Exploring the characteristics of major natural disasters in China and their impacts during the past decades

The exploration of the characteristics of natural disasters (NDs) and their impacts have important implications for guiding disaster prevention and mitigation. This paper discussed the characteristics of the major NDs that occurred in mainland China between 1980 and 2011 based on the number of disasters and fatalities, the affected population, and the resulting economic damages. We further examined the relationships between the level of social/economic development and the disaster losses. At last, we also explored the trend variations in disaster losses and losses expressed as a percentage of gross domestic product (losses/GDP) for 31 provinces in China over the period from 1990 to 2011. The results show that over the past three decades, the number of major NDs and the number of affected population appear to exhibit a detectable increasing trend, while the direct economic losses and the deaths show a slight increase trend. The correlations between the number of disasters and the economic losses as well as deaths and between the economic losses and socioeconomic status were not significant (p > 0.05), which indicates that the growth in the number of disasters do not result in a significant increase in the disaster losses. Further investigations demonstrate that as economies develop, there are fewer losses/GDP in China over the past two decades. The per capita accumulative losses and losses/GDP in the western and central regions were higher than that in the eastern parts of China. There are significant regional differences in the trends in disaster losses and losses/GDP in China. Statistics also indicate that more than 70 % provinces in underdeveloped regions show an increasing trend in disaster losses, whereas exceeding 90 % provinces exhibit a decreasing trend in their losses/GDP. These results suggest that the economic development may have played an important role in improving the capacity of disaster prevention and reduction.     

Integrated risk assessment of multi-hazards in China

Maps of population exposure, vulnerability and risk to natural hazards are useful tools for designing and implementing disaster risk mitigation programs in China. The ranking of provinces by relative risk to natural hazards would provide a metric for prioritizing risk management strategies. Using provinces as our study unit, from the perspectives of hazard exposure, susceptibility, coping capacity and adaptive capacity, this study first constructed China’s disaster risk index for five types of major natural hazards: earthquakes, floods, droughts, low temperatures/snow and gale/hail. Then, the relative risk level at the provincial scale in China was assessed. Finally, the hotspots with the highest hazard exposure, vulnerability and risk were identified. The results showed that high exposure was a significant risk driver in China, whereas high vulnerability, especially social vulnerability, amplified the risk levels. Similar to the population exposure to disasters, the relative risk levels in the southwestern, central and northeastern regions of China were significantly higher than those in the eastern, northern and western regions. The high-risk regions or hotspots of multi-hazards were concentrated in southern China (less-developed regions), while the low-risk regions were mainly distributed in the eastern coastal areas (well-developed regions). Furthermore, a nonlinear relationship existed between the disaster risk level and poverty incidence as well as per capita GDP, demonstrating that disaster losses in middle-income areas are likely to increase if economic policies are not modified to account for the rising disaster risk. These findings further indicated that research on disaster risk should focus not only on hazards and exposure but also on the vulnerability to natural disasters. Thus, reducing vulnerability and population exposure to natural hazards would be an effective measure in mitigating the disaster risk at hotspots in China.     

Spatiotemporal changes in population distribution and socioeconomic development in China from 1950 to 2010

Complex factors, including those associated with human and natural geography, have contributed to a longstanding imbalance in the relationship between population distribution and socioeconomic development in eastern and western China. Applying the population distribution structure index, the Gini coefficient of population distribution, and analysis of the movement of the population center of gravity and spatial autocorrelation, this study simultaneously analyzes the spatial characteristics of population density in China and the trends in its temporal and spatial variation from 1950 to 2010. It was found that while China’s population distribution has increasingly balanced development, the overall pattern of the spatial distribution has not changed significantly. Although the “Hu Huanyong Line” is still a valid representation of the country’s population distribution, the population distribution in parts of Gansu, Ningxia, and Inner Mongolia has extended the boundary of the Hu Huanyong Line. The Chinese population has experienced a trend of movement towards the west. While the congruence between the population distribution and economic development of the country as a whole was relatively low, it was relatively high in the northeast and the relationship is steadily improving. Compared with the eastern and central regions, the western region has experienced a fluctuating and weakening trend.     

Assessment of provincial social vulnerability to natural disasters in China

Assessment of social vulnerability has been recognized as a critical step to understand natural hazard risks and to enhance effective response capabilities. Although significant achievements have been made in social vulnerability researches, little is know about the comprehensive profile of regional social vulnerability in China. In this study, the social vulnerability to natural hazards was firstly divided into socioeconomic and built environmental vulnerability. Then, using factor analysis, we identified the dominant factors that influence the provincial social vulnerability in China to natural hazards based on the socioeconomic and built environmental variables in 2000 and 2010 and explored the spatial patterns of social vulnerability. The results indicated that the provincial social vulnerability in China showed significant regional differences. The social vulnerability in the southeastern and eastern regions of China was greater than its northern and central parts over the past decade. Economic status, rural (proportion of agricultural population and percentage of workers employed in primary industries), urbanization, and age structure (children) were the dominant driving forces of variations in provincial socioeconomic vulnerability in two studied years, while lifelines and housing age could explain most of changes in built environmental vulnerability in 2000 and 2010. There were no statistically significant correlations between social vulnerability and disaster losses (p > 0.05), indicating the impact of disasters was also related to the intensity of hazards and exposure. Disaster relief funds allocated to each province of China depended more on its disaster severity than the regional integrated social vulnerability over the past decade. These findings would provide a scientific base for the policy making and implementation of disaster prevention and mitigation in China.     

中国地质灾害时空分布特征与形成条件

中国地质灾害种类多、分布广、频次高、强度大、灾情严重。在气候、地形、地质构造和社会条件等多种因素影响下, 不同地区地质灾害的种类、强度和破坏程度差异巨大, 全国可分为东部和西部两大灾害区, 两大灾害区又可进一步划分为12个亚区。地质灾害活动具有不规则准周期性和累进性特点。多数地质灾害在强弱变化中显示不断增强的趋势。从可持续发展高度来说, 防治地质灾害是一项长期而又艰巨的任务。     

西部地区交通建设中的泥石流灾害与防治对策

我国西部地区铁路、公路交通干线共有泥石流灾害 4 70 0余处, 占全国道路泥石流灾害的 70 %以上。泥石流分布广泛, 成灾方式多样, 灾害严重, 制约了西部地区交通建设的发展。本文提出了做好路线方案比选, 防患于未然, 正确评判泥石流沟和发育现状, 工程设计要适合泥石流特点, 以及提高防灾减灾勘察设计水平, 开展泥石流防治试验示范工程研究等六条防治对策。     

中国自然灾害的分布与分区减灾对策

文中以中生代以来的地壳运动形成的纬向构造带、北东—北北东向构造带、北西—北北西向构造带、经向构造带所控制的山川地貌及相关的地质环境、气候环境和生态环境为基础 ,综述了中国重大自然灾害的空间分布格局 ,提出了自然灾害宏观分布之东西分区、南北分带的规律 ;从自然灾变、承灾体的密度、价值和脆弱性及社会减灾能力三重因素 ,分析揭示了中国自然灾害的直接损失具有东部和南部高、西部和北部低 ,相对损失呈现中南部高 ,向东、向西和向北都逐渐降低的空间展布特征和自然灾害在时间上呈波动增长的特点。基于中国自然灾害分布的地区差异性 ,文章强调在中国必须实行分区减灾 ,即 ,根据灾情和国情的不同划分减灾区 ,采取不同的减灾对策。基于此 ,文中将中国划分为城市减灾区、东部沿海减灾区、中部减灾区、西部减灾区和海洋减灾区 ,同时还分别提出了与各减灾区特点相适应的分区减灾对策。     

Regional effects of natural disasters in China: investing in post-disaster recovery

We examine the effects of natural disasters on income and investment in China. Using macroeconomic province-level data and the provincial history of disaster exposure over the past two decades, we describe the relationship between disaster mortality and morbidity, disasters’ economic damages, government investment and regional economic activity, and infrastructure development. The Chinese government’s aggressive investment in post-disaster reconstruction is discussed, and the implications of this investment for post-disaster private sector economic activity are analyzed empirically. We further investigate the differential effects of natural disasters on economic activity in China’s diverse geographical regions.     

Regional effects of natural disasters in China: investing in post-disaster recovery

We examine the effects of natural disasters on income and investment in China. Using macroeconomic province-level data and the provincial history of disaster exposure over the past two decades, we describe the relationship between disaster mortality and morbidity, disasters’ economic damages, government investment and regional economic activity, and infrastructure development. The Chinese government’s aggressive investment in post-disaster reconstruction is discussed, and the implications of this investment for post-disaster private sector economic activity are analyzed empirically. We further investigate the differential effects of natural disasters on economic activity in China’s diverse geographical regions.

     

Characterizing the spatial distribution of typical natural disaster vulnerability in China from 2010 to 2017

Natural disaster vulnerability can intuitively reflect the susceptibility of an area to environmental changes. Better understanding the spatial distribution of natural disaster vulnerability is a critical process for taking effective adaptation and management. Although significant achievements have been made in disaster vulnerability, few studies are known about natural disaster vulnerability at the national scale, especially from the typical natural disaster events in China. In this study, with normalizing selected indicators and calculating vulnerability index, we analyzed the spatial distribution of natural disasters vulnerability during 2010–2017 using the geospatial techniques. The results showed that natural disaster vulnerability has certain spatial differences, but different natural disaster can occur in the same area during the study period. Drought disaster can occur in all regions of China, especially in Inner Mongolia. Flood disaster is mainly concentrated in the middle and lower reaches of the Yangtze River and the Yellow River Basin. The wind and storm disaster is chiefly in the northern regions in China. The freezing disaster is widely distributed in China. Furthermore, the regions with low vulnerability were primarily distributed in the eastern coastal region, indicating that the rapid development of economy and technology can resist or mitigate natural disaster to a certain extent. This study offers a solution to study natural disasters and provides scientific basis for disaster prevention and mitigation actions.

     

The regionalization of urban natural disasters in China

An integrated urbanization level (CL) index and an integrated natural disaster intensity (QC) index were developed on the basis of Disaster System Theory and China Natural Disaster Database for integrated urban disaster risk assessment. Integrated quantitative assessments of the urban socio-economic system and the intensity of hazards in China were carried out by the Model-Tupu (map series) and inter-feedback process using digital map technology. On the basis of this assessment, China can be regionalized into three regions, namely, coastal urban disaster region, eastern urban disaster region and western urban disaster region, 15 sub-regions and 22 units. These results can provide a scientific basis for determining a city’s disaster risk management and natural disaster relief regionalization in China.

中国西部大开发中的环境问题

笔者首先从经济、社会的角度阐述了西部大开发战略实施的必要性。依据国际、国内有关经济发展与环境破坏之间联系的研究成果，阐明中国当前发展过程中的环境变化。根据中国西部自然地理条件将广大的西部地区划分为三个地理分区，结合各区的自然条件、资源及产业结构特征，分析了不同分区在经济发展中可能出现的环境问题及可能的解决方法。     

Origin of natural gases and their differences between the eastern and western parts of central Tarim Basin

The origin of natural gases in central Tarim Basin is very complicated and there has been no definite conclusion in this aspect. Based on the results of systematic research on their composition and carbon isotopic characteristics, natural gases in central Tarim Basin are composed mainly of hydrocarbon gas, Ordovician natural gas with the characteristics of crude oil-cracking gas, and Carboniferous natural gas not only originating from kerogen cracking, but also from oil cracking. There are significant differences in composition and carbon isotope of natural gases between the eastern and western areas. The causes for the differences in geochemical characteristics of natural gases are presented as follows: different thermal evolution degrees of organic matter. Natural gases in the western region may have generated from the Middle- Upper Ordovician source rocks, and natural gases in the eatern region may be derived from the Cambrian source rocks, which entered into high to over mature stages; the gases migrated from west to east and caused the different compositional and carbon isotopic characteristics of natural gases; difference in the strength of thermal sulfate reduction between the eastern and western parts, with the reduction in the eastern part being stronger than that in the western part.     

中国的巨灾风险与巨灾防范

巨灾是指对人民生命财产造成特别巨大损失,对社会经济发展产生严重影响的自然灾害事件。我国巨灾主要为特大洪水、大地震以及特大风暴潮、持续性大面积干旱。新中国建立以来,共有18个年份发生巨灾。巨灾频发的根本原因是,自然条件复杂多变,多种异常动力活动强烈;减灾基础薄弱,巨灾防范能力不足。未来时期,巨灾对国家安全和社会经济威胁依然严重,预测有11个高风险区,分布在东部沿海和部分中部地区。巨灾防范对策包括:提高认识、加强研究、建立管理系统及预警系统、制定应急预案、加强国际合作交流等。      

基于风险度的青海省暴雨洪涝灾害风险评估

基于自然灾害风险原理,结合青海省气象数据、地理信息数据、社会经济数据,并利用主成分分析法、GIS自然断点法对青海省暴雨洪涝灾害致灾因子危险度、承载体易损度评估模型以及暴雨洪涝灾害风险度进行评估,结果表明：青海省不同强度降水日数均呈增多趋势,新世纪以来中雨日数及强降水日数增加趋势尤为明显;暴雨洪涝灾害致灾因子危险度呈由东南向西北降低的趋势,承载体易损度为东北部地区最高,南部以及西部地区最低;暴雨洪涝风险较高的地区主要集中在东部地区,互助、湟中、大通、西宁为高风险区,东部大部地区、环青海湖地区为较高风险区,西部地区为低风险区。该评估结果可以在气象灾害风险管理业务中进行应用,可以加强对暴雨洪涝灾害风险的影响程度及影响区域的判定,为地方防灾减灾救灾工作提供科学依据。     

祁连山中东部青海云杉径向生长对气候变暖的响应差异

气候变暖对森林生态系统产生了深刻影响,而树木生长对气候变化做出了不同的响应。本研究利用采自祁连山中、东部不同海拔梯度的青海云杉（Picea crassifolia）树轮样本,分别建立了中部和东部6个树轮宽度年表,分析了树木径向生长与各气候要素的关系以及随时间变化的稳定性。结果表明：祁连山中部青海云杉对降水和scPDSI较东部更为敏感。中部树轮宽度年表与当年5—7月的scPDSI极显著正相关（P<0.001）,东部树轮宽度年表与前一年9月和当年5月scPDSI显著正相关,表明中部LCH区域青海云杉径向生长主要受当年5—7月土壤水分条件的限制;东部XYH区域则受前一年9月和当年5月的土壤水分的限制。20世纪80年代中东部温度显著升高（P<0.001）,中东部树木生长受高温引起的干旱胁迫增强;20世纪90年代以后,由于中部降水增加而东部降水变化不明显,中部树木生长干旱压力得到缓解,东部森林受干旱的限制作用增强。此外,中东部青海云杉与温度、降水和scPDSI的相关关系逐渐趋向一致,未来气候的持续变暖或许将减小中东部树轮-气候关系的差异。     

Methodology for the assessment and classification of regional vulnerability to natural hazards in China: the application of a DEA model

This paper presents a new method for quantifying vulnerability to natural hazards in China. As an important area of vulnerability research, quantitative assessment of vulnerability has raised much focus in academia. Presently, scholars have proposed a variety of methods for quantitative assessment, which usually create an index of overall vulnerability from a suite of indicators, based on the understanding of the cause or mechanism of vulnerability. However, due to the complex nature of vulnerability, this approach caused some arguments on the indicator selection and the weight set for subindices. A data envelopment analysis?Cbased model for the assessment of the regional vulnerability to natural disasters is presented here to improve upon the traditional methods, and a new approach for the classification of vulnerability is proposed. The vulnerability to natural hazards in China??s mainland is illustrated as a case study. The result shows that the overall level of vulnerability to natural hazards in mainland China is high. The geographic pattern shows that vulnerability is highest in western China, followed by diminishing vulnerability in central China, and lowest vulnerability levels in eastern China. There is a negative correlation between the level of vulnerability and the level of regional economic development.     

青海省地质灾害防治资金投入与成效分析

因特殊的地质环境条件,我省地质灾害发育,加之近年来经济增长、城镇扩张、降雨增多等因素共同影响,地质灾害数量和经济损失都呈现上升的趋势,因此地质灾害防治显得尤为必要。为全面认识地质灾害防治投入和社会经济发展的关系,本文通过对近十年的地质灾害现状、地质灾害防治投入和经济发展数据进行分析研究,建立固定经济投入下的总体收益函数,认为虽然青海省近年来地质灾害防治效果较好,但是从整体看,我省地质灾害防治投入较低,未达到最佳收益点。因此,相关部门在兼顾经济发展的同时也要关注地质灾害防治工作,随着经济增长适当调整防治投入,不仅能有效控制地质灾害损失,而且也保障社会其他效益。     

1961 - 2018年河西走廊寒潮频次时空变化特征及其环流影响因素研究

寒潮是我国北方地区冬、 春、 秋季节常见气象灾害之一, 产生的危害严重影响社会经济发展和人们生产生活。河西走廊生态环境脆弱且处于寒潮影响的重要区域, 揭示河西走廊寒潮频次时空变化特征可以为农牧业防灾减灾提供参考。基于1961 - 2018年河西走廊12个气象站逐日最低气温数据, 采用数据统计和空间可视化表达方法, 分析近60 a河西走廊寒潮频次时空变化特征, 并探讨北极涛动（AO）异常与寒潮频次的响应关系。结果表明： 从时间上看, 河西走廊的寒潮主要发生在10月至4月, 其中11月、 12月、 4月为寒潮高发时期, 近60 a河西走廊寒潮频次呈现出下降的趋势, 其中在20世纪80年代出现明显的低值, 下降趋势在季节上表现为秋季>春季>冬季; 河西走廊寒潮发生频次具有显著的空间差异, 其中西部地区最多, 东部地区居中, 中部地区最少; 北极涛动（AO）强弱与河西走廊寒潮频次变化具有时空响应关系, 当AO处于负相位时, 河西走廊各气象站寒潮发生频次较多, 并且在河西走廊东部和西部表现的较为明显。     

关中-天水经济区空间流量经济分析——以铁路客运部门为例

由于经济系统与生态系统存在类质同像性,因此可应用源自生态系统的上升性理论来定量描述经济系统的增长与发展.在简单介绍了上升性理论的基础上,以关中-天水经济区铁路客流为例,对区域经济系统的上升性及其相关指标进行了计算.研究表明:2002-2006年的5 a间,关中-天水经济区的系统总吞吐量、平均相互信息、上升性指数、可持续发展能力和系统的多样性等5项指标均保持增长态势,由此判断关中-天水经济区处于经济系统进化的初级阶段.针对该区域经济系统中存在的自组织程度低下、结构失衡等与系统进化质量相关的缺陷提出了政策建议.