基于集对可拓耦合算法的尾矿库安全综合评价

针对尾矿库安全综合评价中“定性定量评价尾矿库安全等级”和“客观描述尾矿库安全状态变化趋势”的要求,采用集对分析方法和可拓理论,利用可拓距计算原理,建立尾矿库集对可拓耦合安全评价模型和尾矿库集对势的计算方法。利用RSCIE权重计算方法确定尾矿库评价指标的权重,将基于集对可拓耦合算法的尾矿库安全评价模型用于尾矿库各安全等级集对可拓联系度的分析中,并基于最大隶属度原则确定案例中的尾矿库为正常库,其集对可拓联系度为0.040 6,安全状态的集对势为9.26。结果表明:该尾矿库的安全等级为正常库,且其安全状态发展趋势为弱同势,说明尾矿库的安全状况发展趋势为正常库的态势不强,且向不安全状态转变的可能非常大,应该加强该尾矿库的日常安全管理。这与实际情况相符合,有效验证了该评价模型的可行性和实用性。     

重庆市主城区气象要素与空气质量相关性研究

基于重庆主城区2010-2012年逐日的气象要素和大气环境质量监测数据,对气象条件与空气污染指数(API)进行相关性研究,分析气象条件影响空气质量的机制及协同作用,明确显著影响空气质量的气象要素。结果表明,当天的空气质量与前一天的空气质量相关性非常显著;各气象要素之间存在明显的协同作用,共同影响主城的空气质量;主城空气质量与大部分气象要素之间存在着相关性。其中空气污染指数与降雨、风速的相关性尤为密切。以期本研究成果能为重庆蓝天行动提供技术支持。     

城市景观格局与大气颗粒物污染的关系研究

随着城市化和工业化发展,大气颗粒物对城市空气环境造成了严重污染,选取西安市作为研究区,分析不同时间和空间尺度下城市景观格局与大气颗粒物污染的关系。通过GIS软件、Fragstats4.2软件和SPSS软件对西安市2014年土地利用数据和2014年整年的大气颗粒物监测数据进行分析,结果显示,西安市土地利用类型分布较为集中;西安市大气颗粒物浓度的空间分布特征为浓度从市中心至城郊呈梯度递减趋势,在整体上呈现西北高于东南的倾向,大气颗粒物污染物浓度峰值基本都集中出现在建设用地范围内(PM10:102.7μg/m^3;PM2.5:99.7μg/m^3);相关性结果证实了城市景观格局与大气颗粒物浓度的空间分布特征。研究结果为中国西部内陆城市大气颗粒物污染控制、土地利用规划以及生态建设提供参考。     

填料床处理污染河水的冬季运行特性

对冬季填料床处理滇池流域污染河水进行了试验研究。结果表明：通过相关性分析可知,在2～6℃时,废砖块中微生物活性较低,温度回升后,微生物活性也随之增强;2～12℃时,废混凝土/沸石/煤渣组合生物量高,耗氧速率大且较为稳定,COD去除率保持在50%左右。降温期（5～12℃）时,废砖块对TN、NH⁺₄-N和DTP去除率最高,平均可达64.5%、64.7%和69.7%;低温期（2～6℃）时,废混凝土/沸石/煤渣组合对NH⁺₄-N、TN的去除率能达到56.4%～75.1%、56.5%～63.0%,大石子/小石子/煤渣组合削减DTP负荷量达到了2.1 g/(m²·d)。废砖块和大石子/小石子/煤渣组合分别适合在低负荷和高负荷下运行。综上所述,在整个试验过程中（2～12℃）,废混凝土/沸石/煤渣组合表现出了对COD、N和DTP去除率相对稳定的特征,是冬季处理滇池流域污染河水的适宜填料。     

PM2.5 over North China based on MODIS AOD and effect of meteorological elements during 2003‒2015

• The Taihang Mountains was the boundary between high and low pollution areas. • There were one high value center for PM_2.5 pollution and two low value centers. • In 2004, 2009 and after 2013, PM_2.5 concentration was relatively low. Over the past 40 years, PM_2.5 pollution in North China has become increasingly serious and progressively exposes the densely populated areas to pollutants. However, due to limited ground data, it is challenging to estimate accurate PM_2.5 exposure levels, further making it unfavorable for the prediction and prevention of PM_2.5 pollutions. This paper therefore uses the mixed effect model to estimate daily PM_2.5 concentrations of North China between 2003 and 2015 with ground observation data and MODIS AOD satellite data. The tempo-spatial characteristics of PM_2.5 and the influence of meteorological elements on PM_2.5 is discussed with EOF and canonical correlation analysis respectively. Results show that overall R² is 0.36 and the root mean squared predicted error was 30.1 μg/m³ for the model prediction. Our time series analysis showed that, the Taihang Mountains acted as a boundary between the high and low pollution areas in North China; while the northern part of Henan Province, the southern part of Hebei Province and the western part of Shandong Province were the most polluted areas. Although, in 2004, 2009 and dates after 2013, PM_2.5 concentrations were relatively low. Meteorological/topography conditions, that include high surface humidity of area in the range of 34°‒40°N and 119°‒124°E, relatively low boundary layer heights, and southerly and easterly winds from the east and north area were common factors attributed to haze in the most polluted area. Overall, the spatial distribution of increasingly concentrated PM_2.5 pollution in North China are consistent with the local emission level, unfavorable meteorological conditions and topographic changes.     

基于多元统计方法的某地浅层地下水污染来源分析

为查明某地农田灌溉水井水质污染致使作物生长受损事件的污染来源,对研究区10眼水井进行了水质检测分析,并采用多元统计方法判断污染来源。结果表明:研究区水样中全盐量普遍超过农田灌溉水质标准,总硬度、硫酸盐、氨氮和氰化物等也存在不同程度的超标;水样中全盐量、氨氮与氰化物的含量之间存在显著正相关,具有共同的来源,且与河流A补给关系密切;地下水中盐分过高是造成作物受损的主要原因;地下水中全盐量、氨氮及氰化物等主要污染物来源于上游的焦化企业。基于多元统计方法的地下水污染来源分析结果可为当地地下水污染防治及管控提供环境管理依据。     

Considering built environment and spatial correlation in modeling pedestrian injury severity

Objective: This study looks at mitigating and aggravating factors that are associated with the injury severity of pedestrians when they have crashes with another road user and overcomes existing limitations in the literature by focusing attention on the built environment and considering spatial correlation across crashes.

Method: Reports for 6,539 pedestrian crashes occurred in Denmark between 2006 and 2015 were merged with geographic information system resources containing detailed information about the built environment and exposure at the crash locations. A linearized spatial logit model estimated the probability of pedestrians sustaining a severe or fatal injury conditional on the occurrence of a crash with another road user.

Results: This study confirms previous findings about older pedestrians and intoxicated pedestrians being the most vulnerable road users and crashes with heavy vehicles and in roads with higher speed limits being related to the most severe outcomes. This study provides novel perspectives by showing positive spatial correlations of crashes with the same severity outcomes and emphasizing the role of the built environment in the proximity of the crash.

Conclusions: This study emphasizes the need for thinking about traffic calming measures, illumination solutions, road maintenance programs, and speed limit reductions. Moreover, this study emphasizes the role of the built environment, because shopping areas, residential areas, and walking traffic density are positively related to a reduction in pedestrian injury severity. Often, these areas have in common a larger pedestrian mass that is more likely to make other road users more aware and attentive, whereas the same does not seem to apply to areas with lower pedestrian density.     

北京市第三产业用水特征及其发展策略

第三产业在北京市的产业格局中占有日益重要的地位,从水资源配置的视角探寻三产结构优化策略具有重要现实意义。采用LMDI分解方法,定量分析北京市第三产业用水结构变化驱动力特征,基于投入产出法计算各行业部门的用水系数,并进行用水特性和行业关联的聚类分析。结果表明,产业规模的快速增长是第三产业用水需求增长的决定性因素,2007-2013年间,累计使总用水量增加了34 476.24万m~3,产业结构效应和技术效应则对用水量的增加起抑制作用,两者分别使用水量减少2 861.29万m~3和21 908.17万m~3,产业结构效应和技术效应对用水的抑制作用不及经济产出效应对用水的拉动作用,最终导致用水量的增长。不同行业之间的用水系数有较大差异,水利、环境和公共设施管理、教育等行业的用水系数相对较大,批发和零售业、金融业的用水系数相对较小,科学研究技术服务和地质勘查等行业的用水乘数较大。第三产业中的高用水行业包括住宿和餐饮业等7个行业部门,潜在高用水行业包括批发和零售业等6个行业;一般用水行业为居民服务和其他服务业。聚类分析结果表明,对于诸如租赁和商务服务业及科学研究技术服务业等感应度系数较大的行业,应优先保障水资源的供给,使用高配额、低水价的管理方式;对于文化体育业等感应度系数较小的行业,可使用低配额、高水价的管理方式,限制用水量;对于配额高且水耗低的产业,可采取水权转让手段,将富余的水权转让给水耗高且产出高的产业。最后,针对研究结果,提出水权交易、技术推广、政策管理与机制构建四方面建议,为第三产业经济增长与用水之间的协调发展提供借鉴。     

老年人旅游消费与影响因素关联度分析——基于京津冀地区2006-2013年面板数据

我国现阶段65岁以上老年人享有较好的社会保障体系,具有一定的物质基础和精神需求,对出行旅游具有强烈的欲望.在我国人口老龄化趋势逐渐加重的驱使下,刺激老年人出行旅游能够极大的促进消费,带动内需增长.为了科学制定拉动老年人旅游的政策措施,本文从《中国统计年鉴》(2006-2013年)中选取65岁以上人口比、老年抚养比、城镇人口比重、城镇基本养老保险基金支出、文盲人口占15岁及以上人口、接受高等教育人数、以及地区最终消费支出作为主要的比较指标;从《中国旅游统计年鉴》(2006-2013年)中选取65岁以上旅游人数比与65岁以上人口旅游消费支出作为主要参考指标,分别对相关数据进行了灰色关联分析.分析结果显示,选取的比较指标与参考指标之间呈现了中等以上强度的关联性,关联度均在0.6以上,65岁以上人口、老年抚养比、城镇人口比重相对2个参考指标关联度最强,城镇人口数量与受教育情况业是影响65岁以上旅游人数的重要因素,分析结论可以作为国家和地方政府在制定养老产业相关政策时的重要参考.本研究的最后,提出了完善社会福利保障体系和旅游业法律法规,提高养老保险水平,保障老年人旅游市场安全及制定差异化价格战略等措施.