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1.
Given the important role of land ecosystem in social-economic progress at regional, national, and international scale and concurrent degradation of land ecosystems under rapid urbanization, a systematic diagnosis of land ecological security (eco-security) for sustainable development is needed. A catastrophe model for land ecological security assessment was developed in order to overcome the disadvantages in subjectivity and complexity of the currently used assessment methods. The catastrophe assessment index system was divided into hierarchical sub-systems under the pressure-state-response framework. The catastrophe model integrated multiple assessment indices of land eco-security according to the inherent contradictions and relative importance of indices without calculating weights. Specifically, membership degree of higher level index was calculated based on the membership degrees of lower level indices that were subjective to suitable model, such as cusp, fold, swallowtail and butterfly model. This model was applied to evaluate the state of land eco-security in Shanghai. Mann–Kendall’s test was utilized to characterize its temporal trend between 1999 and 2008. Significant downward trend was identified for land eco-security, in terms of pressure sub-index, state sub-index, response sub-index and synthetic index. All these implied that land ecosystem conditions were not optimistic for Shanghai and such situation should draw the attention of policy makers. The calculation procedure presented in this paper does not require a high level of technical expertise to determine the membership degree, making it simple and operational. Being applicable to similar land ecosystems, the catastrophe model is thus believed to provide an alternative approach to land eco-security assessment.  相似文献   

2.
3.
黄河为世界上最长的多沙河流,全河段水沙异质性及其生态健康的空间差异明显。本文基于黄河干流全河段44个断面春秋两季(2019年)底栖动物的系统调查数据,构建黄河底栖动物生物完整性评价体系。该体系融入指示水沙过程变化的ASPT指数及EPT分类单元个体相对丰度,且参照点与受损点得分差异显著,适用于多沙河流生态健康评价。评价结果显示:黄河干流亚健康及以上状态的断面占比为秋季(75.0%)高于春季(54.5%);自源区沿河而下,底栖动物生物完整性指数值呈下降趋势;库区断面底栖动物生物完整性指数低于临近自然河段。回归分析表明,黄河干流底栖动物生物完整性指数与盐度、总氮、城镇及农田用地占比呈显著负相关,与林地及草地占比呈显著正相关。本研究结果可为黄河生态保护与管理提供科学依据。  相似文献   

4.
无定河流域位于黄土高原与毛乌素沙地过渡带,水土流失严重,生态环境具有脆弱性和波动性。于2021年春季(4月)和秋季(10月)对无定河流域上、中、下游及其6条支流和流域内的3个淤地坝开展水生态系统调查,旨在厘清无定河流域底栖动物群落特征,构建底栖动物生物完整性指数并开展健康评价。无定河流域春季共采集到底栖动物105种,平均密度为181 ind./m2,平均生物量为0.760 g/m2,秋季共采集到底栖动物67种,平均密度为94 ind./m2,平均生物量为0.454 g/m2。通过对两季度研究区域内底栖动物27个生物参数开展分布范围检验、判别能力分析和相关性分析,构建无定河流域底栖动物生物完整性指数,对全流域40个样点(6个参照点和34个受损点)进行B-IBI健康评价。评价结果表明,总体上无定河流域底栖动物生物完整性较好,40个样点中春季有19个处于健康或亚健康状态,秋季有23个处于健康或亚健康状态,其中无定河上、中游干支流大都以健康和亚健康为主,无定河下游干支流以及3个淤地坝水体健康状况较差。在不同水土流失类型区域,底栖动物群落特征和生物完整性评价具有显著性差异。本研究结果可为无定河流域河流健康评估提供科学依据。  相似文献   

5.
A recent Chinese policy requires that all enterprises that store and use hazardous chemicals must become part of a chemical industry park. Although this reduces the environmental risk caused by the establishment of uncontrolled sites, it cannot eliminate the risk within the industrial park; on the contrary, it may exacerbate the risk. The storage and use of a wide range of hazardous chemicals in the industrial park increases both the complexity and the diversity of the environmental risk. Identification of the sources of risk will significantly affect the results of regional risk assessments. In this paper, we selected China’s Nanjing Chemical Industry Park as a case study. Based on an environmental risk assessment for every enterprise within the park, we calculated the maximum environmental risk values of each individual risk source and obtained the overall regional environmental risk values by using information-diffusion theory. The regional environmental risk value can be clustered according to the classification criteria described in this paper and depicted using a spatial partitioning map. The result can help administrative managers optimize the distribution of industrial areas and support the development of risk-prevention and -management measures.  相似文献   

6.
樊贤璐  徐国宾 《湖泊科学》2018,30(5):1225-1234
本文首先运用频度分析法构建湖泊生态系统健康评价指标体系;其次,应用变异系数法与信息熵权法相结合的组合赋权法计算指标权重;在此基础上提出了基于生态—社会服务功能协调发展度的湖泊生态系统健康评价方法,并给出从湖泊综合发展水平和湖泊协调发展度两方面度量湖泊生态系统健康水平的等级划分标准.应用此评价方法,以白洋淀生态系统为研究对象,开展其健康状况及协调发展状况的模型实证研究.结果显示:白洋淀生态系统综合发展水平处于不健康病态萎缩状态,湖泊协调发展度属于临界协调发展.该方法综合考虑了生态完整性和社会服务功能两个方面的协调性和发展性进行湖泊健康评价,从协调、发展的角度为湖泊管理建设提供建议.同时研究表明协调发展度湖泊健康评价法具有计算简单、适用性强的特点,同样适用于其他湖泊健康评价.  相似文献   

7.
The use of multimetric indices as tools for assessing aquatic ecosystem health in most of the developing countries such as Togo is still lacking. To fill this gap, we developed a macroinvertebrates-based multimetric index for the Zio river basin of Togo. Forty-two sites were assessed for the development and the validation of the Multimetric Index of Zio River Basin (MMIZB). Thirty-nine candidate metrics belonging to four categories (composition metrics, functional feeding metrics, diversity metrics and tolerance measure metrics) were evaluated. After comprehensive multiple selection procedure, six core metrics were retained to provide the final MMIZB. The results showed that the MMIZB responded to a set of organic pollution (chemical oxygen demand, ammonium, total suspended solid) and hydromorphological alterations, which corresponded to a set of gradients of human pressures affecting the ecological integrity of Zio river basin water bodies (r = 0.78, p < 0.001). The final macroinvertebrate index well distinguished the reference sites and impaired sites of a validation data set (p < 0.001) and showed a significant relationship between water and habitat quality based on Prati’s index (r = 0.73, p < 0.001) and Multimetric Macroinvertebrates Index of Vietnam (MMI_Vietnam) (r = 0.88, p < 0.001). This work underlines the relevance of the MMIZB as an effective tool for biological monitoring and decision making in water management of Zio river basin.  相似文献   

8.
Abstract

Changes in water resources availability, as affected by global climate warming, together with changes in water withdrawal, could influence the world water resources stress situation. In this study, we investigate how the world water resources situation will likely change under the Special Report on Emissions Scenarios (SRES) by integrating water withdrawal projections. First, the potential changes in water resources availability are investigated by a multi-model analysis of the ensemble outputs of six general circulation models (GCMs) from organizations worldwide. The analysis suggests that, while climate warming might increase water resources availability to human society, there is a large discrepancy in the size of the water resource depending on the GCM used. Secondly, the changes in water-stressed basins and the number of people living in them are evaluated by two indices at the basin scale. The numbers were projected to increase in the future and possibly to be doubled in the 2050s for the three SRES scenarios A1b, A2 and B1. Finally, the relative impacts of population growth, water use change and climate warming on world water resources are investigated using the global highly water-stressed population as an overall indicator. The results suggest that population and socio-economic development are the major drivers of growing world water resources stress. Even though water availability was projected to increase under different warming scenarios, the reduction of world water stress is very limited. The principal alternative to sustainable governance of world water resources is to improve water-use efficiency globally by effectively reducing net water withdrawal.
Editor Z.W. Kundzewicz; Associate editor D. Gerten  相似文献   

9.
核电厂一体化堆顶围筒组件是一体化堆顶组件的主要承力件并提供辐射屏蔽保护。在围筒组件的设计阶段需要对其运行工况进行力学分析,以保证围筒组件在极端事故工况下不发生破坏。本文首先分析了围筒组件的工况和荷载组合。在其中条件最为苛刻的D级工况下,采用反应谱法对围筒组件进行了有限元抗震分析,并计算了其它荷载的作用。结果表明围筒组件的设计满足ASME规范要求。因此,围筒组件能够抵御极端事故工况。  相似文献   

10.
设计1个20层SRC框架核心筒结构模型,考虑地震的随机性和结构材料的不确定性,采用拉丁超立方体抽取结构-地震动样本,之后对其进行增量动力分析(IDA),以第1周期谱加速度为强度指标,最大层间位移角为结构需求,定义4个性能水平,研究该结构的易损性。通过引入群体结构震害评估中易损性指数的概念,计算多遇、设防和罕遇地震下的易损性指数。结果表明:以易损性指数作为评价指标,该结构在多遇地震作用下,处于轻微破坏状态;在设防地震作用下,处于中等破坏状态;在罕遇地震作用下,结构处于严重破坏状态。可认为依据我国抗震规范设计的SRC框架核心筒结构能够满足"小震不坏"、"中震可修"和"大震不倒"的抗震设防目标。  相似文献   

11.
由于湖泊生态问题日益突出,湖泊生态系统安全状态已经成为人们关注的热点问题,了解湖泊水生态系统的状况并根据湖泊生态系统健康状况开展精准治理和生态修复与保护尤为重要。本文基于对鄱阳湖及其流域生态环境的长期监测数据和资料收集,采用综合指标体系法,从物理形态、水文、水环境、水域生态、湿地生态和社会服务6个方面构建了鄱阳湖生态系统健康评估的指标体系,主要涵盖了湖泊口门状况、“五河”入湖径流变异程度、入湖河流水质达标率等26个指标。依据设置的阈值等级得到鄱阳湖生态系统健康评价各层次健康状况等级,通过对各湖泊生态系统各指标得分进行加权计算,得出生态系统健康评估准则层和目标层的得分,最终对鄱阳湖生态系统健康进行了客观的评价。结果表明,构建的湖泊生态系统健康评价体系针对性强、科学全面、具有可操作性,可为鄱阳湖及类似通江湖泊的生态系统健康评价提供案例和方法借鉴。评价结果表明鄱阳湖健康体征状况目标层得分为73.45分,评价结果为亚健康,鄱阳湖水生态系统健康主要受泄流能力、水文节律变化、富营养化程度和物种多样性的影响。最后根据鄱阳湖的水生态系统健康评分等级探讨了鄱阳湖水生态系统中亟需解决的问题,针对性地提出了...  相似文献   

12.
Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched delta15N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched delta15N values in fish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this.  相似文献   

13.
The "bioeffect assessment index" (BAI) is based on the integration of several pathological endpoints measured in the liver of European flounder (Platichthys flesus (L.)) during a long term study of biological effects of pollution in the German Bight. The BAI represents a modification of the "health assessment index" since it includes solely validated biomarkers reflecting toxically induced alterations at different levels of biological organisation in order to quantify the effects of environmental pollution. The concept of the BAI is based on the observation of progressive deleterious effects from early responses to late effects. Specific "key events" were detected, representing progressive stages of functional deterioration. The biomarkers selected from a whole battery of cellular markers for the BAI calculation reflect deleterious effects of various classes of contaminants such as heavy metals, organochlorines, pesticides, PAHs, and therefore reflect general toxicity in an integrative manner. Selected biomarkers were: lysosomal perturbations (reduced membrane stability), storage disorders (lipid accumulation) as early markers for toxic effects of liver cells, and the size of macrophage aggregates and their acid phosphatase activity. The latter two markers are indicative for the modulation of non-specific immune response which represents longer time scale responses after chronic exposure.  相似文献   

14.
As lake ecosystem assessment is the foundation to achieve lake monitoring, environmental management and ecological restoration, a new concept of lake ecosystem health and driving force-pressure-state-impact-response-management framework was proposed to find out the causal relationship of the system and health distance model was taken to represent the health level of ecosystem. An assessment indicator system comprised of water quality, ecological and socio-economic criteria was established. The evaluation models were applied for the assessment of the ecosystem health level of a typical lake, Nansi Lake, China. Depends on the values of health distance, the heath level was described as 5°: very healthy, healthy, general healthy, sub-healthy and diseased. Using field investigation data and statistic data within the theory and applied models, the results of comprehensive assessment show that: (1) the health distances of water quality indicators, ecological indicators, socio-economic indicators and comprehensive health distance were 0.3989, 0.2495, 0.4983 and 0.4362, respectively. The health level was in general healthy condition. Ecological indicators were in healthy condition, which indicate that the stability was high. The distance of water quality had shown a tendency to approach general healthy level. As the health distance of socio-economic indicators have shown a bad impact form human beings, more effective measures need to be developed. (2) The results of a case study demonstrated that the methods in this paper provide a similar result corresponding with the actual lake health condition. Therefore, this paper shows that the proposed method is efficient and worths generalization.  相似文献   

15.
目前的既有钢混结构地震损伤研究没有同时考虑不同抗震设计规范差异和耐久性两个因素对结构抗震性能的影响,且损伤指标较简单,在动力损伤分析中也存在局限。基于云模型的特点,提出了包括弹塑性耗能差率、刚度损伤指数、层间位移角和顶点位移角的多元结构损伤状态综合评估方法,能够同时考虑结构各损伤指数的随机性和模糊性。考虑不同版本抗震设计规范造成的结构性能差异和耐久性下降对结构性能的影响,设计3个典型五层钢混框架结构,进行增量动力分析,验证损伤评估方法的准确性。结果表明:随着抗震规范版本的更新,结构的损伤程度有适当减轻;同一结构的损伤程度因混凝土碳化作用先减轻后加重;采用弹塑性耗能差率表征既有结构的地震损伤效果优于刚度损伤指数;基于多指标云模型损伤评估方法获得的云模型综合隶属度和综合损伤值能够更加细化和精确地描述结构损伤状态。  相似文献   

16.
各类应用服务的不断深化,对地震数据服务的可视化和便捷性需求提出更高要求,而当前数据服务多依赖于电脑环境,直观性与通用性有所欠缺。利用天地图、Highcharts等先进技术,构建基于Android的地震科学数据可视化综合服务平台。通过丰富、直观的表现形式,向公众展示河南省区域内地震监测台站分布与概况、地震目录及测震波形等信息,提供观测数据查询下载、可视化动态浏览,同时具备震情速递、地震科普宣传功能。利用该平台将建立触手可及、高效便捷的地震科学数据传输渠道,大幅度提升社会服务能力,增强地震科学数据的可读性与普及性,实现数据服务与防震减灾的有机融合。  相似文献   

17.
根据鉴江流域21个观测点鱼类调查所收集的数据,结合历史资料的记录,初步构建基于鱼类生物完整性评价的26个初选指标,并根据指标属性分类进行初筛,对10个通过的候选指标进行分布范围、判别能力和Pearson相关性分析,确定了由总的种类数占期望值的百分比、鲤科鱼类占总种类数的百分比、鳑鲏亚科鱼类占总种类数的百分比、耐受性强鱼类占总种类数的百分比和产漂流性卵鱼类占总种类数的百分比共5个主评指标组成的生物完整性指数体系,并用于鉴江流域部分河段的生态健康评价.结果表明,凌江鱼类完整性相对较好,罗江一般,平定水、袂花江和鉴江干流较差,小东江最差;鉴江流域大多数河段的综合健康状态处于较差状态,需要对鉴江流域进行生态修复以达到相对健康状态.评价结果与河流受人为干扰的实际情况相吻合,研究构建的评价体系可供周边地区使用和借鉴.  相似文献   

18.
Water quality was estimated from 205 samples of benthic invertebrates collected between 1982 and 1986 in 51 rivers of western Switzerland (canton of Vaud). Each sample consisted of the combined list of taxa resulting from one spring sample pooled with one summer sample. Water quality was indicated by total number of taxa and number of taxa intolerant of pollution: i. e. Heptageniidae, Plecoptera, and Trichoptera with a case. Six classes of values were delimited for each of these two variables by cluster analysis. Values from zero to five were attributed to each class. The index of water quality was computed by adding these two values in each sample. According to this index, good water quality was indicated by 42% of samples. This index can be adapted to other rivers because its components are easily modified.  相似文献   

19.
Within the Western Mediterranean Permo-Triassic province, the Scandola-Senino area represents one of the best sites for the study of the successive volcanic episodes and their relationships. With this purpose, new mineralogical and geochemical data on basic and intermediate rocks are presented.The first volcanic episode, including andesites, dacites, and rhyolitic ignimbrites of Early Permian age, is calc-alkaline with a strong LILE enrichment, particularly in K, U and Th. Andesite evolution is controlled by fractional crystallization with an important crustal component.Subsequent permian volcanism corresponds to the emplacement of bimodal volcanic products (basalt-ignimbritic rhyolite) into a caldera structure. The basalts are interpreted as derived from a mantle source still modified by subduction component.The last volcanic episode is represented by doleritic dykes derived from a within plate or OIB-type source devoid of any arc signature (no Ta anomaly).Permian magmatism in Corsica is interpreted as the progressive fading-out of an arc-signature in favour of a primitive mantle source. The magmatic features and the structural setting agree with an inferred post-orogenic geotectonic regime during the period between the Hercynian and Early Alpine orogenic events.  相似文献   

20.
应用底栖动物完整性指数评价太湖生态健康   总被引:12,自引:4,他引:12  
依据2010年春季至2012年秋季,太湖32个样点的底栖动物和环境变量共11次的季节性调查结果,采用干扰程度最小系统法定义构建底栖动物生物完整性指数的参照系统,提出了确定参照系统的4个基本条件,进而按非湖心区和湖心区两个生态区分别构建太湖底栖动物完整性指数(LTB-IBI).通过对候选生物参数的分布范围筛选、判别能力分析、与理化因子的相关性和参数间的冗余分析,获得了非湖心区LTB-IBI的4个构成指数:总分类单元数、Simpson多样性指数、前3位优势单元%和BMWP指数,以及湖心区LTB-IBI的5个构成指数:总分类单元数、Simpson多样性指数、甲壳+软体分类单元数、前3位优势单元%和BMWP指数.采用比值法统一构成指数量纲,分别构建了非湖心区和湖心区LTBIBI指数,评价太湖水生态健康的等级.2010-2012年,太湖生态健康总体上呈现逐步提升的趋势.影响太湖底栖动物完整性的重要环境变量是水体中的氮含量.研究表明,连续观察数据可较大程度上提高太湖LTB-IBI指数的可靠性和评价结果的合理性.  相似文献   

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