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1.
The contents of 90Sr and 137Cs and the pattern of their redistribution in the soil and plant cover of floodplain ecosystems have been assessed. It is shown that the radionuclide distribution across the floodplain and along the river flow is determined by the formation of a barrier to their migration near the river channel, at which less mobile 137Cs accumulates. The soil and plant cover of the central floodplain are enriched with 90Sr. Differences in radionuclide migration in floodplain soils and their input into plants are determined by the relationship between the processes of their immobilization and migration with soil water.  相似文献   

2.
生态流量保障的重难点在于流域生态流量不足问题的妥善解决。生态流量不足基于产生的原因可分为“自然型”和“人为型”。“人为型”生态流量不足的根源在于《水法》第4条规定的三生用水关系未得到妥善处理,实质上是水资源分配和管理不合理所致。具体表现为水资源保护理念镶嵌在制度表层、生态流量缺乏核心制度保障、流域规划匮乏强效监督机制、流域水资源分配信息公开不足、末端行政考核制度偏重水质管控、生态用水制度顶层设计与地方实施间落差巨大等。流域立法作为立法体系的中间环节,对上位法具有填补协调功能,对地方立法具有引领指导作用。建议在流域立法过程中,通过制度设计解构流域生态流量保障现存的制度困境,主要包括以下几个方面:一是完成流域特有保护理念到实体制度的转型。二是基于流域生态修复、水资源生态红线管控制度的开展以及有效衔接规划环境影响评价制度的需要,建立生态流量管控指标制度体系不可或缺。三是基于流域规划对三生用水的初始分配性,将生态流量供给纳入流域规划体系中,从水资源分配初始阶段保障生态流量,同时强化流域水资源规划制度的监督机制,健全规划制定的程序性规范,明确科学考察和调查评价人员的构成规则、方式及模式。四是依法加深政府信息公开程度保障公众的知情权、参与权及监督权。五是完善行政考核制度体系强化对生态流量供给的考核。  相似文献   

3.
The concept of participation in rural development has been evolutionary for the past two decades with those involved, such as development agencies and governments, particularly in rural water supply, re-evaluating their active role. The move towards effective community participation has encouraged a shift from the traditional top-down to a bottom-up approach whereby there is a decentralisation of unevenly distributed resources and power to empower a community and allow mobility of ‘people participation’. The Molinos water project is the first large-scale development project of its kind introduced into the village of Molinos in an under-developed area of Chile, where there has been no tradition of people participation. The project objective was to implement a low technology, low budget water treatment plant to the village of Molinos. Various aspects have hindered the continued development of the project including both technical and financial. In terms of people participation, the initial approach used was the top-down approach. There was a failure to fully integrate the community or inform the community in a formal manner about the project and consult them regarding key project issues. This case study illustrates that the lack of comprehensive consultation and the low level of participation of the community on the participatory scale does not achieve much in terms of people-centred benefits. For governance at the local level to be effective, participation should be inclusive and communicative so as to enhance transparency throughout the project lifetime. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

4.
The micronucleus test of peripheral blood erythrocytes was used to study cytogenetic stability in bream (Abramis brama L.), perch (Perca fluviatilis L.), roach (Rutilus rutilus L.), and pike (Esox lucius L.) from a eutrophic water body not affected by anthropogenic factors. The dependence of the rate of spontaneous micronucleus formation on fish age was estimated. The effect of natural variation in abiotic environmental factors on the cytogenetic stability of species was analyzed.  相似文献   

5.
There is an obvious departure from the regional equilibrium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in "the effects of contra-geography-grads development". It is mainly because the upriver mountainous areas have been deeply stuck in industrialization delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of "the vicious circle of poverty" by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environmental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called "the Local Area Quotas for Industrial Emissions along the Pearl River" is put forward supposed to give corresponding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.  相似文献   

6.
Abstract

There is an obvious departure from the regional equilibrium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in “the effects of contra-geography-grads development”. It is mainly because the upriver mountainous areas have been deeply stuck in industrialization delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of “the vicious circle of poverty” by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environmental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called “the Local Area Quotas for Industrial Emis-sions along the Pearl River” is put forward supposed to give corresponding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.  相似文献   

7.
赣江是长江中下游的重要支流,赣江流域的水生态安全直接关系到长江经济带建设的可持续与绿色发展。然而,近些年来,人类活动干扰对赣江流域水生态的影响还在持续增加。该文综述了截止2017年12月赣江流域的水环境、鱼类资源及人类活动干扰影响的相关文献。目前,赣江流域水环境处于中度污染级别,有机污染物增加,无机污染物无显著变化。鱼类共有124种,隶属10目32科。经统计近10年的鱼类资源,赣江流域鱼类有7目35科120种,其中上游鱼类4目14科22种,中游鱼类6目28科82种,下游鱼类7目28科91种。全流域10年中未发现的鱼类包括中华鲟、鲥鱼、刀鲚、弓斑东方鲀、斑条鱊、短须鱊、拟尖头红鲌、似鱎、条纹小鲃、泉水鱼等33种。该文分析了影响赣江流域水生态的三类主要人类活动干扰:水电站建设,工农业污染和航运、采砂等,这些干扰增加了水体中营养盐和有机污染物的含量,同时破坏了水生生物生境,进而影响了鱼类的生存。随着赣江流域多个大型水电站的规划和建设,建议今后应进一步加强水电开发对水环境和鱼类资源的影响研究,同时开展生态修复,加强生境保护,严控涉水行为,完善生态补偿机制,以保证赣江流域的绿色发展。  相似文献   

8.
在可持续发展过程中。政府、民间组织、企业和个人都有其能够发挥作用的地方.但是。地方政府可以说是实现地方可持续发展之关键。以浙江省东阳市横店镇可持续发展实验区为个案。深入探讨地方政府与地方可持续发展的关系。文章的一个基本结论是,从横店镇可持续发展实验区案例来看.我国乡村的可持续发展应该走政府主导的模式.而只有强化地方政府的能力(包括规划、资源与领导能力等)。方能培育地方良治(good governance)与支持可持续发展。  相似文献   

9.
This paper explores the role that Internet and online technologies played in research dissemination and knowledge mobilization in a recent climate change research project, MC3. In addition, the team looked at the potential of online expert-practitioner research collaborations for these purposes. Electronic communication was seen as a key element for creating distributed networks essential to the project and for building new practitioner/research knowledge collaboratives. The paper discusses how online communication strategies and technologies were used for wide dissemination of its research outcomes. MC3's research dissemination and knowledge mobilization strategies are analyzed, using engagement as the primary measure, to gain insights on the effectiveness and challenges of using Internet-based tools for communicating climate change innovations and actions.  相似文献   

10.
中国正处于经济转型的交叉路口,水环境日趋恶化已成为中国经济发展的最大障碍。跨行政区水污染问题为资源环境有效配置、地区经济可持续发展、上下游地方政府及人民之间矛盾解决及社会稳定等问题提出了严峻挑战。以江苏浙江边界水污染治理为例,结合国外跨行政区水资源管理经验,研究适合中国国情的跨行政区水污染治理管理机制。研究发现,当前中国跨行政区水污染治理面临的最主要问题,是流域管理与行政区域管理间的矛盾。解决跨行政区水污染治理较为可行的方案是:保持以条块结合的政府层级结构基础上的管理体制,通过机构、机制、法规等综合性改革来协调当前管理体制中流域及区域中不同部门、不同层级间的矛盾。  相似文献   

11.
Data on the numbers and biomass of caddis fly species (Trichoptera) in the benthos and in the diets of fish from streams of the Pechora-Ilych State Reserve (the northern Urals) are provided. In the diets of grayling and juvenile Atlantic salmon caught in the rivers of the reserve, 17 and 10 species of caddis flies have been identified. As a rule, one to three species (in most cases, two species) prevail in the diet of fish.  相似文献   

12.
It is widely assumed nowadays that in order to effectively respond to environmental challenges, humanity must cultivate cosmopolitan ethical consciousness. An important role, according to this outlook, should be assigned to journalists, who must possess a cosmopolitan sense of responsibility. How can this global responsibility emerge out of the local sense of belonging? To examine this question, we present the case study of the decision of 107495 the Kharkov (Ukraine) municipal council to cut down a local recreation forest. The content of local news and the interviews with journalists are presented and analyzed. The study shows that local patriotism appears not to be a decisive factor in forming journalists’ sentiments toward the issues of global responsibility. Rather, it is a sense of exclusion from the global community that explains the fact that no news medium under analysis has managed to relate local events to the global problem of deforestation.  相似文献   

13.
There is no universally-accepted definition of tourism carrying capacity(TCC).Numerical TCC focuses on use level and is considered as"a magic number"of the saturation point for tourism.There are several reasons why numerical tourism capacity is inadequate.Alternatively,tourism capacity can be defined in terms of limits of acceptable change,which shifts the focus from"how much use is too much"to"how much change is acceptable".This article proposes an improved conceptual framework for evaluating carrying capacity for the tourism city based on approaches used in US national parks,which consider the impact of human use on a city's economic,environmental/resource,and socio-cultural conditions.Based on the basic data of indicator values and relevant standards,the framework monitors the current indicators and predicts future indicator values; it can also be used to assess and predict TCC.  相似文献   

14.
A sediment core collected from the sub-aqueous delta of the Yangtze River estuary was subjected to analyses of 137Cs and plutonium (Pu) isotopes. The 137Cs was measured using γ-spectrometry at the laboratories at the Nanjing University and Pu isotopes were determined with Accelerator Mass Spectrometry (AMS), measurements made at the Australian National University. The results show considerable structure in the depth concentration profiles of the 137Cs and 239+240Pu. The shape of the vertical 137Cs distribution in the sediment core was similar to that of the Pu. The maximum 137Cs and 239+240Pu concentrations were 16.21 ± 0.95 mBq/g and 0.716 ± 0.030 mBq/g, respectively, and appear at same depth. The average 240Pu/239Pu atom ratio was 0.238 ± 0.007 in the sediment core, slightly higher than the average global fallout value. The changes in the 240Pu/239Pu atom ratios in the sediment core indicate the presence of at least two different Pu sources, i.e., global fallout and another source, most likely close-in fallout from the Pacific Proving Grounds (PPG) in the Marshall Islands, and suggest the possibility that Pu isotopes are useful as a geochronological tool for coastal sediment studies. The 137Cs and 239+240Pu inventories were estimated to be 7100 ± 1200 Bq/m2 and 407 ± 27 Bq/m2, respectively. Approximately 40% of the 239+240Pu inventory originated from the PPG close-in fallout and about 50% has derived from land-origin global fallout transported to the estuary by the river. This study confirms that AMS is a useful tool to measure 240Pu/239Pu atom ratio and can provide valuable information on sedimentary processes in the coastal environment.  相似文献   

15.
Environment, Development and Sustainability - Groundwater is the major primary source of drinking and irrigation water for nearly 500 million inhabitants in both rural and urban areas of the Ganga...  相似文献   

16.
The integrated use of remotely sensed data and GIS to monitor a rapid recent delta formation was undertaken in the Tacarigua Lagoon, a mangrove coastal protected wetland in the north-central coast of Venezuela. Recently, the resource value of coastal wetlands such as coastal lagoons and deltas, has brought about a need to protect and conserve these ecosystems. To that end, valuable resources such as these should be continuously monitored so that temporal changes in their environment can be analysed. The importance of determining the cause, extent, and spatial distribution of these changes can then be used in different aspects of environmental studies, land suitability analyses and for wise resource management. Aerospace data interpretation and a field survey were utilised to study the formation of the Guapo River delta within the Tacarigua Lagoon and to map the expansion that this depositional environment has undergone. A historical set of aerial photographs and a radar image, together with a GIS, were used to assess the growth of the delta from the beginning of its formation up to the present time.  相似文献   

17.
The distribution of dissolved rare earth elements (REE) in the Rhine River, Germany, shows the anthropogenic gadolinium (Gd) microcontamination that is commonly observed in rivers in densely populated countries with a highly evolved health care system. However, the Rhine River also carries anomalously high concentrations of lanthanum (La), which produce very large positive La anomalies in normalized REE distribution patterns. These positive La anomalies first occur north of the City of Worms and then decrease in size downstream, but are still significant approximately 400 km downstream, close to the German-Dutch border. The strong La enrichment is of anthropogenic origin and can be traced back to effluent from a production plant for fluid catalytic cracking catalysts at Rhine river-km 447.4. This effluent is characterized by extremely high dissolved total REE and La concentrations of up to 52 mg/kg and 49 mg/kg, respectively. Such La concentrations are well-above those at which ecotoxicological effects have been observed. The Rhine River is the first case observed to date, where a river's dissolved REE inventory is affected and even dominated by anthropogenic La. Our results suggest that almost 1.5t of anthropogenic dissolved La is exported via the Rhine River into the North Sea per year. This reveals that the growing industrial use of REE (and other formerly "exotic" elements) results in their increasing release into the environment, and highlights the urgent need to determine their geogenic background concentrations in terrestrial surface waters.  相似文献   

18.
Sequential extraction techniques have been developed to assess partitioning of anthropogenic radionuclides (240Pu, 239Pu, and 237Np), originating from a variety of sources, as identified by using bulk sediment isotopic composition. Sediments were leached sequentially with a series of six chemical treatments designed to approximate different environmental processes that may occur or to selectively extract trace metals contained in different solid phases of the sediments (i.e., exchangeable, reducible, carbonate, organic, acid leachable, and refractory). Results indicate the majority of Pu and Np is similarly distributed within many of the extracted fractions, with the largest percentage (66–97%) of both elements being observed in sediments treated with buffered citrate dithionite (CDB), which targets easily reduced constituents such as Mn and Fe hydrous oxides. While these results do indicate an association of Pu and Np with redox sensitive elements, the environmental implications are unclear given that the CDB treatment is more extreme than naturally occurring conditions. Minor amounts of Np partition differently from Pu in sediments. The NH4-acetate treatment, which is designed to liberate trace metals that are loosely adsorbed onto the surfaces of sedimentary materials such as hydrated iron oxides and humic substances, or present at exchangeable sites in clay minerals, mobilized ∼12% of the total Np while Pu levels were below detection. The H2O2 treatment, which is designed to liberate trace metals bound to organic matter, mobilized ∼8 and ∼1% of Np and Pu, respectively. These results indicate that a minor portion of the total Np may be affected by environmental conditions that have little or no effect on Pu. Between 7 and 24% of the Pu was observed in treatments designed to liberate Pu and Np that are tightly bound to lithogenic phases or refractory silicates. The 240Pu/239Pu observed in accessible and refractory fractions ranged between 0.11 and 0.18. With the exception of one sample, the 240Pu/239Pu isotope ratios measured in the refractory fractions are essentially identical having a mean ratio value of 0.123 ± 0.001 (1σ). The 240Pu/239Pu ratios provide isotopic evidence that suggests a portion of non-fallout contamination has a refractory nature. The presence of similarly low 240Pu/239Pu ratios in refractory fractions of sediments from the Ob and Irtysh Rivers suggests the existence of a source of refractory Pu which is consistent with refractory “hot particles” derived from surface tests at the Semipalitinsk test site.  相似文献   

19.
The cause-and-effect relationships existing in freshwater biogeocenoses and changing with time are conventionally divided into three groups: direct, directly mediated, and indirect. The possibility of using the indirect relationships for the control over natural systems is exemplified by a new scheme of eutrophication control and water quality improvement.  相似文献   

20.
人地挂钩制度是促进城乡之间劳动力与土地要素优化配置的重要创新,对于解决人口城镇化与土地城镇化发展失衡问题有重要作用。研究从中国特殊体制制度框架下人口城镇化与土地城镇化的关系出发,基于"人地挂钩"的城镇化协调发展模式,构建指标体系,运用弹性系数法和重心移动模型,对2009~2016年长江经济带上游地区人口城镇化与土地城镇化协调发展关系进行分析。结果表明:(1)长江经济带上游地区人口城镇化与土地城镇化发展成效显著,空间"抱团"特征逐步显化;(2)研究区西部人口城镇化发展更快,东部则相反,黔中城市群为人口城镇化与土地城镇化发展热点,但土地城镇化发展更快,有城镇化发展失衡倾向;(3)研究区人口城镇化与土地城镇化基本处于协调发展状态,末期与初期相比,二者协调关系提升明显。据此建议,长江经济带上游地区西部,要继续有序推进人口城镇化,严格控制土地城镇化;地区东部尤其是黔中城市群,要杜绝"大开发",注重产业培养,提升城市魅力,以提高人口城镇化水平,最终实现地区人口城镇化与土地城镇化协调发展。  相似文献   

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