伊犁河谷城市群夏季不同粒径大气颗粒物组分特征及来源解析

为研究伊犁河谷城市群不同城市不同粒径大气颗粒物的组分特征和来源,于2021年7月19—29日,在伊犁河谷城市群的伊宁市、伊宁县、察布查尔锡伯自治县（简称察县）和霍城县布设6个采样点采集大气PM_2.5和PM₁₀样品,对样品中的化学组分(无机元素、水溶性离子和碳组分)进行分析,并使用化学质量平衡模型对其来源进行解析。结果表明：研究期间伊犁河谷核心区城市群PM_2.5和PM₁₀浓度均处于较低水平,分别为（22.81±2.79）和（58.81±6.95）μg/m³;从空间分布来看,伊宁市和伊宁县的颗粒物浓度相对较高,霍城县和察县的浓度相对较低。化学组分质量重构结果表明,地壳元素是研究期间PM_2.5和PM₁₀的主要组分,占比分别为39.8%和54.1%;其次为有机物,占比分别为33.2%和19.8%;二次无机离子在PM_2.5和PM₁₀中也有一定占比,分别为20.2%和10.7%。源解析结果表明,PM_2.5主要来自二次颗粒物（29.1%）和扬尘源（28.3%）的贡献,工业源（16.1%）、机动车（10.5%）、燃煤源（9.3%）也均有一定贡献;PM₁₀中则以扬尘源的贡献最大（42.3%）,远高于二次颗粒物（14.7%）、工业源（14.1%）、机动车（8.4%）和燃煤源（7.3%）。

     

Cattle Grazing Mediates Climate Change Impacts on Ephemeral Wetlands

Abstract:  Climate change impacts depend in large part on land-management decisions; interactions between global changes and local resource management, however, rarely have been quantified. We used a combination of experimental manipulations and simulation modeling to investigate the effects of interactions between cattle grazing and regional climate change on vernal pool communities. Data from a grazing exclosure study indicated that 3 years after the removal of grazing, ungrazed vernal pools dried an average of 50 days per year earlier than grazed control pools. Modeling showed that regional climate change could also alter vernal pool hydrology. Increased temperatures and winter precipitation were predicted to increase periods of inundation. We evaluated the ecological implications of interactions between grazing and climate change for branchiopods and the California tiger salamander (  Ambystoma californiense ) at four sites spanning a latitudinal climate gradient. Grazing played an important role in maintaining the suitability of vernal pool hydrological conditions for fairy shrimp and salamander reproduction. The ecological importance of the interaction varied nonlinearly across the region. Our results show that grazing can confound hydrologic changes driven by climate change and play a critical role in maintaining the hydrologic suitability of vernal pools for endangered aquatic invertebrates and amphibians. These observations suggest an important limitation of impact assessments of climate change based on experiments in unmanaged ecosystems. The biophysical impacts of land management may be critical for understanding the vulnerability of ecological systems to climate change.     

赠曲河流域开发规划的环境影响优化调整方案研究

针对四川省甘孜州白玉县赠曲河流域开发规划进行了分析,发现在该流域实施梯级电站建设,存在淹没实物指标较大、破坏保护鱼类栖息地和淹没尾矿库等问题。论文结合当地环境条件和防护要求,从环境保护角度提出了调整规划河段范围、放弃支沟引水、调整梯级正常蓄水位和枢纽布置以及搬迁尾矿库等优化调整方案,为规划的合理实施和规划环评的开展提供了可资借鉴的参考。     

Environmental Contaminants in Blood, Hair, and Tissues of Ocelots from the Lower Rio Grande Valley, Texas, 1986–1997

The ocelot (Felis pardalis) isan endangered neotropical cat distributed within asmall range in the Lower Rio Grande Valley (LRGV), inTexas, U.S.A. Studies of the impacts of environmentalcontaminants in wild cats are few. Approximately onefourth of the estimated population (about 100) ofocelots in the LRGV was sampled to evaluate theimpacts of chlorinated pesticides, polychlorinatedbiphenyls, and trace elements on the population. Hairwas collected from 32 ocelots trapped between 1986–1992,and blood was collected from 20 ocelots trappedbetween 1993–1997. A few blood samples were obtainedfrom individuals recaptured two or three times. Tissue samples from 4 road-killed ocelots were alsoanalyzed. DDE, PCBs, and Hg were some of the mostcommon contaminants detected in hair and blood. MeanHg levels in hair ranged from 0.5 to 1.25 g g^-1 dw,Se from 1.5 to 3.48 g g^-1 dw, and Pb from 0.56 to26.8 g g^-1 dw. Mean DDE concentrations in plasma ranged from 0.005 g g^-1 ww to 0.153 g g^-1 ww, and PCBs ranged from 0.006 g g^-1 ww to 0.092 g g^-1 ww. Mean Hg levels in red blood cells rangedfrom 0.056 g g^-1 dw to 0.25 g g^-1 dw. Concentrations of DDE, PCBs, or Hg, did not increasesignificantly with age, although the highestconcentrations of DDE and Hg were found in olderanimals. Overall, concentrations of DDE, PCBs, and Hgwere low and at levels that currently do not pose anythreat to health or survival of the ocelot. This isfurther supported by good reproduction of the ocelotin the LRGV, where adult females averaged about 1.5kittens/litter. Thus, it seems that the current majorthreat to recovery of the ocelot in the LRGV may behabitat loss, although potential impacts of newgeneration pesticides, such as organophosphorus andcarbamate insecticides need further study.     

金沙江河谷大气二氧化碳浓度变化特征及影响因子

大气CO₂是重要的温室气体,其浓度变化与气候变化、植物生长、人类活动等密切相关.为了解高原地区近自然状态下大气CO₂浓度变化及其影响因子,选取气象要素变化较明显、人为干扰较少的金沙江河谷为研究对象,在谷底江岸边的稀树草坪上设置观测点,对大气CO₂浓度和主要气象要素进行连续对照观测,经数据计算并采用Pearson相关系数对其相关性进行分析.结果表明:①研究区大气c（CO₂）日变化和年变化均具有波动性,日最高值（316.2 μmol/L）和最低值（291.0 μmol/L）分别出现在09:00和13:00左右,年最高值（338.9 μmol/L）和最低值（228.5 μmol/L）分别出现在10月和7月;季节性变化呈春、夏两季低于秋、冬两季的特征.②研究区大气c（CO₂）与温度呈显著负相关（r=-0.97,P < 0.01）,即白天温度高而大气c（CO₂）低,夜间温度低而大气c（CO₂）高.研究区大气c（CO₂）与相对湿度呈显著正相关（r=0.97,P < 0.01）,00:00-07:00大气c（CO₂）和相对湿度均缓慢上升,09:00-12:00大气c（CO₂）和相对湿度均快速下降.研究区大气c（CO₂）与风速呈显著负相关（r=-0.93,P < 0.01）,其与风对大气c（CO₂）有扩散作用相关;不同季节大气c（CO₂）最高值或最低值所对应的风向有所不同.研究显示,金沙江河谷大气c（CO₂）的时间变化特征明显,其与温度、相对湿度、风速、风向等气象要素的变化密切相关.      

1998年长江流域暴雨洪水环流背景分析

１９９８年主汛期,由于西太平洋副热带持续偏南、偏强,中高纬度维持稳定的阻塞形势,６、７月雨带长期在鄱阳湖、没庭湖地区徘徊,造成长江中下游地区严重洪涝;８月随着副高北抬,长江上游出现多次强降水过程,长江干流受中下游洪水顶主上游洪峰下泻的影响,水位居高不下,多数水文站出现了超记录的历史最高水位。１９９８年的已成为一次少有的新的长江大洪水的典型。     

What is in a name? Language,framing and environmental justice activism in California's Central Valley

According to the environmental justice (EJ) literature, one important factor in the movement's success is the development of a frame linking inequality to the disproportionate presence of environmental toxins in low-income communities of colour. This article highlights the resonance of this frame among grassroots activists and professional advocates in California's Central Valley. However, through interviews and focus groups with activists and advocates in six Central Valley communities, we found that only the latter identified their work as EJ. Grassroots activists instead identified their work as about health, community development and environmentalism. Moreover, some were unfamiliar with EJ as a concept while others denied its applicability to their work. Theoretically, our findings suggest that frame resonance needs to be delinked conceptually from movement identification; it is possible for a movement's analysis of social problems and solutions to resonate among those who do not identify with the movement itself. Pragmatically speaking, this can prevent some grassroots activists who are directly affected by environmental racism from accessing the resources and networks that the EJ movement has painstakingly built, and suggests that movement leaders may need to increase their outreach to community groups.     

云南怒江流域可持续发展对策研究

论述了云南怒江流域可持续发展的战略意义 ,分析了该区域生态经济格局与资源环境特征 ,并提出了怒江流域可持续发展的对策建议。     

清江流域国土资源与可持续发展初探

国土资源是社会发展的基础要素 ,合理开发和高效利用国土资源是区域持续发展的根本保证。从清江流域的国土资源出发 ,分析了清江流域优越的水能资源、丰富的旅游资源、独特的气候资源、种类繁多的生物资源与矿产资源等区域持续发展的基础和优势。另一方面 ,清江流域脆弱的生态环境、频繁的自然灾害和落后的经济等在一定条件下限制着本区域的可持续发展。在综合分析的基础上 ,初步提出了清江流域在农业资源、水资源、旅游资源及人力资源开发、灾害治理方面的建议和对策 ,以期实现本区域社会经济的可持续发展。     

Distribution of polychlorinated biphenyls in the Fort Edward,New York,water system

Levels of polychlorinated biphenyls (PCBs) have been determined in the water, in the soils and sediments, and in the biota of a small upstate New York public water supply system, which is near the heavily polluted section of the Hudson River and a disposal site for PCB-containing waste. The impounded water exhibits a significant and relatively uniform level of Aroclor 1016, whereas the ground and surface waters supplying the reservoir do not. Rainfall, which exhibits a high level of Aroclor 1016, constitutes a small but significant source of PCB input. Soil and sediment samples exhibit significant median levels of both Aroclor 1016 and Aroclor 1254, but the local concentrations vary widely. The biota exhibit much higher PCB levels than the water or sediments, and show a strong preference for Aroclor 1254. The PCB levels in the macroinvertebrates are particularly high, suggesting that these organisms may provide a useful indicator for monitoring PCB contamination in aquatic systems. Risk assessment indicates that the lifetime incremental risk of cancer associated with the drinking water is below 10^–6. Management of such low levels of PCB contamination is best achieved by reducing the input of PCBs.