Rapid estimation of an earthquake impact area using a spatial logistic growth model based on social media data

Rapid estimates of impact areas following large earthquakes constitute the cornerstone of emergency response scenarios.However,collecting information through traditional practices usually requires a large amount of manpower and material resources,slowing the response time.Social media has emerged as a source of real-time‘citizen-sensor data’for disasters and can thus contribute to the rapid acquisition of disaster information.This paper proposes an approach to quickly estimate the impact area following a large earthquake via social media.Specifically,a spatial logistic growth model(SLGM)is proposed to describe the spatial growth of citizen-sensor data influenced by the earthquake impact strength after an earthquake;a framework is then developed to estimate the earthquake impact area by combining social media data and other auxiliary data based on the SLGM.The reliability of our approach is demonstrated in two earthquake cases by comparing the detected areas with official intensity maps,and the time sensitivity of the social media data in the SLGM is discussed.The results illustrate that our approach can effectively estimate the earthquake impact area.We verify the external validity of our model across other earthquake events and provide further insights into extracting more valuable earthquake information using social media.

Numerical Study on the Impacts of Heterogeneous Reactions on Ozone Formation in the Beijing Urban Area

The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore the impacts of four heterogeneous reactions on O3 formation in an urban area. The results showed that the impacts were obvious and exhibited the characteristics of a typical response of a VOC-limited regime in the urban area. For the four heterogeneous reactions considered, the NO2 and HO2 heterogeneous reactions have the most severe impacts on O3 formation. During the O3 formation period, the NO2 heterogeneous reaction increased new radical creation by 30%, raising the atmospheric activity as more NO→NO2 conversion occurred, thus causing the O3 to rise. The increase of O3 peak concentration reached a maximum value of 67 ppb in the urban area. In the morning hours, high NO titration reduced the effect of the photolysis of HONO, which was produced heterogeneously at night in the surface layer. The NO2 heterogeneous reaction in the daytime is likely one of the major reasons causing the O3 increase in the Beijing urban area. The HO2 heterogeneous reaction accelerated radical termination, resulting in a decrease of the radical concentration by 44% at the most. O3 peak concentration decreased by a maximum amount of 24 ppb in the urban area. The simulation results were improved when the heterogeneous reactions were included, with the O3 and HONO model results close to the observations.

A Review of Assessment and Adaptation Strategy to Climate Change Impacts on the Coastal Areas in South China

This paper reviews assessment of climate change impacts on economy,society and ecological environment in the coastal areas of South China based on published literatures;it also proposes suitable adaptation strategies and countermeasures.Review shows that climate change has resulted in sea level rise in the coastal areas of South China,increasing the occurrence and intensity of storm surges,aggravating the influence of saltwater intrusion,coastal erosion,urban drainage and flood control,threatening the coastal facility and infrastructures,inundating lowland areas,ofsetting mudflat silting,and degrading mangroves and coral reef ecosystem.Therefore,in order to reduce the adverse efects of climate change and to support the sustainable development in the coastal areas of South China,it is critical to improve the monitoring and early warning system,enhance prevention criteria,fortify coastal protection engineering,strengthen salt tide prevention,and reinforce the ecological restoration and protection.

Assessment of Human Impacts on Vegetation in Built-up Areas in China Based on AVHRR,MODIS and DMSP_OLS Nighttime Light Data,1992–2010

Since the reform and opening-up program started in 1978,the level of urbanization has increased rapidly in China.Rapid urban expansion and restructuring have had significant impacts on the ecological environment especially within built-up areas.In this study,ArcGIS 10,ENVI 4.5,and Visual FoxPro 6.0 were used to analyze the human impacts on vegetation in the built-up areas of 656Chinese cities from 1992 to 2010.Firstly,an existing algorithm was refined to extract the boundaries of the built-up areas based on the Defense Meteorological Satellite Program Operational Linescan System(DMSP_OLS)nighttime light data.This improved algorithm has the advantages of high accuracy and speed.Secondly,a mathematical model(Human impacts(HI))was constructed to measure the impacts of human factors on vegetation during rapid urbanization based on Advanced Very High Resolution Radiometer(AVHRR)Normalized Difference Vegetation Index(NDVI)and Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI.HI values greater than zero indicate relatively beneficial effects while values less than zero indicate proportionally adverse effects.The results were analyzed from four aspects:the size of cities(metropolises,large cities,medium-sized cities,and small cities),large regions(the eastern,central,western,and northeastern China),administrative divisions of China(provinces,autonomous regions,and municipalities)and vegetation zones(humid and semi-humid forest zone,semi-arid steppe zone,and arid desert zone).Finally,we discussed how human factors impacted on vegetation changes in the built-up areas.We found that urban planning policies and developmental stages impacted on vegetation changes in the built-up areas.The negative human impacts followed an inverted′U′shape,first rising and then falling with increase of urban scales.China′s national policies,social and economic development affected vegetation changes in the built-up areas.The findings can provide a scientific basis for municipal planning departments,a decision-making reference for government,and scientific guidance for sustainable development in China.

Impact on Mountainous Agricultural Development in the Three Gorges Reservoir Area forced by Migrants of the Three Gorges Project

The Three Gorges Project attracts worldwide attention because of the Three Gorges migrants, and the agriculture of the Three Gorges Reservoir Area is a foundation for the development of the Three Gorges migrants. The Three Gorges Reservoir Area is situated at the mountainous area with bad agricultural development conditions and relatively low levels of development. As a result, the large-scale migration has special influence on its agricultural development, which has attracted much attention. The paper analyzes influence that the migrants have forced on its agricultural development based on the scientific data, and makes some explorations on the models that are suitable for the development of mountainous agriculture in the Three Gorges Reservoir

Assessment and impact of anthropogenic disturbances in protected areas of northern Togo

These days, human activities in the savanna and the remaining dry and riparian forests of the Sudanian ecoregions continue to have their impact. These anthropogenic practices are still the main cause of disturbances in these areas. In order to investigate and assess the importance of these disturbances, caused by people bordering on protected areas and to determine the relation between these activities and the environment in which they are carried out, 220 samples were selected in the three main protected areas of northern Togo. The investigation was mainly qualitative, considering the floristic sampling of this drought area; any anthropogenic activities observed were recorded. A simple investigative questionnaire about the activities of rural people in the reserved areas was distributed to individuals encountered in the study area. Each sample in the investigation ended with a site description of its ecologi- cal characterization, i.e., soil features, topography, fauna footprints, dominant plant species and GPS position; we also took photo- graphs of the site. Data processing was entirely based on descriptive statistics and a factor analysis. The results show that eight kinds of human activities, i.e., the use of pastures, tree cutting, bush fires, charcoal production, harvesting of plant material, fanning, honey harvesting and hunting, were noted to be serious disturbances to the integrity of the ecosystems. Among these disturbances, three are recurrent in all the sampled areas of which the use of pastures accounts for 31.88%, tree cutting for 30.35% and bush fires for 30.13%. Fire and pasture disturbances are closely linked and are responsible for the current features of the savanna area of the region. Tree cutting is more a direct function of the need for the production of wood fuel, generally used by city populations. Hunting, farm- ing and honey production are of lesser importance in the area and therefore, do not pose a significantly negative effect on the growth of fauna and flora. Knowledge of these disturbances in the context of requalification and a renewed demarcation of protected areas in Togo is essential for their sustainable management.

A numerical study of the impact of SST anomaly in the warm pool area on atmospheric circulation in winter

In this paper the impacts of the anomalous SST in the warm pool area of the Western Equatorial Pacific on the winter time circulation and the East Asian monsoon are studied by using the NCAR CCM. It is found that the abnormal heating in the warm pool area will change the strength and the position of the Walker Cell in the Equatorial Pacific and the anti-Walker Cell in the equatorial Indian Ocean. Both the Walker and anti-Walker Cells are strengthened. The local Hadley Cells over two hemispheres near the warm pool are also strengthened. The subtropical highs in two hemispheres become stronger and move poleward slightly. The westerly jets in the extratropical regions have similar changes as the subtropical highs. The winter monsoon in South-East Asia is weakened by the abnormal heating in the warm pool. The experiment also show that there are wave trains emanating from surrounding areas of the warm pool to the high latitudes, causing various changes in circulations and local weather.

Socio economic impact of vegetable production in Senegal:a case study of Niayes area

Vegetable production plays a very important role not only as a source of foreign exchange for Senegal and an appreciation of the dietary needs of populations,but also in the context of the policy of diversification.Thus the aim of this analysis is to measure the important economic impact and vegetable industrial actors,find the limited factors of the horticulture development and the perspectives for improving the vegetable production in the area.Our results show that the National production of fruits and vegetables is estimated approximately at 370,000 tons and the Niayes zone constitutes 80%of the domestic production.Horticulture is a sector which creates employments in that area with important incomes earned by both producers and the various intermediaries(commercial process) .The volume of exports has reached 14,321.588 tons in(2002-2003) against 11,125.132 tons in(2001-2002) witnessing than an increase of 28.7%,but the one of imports is very important and represents an outflow of foreign currency estimated at about 3 billion per year.

Characteristics and Methods of Groundwater Environmental Impact Assessment in Mining Areas of Guizhou Province:A Case Study of Zhijin Area of Zhina Mining Area

In Guizhou Province,karst areas and springs are widely distributed,and hydrogeological conditions are complex in mining areas. Usually there are many hydrogeological units in a mining area,and the hydrogeological conditions are very different from that of most northern mining areas in China. In view of the uniqueness of mining areas in Guizhou Province,taking Zhijin area of Zhina mining area as an example,the planning characteristics of mining areas and characteristics of groundwater environment in Guizhou Province were analyzed firstly,and then the characteristics and key considerations of groundwater environmental impact assessment in mining areas of Guizhou Province were studied. For example,when the height of water flowing fractured zone,impact radius,and the amount of water resources affected are calculated,it is necessary to analyze and evaluate as many typical mines as possible. The impact on springs as the sources of residents＇ drinking water should be analyzed one by one.

BBNJ协定在国际海洋法上的制度创新

2023年在联合国总部通过的BBNJ协定是全球海洋治理的一个里程碑。该协定聚焦国际海洋法领域的重大和前沿问题,创设了规范海洋遗传资源的特殊法律制度、确立了适用于全球公海的海洋保护区制度、丰富了规范海洋活动的环境影响评价制度。为避免因不当介入国家间陆地或海洋争端而妨害协定的实施,BBNJ协定设计了若干条款,确保将协定排除适用于国家管辖海域或争议海域。上述成果填补了国际海洋法的许多空白,拓展了国际海洋法的调整对象,为发展海洋法律制度、推进全球海洋治理作出了贡献。

山区铁路隧道工程资源环境影响效应评估研究

山区地质复杂、环境敏感、生态脆弱,致使铁路隧道建设难度大,且在资源节约、环境保护等方面面临较高要求。绿色设计作为绿色建设的先行环节,对减少隧道建设对资源环境的扰动作用,达到资源节约、环境友好的目的起关键引领作用。为定量评估山区铁路隧道工程的资源环境影响效应、衡量隧道设计的绿色程度,提出一种山区铁路隧道工程资源环境影响效应分析方法。首先,基于“驱动力-状态-响应”模型(Driving force-State-Response,DSR),以隧道设计参数为驱动力指标、资源环境状况为状态指标、隧道设计措施为响应指标,构建山区铁路隧道工程资源环境影响效应评估指标体系,并建立各指标分级标准;其次,运用一种具有自学习自调整能力的支持向量回归模型(Support Vector Regression,SVR)对隧道工程的资源环境影响效应进行评估;再次,以驱动力指标和响应指标为分析对象,运用考虑指标间关联关系及叠加效应的敏感性分析法,甄别对隧道工程资源环境影响效应优化具有重要影响的隧道设计因素;最后,以某山区铁路隧道工程为例,得到该隧道工程的资源环境影响效应值为4.7157,对应等级为较好,表明该隧道工程绿色设计水平较好,资源集约节约利用较合理、环境保护力度较大,可为其他类似工况隧道工程的绿色设计提供借鉴。此外,分析结果显示,注浆加固效果是导致该隧道工程资源环境影响效应变化最敏感的因素,其次为清污分流比例,可着重从这2个方面进行优化设计,以实现隧道工程资源环境影响效应的进一步优化。研究结果验证了本文研究方法的适用性和可操作性,可为山区铁路隧道工程资源环境影响效应评估及明确隧道工程优化设计方向提供科学依据。

“三农”领域高校智库建设现状及发展路径探析

“三农”领域高校智库在“三农”问题分析、决策拟定及政策工具弥补纠正等方面发挥着重要作用。为促进中国“三农”领域学术研究与智库研究有效对接,分析相关高校智库建设现状,总结其发展行为、运行机制、成果水平等方面及特点。研究发现,中国“三农”领域的高校智库建设主要依托一批专业化的研究团队和学术机构,在“三农”领域智库中数量占比最高且呈现快速增长趋势,并表现出强烈的地域性特征,在推动农业产业高质量发展方面发挥重要作用;但面临着服务乡村振兴的激励有限、协同合作能力有限、农业生产活动复杂性与农村调查公益性、成果实效水平不高和政策转化力度不够、资源及资金投入缺乏多元化与灵活性等困境。针对此,提出发挥涉农学科优势、推动成果评价制度改革、营造良好生态体系、畅通资政服务渠道、打造政产学研联盟共同体、构建“旋转门”机制、与新农村发展研究院协同建设等对策建议,以期对“三农”领域高校智库体系的建设与转型升级有所裨益,更好地满足新时期全面推进乡村振兴战略的智力需求。

甘肃民族地区旅游影响感知对国家认同感的影响评价--以临夏回族自治州八坊十三巷景区为例

旅游目的地居民对国家认同感的持续提升是民族地区旅游业可持续发展的重要目标。文章以临夏州八坊十三巷景区为例,从居民旅游影响感知视角,探讨了旅游发展对当地居民国家认同感的影响,得出以下结论:(1)从旅游影响对国家认同感的影响感知来看,民族地区旅游目的居民对当地旅游发展带来的国家认同感更为敏感;(2)从旅游影响对国家认同感的影响评价来看,民族地区居民的旅游影响感知对国家认同感的综合影响评价较高。旅游业的发展进一步增强了人们的民族自豪感、文化自信以及对国家的功能依赖。

三峡库区弯曲河段大偏角船桥碰撞力分析

为研究船舶在大角度和高流速下与大跨度斜拉桥发生的碰撞响应,结合国内外相关规范对船桥碰撞中最大撞击力计算方法和撞击方式,对内河航运过程中可能发生的碰撞角度和方式进行分析,并以重庆外环江津长江大桥作为依托工程,采用附加质量法建立了7 000 t级散货船和等比例斜拉桥模型,计算了船舶在四种通航水位下的正撞、侧撞和漂撞的最大撞击力,比较各规范的计算值与数值模拟结果,对不同情况下的计算结果进行对比研究。结果表明,国内外各规范更适用于船舶撞击桥塔,撞击点位于桥梁承台时最大撞击力将远高于规范计算值;在船舶与桥梁正面碰撞中,《美国公路桥梁设计规范》(American Association of State Highway and Transportation Officials, AASHTO)计算值与模拟值吻合程度高;在侧撞中,尤其在撞击角度为10°~25°时,建议采用《公路桥梁抗撞设计规范》;船舶漂撞桥塔产生的撞击力大约为正向撞击的1/4,该情况可采用《铁路桥涵设计规范》进行计算。多角度船桥碰撞研究结果可为三峡库区高变幅水位下船桥碰撞安全风险评估和桥梁抗撞设计提供参考。

清至民国安康地区水旱灾害时空特征及对民众影响

探究历史时期水旱灾害发生规律可为灾害防治提供借鉴。以灾害文献为数据源,运用数理统计、空间分析和小波分析等方法,对研究区水旱灾害发生时空特征及对民众影响进行分析。结果表明:(1)清至民国安康地区发生水灾99次,平均3.09年发生1次;旱灾34次,平均9.00年发生1次。水旱灾害呈阶段性波动增加。(2)水旱灾害发生凸显季节性,春、夏和秋季水灾发生频次较高,旱灾集中在春季和夏季。双季节水旱灾害夏秋季较为显著。(3)水旱灾害发生呈空间差异性,水灾集中发生在安康县(市)、洵(旬)阳县、平利县和白河县;旱灾集中发生在汉阴县、平利县和白河县。(4)水旱灾害发生呈现周期性,灾害造成人口大量死亡、农业生产受损和民众的基础设施遭破坏。

山区涉河桥梁墩柱冲磨破坏机理及防护措施

近年来自然灾害频发,山区桥梁水毁事故时有发生,针对山区涉河桥梁墩柱冲磨性能的提升正逐渐成为研究热点。该文综述山区涉河桥梁墩柱冲磨破坏机理及防护措施研究现状,并针对一种新型防护措施的防护效果进行数值模拟分析,以期为应对桥梁结构冲磨破坏问题提供参考。

本钢板材炼钢厂氧枪喷头工作参数分析

氧枪是氧气转炉中的最重要工艺设备之一,其性能特征直接影响到冶炼效果和吹炼时间,从而影响最终的钢材性能和钢产量。氧枪通过氧气射流流股与熔池的相互作用来实现吹炼交互,这种作用取决于氧气射流达到熔池表面时的速度大小和其冲击面积、冲击深度,因此优化氧枪喷头的工艺参数和合理的结构设计非常重要。通过对本钢板材炼钢厂的氧枪喷头工作参数进行计算,结合现场的实际工况,得出最适合本钢的操作模式。

基于地理探测器和污染物实测的城市功能区PM2.5影响机制探究

为了探析不同用地的大气污染情况,文章选取了沈阳市和大连市的5种用地类型地块作为研究区,基于移动监测法对地面大气颗粒物浓度进行水平分布的实地监测,采用地理探测器模型探究PM2.5浓度与城市环境因子之间的影响机制。结果表明,在不同功能的区域中,土地利用性质不同,影响大气污染物空间分异的主要因素根据实际情况也有所不同。居住、工业、文教、旅游、商业区内影响大气污染物浓度的最主要因子分别是街道走向、天空开阔度、近水距离、贴线率和交通量,最主要因子与其他因子的交互增强作用也相对明显。