企业安全氛围测评的实证研究

安全氛围是影响企业安全生产的重要因素,首先在理论分析的基础上明确安全氛围的定义及其包含的主要研究内容,提出安全氛围构成的关键元素,开发测评工具,并构建基于主成分分析法和四分象限图分析法的测评数据分析模型。采用主成分分析法具体描述各关键元素对企业安全氛围的影响度值;应用四分象限图分析法进一步分析,根据元素的影响度值将元素划分至"优势区"、"优先改进区"、"深入改进区"和"维持优势区"4个区域,为企业改进安全氛围提供更为具体直观的参考。提出的测评工具及测评数据的定量分析模型在一定程度上克服定性评价的不足,可以在不同类型的企业应用。     

小波分析在PM10浓度时间序列分析中的应用

以西安市PM10日平均浓度时间序列为例,根据小波分析的基本原理,应用小波分解和重构对PM10浓度时间序列的变化进行了分析,得到PM10的年变化趋势和突变特征。研究结果表明,用小波分析应用于大气污染物浓度时间序列的分析是可行的。     

青南地区城镇污水处理厂综合效率评估分析

青南地区地处青藏高原腹地,是我国多条大江大河发源地,该地区污水处理对下游江河水环境质量改善具有重要意义.对青南地区(玉树、果洛和黄南)污水处理厂的综合效率进行定量评估分析并指出制约其效率提升的因素,对推动该地区污水处理产业的后续发展具有重要意义.因此,本文以青南地区11座城镇污水处理厂为研究对象,利用层次分析法和模糊综...     

环境变化对滦河流域径流影响的定量研究

为了研究气候变化和人类活动(环境变化)对地表径流的定量影响程度,应用有序聚类分析法等确定了滦河流域径流变化的基准期和人类活动影响期,采用HBV模型还原了人类活动影响期间滦河流域天然径流量,识别了气候变化、人类活动对滦河流域人类活动影响期间径流的定量影响程度.研究结果表明:1979年之前是滦河流域径流序列的基准期,基准期内HBV水文模型对滦河流域天然径流过程具有良好的模拟效果.1980年以后人类活动对滦河流域地表径流影响加剧,天然径流与实测径流产生分离,人类活动影响期(1980-2007年)相对于基准期(1960-1979年)的变化而言,气候变化、人类活动影响因素对地表径流的影响分别占径流减少总量的55%和45%,人类活动在不同水平年对地表径流量的影响不同.随着人类活动影响的加剧,气候变化对滦河流域径流的影响在逐渐减弱,人类活动对该流域的影响在增强.     

Impacts of Variable Climate and Effluent Flows on the Transboundary Santa Cruz Aquifer

Assessing groundwater resources in the arid and semiarid borderlands of the United States and Mexico represents a challenge for land and water managers, particularly in the Transboundary Santa Cruz Aquifer (TSCA). Population growth, residential construction, and industrial activities have increased groundwater demand in the TSCA, in addition to wastewater treatment and sanitation demands. These activities, coupled with climate variability, influence the hydrology of the TSCA and emphasize the need for groundwater assessment tools for decision‐making purposes. This study assesses the impacts of changes in groundwater demand, effluent discharge, and climate uncertainties within the TSCA from downstream of the Nogales International Wastewater Treatment Plant to the northern boundary of the Santa Cruz Active Management Area. We use a conceptual water budget model to analyze the long‐term impact of the different components of potential recharge and water losses within the aquifer. Modeling results project a future that ranges from severe long‐term drying to positive wetting. This research improves the understanding of the impact of natural and anthropogenic variables on water sustainability, with an accessible methodology that can be globally applied.     

Trends in Raindrop Kinetic Energy with Modeled Climate Warming in the Lake Tahoe Basin

Two means by which climate change may increase surface soil erosion in mountainous terrain are: (1) increasing the frequency of extreme rainfall events and (2) decreasing the duration of snow cover on bare soil. We used output from four general circulation models (GCMs) and two greenhouse gas trajectories to produce a suite of hydrologic variables at a daily time‐step for historic and projected 21st Century conditions. We statistically disaggregated the daily rainfall to hourly, using hourly rainfall from a network of nine weather stations in the Tahoe Basin, and filtered out rain falling on a snowpack. We applied published equations to convert hourly intensity to raindrop kinetic energy (KE) for each day and grid cell in the Basin, averaged across grid cells, and created time series of total annual and maximum annual hourly kinetic energy (TKE and MKE) on snow‐free ground. Using the Generalized Extreme Value distribution, we calculated the significance of long‐term trends in KE on snow‐free ground, and estimated energy levels for return periods of 2, 20, and 100 years. We then detrended the snowpack data and compared the resulting trends in KE with the trends resulting from changes in both rainfall energy and snowpack under two GCMs. Principal findings include (1) upward trends in MKE, (2) stronger upward trends in TKE; and (3) an effect of increasing rainfall intensities on KE in some cases, and a strong effect of reduced snowpack in all cases examined.     

Impact of Changing Climate and Land Cover on Flood Magnitudes in the Delaware River Basin,USA

Changing climate and land cover are expected to impact flood hydrology in the Delaware River Basin over the 21st Century. HEC‐HMS models (U.S. Army Corps of Engineers Hydrologic Engineering Center‐Hydrologic Modeling System) were developed for five case study watersheds selected to represent a range of scale, soil types, climate, and land cover. Model results indicate that climate change alone could affect peak flood discharges by ?6% to +58% a wide range that reflects regional variation in projected rainfall and snowmelt and local watershed conditions. Land cover changes could increase peak flood discharges up to 10% in four of the five watersheds. In those watersheds, the combination of climate and land cover change increase modeled peak flood discharges by up to 66% and runoff volumes by up to 44%. Precipitation projections are a key source of uncertainty, but there is a high likelihood of greater precipitation falling on a more urbanized landscape that produces larger floods. The influence of climate and land cover changes on flood hydrology for the modeled watersheds varies according to future time period, climate scenario, watershed land cover and soil conditions, and flood frequency. The impacts of climate change alone are typically greater than land cover change but there is substantial geographic variation, with urbanization the greater influence on some small, developing watersheds.     

The effect of summer drought on the predictability of local extinctions in a butterfly metapopulation

The ecological impacts of extreme climatic events on population dynamics and community composition are profound and predominantly negative. Using extensive data of an ecological model system, we tested whether predictions from ecological models remain robust when environmental conditions are outside the bounds of observation. We observed a 10-fold demographic decline of the Glanville fritillary butterfly (Melitaea cinxia) metapopulation on the Åland islands, Finland in the summer of 2018 and used climatic and satellite data to demonstrate that this year was an anomaly with low climatic water balance values and low vegetation productivity indices across Åland. Population growth rates were strongly associated with spatiotemporal variation in climatic water balance. Covariates shown previously to affect the extinction probability of local populations in this metapopulation were less informative when populations were exposed to severe drought during the summer months. Our results highlight the unpredictable responses of natural populations to extreme climatic events.     

气候变化研究的中国知识贡献及其影响局限

气候变化知识的不断深化和积累是全球气候治理的基础。政府间气候变化专门委员会(IPCC)邀请全球有代表性的科学家,通过分析评估国际上正式发表的文献,提供关于全球气候变化科学进展的最新认识结论。本文基于文献计量学,通过统计中国在气候变化十大重要领域的科技成果产出量和影响力、中国政府和科学家对IPCC评估报告的参与以及中国大陆引文在IPCC第五次评估报告中的贡献,分析了中国对全球气候变化知识的贡献与局限。结果表明:近十年来,中国在气候变化大多数领域的科技成果产出量已居全球第二或第三位,但在海洋与气候变化、适应气候变化和全球气候治理领域的国际论文量明显落后;与美国和英国相比,中国气候变化科技成果的各类影响力指标明显偏低;中国对IPCC评估报告的参与度和影响力在不断提升,中国积极组织相关机构和专家参与IPCC评估工作,对全球气候治理起到了重要的科学支撑作用;但从IPCC第五次评估报告中国大陆引文的角度看,中国贡献仍整体偏弱,中国大陆引文的贡献呈领域分布不均衡,优势领域少,成果影响面窄的特点。与科学基础领域相比,中国在影响和适应、减缓和国际合作领域的科学贡献更弱,对全球视角关注不够,但中国大陆引文总体的国际科学合作活跃度较高。后巴黎时代,中国需要更加面向国家需求、气候公约和《巴黎协定》目标以及国际气候变化科技前沿,加强全球视野和原始创新,突出中国优势和特色,使气候变化的中国研究成果更多支撑全球气候治理进程的推进。     

中国农村环境问题的法律思考

改革开放以来,随着中国农村经济的快速发展,农村环境问题也日益突出,严重影响了社会主义新农村建设的“生产发展、生活宽裕、乡风文明、村容整洁、管理民主”目标和要求的实现,阻碍了农村乃至全国经济、社会和环境的协调发展。加强农村环境保护,是新农村建设的当务之急,是全面建设小康社会和构建和谐社会的迫切要求。文中在现有研究的基础上,考察农村环境问题之现状,从法律视角,深入分析农村环境的问题之所在,提出解决农村环境问题的对策,努力探寻一条与中国农村实际相适合的生态环境保护道路。