly and the vertical zone spectrum of special mountain natural disasters is formed. This research is helpful to finding effective measures to prevent disasters, avoiding and reducing the harm of natural disasters to industrial and agricultural production. There are 12 disasters in Tianshan Mountains, which can be divided into three zones. (1) Base zone (torrential rain collapse zone): types of the various disasters in this zone are caused by suddenly rain in the low middle mountain of the arid area. The disasters occur mainly from May to August, thus, the frequent periods of their bursts are simultaneous with the maximum period of precipitation in every year. (2) Middle zone (snowmelt water icing zone): most disasters, which happen in the middle high mountain area, have close relation with variation of temperature. (3) Upper zone (snow drift avalanche zone): the movement of snow mantle creates disaster in this zone. The slope direction and height of mountain greatly influence the frequency of hazards and the formation of vertical zone spectrum of natural disasters. Due to the regional diversities of temperature and precipitation, the vertical zone spectrum of natural disasters in mountains are different in different latitude and longitude zones.

Disaster Reduction Decision Support System Against Debris Flows and Landslides Along Highway in Mountainous Area

Highways in mountainous areas are easy to be damaged by such natural disasters as debris flows and landslides and disaster reduction decision support system (DRDSS) is one of the important means to mitigate these disasters. Guided by the theories and technologies of debris flow and landslide reduction and supported by geographical information system (GIS), remote sensing and database techniques, a DRDSS against debris flow and landslide along highways in mountainous areas has been established on the basis of such principles as pertinence, systematicness, effectiveness, easy to use, open and expandability. The system consists of database, disaster analysis models and decisions on reduction of debris flows and landslides, mainly functioning to zone disaster dangerous degree, analyze debris flow activity, simulate debris flow deposition and diffusion, analyze landslide stability, select optimal highway renovation scheme and plan disaster prevention and control engineering. This system has been applied successfully to the debris flow and landslide treatment works along Palongzangbu Section of Sichuan-Tibet Highway.

Landslide risk perception and communication for disaster risk management in mountain areas of developing countries：a Mexican foretaste

The increasing impact of disasters at local,national,regional and global scales in recent decades has provided enough evidence to urgently direct attention towards the necessity of disaster risk reduction and management,and this requires knowledge.Knowledge without communication is barren,and to communicate the risk of disaster it is necessary to understand the perception of the people at risk.In particular,this paper deals with the necessity to delineate strategies of risk communication in pursuance of risk knowledge as a core of disaster risk reduction and management,especially in mountain areas of developing countries.To portray this issue,an analysis of landslide risk perception in terms of experience,landslide risk awareness,exposure,preparedness,and risk communication and trust was undertaken in the municipality of Teziutlán,Puebla,Mexico,an area that has been affected for several decades by episodes of mass movement.Analysis of the responses to a risk perception questionnaire has offered valuable insights in terms of the information and knowledge most required by the people living in the area of interest,in order to devise a realistic and functional strategy to communicate the risk of a landslide disaster.This includes better understanding of controlling factorsand drivers of this risk,and the establishment of potential trusted sources of risk communication.Beyond considering practical matters of risk assessment and management,risk perception and communication can increase the resilience of vulnerable people,and can enhance capacity building for present and future generations.

Disaster risk reduction in mountain areas: a research overview

This paper gives an account of the diverse dimensions of research on disaster risk reduction in mountain regions derived from an open call of the Journal of Mountain Science that brought 21 contributions.This special issue includes topics as diverse as landslide dynamics and mechanisms,landslide inventories and landslide susceptibility models,insights to landslide hazards and disasters and mitigation measures,disaster response and disaster risk reduction.The overall structure of the paper takes the form of three sections.The first part begins by laying out the significance of disaster risk reduction in mountain areas,whereas the second one looks at the research insights on disaster risk reduction in mountains provided by the contributions comprised in the special volume.The final section identifies areas for further research.

Analysis on the Cause of Mayang Stream’s Mountain Torrent Disaster of the Typhoon Meranti (201614)

Based on the flood area hydrodynamic model, this paper backs the analysis of the risk warning point of the Mayang Stream in the typical flood process, to determine the disaster-caused critical precipitation and the corresponding flood risk map at different depths of submergence. The result is used as the mountain torrent disaster monitoring and warning indicators and risk assessment of the Mayang Stream. Then based on the flood risk warning service system of small and middle rivers of Fujian Province, the risk warning service of mountain torrent disaster is developed during the impact time of Meranti in 2016. After the process of typhoon, the mountain torrent caused by Meranti was back analyzed by using the decided flood area model, then compared with the results of filed investigation to verify the accuracy of the disaster-caused critical precipitation forecast and the effect of monitoring and early warning services. The result shows that the cause of Mayang Stream’s mountain torrent disaster of the typhoon Meranti is the heavy rainfall and the strong wind. The highest mountain torrent disaster was forecasted by the refine precipitation based on the disaster-caused critical rainfall of the Mayang Stream. The simulated flood scenarios and the field trip’s results were basically matched in upstream and not matched in the downstream. The post-mountain simulation assessment also showed that the flood inundation range basically matched with reality, but the flood process was biased. The reason was that in addition to the differences between the surface rainfall forecast and the real situation, many actual situations cannot be ignored. For example, Meranti caused serious damage to trees, increased river blockages, resulting in changes in flood inundation time and depth, affecting the flood process. It showed the tourism development would cause the river way blocking and increase the risk of flood. In order to prevent and reduce the flood disasters accurately and effectively, the flood risk forecast and the disaster-caused facts should be considered at the same time.

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 Environmental-Geological Problem and Ecosystem Re-establishment Countermeasures About Quarry and Damaged Mountain in Peri-urban

The quarry and damaged mountain in peri-urban have an important influence to ecological environment. They have had a series of serious environmental -geological problems to the socio-economic development and urban modernization process, such as increased environmental pollution and soil erosion,destruction of landscape aesthetic。

A Potential Flood Hazard Caused by Tianchi Volcano Eruption in Changbai Mountain, Northeast China

Geohazards appear to be increasing in frequency globally. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented by the huge volume of water in Tianchi Lake, the unique geography of Changbai Mountain, and the limited flood control ability in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changbai volcano cooperatively, and Chinese government especially needs to prepare plans for fighting a flood in advance.

2023年12月18日甘肃积石山M_(S)6.2地震触发次生灾害快速评估

2023年12月18日甘肃积石山县发生M_(S)6.2地震,该次地震触发官亭盆地中川乡金田泥流灾害,造成严重的破坏和人员伤亡。通过震前、震后的高分辨率卫星影像对比分析,初步判断此次地震没有引发大型同震滑坡与密集砂土液化,但是震前震中区发育的大量大型黄土滑坡和密集液化砂脉是由更老的地震事件触发。金田泥流灾害是物源区高含水量黏性土在强震动条件下沿沟谷发生流动所致,其发生可能与人类的耕作方式(引黄灌区震前冬季灌溉导致浅表土层含水量提高)有关。

铁路地质灾害勘察识别与监测预警

地质灾害对铁路建设、安全运营构成了极大威胁,“天空地”一体化综合勘察技术有效解决了地质灾害勘察识别难题。“天”基多源立体卫星遥感技术实现艰险复杂山区地质灾害的大范围精准判识,长时序InSAR与高精度GPS实现高陡岸坡的稳定性监测分析;“空”基真实感大场景、机载倾斜摄影和机载LiDAR扫描技术实现高植被覆盖区隐蔽性地质灾害判识;“地”基三维立体勘探技术获取岩土体结构、属性、参数;共同构建沟谷山地灾害链风险评价方案,为建设工程合理选址和工程设置提供依据。介绍地质灾害监测预警的方法、内容、技术和预警模型,对监测预警技术发展方向进行展望。

小尺度山区地质灾害隐患的无人机精细化识别方法与实践

本文针对小空间尺度范围内以滑坡、崩塌为主的山区地质灾害,提出了一套基于小型无人机摄影测量的精细化隐患识别方法。首先,针对工作区开展至少两期无人机摄影测量作业,经处理后得到实景三维模型、数字正射影像(DOM)、数字表面模型(DSM)等精细化成果;其次,以两期DOM与DSM变化检测为主实现灾害体识别;然后,基于灾害体共性特征建立典型识别标志,并依此采用三维实景目视解译为主方法实现孕灾体识别;最后,通过地面核查确认或排除隐患。将该套方法应用到三峡库首秭归泄滩河左岸顺向斜坡区域,共识别出10处不同类型隐患,证明了方法的可行性。

横断山区水电工程扰动灾害及风险分析

水电作为全球公认的清洁能源,但水电站的大量建设会人为的改变流域水文条件,对流域内地质环境的影响也仍未可知,因此亟需查明水电工程与地质环境之间的互馈作用。以我国水电工程密集区——横断山区作为研究区,首次对横断山区内的水电工程及扰动灾害进行系统的研究,通过遥感解译及现场验证,获得金沙江、澜沧江、岷江、雅砻江、大渡河以及怒江6个流域内的水电工程共计162座,水电工程扰动灾害共计2841处,并对灾害空间分布规律进行分析。结合前人研究和团队最新成果,对水库水位抬升及循环涨落作用下的库水作用,水库滑坡特征开展分析,揭示了水库滑坡失稳原因。在此基础上提出了水电工程扰动灾害风险分析方法,对6个流域分别开展风险评价,获得了各个流域在不同规模灾害下的经济及人口风险分区图。本研究可为横断山区及其周边区域未来水电开发提供指导,这对保障区域工程的安全建设具有重要意义。

山地旅游景区落石灾害风险评估—以浙江三门县蛇蟠岛景区为例

以浙江省三门县蛇蟠岛景区为研究背景,通过现场勘察与数值分析等手段,全面分析了山地旅游景区落石灾害的影响因素,基于RHRS风险评分方法建立了山地旅游景区落石灾害风险评估体系。研究结果表明:古洞室群围岩的严重扰动、岩石的风化作用、相邻洞室公共墙体的凿去为落石的三个主要影响因素;基于RHRS风险评分方法将落石灾害风险划分为5个等级,并在此基础上建立了山地旅游景区落石灾害风险评估体系;工程实践表明,建立的山地旅游景区落石灾害风险评估体系分析结果可靠,该评价体系可为落石灾害的发生提供预警及治理提供依据。

基于AHP-EWM的流域山洪风险综合评价研究

为合理评估并量化小流域山洪灾害风险,结合小流域山洪特点,从危险性、脆弱性和防灾减灾3个方面构建小流域山洪风险评价指标体系。采用层次分析法(AHP)、熵权法(EWM)分别确定指标的主、客观权重,结合博弈集结模型确定指标综合权重,最后基于幂指数法得到小流域山洪风险综合评价值,从而确定综合风险等级。以湖北省随州市柳林镇8·12山洪为例开展小流域山洪风险评价,最终得出其综合评价值为0.634 9,为较高风险,与柳林镇实际情况一致。该研究结果可为小流域山洪灾害预防提供理论指导,为灾害的应急救援提供决策支持。

考虑泥沙因子的四川省山洪风险评价研究

近年来,山洪灾害频发高发,为进一步提高山洪灾害预警防控水平,提出将泥沙因子纳入山洪风险评价中。以四川省为例,从洪水危险性、脆弱性和防灾能力3个方面选取12个山洪风险指标,运用层次分析法构建山洪风险评估指标体系,分别建立了不考虑泥沙因子和考虑泥沙因子的山洪灾害风险评估模型。结果表明:泥沙因子对山洪危险性和风险性有较大影响。不考虑泥沙因子的模型将低估山洪高风险、较高风险区域和中等风险区面积,而高估低风险、较低风险区域面积。研究成果可为山洪风险评价与灾害预防提供参考。

基于湖北输电线路灾情的山火分布特征分析

[目的]利用湖北输电线路山火历史灾情数据对山火分布特征进行分析。[方法]基于2016~2021年湖北省输电线路山火灾情资料,运用数理统计、气候统计和GIS空间叠加方法,对全省输电线路山火时空分布及山火与气象、下垫面、社会人文等影响因子的关系特征进行分析。[结果]时间上,2019年为近几年湖北输电线路山火发生最多的年份,秋冬季是高发季节,其中2月和9月为易发月份;空间上,鄂东地区是山火的频发区域,宜昌及荆门地区为次高发区域。山火与气象关系,大部分山火爆发前1个月降水偏少30%~100%、气温偏高0.5~3℃、湿度偏小3.8%~23%、风速偏大0.1~1.9 m/s。山火与下垫面关系,山火主要发生在耕地,占总数50.32%;山火主要集中在海拔高度150 m以下、坡度6°以下的区域,76.90%的山火发生在阳坡。山火与社会人文关系,山火主要发生在人口密度100~600人/km2的城市圈周边的乡镇及距离道路1.6 km缓冲区的区域。[结论]掌握湖北输电线路山火分布特征,有助于山火风险预警模型指标选取和阈值确定。

极端降雨与强人类活动复合作用下山洪灾害研究构想和成果展望

全球气候变暖导致山丘区极端降雨事件多发,降雨强度与量级不断突破区域历史极值,同时叠加区域脆弱环境和强人类活动影响,致使山洪形成及演进致灾成因复杂多变,由此加重了暴雨山洪引发的人员伤亡和财产损失。山洪灾害具有显著的自然和社会双重属性,其形成发展是山丘区环境孕灾承灾因子复合作用的结果。中国山丘区局地气候独特,地质地貌类型众多,溪河水系复杂,人类活动影响突出。大量重大山洪灾害事件表明,极端降雨诱发的山洪过程及致灾特征各异,给山洪灾害预报预警防御造成极大困扰,山洪灾害研究仍是当前重大自然灾害防控的重点和难点。长期以来,中国山洪灾害研究多偏重于雨水情时空变化规律,着重研究降雨影响的山洪洪水淹没特征,据此推算山洪灾害防治区的临界雨量与水位阈值,在山洪灾害防治实践应用中取得了较为显著的成效,山洪灾害事件导致的人员伤亡数总体显著下降。然而,受山丘区降雨特征、下垫面组成、溪河形态及人类活动等多因素影响,山洪洪水形成演进时挟带大量泥沙,从而表现为山洪水沙、山洪泥石流等物理过程,导致的局地冲毁、淤埋、淹没等致灾成因及阈值与山洪洪水致灾也存在本质差异,这也是近年来中国重大山洪灾害事件多发的主要原因。针对极端降雨诱发多类型山洪形成演进与强人类活动复合作用致灾防御难题,亟需利用气象学、水文学及河流动力学等多学科知识,采用现场调查、物理试验、数值模拟及理论分析相结合的方法,从传统单一的山洪洪水灾害研究扩展为全类型山洪灾害(山洪洪水灾害、山洪水沙灾害、山洪泥石流灾害)研究,开展全类型山洪引发的冲毁—淤埋—淹没等复合致灾研究,系统探究中国重灾省区重大山洪灾害事件的强降水时空演变规律,剖析极端降雨与强人类活动复合作用下多类型山洪形成及其演进致灾范围、规模特征,揭示气象水文溪河响应与强人类活动影响的不同类型山洪灾害致灾成因,建立气象水文水沙动力过程模拟方法,辨识山丘区流域全类型山洪冲毁—淤埋—淹没风险,提出不同类型山洪灾害易发区识别方法,构建山洪洪水灾害、山洪水沙灾害及山洪泥石流灾害分区分级多指标预警防御方法。该研究有利于提升中国山洪灾害理论技术研究水平,进一步完善中国山洪灾害防治对策。