Prediction and prevention of the impacts of sea level rise on the Yangtze River Delta and its adjacent areas

The Yangtze River Delta region is characterized by high density of population and rapidly developing economy. There are low lying coastal plain and deltaic plain in this region. Thus, the study area could be highly vulnerable to accelerated sea level rise caused by global warming. This paper deals with the scenarios of the relative sea level rise in the early half period of the 21st century in the study area. The authors suggested that relative sea level would rise 25 50 cm by the year 2050 in the study area, of which the magnitude of relative sea level rise in the Yangtze River Delta would double the perspective worldwide average. The impacts of sea level rise include: (i) exacerbation of coastline recession in several sections and vertical erosion of tidal flat, and increase in length of eroding coastline; (ii) decrease in area of tidal flat and coastal wetland due to erosion and inundation; (iii) increase in frequency and intensity of storm surge, which would threaten the coastal protection works; (iv) reduction of drainage capacity due to backwater effect in the Lixiahe lowland and the eastern lowland of Taihu Lake region, and exacerbation of flood and waterlogging disasters; and (v) increase in salt water intrusion into the Yangtze Estuary. Comprehensive evaluation of sea level rise impacts shows that the Yangtze River Delta and eastern lowland of Taihu Lake region, especially Shanghai Municipality, belong in the district in the extreme risk category and the next is the northern bank of Hangzhou Bay, the third is the abandoned Yellow River delta, and the district at low risk includes the central part of north Jiangsu coastal plain and Lixiahe lowland.     

Quantitative multi-hazard risk assessment with vulnerability surface and hazard joint return period

Risk assessment plays an important role in disaster risk management. Existing multi-hazard risk assessment models are often qualitative or semi-quantitative in nature and used for comparative study of regional risk levels. They cannot estimate directly probability of disaster losses from the joint impact of several hazards. In this paper, a quantitative approach of multi-hazard risk assessment based on vulnerability surface and joint return period of hazards is put forward to assess the risk of crop losses in the Yangtze River Delta region of China. The impact of strong wind and flood, the two most prominent agricultural hazards in the area, is analyzed. The multi-hazard risk assessment process consists of three steps. First, a vulnerability surface, which denotes the functional relationship between the intensity of the hazards and disaster losses, was built using the crop losses data for losses caused by strong wind and flood in the recent 30 years. Second, the joint probability distribution of strong wind and flood was established using the copula functions. Finally, risk curves that show the probability of crop losses in this multi-hazard context at four case study sites were calculated according to the joint return period of hazards and the vulnerability surface. The risk assessment result of crop losses provides a useful reference for governments and insurance companies to formulate agricultural development plans and analyze the market of agricultural insurance. The multi-hazard risk assessment method developed in this paper can also be used to quantitatively assess multi-hazard risk in other regions.     

Impact assessment of urbanization on flood risk in the Yangtze River Delta

The Yangtze River Delta region is the region with highest urbanization speed in China. In this study, 6 typical urbanization areas in Yangtze River Delta were selected as the objectives of study. Flood risk assessment index system was established based on the flood disaster formation mechanism, and analytic hierarchy process was utilized to define the weight of indices. The flood hazard, the exposure of disaster bearing body, the vulnerability of disaster bearing body and the comprehensive flood risk corresponding to three typical years in different urbanization stages, 1991, 2001 and 2006 were assessed. The results show that the flood hazard and the exposure of disaster bearing body in the 6 areas are all with an increasing trend in the process of urbanization, among which, the increasing trend of the exposure of disaster bearing body is especially obvious. Though the vulnerabilities of disaster bearing body in the 6 areas are all with decreasing trend owe to the enhancement of flood control and disaster mitigation capability, the comprehensive flood risks in the 6 areas increased as a whole, which would pose a serious threat to urban sustainable development. Finally, effective countermeasures for flood risk management of urbanization areas in Yangtze River Delta were put forward based on the assessment results.     

2014年鲁甸MS6.5地震后地质灾害发育分布特征

2014年云南鲁甸“8·03”M_S6.5地震造成了重大人员伤亡和财产损失,诱发了大量滑坡、崩塌、泥石流等地质灾害。基于对鲁甸县龙头山幅（G48E006006）地质灾害调查数据和对典型地质灾害的剖析,震后地质灾害发育分布有特征如下：（1）震后地质灾害较震前成倍增长,震前地质灾害多以中小型浅层崩滑为主,地震诱发了诸如甘家寨、红石岩等大型—特大型滑坡、崩塌,大量沟谷崩滑堆积物为泥石流储备了丰富的物源;（2）震中高烈度区域地质灾害密度大,沿发震断裂带NNE—NE向构造密集发育,震中区龙头山镇地质灾害发育最为集中;（3）地质灾害呈带状分布,明显受控于河流水系（牛栏江、沙坝河、龙泉河等）、公路（昭巧二级公路、沙乐公路）等线性地貌单元和线性工程,人类活动影响明显。     

钱塘江河口周边钻孔磁性地层学研究及意义

长江三角洲地区的沉积历史和特征,是揭示我国东部沿海区域新生代以来构造演化与地理格局形成过程的重要窗口.本文基于磁性地层学方法,结合AMS14 C和光释光测年数据以及该地区硬质黏土标志层,对分布于钱塘江河口两侧的五个钻孔建立年代地层框架.结果表明,除河口北部一个钻孔底部年龄至高斯正极性期外,其余钻孔显示南部地区约200ka BP以来才开始沉积,最南端晚至约60ka BP.与该地区已有钻孔磁性地层学资料进行对比,认为长江三角洲部分区域沉积年龄超过百万年和"北厚南薄、东厚西薄"的特征,主要是受早期区域构造背景的影响,而长江三角洲大范围的沉积发生自约200ka BP以来,受构造缓慢沉降和海平面变化控制的细颗粒(黏土-粉砂粒级)从晚更新世才开始沉积,约60ka BP以后扩大至整个三角洲区域.     

基于GIS的地震灾害损失预测

在地震危险性分析及建筑物和生命等的易损性分析的基础上，预测未来地震造成自然和人工建筑环境的灾害及其损失，这是地震灾害及其损失研究的基本思路。本文基于宏观经济指标的地震灾害损失预测模型，以2000年全国不变价格计算的人均GDP作为地震宏观易损性的分类指标，以某市（A、B县）为例进行未来15年地震灾害损失预测。其预测结果包括两大部分：县行政区预测结果和网格预测结果，其预测结果可以为确定地震重点监视防御区提供参考依据。     

长江三角洲地区全新世以来海面变化与古洪水发生关系探讨

通过对长江三角洲地区埋藏古树、泥炭、以及海相贝壳测年资料以及地方志、历史文献当中关于研究区洪灾事件记录的搜集、整理,研究结果表明,由于长江三角洲地区地势低平这一地貌特点,使得海面变化对于研究区洪灾的发生有着重要的影响.在长江中下游地区,海面的上升是导致冰后期长江河谷泥沙加积的主要原因,随着海面的上升和河床的抬高,长江中下游的水位也随之上升,从而导致长江洪水期排泄不畅,加重了洪灾的影响,加上长江三角洲地势低平,使海面变化成为长江三角洲地区洪灾发生的一个重要影响因子.同时,海面上升对长江水流的顶托作用也是加剧洪灾危害的一个重要原因.本文对于未来研究区洪水发生的预测,加强海岸带地区自然灾害的预防工作,减少生命财产的损失,具有一定的理论与实践意义.     

Stable Continental Region Earthquakes in South China

— This paper reviews some remarkable characteristics of earthquakes in a Stable Continental Region (SCR) of the South China Block (SCB). The kernel of the SCB is the Yangtze platform solidified in late Proterozoic time, with continental growth to the southeast by a series of fold belts in Paleozoic time. The facts that the deviatoric stress is low, the orientations of the major tectonic features in the SCB are substantially normal to the maximum horizontal principal stress, and a relatively uniform crust, seem to be the major reasons for lack of significant seismicity in most regions of the SCB. Earthquakes in this region are mainly associated with three seismic zones: (1) the Southeast China Coast seismic zone related to Guangdong-Fujian coastal folding belt (associated with Eurasia-Philippine Sea plate collision); (2) the Southern Yellow Sea seismic zone associated with continental shelf rifts and basins; and (3) the Downstream Yangtze River seismic zone spatially coinciding with Tertiary rifts and basin development. All three seismic zones are close to one or two major economic and population centers in the SCB so that they pose significant seismic hazards. Earthquake focal mechanisms in the SCB are consistent with strike-slip to normal faulting stress regimes. Because of the global and national economic significance of the SCB and its dense population, the seismic hazard of the region is of outstanding importance. Comparing the SCB with another less developed region, a pending earthquake with the same size and tectonic setting would cause substantially more severe social and economic losses in the SCB. This paper also compiles an inventory of historic moderate to great earthquakes in the SCB; most of the data are not widely available in English literature.     

广东揭汕潮地区城市群地震灾害及地震易损性分析

从历史最大地震烈度分布图分析,可知揭阳、汕头、潮州三市位于Ⅶ～Ⅷ度高地震烈度区。该城市群地震灾害有以下特点:市区发生破坏性地震的潜在危险性大;地震时市区地震烈度高,地震灾害大,损失严重。采用宏观经济易损性的地震损失分析方法,重演该区的历史破坏性地震。分析表明:抓好该区的防震减灾工作是保持社会和经济建设持续发展的一项重要工作。     

The down-faulted basin zone and high disaster risk zone in Shanxi Province, China

Introduction Since 1920s, with increasing awareness of disaster prevention and reduction in various as-pects and gradually deepened development of International Decade for Natural Disaster Reduction (IDNDR) activities in China, the role and position of disaster risk analysis and risk management work are increasingly prominent. In the final report of the IDNDR activities in 1999, the Science and Technology Committee of IDNDR had presented 5 challenge fields, which the international dis…     

山西断陷盆地带与灾害高风险区

山西省是我国地震、洪涝、气象和地质灾害及农作物生物灾害等众灾频发的地区.研究表明，山西断陷盆地带的形成与发展，为这些灾害的孕育发生创造了有利环境和条件，致使盆地地区成为山西地震、洪涝、气象和地质灾害及农业生物灾害等众灾频发，且相互作用、相互强化最严重的地区；加之盆地地区恰是山西人口、工农业生产和社会经济财产最集中的部位，两方面因素的共同影响，使得该地区成为山西最严重的灾害高风险区. 为了减轻山西省的自然灾害，保障其社会经济可持续发展，必须将盆地地区作为山西省的减灾重点区域，并进行综合减灾.      

通过望虞河引长江水济太湖的生态意义

Taihu Lake is the third largest fresh water lake in China, locating in Yangtze Delta as the richest area of China. At present, eutrophication problem is severe in Taihu Lake. This paper, in view of ecological system, presents analysis of the composition structural characteristics of Taihu Lake environment regarded as a whole ecological system, energy and substances circulation between ecological factors. The Taihu Lake ecological environment is proceeding a lake evolution period, i.e. middle-eutrophic to eutrophic. Therefore the diversion water''from Yangtze River to Taihu Lake through the Wangyu River acts to change external agent function for Taihu ecological system, i.e. increasing water quantity of Taihu Lake may rise water level and speed up flow exchanging. Moreover, with harnessing measures for pollution sources to reduce input of nutrients, natural evolution procedure of Taihu ecological environment may slow down to subsequently improve Taihu ecological environment.     

从汶川和芦山地震浅析四川地震次生地质灾害的特点及减灾对策

汶川和芦山地震后四川地震次生灾害频繁发生,以崩塌、滑坡、泥石流和堰塞湖最为常见,主要分布在川西高原、川西南山地的深切河谷地区以及四川地区周围山地.这些次生灾害以活动断裂为地质构造基础,以地表大量松散固体为物质来源,以强烈频繁的余震、坡面流水和暴雨洪水为动力条件,由此形成巨大的灾害链,造成大量人员伤亡和经济损失,其严重后果甚至极大地影响了抗震救灾工作的顺利开展.对于四川地震次生灾害的防治要加强监控,建立预警机制,开展风险评估,因害设防,分层防御.     

The trend, seasonal cycle, and sources of tropospheric NO2 over China during 1997-2006 based on satellite measurement

The characteristics of spatial and temporal distribution of tropospheric NO2 column density concentration over China are presented, on the basis of measurements from the satellite instruments GOME and SCIAMACHY. From these observations, monthly averaged tropospheric NO2 variations are determined for the period of 1997 to 2006. The trend and seasonal cycle are also investigated. The possible source of tropospheric NO2 over megacity area is discussed in this paper. The results show a large growth of tropospheric NO2 over eastern China, especially above the industrial areas with a fast economical growth, such as, Yangtze Rive Delta region and Pearl River Delta region because of the prominent anthropogenic activity. There is a rapid increase of tropospheric NO2 over megacities in China. For instance, Shanghai had a linear significant increase in NO2 columns of ～20% per year (reference year 1997) in the period of 1997-2006, which is the rapidest increase among all the selected cities. The seasonal pattern of the NO2 concentration shows a difference between the east and west in China. In the eastern part of China, an expected winter maximum in seasonal cycle is found because of the prominent anthropogenic activity and meteorological conditions. In the western part this cycle shows a NO2 maximum in summer time, which is attributed to natural emissions, especially soil emissions and lightning. A quickly increasing vehicle population may contribute to the increase of tropospheric NO2 over megacities in China for the remarkable correlation for vehicle population with tropospheric NO2.     

减轻地震灾害://c

回顾了过去4年来中国在减轻地震灾害方面的研究进展．地震灾害定量化的研究结果表明，随着社会经济的发展和人口城市化的加快，地震造成的灾害将越来越严重．减轻地震灾害的研究，出现了一些新的趋势:从研究地震危险性向研究地震危害性的过渡；从研究工程灾害向研究社会灾害的过渡；以及发展了以社区为中心的减灾体系．      

Application of the hidden Markov model in a dynamic risk assessment of rainstorms in Dalian,China

Disaster risk evolves spatially and temporally due to the combined dynamics of hazards, exposure and vulnerability. However, most previous risk assessments of natural disasters were static and typically based on historical disaster events. Dynamic risk assessments are required to effectively reduce risks and prevent future losses. Based on rainstorm disaster data and meteorological information collected in Dalian, China, from 1976 to 2015, the hidden Markov model (HMM) was used to detect inter-annual changes in rainstorm disaster risks. An independent sample test was conducted to assess the reliability of the HMM in dynamic risk assessments. The dynamic rainstorm risk in Dalian was simulated based on the observation probability matrix, which characterized the relationship dependence between rainstorm hazard and risk, and the probability matrix of state transition, which reflected the probability of changes for the risk level. High rainstorm risk was associated with high-hazard rainstorms and continuously appeared with little probability in several successive years. The reliability applied the HMM to simulate the rainstorm disaster risk was approximately 67% in the dynamic risk assessment. Additionally, the rainstorm disaster risk in Dalian is predicted to be at a medium-risk level in 2017, with a probability of 0.685. Our findings suggest that the HMM can be effectively used in the dynamic risk assessment of natural disasters. Notably, future risk levels can be predicted using the current hazard level and the HMM.     

以徐州为例初探城市社会因素地震易损性分析

徐州是我国震害预测试点城市之一。影响城市震害的主要因素是城市所处的地质背景——地质因素和城市现状——社会因素。本文以现场调查资料为基础,以宏观震害经验为依据,考虑建筑物结构类型、建筑质量、建筑密度、人口、空旷场地、道路和危险工业等社会因素,运用多因素易损性(vulnerabiliy)分析法,完成了徐州市社会因素地震易损性分析,指出了该市抗震的薄弱环节和薄弱地区,为抗震防灾提供了依据。 地震易损性分析的结果是地震易损性分析图,总的易损性指数M是编制易损性分析图的依据。在总的易损性指数M中,建筑物易损性指数b占60—70%,其为建筑物易损性趋势矩阵A乘以建筑物组成矩阵B的转置阵矩阵BT所得矩阵C的迹。      

长江中游城市群水资源承载力时空格局及耦合协调性

长江中游城市群是实施生态优先绿色发展战略的重点区域,从水资源承载系统内的水资源、社会、经济、生态环境4个子系统中选取24项指标构建水资源承载力评价体系,综合运用改进熵权TOPSIS模型、空间自相关分析和耦合协调发展模型定量评价2012-2018年长江中游城市群水资源承载力时空变化过程及子系统间的耦合协调性.结果表明,（1）长江中游城市群整体水资源承载力水平表现为：缓慢上升（2012-2015年）、下降（2015-2017年）、再上升的趋势（2017-2018年）;（2）水资源承载力的空间差异不明显（仅2016年差异显著）,武汉城市圈水资源承载力的空间差异相对较大且呈现低值包围高值的空间分布特征;（3）各城市生态环境子系统承载力得分较为均衡,但其他子系统的承载力均差异较大;（4）影响水资源承载力的主要因素依次为城市污水处理厂日处理能力、人均GDP、城镇化率、第三产业比重和人均水资源量;（5）长江中游城市群水资源承载系统的耦合协调度总体处于中等水平,且水资源承载力与耦合协调度有极强的正相关关系.研究结果可为长江中游城市群水资源承载力改善及水资源优化配置提供依据.     

Reduction of earthquake disasters

The article summarizes the researches on mitigating earthquake disasters of the past four years in China. The studyof earthquake disasters′ quantification shows that the losses increase remarkably when population concentrates inurban area and social wealth increase. The article also summarizes some new trends of studying earthquake disas-ters′ mitigation, which are from seismic hazard to seismic risk, from engineering disaster to social disaster andintroduces the community-centered approach.     

中国大陆地震灾害时空分布特征及地形影响因素分析

基于1990—2020年地震灾害损失(包括经济损失、人员死亡和人员受伤)数据,分析了过去30年中国大陆地区地震灾害损失的时空分布特征。采用常规标准化方法分析了1990—2019年我国大陆地区地震灾害经济损失的时间分布,认为地震灾害在过去30年间逐渐由人身安全威胁向经济财产威胁转变。通过整理分析2011—2020年各省地震灾害的空间分布特征,认为有必要进一步强化四川、云南、甘肃的抗震设防工作,提升其抵御灾害地震风险的能力;在中东部经济较发达地区,应尤其关注地震造成的间接经济损失和人员受伤情况。通过各省的提取地形坡度因素,采用地统计方法定量计算地震损失与地形坡度因素间的空间相关性系数,认为在以自然条件为基础分析地震灾害的过程中,因震致死与地形的空间相关性不如经济损失和因震致伤高,结合过去30年地震灾害的时间分布特征,得出因震致死和因震致伤总体保持平稳,但经济损失急剧增长,且增长趋势越来越显著,这主要是由经济发展等社会人文因素导致。