Assessing conditional extremal risk of flooding in Puerto Rico

We model multivariate hydrological risks in the case that at least one of the variables is extreme. Recently, Heffernan JE, Tawn JA (2004) A conditional approach for multivariate extremes. J R Stat Soc B 66(3):497–546 (thereafter called HT04) proposed a conditional multivariate extreme value model which applies to regions where not all variables are extreme and simultaneously identifies the type of extremal dependence, including negative dependence. In this paper we apply this modeling strategy and provide an application to multivariate observations of five rivers in two clearly distinct regions of Puerto Rico Island and for two different seasons each. This effective dimensionality of ten-dimensions cannot be handled by the traditional models of multivariate extremes. The resulting fitted model, following HT04 model and strategies of estimation, is able to make long term estimation of extremes, conditional than other rivers are extreme or not. The model shows considerable flexibility to address the natural questions that arise in multivariate extreme value assessments. In the Puerto Rico 5 rivers application, the model clearly puts together two regions one of two rivers and another of three rivers, which show strong relationships in the rainy season. This corresponds with the geographical distribution of the rivers.

居住迁移对居民健康的影响研究进展述评

进入城市时代以来,居住环境与居民健康的联系愈发密切,尤其在“流动性"增强的大背景下,居住迁移对居民健康的影响问题受到广泛关注。论文结合知识图谱分析和文献研究法,系统评述居住迁移影响居民健康问题的最新进展。研究发现：① 近15 a来,该领域的文献数量逐年增多,关注度持续上升;文献空间分布主要集中在发达国家,但不同地区的研究内容存在显著差异。② 主要研究对象由“同质性群体”向“异质性群体”转变,从“一般性群体”向“特殊群体”转变;研究方法由数理统计向混合研究、综合应用转变。③ 研究视角经历“人口迁移—个体健康”“居住迁移—环境—个体健康”与“迁居轨迹—环境演变—个体健康发展”等3个演变阶段。④ 近期研究重点有：迁居行为与儿童健康,迁居时空特征与身心健康,住房生涯与身心健康,邻里环境、累积剥夺与健康发展等。结合以上分析,提出如下建议：注重“整合性”分析;关注城市内部迁居行为和多次迁居轨迹对居民健康的影响;扩大迁居引发的“环境”因素(如居住隔离、社会分异、职住空间错位等)研究;更多关注迁居对二代流动人口儿童健康的影响,侧重对非正规居住空间如“城中村”等的研究。     

中国城镇化对老年人健康的影响

基于2010年第六次全国人口普查微观数据和夜间灯光数据等,运用多层级logistic回归模型估计中国城镇化水平和速度与老年人自评健康的关联,分析城镇化健康效应在不同老年人群体间的差异,并运用倾向得分匹配方法,控制“自选择”机制对分析结果的干扰。结果表明：1）中国县区城镇化水平和速度与老年人自评健康呈显著正相关关系,居住于城镇化水平中等和城镇化速度较快县区的老年人更可能自评为健康;2）城镇化水平和速度与老年人自评健康的关系在不同受教育程度和户口状态的老年人群体间存在显著差异,城镇化水平和速度对受教育程度较低、持有本地户口老年人健康水平的提升效益更大;3）控制了老年人居住“自选择”的干扰后,县区城镇化水平和速度与老年人自评健康的正向关联依然稳健,表明“自选择偏误”对中国县区城镇化水平和速度与老年人自评健康的关系没有显著的影响。     

Health risk assessment for typical and abandoned chromium-contaminated sites

Chromium pollution were investigated by sampling the abandoned chromium contaminated sites in Chongqing. Its health risk was assessed following the procedures made by USEPA. The results showed that the most seriously polluted land was found at the former production area （G4） with average Cr（VI） concentration of 3369.2 mg kg-1 on the surface soil. The assessment indicated that there was high risk of non-carcinogens for children. The assessed risk of the first layer of office area （G1） for children, chromium slag transition （G2）, drainage pipeline chromium slag transition （G3） and production area （G4） for both children and adults were not acceptable （〉1.00× 106）. It was strongly suggested that the accessible measures of remediation should be taken for a portion of contaminated sites before the reuse of abandoned lands.     

传感器布设中有效独立法的简捷快速算法

本文提出一个通过正交三角分解快速计算有效独立法系数的方法。有效独立法是传感器布设中影响最广泛的一种方法,它使目标模态尽可能线性独立。传统的有效独立法计算需要对信息阵进行特征值分解或者计算矩阵逆,计算量较大。本文在笔者以前得出的有效独立法与模态动能法关系的基础上,提出先通过对模态矩阵进行正交三角分解（QR）,然后比较其行范数即可得到有效独立法的系数,进而对各待选传感器位置进行排序并迭代依次删除。在待选传感器位置比感兴趣的模态数较多时,该法的计算效率明显提高。同时,采用正交三角分解删除一行后的更新算法,进一步提高了迭代计算的效率。最后通过I-40桥的算例表明该法的有效性。     

Carbon dioxide and radon gas hazard in the Alban Hills area (central Italy)

The sudden and catastrophic, or slow and continuous, release at surface of naturally occurring toxic gases like CO₂, H₂S and Rn poses a serious health risk to people living in geologically active regions. In general this problem receives little attention from local governments, although public concern is raised periodically when anomalous toxic-gas concentrations suddenly kill humans or livestock. For example, elevated CO₂ concentrations have been linked to the death of at least 10 people in the central Italian region of Lazio over the last 20 years, while it was the CO₂ asphyxiation of 30 cows in a heavily populated area near Rome in 1999 which prompted the present soil-gas study into the distribution of the local health risk. A detailed geochemical survey was carried out in an area of about 4 km² in the Ciampino and Marino districts, whereby a total of 274 soil-gas samples were collected and analysed for more than 10 major and trace gas species. Data were then processed using both statistical and geostatistical methods, and the resulting maps were examined in order to highlight areas of elevated risk. General trends of elevated CO₂ and Rn concentrations imply the presence of preferential pathways (i.e. faults and fractures) along which deep gases are able to migrate towards the surface. The CO₂ and Rn anomalous trends often correspond to and are usually elongated parallel to the Apennine mountain range, the controlling structural feature in central Italy. Because of this fundamental anisotropy in the factors controlling the soil-gas distribution, it was found that a geostatistical approach using variogram analysis allowed for a better interpretation of the data. With regard to the health risk to local inhabitants, it was found that although some high risk areas had been zoned as parkland, others had been heavily developed for residential purposes. For example, many new houses were found to have been built on ground which has soil-gas CO₂ concentrations of more than 70% and radon values of more than 250 kBq m⁻³. It is recommended that land-use planners incorporate soil-gas and/or gas flux measurements in environmental assessments in areas of possible risk (i.e. volcanic or structurally active areas).     

FARM BILL MAY MEAN FUNDS FOR GEOGRAPHICAL RESEARCH

Millicent Todd Bingham was the first and only woman to earn a Ph.D. in the Department of Geology and Geography at Harvard. A talented linguist, she published in the classic tradition of the French school of human geography. Her professional geographic career came to a halt when she elected to edit the poems and letters of Emily Dickinson, work originally begun by her mother, Mabel Loomis Todd. Bingham's efforts resulted in the publication of several books and articles fundamental to the Dickinson scholarship. She credits her geographic training for much of her literary success.     

某农药厂场地土壤地下水污染修复指导值探讨

参考加拿大Alberta SGRG层次性分析模式,选择其中Tier 1、Tier 2两层次进行分析,结合适合我国的参数计算出了某农药厂土壤地下水中的有机污染物1,2-二氯乙烷、1,2-二氯丙烷修复值,得到了通用的Tier 1修复指导值分别为:渗坑土壤中1,2-二氯乙烷6.2μg/kg,1,2-二氯丙烷67μg/kg;场地地下水中1,2-二氯乙烷、1,2-二氯丙烷均为5μg/L。在此基础上,结合实地调查获取场地参数,利用Tier 2评价对指导值进行修正,确定了场地最终修复目标值:渗坑土壤中1,2-二氯乙烷为11μg/kg,1,2-二氯丙烷为45μg/kg;地下水中1,2-二氯乙烷、1,2-二氯丙烷仍为5μg/L。各途径修复值的改变较符合层次性评价的理论,即Tier 2修复值较Tier 1宽松;但1,2-二氯丙烷的保护DUA途径修复值较Tier 1更加严格,这是由于场地特定条件造成的。     

一种基于改进SEIR模型的突发公共卫生事件风险动态评估与预测方法——以欧洲十国COVID-19为例

突发公共卫生事件会严重影响社会公众生命健康,风险评估和预测可为突发公共卫生事件有效防控提供科学依据.本文提出了一种基于SEIR模型的突发公共卫生事件风险动态评估与预测方法,将突发公共卫生事件传播与人口、医疗、经济情况相结合,耦合危险性与脆弱性,建立合理的风险评估综合指标体系,利用熵值一层次分析组合模型实现突发公共卫生事...