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241.
胡东滨  林媚  陈晓红 《中国环境科学》2022,42(11):5447-5456
基于2000~2019年浙江和安徽26个地级市的面板数据,使用合成控制法定量分析新安江3轮横向生态补偿试点政策对其水环境效益的总体性和结构性影响结果表明:政策效果在时间上存在异质性。第1、2轮政策试点显著的提升了新安江流域整体的水环境,但第3轮试点对上游水环境的影响是负的。政策效果在空间上存在异质性。流域横向生态补偿政策使下游的生物多样性价值平均提高了0.068亿元,但使上游生物多样性价值平均降低了0.015亿元。政策效果在结构上存在异质性。通过对水环境效益的结构性分解,发现横向生态补偿政策使新安江流域的水质净化能力价值平均提高了31.874亿元,但使其产品供给价值平均下降了13.402亿元。政策效果存在预期效益。流域横向生态补偿的政策效果在政策正式实施前2年已经出现。  相似文献   
242.
基于内容分析法的河流健康内涵及表征   总被引:2,自引:1,他引:2  
运用内容分析法对近10~15年中外文献中有影响力的36个河流健康概念进行分析,经过样本选取、指标提取、量化处理等过程提炼出最频繁出现的能代表其内涵的6个标准,即:维持结构完整性、自然生态功能发挥、满足人类社会合理需求、处于良好状态、河流管理工具和目标、建立河流基准状态。基于此,对河流健康概念进行了重新架构:河流健康是指河流生态系统特定的良好状况,可以作为河流基准状态以及河流管理的目标,在这一状态下,河流生态系统能够维持其生态系统结构完整性,充分发挥其自然生态功能,并满足人类社会合理需求,提供相应的社会服务功能。通过对30个有关河流健康表征指标及评价方法的文献进行分析,识别生物指标、水质参数、形态结构、河床底质、水文条件以及河岸带状况等是目前使用最广泛的6个指标,指出河流健康的表征指标及评价标准应根据区域特征、人类活动影响以及功能定位而有所差异。  相似文献   
243.
流域开发的外部性及其内部化   总被引:10,自引:3,他引:10  
流域是地表水的集水区域。流域问题的本质是水。水是可持续发展的基础和条件,是环境与发展问题的核心。流域开发是以水资源为先导和主体的综合资源开发。实现流域经济可持续发展实质就是实现流域水资源可持续开发和利用。外部性是流域开发的基本特征,水资源的特性决定了流域开发的外部性。实现流域开发的外部性内部化是流域经济可持续发展的关键。实现流域开发外部性内部化,必须界定流域资源产权,明确流域开发主体;建立税收-补贴体系,对水资源合理定价;坚持“排污者付费原则”;建立流域水资源市场,实现水资源资产化管理。同时,政府要加强流域的管理;建立健全水资源保护与流域开发的法律体系;普及保护环境和水资源的教育,建立节水观念;支持和鼓励流域开发企业实行外部成本内部化措施;调整产业结构,深化国有企业改革。  相似文献   
244.
城市河流是城市的生命线,对于当地经济发展和居民身心健康均有不可替代的重要作用。通过分析我国城市河流污染的总体现状发现,我国城市河流治污面临着城市化进程、区域利益分化、职能部门能力缺失等困境,以此为前提,分别从树立正确的城市河流治污观念、设立流域综合管理机构、预防为主和防控结合、建立科学合理的城市河流生态系统修复模式几方面提出完善对策。  相似文献   
245.
Spatially comprehensive estimates of the physical characteristics of river segments over large areas are required in many large‐scale analyses of river systems and for the management of multiple basins. Remote sensing and modeling are often used to estimate river characteristics over large areas, but the uncertainties associated with these estimates and their dependence on the physical characteristics of the segments and their catchments are seldom quantified. Using test data with varying degrees of independence, we derived analytical models of the uncertainty associated with estimates of upstream catchment area (CA), segment slope, and mean annual discharge for all river segments of a digital representation of the hydrographic network of France. Although there were strong relationships between our test data and estimates at the scale of France, there were also large relative local uncertainties, which varied with the physical characteristics of the segments and their catchments. Discharge and CA were relatively uncertain where discharge was low and catchments were small. Discharge uncertainty also increased in catchments with large rainfall events and low minimum temperature. The uncertainty of segment slope was strongly related to segment length. Our uncertainty models were consistent across large regions of France, suggesting some degree of generality. Their analytical formulation should facilitate their use in large‐scale ecological studies and simulation models.  相似文献   
246.
In policy support of municipal solid waste (MSW) management, life cycle assessment (LCA) can serve to compare the environmental or economic impacts of two or more options for waste processing. The scope of waste management LCAs generally focuses less attention on future developments, e.g., where will recycling take place, and more on the environmental performance of prototypes, e.g., the incineration of all waste compared to recycling. To provide more robust support for Swiss waste glass-packaging disposal, scenarios of Swiss waste glass-packaging are assessed from a life cycle perspective. The scenarios consist in schemes for the disposal of the total amount of Swiss waste glass-packaging, i.e., different combinations of recycling and downcycling in Switzerland or abroad developed in Part I, Meylan et al. (2013). In this article (Part II), the disposal schemes are assessed with respect to eco-efficiency, an indicator that combines total environmental impacts and gross value added in Switzerland. Results show that no policy alternative guarantees environmental impact reductions and gross value added gains under all developments of exogenous constraints. Downcycling to foam glass in Switzerland is not only an environmentally sound disposal option, but it also buffers gross value added losses in case domestic recycling (and thus glass-packaging production in Switzerland) ceases in the future. The substitution of products based on raw materials other than Swiss cullet is the main responsible for change in environmental and economic impacts. Hence, an eco-efficiency maximizing policy should consider the products of disposal schemes. The combination of scenario analysis and eco-efficiency assessment as presented in this paper can be applied to other contexts (i.e., countries, waste fractions).  相似文献   
247.
解江  郭琦  高军 《环境技术》2014,(2):20-25
作为装备贮存可靠性与贮存寿命评价的关键技术,加速寿命试验和加速退化试验已在工程中广泛应用,基于物理分析的贮存寿命特征检测技术也逐步在贮存寿命评价工程中开展。贮存寿命评价技术已有一套完整的理论基础并积累了大量的工程实践经验,但行业内至今仍缺少专门针对贮存寿命评价的软件工具。本文通过对贮存寿命评价工具箱的需求分析研究工作,构建了工具箱的技术框架,并给出工具箱各主要模块的业务流程图和业务概念图,为贮存寿命工具箱的开发提供了支撑。  相似文献   
248.
The temporal variation of greenhouse gas concentrations in China during the COVID-19 lockdown in China is analyzed in this work using high resolution measurements of near surface △CO2, △CH4 and △CO concentrations above the background conditions at Lin'an station (LAN), a regional background station in the Yangtze River Delta region. During the pre-lockdown observational period (IOP-1), both △CO2 and △CH4 exhibited a significant increasing trend relative to the 2011-2019 climatological mean. The reduction of △CO2, △CH4 and △CO during the lockdown observational period (IOP-2) (which also coincided with the Chinese New Year Holiday) reached up to 15.0 ppm, 14.2 ppb and 146.8 ppb, respectively, and a reduction of △CO2/△CO probably due to a dramatic reduction from industrial emissions. △CO2, △CH4 and △CO were observed to keep declining during the post-lockdown easing phase (IOP-3), which is the synthetic result of lower than normal CO2 emissions from rural regions around LAN coupled with strong uptake of the terrestrial ecosystem. Interestingly, the trend reversed to gradual increase for all species during the later easing phase (IOP-4), with △CO2/△CO constantly increasing from IOP-2 to IOP-3 and finally IOP-4, consistent with recovery in industrial emissions associated with the staged resumption of economic activity. On average, △CO2 declined sharply throughout the days during IOP-2 but increased gradually throughout the days during IOP-4. The findings showcase the significant role of emission reduction in accounting for the dramatic changes in measured atmospheric △CO2 and △CH4 associated with the COVID-19 lockdown and recovery.  相似文献   
249.
Abstract

A commercial formulation of Bacillus thuringiensis Berliner var. kurstaki (BTK), Foray® 48B, was sprayed aerially over four blocks B13, B14, B15A and B15B in an oak forest in Wayne County, Pennsylvania during May 1990. B13 and B14 were sprayed at 75 billion international units (BIU) in 5.91 litres/ha and the other two at 50 BIU in 3.94 litres/ha. Oak foliage was collected at different intervals of time after treatment. Three types of bioassays were conducted against fourth instar gypsy moth larvae, viz., direct feeding of sprayed foliage, feeding on diet containing homogenized foliage, and force‐feeding of foliar extracts. Larval mortalities were converted into international units of BTK activity per unit area (IU/cm2) of foliage. Foliar extracts were also subjected to enzyme‐linked immunosorbent assay (ELISA) to determine the concentration of delta‐endotoxin protein. Regardless of the type of bioassay used, bioactivity of BTK persisted in foliage for about a week in all the blocks. The half‐life of inactivation, DT50, ranged from ca 12 to 22 h. The immunoassay data indicated a shorter duration of persistence (i.e., about 2 d) of the delta‐endotoxin protein, with DT50 values ranging from 10 to 15 h. Formulation ingredients present in Foray 48B played a role in the toxicity of BTK to gypsy moth larvae.  相似文献   
250.
甘肃河西内陆河流域社会化水资源稀缺评价   总被引:2,自引:0,他引:2  
水资源稀缺是我国经济社会发展所面临的严重制约因素。水资源稀缺评价是水资源管理中最基础性的工作。借助Karshenas模型对资源利用同经济发展之间的关系进行了诠释;在界定水资源管理阶段的基础上。引入社会适应性能力概念。着重论述了其内在结构及其度量指标。从而将水资源稀缺问题拓展到了社会经济领域。强调社会资源在水资源稀缺评价中的作用。同时。建立社会化水资源稀缺指数。并以甘肃省河西内陆河流域五市为例进行了实证研究.结果表明:嘉峪关市由于相对较高的社会适应性能力。其社会化水资源稀缺程度指数的相对排序得到改善;而武威市则因相对较低的社会适应性能力。社会化水资源稀缺指数的排序有所降低;金昌市和张掖市尽管社会化水资源稀缺指数的相对排序没有变化。但由于考虑了社会适应性能力。水资源稀缺程度得到有效的缓解。社会化水资源稀缺指数更能如实反映水资源状况。社会适应性能力是一种重要的资源。对缓解水资源紧缺程度具有重要的作用。  相似文献   
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