地震灾害死亡人口快速评估方法对比研究   总被引：1，自引：0，他引：1  

王曦  周洪建  张弛 《地理科学》2018,38(2):314-320

中国是世界上地震活动最为频繁的国家之一,属于地震多发区。在收集分析国内外关于地震灾害死亡人口评估模型的基础上,选取10种模型以2000年以来中国典型地震灾害为案例验证其适用性。结果表明：① 对于5.7级（含）以下地震,10种模型的评估结果基本都在合理范围内,可采用各评估结果的区间值来支撑应急决策;5.7~6.6级（含）地震,10种评估方法得到的结果表现出不同程度的偏差,可采用多数评估结果指向的死亡人口数量级来支撑应急决策;6.6级以上地震,则只能采用有特定适用范围的基于结构易损性的评估结果来支撑应急决策,且也存在较大的不确定性。② 从地震灾害人员伤亡动态评估方法、地震—地质灾害死亡人口快速评估方法和快速评估软件系统方面进行了相关讨论。此研究可为地震灾害死亡人口快速评估模型的改进与发展提供借鉴。  相似文献   

基于地貌分区的1990-2015年中国耕地时空特征变化分析   总被引：7，自引：0，他引：7  

程维明  高晓雨  马廷  徐新良  陈印军  周成虎 《地理学报》2018,73(9):1613-1629

地形地貌通过分配地表水分和热量制约耕地的利用形式和成效,对耕地质量具有非常重要的决定意义,以地貌分区的视角研究中国耕地变化具有重要意义。根据1990-2015年中国6期土地利用空间数据和地貌分区数据,运用GIS空间叠加分析方法,分析中国耕地1990-2015年的面积变化和空间分布格局,进一步探讨不同地貌分区下的耕地新增与流失方向。结果表明,中国耕地面积略有增加,但总体变化不大,耕地面积从1990年的17715万hm²增加到2015年的17851万hm²,平均每年增加5.44万hm²,每年增幅仅为0.03%。耕地主要分布在平原地区,台地、丘陵次之;新增耕地主要来源为草地、林地和未利用地。东部平原低山丘陵区（I）耕地面积最大,而西北高中山盆地高原区（IV）耕地动态度明显高于其他地貌区。空间上呈现“南减北增,新增耕地的重心向西北移动”的特征。1990-2015年间,西北高中山盆地高原区（IV）和东部平原低山丘陵区（I）为耕地面积增长区,平均每年增加耕地面积分别为8.9万hm²和5.4万hm²;东南低山丘陵平原区（II）和西南中低山高原盆地区（V）为耕地面积减少区,平均每年减少耕地面积分别为5.9万hm²和2.8万hm²;而华北—内蒙东中山高原区（III）和青藏高原高山极高山盆地谷地区（VI）耕地面积几乎没有变化,平均每年变化仅为0.15 万hm²和0.06万 hm²。耕地流失主要发生在东部平原低山丘陵区（I）和东南低山丘陵平原区（II）,主要原因为城镇化进程加快带来的建设用地对优质耕地的大量占用;而新增耕地主要发生在西北高中山盆地高原区（IV）,多来自于对草地和未利用地的开垦。  相似文献   

柴达木盆地盐湖锂矿床成矿过程及分布规律   总被引：2，自引：1，他引：1  

余俊清  洪荣昌  高春亮  成艾颖  张丽莎 《盐湖研究》2018,26(1):7-14

柴达木盆地盐湖蕴藏230×10~4t锂,集中分布在别勒滩、东西台等4个盐湖,占我国卤水锂资源总量~80%,战略资源地位不言而喻。近年来提锂技术及工程化研究倍受重视,而对盐湖锂矿成因和分布规律的了解凸显不足,锂矿资源流失严重与之不无关联。研究查明,昆仑山高温热泉群含锂泉水长期注入洪—那河,流入终端盐湖,蒸发富集成矿;锂的年输入通量748.8 t,结合区内盐湖锂矿总储量保守估算,成矿期始于14 ka BP之后;洪—那河早期主要流向别勒滩,在山前冲积扇向北推进、扇前河改道北流后,方才形成含锂河水当前分配格局。据此,破解了别勒滩锂矿在研究区储量最大的原由。还查明了锂矿床仅存在于别勒滩,而在达布逊等3个区段不能成矿的原因。阐明了锂的来源与新生代火山喷发岩、深部岩浆房、昆仑大断裂活动有关,以及含锂热水持续远程输送至盐湖成矿的地貌和水文气候动因。企业应当根据锂的分布规律和矿床特征,迅速转变钾肥生产模式。  相似文献   

晚冰期以来大柴旦盐湖沉积记录的古气候演变及其尘暴事件          下载免费PDF全文

高春亮  余俊清  闵秀云  成艾颖  洪荣昌  何先虎  张丽莎 《盐湖研究》2018,26(1)

本文选择大柴旦盐湖DCD03沉积剖面柱硼镁石矿层下伏土黄色淤泥质粉砂层为研究对象,基于AMS ₁₄C年代学、岩性地层学、矿物学以及地球化学等研究方法,旨在探讨土黄色湖相淤泥质粉砂沉积记录的尘暴事件,以及重建晚冰期以来西风环流显著影响区的水文气候变化。研究结果表明,DCD03沉积剖面的淤泥质粉砂样品粒度频率曲线呈现为双峰态,主峰(均值10 μm)反映了河流作用携带入湖的细粒组分,次峰(﹥32 μm)则反映了风力作用以及河流作用等携带入湖的粗粉砂粒组分。大于64 μm的砂砾组分可能代表外源风尘物质的输入,由尘暴天气携带入湖。大柴旦地区晚冰期以来依次出现了博令和阿勒罗德暖期(12.94~12.17 cal. ka BP)、新仙女木冷期(12.17~11.37 cal. ka BP)、不稳定的早全新世气候(11.37~8.64 cal. ka BP)以及趋于偏冷干的中全新世早期(8.64~7.39 cal. ka BP)。  相似文献   

Village-level multidimensional poverty measurement in China: Where and how   总被引：2，自引：2，他引：0  

Yanhui Wang  Yefeng Chen  Yao Chi  Wenji Zhao  Zhuowei Hu  Fuzhou Duan 《地理学报(英文版)》2018,28(10):1444-1466

Village is an important implementation unit of national poverty alleviation and development strategies of rural China, and identifying the poverty degree, poverty type and poverty contributing factors of each poverty-stricken village is the precondition and guarantee of taking targeted measures in poverty alleviation strategies of China. To respond it, we construct a village-level multidimensional poverty measuring model, and use indicator contribution degree indices and linear regression method to explore poverty factors, while adopting Least Square Error (LSE) model and spatial econometric analysis model to identify the villages’ poverty types and poverty difference. The case study shows that: (1) Spatially, there is obvious territoriality in the distribution of poverty-stricken villages, and the poverty-stricken villages are concentrated in contiguous poverty-stricken areas. The areas with the highest VPI, in a descending order, are Gansu, Yunnan, Guizhou, Guangxi, Hunan, Qinghai, Sichuan, and Xinjiang. (2) The main factors contributing to the poverty of poverty-stricken villages in rural China include road construction, terrain type, frequency of natural disasters, per capita net income, labor force ratio, and cultural quality of labor force. The main causes of poverty include underdeveloped road construction conditions, frequent natural disasters, low level of income, and labor conditions. (3) Chinese poverty-stricken villages include six main subtypes, and most poverty-stricken villages are affected by multiple poverty-forming factors, reflected by a relatively high proportion of the three-factor dominant type, four-factor coordinative type, and five-factor combinative type. (4) There exist significant poverty differences in terms of geographical location and policy support, and the governments still need to carry out targeted poverty alleviation measures according to local conditions. The research can not only draw a macro overall poverty-reduction outline of impoverished villages in China, but also depict the specific poverty characteristics of each village, helping the government departments of poverty alleviation at all levels to mobilize all kinds of anti-poverty resources.  相似文献   

Quantitative Analysis of Central Asian Countries’ Energy Security and Its Political Influence Factors     

CHEN Xiaopeng  CHENG Shengkui  WU Liang 《资源与生态学报(英文版)》2018,9(4):434-443

Central Asian countries are located in the heartland of the Eurasian Continent. Their geographic location puts their energy flows under tremendous geopolitical pressure from the countries along their limited number of pipelines. With energy trade data from the United Nations Comtrade Statistics Database in the period from 2005 to 2016, this paper evaluates energy security of Kazakhstan and Turkmenistan (exporter) and Kyrgyzstan (importer) using three standards: correlativeness, diversity, and the impact of international relations. It concludes that Kazakhstan and Turkmenistan’s oil markets are balanced in terms of correlation and diversification, and thus less subject to geopolitical pressure. Turkmenistan’s gas markets, on the other hand, still have tremendous exposure to geopolitical risks for lack of diversification. Kyrgyzstan, as an energy importer, could rely on a few neighboring countries for energy supply. We found out that the three Central Asian countries’ energy security is largely determined by four political factors: the relationship with Russia, the new “great game” in Eurasia, the rise of China, and Central Asian regional geopolitical configuration.  相似文献   

Estimating the Correlated Observation-Error Characteristics of the Chinese FengYun Microwave Temperature Sounder and Microwave Humidity Sounder     

Ting WANG  Jianfang FEI  Xiaoping CHENG  Xiaogang HUANG  Jian ZHONG 《大气科学进展》2018,35(11):1428-1441

In operational data assimilation systems, observation-error covariance matrices are commonly assumed to be diagonal.However, inter-channel and spatial observation-error correlations are inevitable for satellite radiances. The observation errors of the Microwave Temperature Sounder(MWTS) and Microwave Humidity Sounder(MWHS) onboard the FengYun-3A(FY-3A) and FY-3B satellites are empirically assigned and considered to be uncorrelated when they are assimilated into the WRF model's Community Variational Data Assimilation System(WRFDA). To assimilate MWTS and MWHS measurements optimally, a good characterization of their observation errors is necessary. In this study, background and analysis residuals were used to diagnose the correlated observation-error characteristics of the MWTS and MWHS. It was found that the error standard deviations of the MWTS and MWHS were less than the values used in the WRFDA. MWTS had small inter-channel errors, while MWHS had significant inter-channel errors. The horizontal correlation length scales of MWTS and MWHS were about 120 and 60 km, respectively. A comparison between the diagnosis for instruments onboard the two satellites showed that the observation-error characteristics of the MWTS or MWHS were different when they were onboard different satellites. In addition, it was found that the error statistics were dependent on latitude and scan positions.The forecast experiments showed that using a modified thinning scheme based on diagnosed statistics can improve forecast accuracy.  相似文献   

Comparison of a Manual and an Automated Tracking Method for Tibetan Plateau Vortices     

Julia CURIO  Yongren CHEN  Reinhard SCHIEMANN  ANDrew G.TURNER  Kai Chi WONG  Kevin HODGES  Yueqing LI 《大气科学进展》2018,35(8):965-980

Tibetan Plateau vortices(TPVs) are mesoscale cyclones originating over the Tibetan Plateau(TP) during the extended summer season(April–September).Most TPVs stay on the TP,but a small number can move off the TP to the east.TPVs are known to be one of the main precipitation-bearing systems on the TP and moving-off TPVs have been associated with heavy precipitation and flooding downstream of the TP(e.g.,in Sichuan province or over the Yangtze River Valley).Identifying and tracking TPVs is difficult because of their comparatively small horizontal extent(400–800 km) and the limited availability of soundings over the TP,which in turn constitutes a challenge for short-term predictions of TPV-related impacts and for the climatological study of TPVs.In this study,(i) manual tracking(MT) results using radiosonde data from a network over and downstream of the TP are compared with(ii) results obtained by an automated tracking(AT) algorithm applied to ERA-Interim data.Ten MT-TPV cases are selected based on method(i) and matched to and compared with the corresponding AT-TPVs identified with method(ii).Conversely,ten AT-TPVs are selected and compared with the corresponding MT-TPVs.In general,the comparison shows good results in cases where the underlying data are in good agreement,but considerable differences are also seen in some cases and explained in terms of differences in the tracking methods,data availability/coverage and disagreement between sounding and ERA-Interim data.Recommendations are given for future efforts in TPV detection and tracking,including in an operational weather forecasting context.  相似文献   

Acidity of Aerosols during Winter Heavy Haze Events in Beijing and Gucheng,China     

Xiyuan?Chi  Pengzhen?He  Zhuang?Jiang  Xiawei?Yu  Fange?Yue  Longquan?Wang  Bokun?Li  Hui?Kang  Cheng?Liu  Zhouqing?XieEmail author 《Acta Meteorologica Sinica》2018,32(1):14-25

We investigated the acidity and concentrations of water-soluble ions in PM_2.5 aerosol samples collected from an urban site in Beijing and a rural site in Gucheng, Hebei Province from November 2016 to January 2017 to gain an insight into the formation of secondary inorganic species. The average SO₄^2–, NO₃^–, and NH₄⁺ concentrations were 8.3, 12.5, and 14.1 μg m^–3, respectively, at the urban site and 14.0, 14.2, and 24.2 μg m^–3, respectively, at the rural site. The nitrogen and sulfur oxidation ratios in urban Beijing were correlated with relative humidity (with correlation coefficient r = 0.79 and 0.67, respectively) and the aerosol loadings. Based on a parameterization model, we found that the rate constant of the heterogeneous reactions for SO₂ on polluted days was about 10 times higher than that on clear days, suggesting that the heterogeneous reactions in the aerosol water played an essential role in haze events. The ISORROPIA II model was used to predict the aerosol pH, which had a mean (range) of 5.0 (4.9–5.2) and 5.3 (4.6–6.3) at the urban and rural site, respectively. Under the conditions with this predicted pH value, oxidation by dissolved NO₂ and the hydrolysis of N₂O₅ may be the major heterogeneous reactions forming SO₄^2– and NO₃^– in haze. We also analyzed the sensitivity of the aerosol pH to changes in the concentrations of SO₄^2–, NO₃^–, and NH₄⁺ under haze conditions. The aerosol pH was more sensitive to the SO₄^2– and NH₄⁺ concentrations with opposing trends, than to the NO₃^– concentrations. The sensitivity of the pH was relatively weak overall, which was attributed to the buffering effect of NH₃ partitioning.  相似文献   

市域脑卒中疾病与气象因素的关系及预测     

程学伟  韩兆洲 《气象》2018,44(6):837-843

为了帮助医疗机构合理调配医务力量、床位和医疗药物,同时也帮助脑卒中高危人群及时采取干预措施,降低发病风险。本文对某市[1]四家医院2013—2016年脑卒中的就诊病例进行数据分析,将日就诊人数分为6个等级。然后,调取相应时段当地的逐日气象资料,采用支持向量机(SVM)和随机森林(RF)方法分别建立了日就诊人数预测模型和日就诊人数与气象因素的关系模型。研究结果表明:(1)脑卒中的日就诊人数为不平衡数据,这种数据特征将导致传统的预测模型正确率较低;(2)通过不断调整SVM预测模型的初始权重,经历了4次优化之后,使得日就诊人数的预测正确率从52.46%上升到94.56%;(3)随机森林模型的结果显示,影响脑卒中发病率的三大气象因素分别是最高气温、最低气温和平均气温。基于机器学习模型的脑卒中疾病与气象因素的研究成果,提高了医疗气象统计模型的预报准确率,具有较高的应用和推广价值。  相似文献