scholarly journals Microplastic Pollution in Surface Water of Urban Lakes in Changsha, China

Author(s):  
Lingshi Yin ◽  
Changbo Jiang ◽  
Xiaofeng Wen ◽  
Chunyan Du ◽  
Wei Zhong ◽  
...  

As emerging pollutants, microplastics have attracted the attention of scholars from all over the world. However, there is a lack of research on freshwater areas, even in densely populated urban areas. This study investigated eight urban lakes in Changsha, China. It was found that microplastic concentrations ranged from 2425 ± 247.5 items/m3 to 7050 ± 1060.66 items/m3 in the surface water of research areas and the maximum concentration was found in Yuejin Lake, a tourist spot in the center of the city. Anthropogenic factors are an important reason for microplastic abundance in urban lakes. The major shape of microplastics was linear and most of the microplastics were transparent. More than 89.5% of the microplastics had a size of less than 2 mm. Polypropylene was the dominant type in the studied waters. This study can provide a valuable reference for a better understanding of microplastic pollution in urban areas of China.

2020 ◽  
Author(s):  
Thi Dieu Phuong Nguyen

Abstract Hanoi, the capital of Vietnam, is one of the most densely populated areas in the world, with about 3,000 people km-2. Traditionally, aquaculture is practiced in ponds, reservoirs and urban lakes, rice fields, wastewater and VAC [an acronym from the Vietnamese words for garden (vuon), pond (ao) and livestock quarters (chuong)] systems. With over 5,000 ha of surface area and 3,000 ha of lowland rice fields, Hanoi has potential for further aquaculture development and tourism-entertainment services. The importance of aquaculture has long been recognized as a source of income and employment. Nowadays, pond aquaculture in peri-urban areas is decreasing due to urbanization, while in areas far from the city it is increasing through the conversion of lowland rice fields to fish ponds.


2015 ◽  
Vol 26 (3-4) ◽  
pp. 116-123
Author(s):  
A. P. Korzh ◽  
T. V. Zahovalko

Recently, the number of published works devoted to the processes of synanthropization of fauna, is growing like an avalanche, which indicates the extreme urgency of this theme. In our view, the process of forming devices to coexist with human and the results of his life reflects the general tandency of the modern nature evolution. Urbanization is characteristic for such a specific group of animals like amphibians, the evidence of which are numerous literature data. Many researchers use this group to assess the bioindicative quality of the environment. For this aim a variety of indicators are used: from the cellular level of life of organization up to the species composition of the group in different territories. At the same time, the interpretation of the results is not always comparable for different areas and often have significantly different interpretations by experts. Urban environment, primarily due to the contamination is extremely aggressive to amphibians. As a consequence, the urban populations of amphibians may be a change in the demographic structure, affecting the reproductive ability of the population, the disappearance of the most sensitive species or individuals, resizing animals, the appearance of abnormalities in the development, etc. At the same time play an important amphibians in the ecosystems of cities, and some species in these conditions even feel relatively comfortable. Therefore, it is interesting to understand the mechanisms of self-sustaining populations of amphibians in urban environments. To assess the impact of natural and anthropogenic factors on the development of amphibian populations were used cognitive modeling using the program Vensim PLE. Cognitive map of the model for urban and suburban habitat conditions were the same. The differences concerned the strength of connections between individual factors (migration, fertility, pollution) and their orientation. In general, factors like pollution, parasites, predators had negative impact on the population, reducing its number. The birth rate, food and migration contributed to raising number of individuals. Some of the factors affected on the strength to of each other as well: the majority of the factors affected the structure of the population, had an influence on the fertility. Thanks to it the model reflects the additive effect of complex of factors on the subsequent status of the population. Proposed and analyzed four scenarios differing strength and duration of exposure. In the first scenario, a one-time contamination occurs and not subsequently repeated. The second and third scenario assumes half board contamination, 1 year (2 scenario) and two years (scenario 3). In the fourth scenario, the pollution affected the population of amphibians constantly. In accordance with the results of simulation, much weaker than the natural populations respond to pollution - have them as an intensive population growth and its disappearance at constant pollution is slow. Changes to other parameters of the model showed that this pollution is the decisive factor -only the constant action leads to a lethal outcome for the populations. All other components of the model have a corrective effect on the population dynamics, without changing its underlying trand. In urban areas due to the heavy impact of pollution maintaining the population is only possible thanks to the migration process – the constant replenishment of diminishing micropopulations of natural reserves. This confirms the assumption that the form of existence metapopulations lake frog in the city. In order to maintain the number of amphibians in urban areas at a high level it is necessary to maintain existing migration routes and the creation of new ones. Insular nature of the placement of suitable habitats in urban areas causes the metapopulation structure of the types of urbanists. Therefore, the process of urbanization is much easier for those species whicht are capable of migration in conditions of city. In the initial stages of settling the city micropopulationis formed by selective mortality of the most susceptible individuals to adverse effects. In future, maintaining the categories of individuals is provided mainly due to migration processes metapopulisation form of the species of existence is supported). It should be noted that the changes in the previous levels are always saved in future. In the case of reorganizations of individuals we of morphology can assume the existence of extremely adverse environmental conditions that threaten the extinction of the micropopulations. 


Author(s):  
Minh-Tung Tran ◽  
◽  
Tien-Hau Phan ◽  
Ngoc-Huyen Chu ◽  
◽  
...  

Public spaces are designed and managed in many different ways. In Hanoi, after the Doi moi policy in 1986, the transfer of the public spaces creation at the neighborhood-level to the private sector has prospered na-ture of public and added a large amount of public space for the city, directly impacting on citizen's daily life, creating a new trend, new concept of public spaces. This article looks forward to understanding the public spaces-making and operating in KDTMs (Khu Do Thi Moi - new urban areas) in Hanoi to answer the question of whether ‘socialization’/privatization of these public spaces will put an end to the urban public or the new means of public-making trend. Based on the comparison and literature review of studies in the world on public spaces privatization with domestic studies to see the differences in the Vietnamese context leading to differences in definitions and roles and the concept of public spaces in KDTMs of Hanoi. Through adducing and analyzing practical cases, the article also mentions the trends, the issues, the ways and the technologies of public-making and public-spaces-making in KDTMs of Hanoi. Win/loss and the relationship of the three most important influential actors in this process (municipality, KDTM owners, inhabitants/citizens) is also considered to reconceptualize the public spaces of KDTMs in Hanoi.


2009 ◽  
Vol 11 (2) ◽  
pp. 9
Author(s):  
Andrés Rodríguez-Pose ◽  
Riccardo Crescenzi

Thomas Friedman (2005) argumenta que a expansão do comércio, a internacionalização das firmas, o crescimento acelerado do processo de outsourcing e a possibilidade de conexão em redes a custos cada vez mais baixos estão criando um “mundo plano”: um campo competitivo de condições homogêneas de concorrência no qual os indivíduos têm maior poder e melhores condições de vida. Este artigo desafia essa visão do mundo, argumentando que embora a globalização traga mudanças, oportunidades e desafios, nem todos os territórios têm a mesma capacidade de maximizar os benefícios e as oportunidades e de minimizaras ameaças circundantes. Numerosas forças estão se fundindo no sentido de provocar a emergência de “montanhas” urbanas, onde a riqueza, a atividade econômica e a capacidade de inovação se aglomeram. Estas forças “tectônicas” incluem fatores como a inovação, os transbordamentos, os encadeamentos para trás e para frente nas cadeias produtivas, a dinâmica de especialização versus diversificação, o capital social e comunitário e, por último, mas não menos importante, o “buzz” da cidade. As interações destas forças na proximidade geográfica das grandes áreas urbanas dão forma a uma geografia muito mais complexa da economia mundial e permitem a ascensão de novos players econômicos. Mas esta geografia, ao contrário de ser plana, é repleta de montanhas, em que as grandes aglomerações urbanas representam os picos mais altos. A maioria da população mundial, ao contrário de ter maior poder, permanece mal preparada para encarar estes desafios. Palavras-chave: progresso tecnológico; nova geografia econômica; vantagem competitiva. Abstract: Thomas Friedman (2005) argues that the expansion of trade, the internationalization of firms, the galloping process of outsourcing, and the possibility of networking at increasingly low prices is creating a ‘flat world’: a level playing field where individuals are empowered and better off. This paper challenges this view of the world by arguing that although globalization implies changes, opportunities, and threats, not all territories have the same capacity to maximize the benefits and opportunities and minimize the threats at hand. Numerous forces are coalescing in order to provoke the emergence of urban “mountains” where wealth, economic activity, and innovative capacity agglomerate. These “tectonic” forces include factors such as innovation, spill overs, backward and forward linkages, specialisation vs. diversification dynamics, community and social capital, and, last but not least, the buzz of the city. The interactions of these forces in the close geographical proximity of large urban areas give shape to a much more complex geography of the world economy and allows for new economic players to emerge. But this geography, rather than flat, is full of mountains, with large urban agglomerations representing the highest peaks. The majority of the world population, far from being empowered, remains ill-prepared to face these challenges. Keywords: technological progress; new economic geography; competitive advantage.


Author(s):  
Elina Hankela

Theologians speak of the silence of churches’ prophetic voice in the ‘new’ South Africa, whilst the country features amongst the socio-economically most unequal countries in the world, and the urban areas in particular continue to be characterised by segregation. In this context I ask: where is liberation theology? I spell out my reading of some of the recent voices in the liberationist discourse. In dialogue with these scholars I, firstly, argue for the faith community to be made a conscious centre of liberationist debates and praxis. Secondly, I do this by suggesting two theoretical building blocks (i.e. critical deconstruction and radical friendship) for local faith communities that wish to grow in a liberationist fashion.


2017 ◽  
Vol 13 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Piotr Hulisz ◽  
Arkadiusz Krawiec ◽  
Sylwia Pindral ◽  
Łukasz Mendyk ◽  
Kamila Pawlikowska

AbstractThe article presents the influence of natural and anthropogenic factors on the chemical and physical properties of surface water and groundwater in the area of the city of Inowrocław. It has been shown that the properties of the waters were most strongly affected by the specific geological structure (the city is located within the Zechstein salt dome) as well as the long-term influence of a salt mine and soda plant. The composition of most analysed samples was dominated by Ca2+, Na+and Cl−ions. In places of heavy industrial activity, some water parameters were several time higher than permissible limit values according to Polish standards. It is concluded that, due to the threat to the city’s drinking groundwater resources and fertile soils, the surface water and groundwater in the area in question require permanent monitoring.


Author(s):  
K. T. N. Ihsan ◽  
A. D. Sakti ◽  
K. Wikantika

Abstract. Increasing the production of clean and environmentally friendly energy has become one of the world agendas as a strategic effort in dealing with long-term climate change. Seeing the potential of the energy produced, the ease in the installation process, with the small risk of harm generated, solar energy has received significant attention from many countries in the world. The potential for solar energy in Indonesia alone reaches 207 GWp, but only 145.81 MWp has been utilized. Currently, the Indonesian government has set a target to build a Solar Power Plant capacity in 2025 of 6.5 GWh. Urban areas are areas with higher energy demand than rural areas, but the availability of vacant land in urban areas is very minimal for installing solar power plants. Therefore, rooftop solar PV(Photovoltaic) can be a solution in dense areas such as cities. Good planning by looking at the potential resources and energy needs in spatial is needed to manage and utilize energy optimally and sustainably in urban areas. This study aims to develop a geospatial assessment for plan smart energy city that uses rooftop solar PV's potential energy in every building that is effective and efficient. The novelty in the analysis of the distribution of the potential for rooftop solar PV development in urban areas integrates meteorological and spatial aspects and socio-economic aspects. Integration of multi-dynamic spatial data uses in determining the rooftop solar PV construction location, such as meteorological data for solar energy potential, increasing energy needs of each building, and socio-economy data. The data source used comes from statistical data and remote sensing data. The analysis will be carried out temporally (2008, 2013, and 2018) to see the pattern of changes in aspects used in a certain period so that the development plan can be carried out more optimally. This research's output is the formation of a priority analysis of solar PV rooftop construction in urban areas, especially the city of Bandung. The result of energy can also produce by the construction of rooftop solar PV in a potential area. This research is expected to be utilized by policymakers to develop renewable energy in the city of Bandung and increase community participation in switching to renewable energy.


2017 ◽  
Author(s):  
Tales Carvalho-Resende

Ramsar Sites are wetlands considered to be of international importance. The international convention which forms the basis for their identification is commonly referred to as the "Ramsar Convention" after the city in Iran where the convention was signed in 1971. The Convention is an intergovernmental treaty that provides the framework for the conservation and wise use of wetlands and their resources. There are currently over 2,200 Ramsar Sites around the world. They cover over 2.1 million square kilometres, an area larger than Mexico. For more information, visit: www.ramsar.org Biodiversity Surface water


2011 ◽  
Vol 8 (3) ◽  
pp. 64-66 ◽  
Author(s):  
Daniel Moldavsky ◽  
Ceri Savage ◽  
Enrique Stein ◽  
Andy Blake

Argentina, the second largest country in South America is a federation of 23 provinces and its capital, the autonomous city of Buenos Aires. Its population is a little over 40 million, 50% of whom reside in its five largest metropolitan areas. The rural areas are extensively under-populated. The city of Buenos Aires and its suburb contain 15.5 million inhabitants, making it one of the largest urban areas in the world.


2013 ◽  
Vol 430 ◽  
pp. 244-250 ◽  
Author(s):  
Momir Praščevič ◽  
Darko Mihajlov ◽  
Dragan Cvetkovic ◽  
Aleksandar Gajicki ◽  
Nikola Holecek

The great majority of cities in the world have resolved problem of acoustic zoning in the urban part of the city. Two approaches are usually applied in acoustic zoning: acoustic zoning of the territory in accordance with land-use where the allowed values of noise indicator are defined and acoustic zoning by preparing noise maps around dominant sources of noise in urban areas and defining land-use in relation to calculated isofonic lines. As international standard and internationally recognized methodology for preparation of acoustic zoning does not exist, the authors of this paper initiated preparation of methodology for acoustic zoning. The concept of methodology is demonstrated in this paperwork. The methodology has been applied on the City of Nis example starting from the specificity of Nis urban area as well as requests and goals that have been set and defined during sustainable planning of Nis City development. Based on defined acoustic zones and noise measurement results for five years period on the territory of Nis City, the evaluation of the condition of noise level has been done and this paperwork presents results obtained.


Sign in / Sign up

Export Citation Format

Share Document