Greenhouse gas dynamics in an anthropogenically modified tropical river continuum

2021 ◽  
Author(s):  
Siddhartha Sarkar ◽  
Ajayeta Rathi ◽  
Sanjeev Kumar
Keyword(s):  
Flow Regime ◽  
Residence Time ◽  
Large Scale ◽  
Channel Length ◽  
Western India ◽  
River Continuum ◽  
Significant Control ◽  
Process Dynamics ◽  
Sabarmati River ◽  
The City

<p>Recent decades have witnessed large scale modifications in the natural flow regime of river systems. What follows are shifts in various instream processes that ultimately govern the air-water fluxes of major greenhouse gases (GHGs) like CH<sub>4</sub>, CO<sub>2</sub>, and N<sub>2</sub>O. However, due to paucity of data, the process dynamics and controls on fluxes of GHGs in tropical rivers are understudied, contributing to uncertainty in their global budget. In this study, an attempt was made to estimate the fluxes of GHGs and thereby decipher the controls on evasive processes in an anthropogenically affected Sabarmati River (catchment ~ 27,674 km<sup>2</sup> and channel length ~371 km) located in semi-arid western India. After originating from a relatively pristine region, Sabarmati passes through a major twin city (Ahmedabad-Gandhinagar), where construction of a riverfront resulted in increased residence time of water within the city limits.</p><p>To compare and understand changes in in-stream biogeochemical processes as a result of human interventions, sampling was carried out at 50 sites along the Sabarmati river continuum and a parallel running, but not so anthropogenically modified, Mahi River along with their tributaries. Results indicated relatively lower fluxes of GHGs in pristine upstream of Sabarmati and Mahi River continuum with CH<sub>4</sub>, CO<sub>2</sub> and N<sub>2</sub>O fluxes at 0.99 ± 0.35 mg C m<sup>-2 </sup>d<sup>-1</sup>, 4250.99 ± 477.74 mg C m<sup>-2 </sup>d<sup>-1 </sup>and 0.055 ± 0.026 mg N m<sup>-2 </sup>d<sup>-1</sup> respectively. The effect of higher residence time of water could be seen in the riverfront with increased CH<sub>4 </sub>and N<sub>2</sub>O fluxes at 3.27 ± 1.02 mg C m<sup>-2 </sup>d<sup>-1 </sup>and 0.129 ± 0.024 mg N m<sup>-2 </sup>d<sup>-1</sup>, respectively. However, the CO<sub>2</sub> flux did not show much increase. The fluxes increased significantly post city limits until its mouth in the Arabian Sea with extremely large flux for methane (CH<sub>4</sub>: 102.84 ± 41.32 mg C m<sup>-2 </sup>d<sup>-1</sup>, CO<sub>2</sub>: 9563.58 ± 1252.43 mg C m<sup>-2 </sup>d<sup>-1</sup>, and N<sub>2</sub>O: 0.16 ± 0.11 mg N m<sup>-2 </sup>d<sup>-1</sup>, respectively). Overall, it appeared that even within the anthropogenically stressed river, the nature of flow regime, exerts significant control on cycling of elements leading to differential fluxes. Also, the level of coupling between nitrogen and carbon appeared to change within the course of the river.</p>

CONCEPT OF THE IMPROVEMENT OF A KEY PUBLIC SPACE (USING THE EXAMPLE OF «ALLEY OF ARCHITECTS», VORONEZH)

2020 ◽  
pp. 97-109
Author(s):  
С. Л. Подвальный ◽  
О. А. Сотникова ◽  
Я. А. Золотухина
Keyword(s):  
Urban Environment ◽  
Public Space ◽  
Large Scale ◽  
Economic Value ◽  
Ecological Condition ◽  
Territory Design ◽  
Definition Of ◽  
The City ◽  
Modern Technologies ◽  
Intensive Growth

Постановка задачи. В настоящее время формирование современной комфортной городской среды приобретает особое социально-экономическое значение и выдвигается в число приоритетных государственных масштабных программ. В связи с этим необходимо разработать концепцию благоустройства ключевого общественного пространства, а именно: определить основные и сопутствующие функции данной территории, создать эскизное предложение проекта благоустройства с учетом всех необходимых норм и стандартов, внедрить современные технологии. Результаты. Выполнен эскизный дизайн-проект «Аллеи архитекторов» по ул. Орджоникидзе г. Воронеж, включающий в себя основные элементы по зонированию территории, проектированию акцентных объектов и внедрению инновационных технологий «умного города», позволяющих повысить уровень комфорта горожан. Выводы. Благоустройство населенных мест приобретает особое значение в условиях дискомфорта среды. С выполнением комплекса мероприятий, направленных на благоустройство, и с внедрением современных технологий значительно улучшается экологическое состояние, внешний облик города. Оздоровление и модернизация среды, которая окружает человека в городе, благотворно влияет на психофизическое состояние, что особенно важно в период интенсивного роста городов. Statement of the problem. Currently the formation of the modern comfortable urban environment is gaining a special social and economic value and moving forward in the priorities of state large-scale programs. The purpose of development of the concept of improvement of public space is definition of the main and accompanying functions of this territory, design of the outline offer of the project of improvement considering all necessary norms and standards and implementation of modern technologies. Results. The conceptual project of “Alley of Architects” includes the basic elements of territory zoning, design of accent objects and implementation of technologies of a “smart-city”. These elements allow one to increase the level of comfort of inhabitants. Conclusions. Improvement of the inhabited places is of particular importance in the conditions of discomfort of the environment. Carrying out a complex of the actions directed to gardening and improvement, introducing modern technologies, the ecological condition, the physical appearance of the city considerably improves. Improvement and modernization of the environment which surrounds the person in the city influences a psychophysical state well that especially important during intensive growth of the cities.

Removal of trichloroethylene and trichloroethane using a novel hollow-fibre gas-permeable membrane

2003 ◽  
Vol 3 (5-6) ◽  
pp. 67-72
Author(s):  
S. Takizawa ◽  
T. Win
Keyword(s):  
Boundary Layer ◽  
Flow Regime ◽  
Removal Efficiency ◽  
Residence Time ◽  
Flow Rate ◽  
Air Flow ◽  
Hollow Fibre ◽  
Permeation Rate ◽  
Permeable Membrane ◽  
Diffusional Boundary Layer

In order to evaluate effects of operational parameters on the removal efficiency of trichloroethylene and 1,1,1-trichloroethene from water, lab-scale experiments were conducted using a novel hollow-fibre gaspermeable membrane system, which has a very thin gas-permeable membrane held between microporous support membranes. The permeation rate of chlorinated hydrocarbons increased at higher temperature and water flow rate. On the other hand, the effects of the operational conditions in the permeate side were complex. When the permeate side was kept at low pressure without sweeping air (pervaporation), the removal efficiency of chlorinated hydrocarbon, as well as water permeation rate, was low probably due to lower level of membrane swelling on the permeate side. But when a very small amount of air was swept on the membrane (air perstripping) under a low pressure, it showed a higher efficiency than in any other conditions. Three factors affecting the permeation rate are: 1) reduction of diffusional boundary layer within the microporous support membrane, 2) air/vapour flow regime and short cutting, and 3) the extent of membrane swelling on the permeate side. A higher air flow, in general, reduces the diffusional boundary layer, but at the same time disrupts the flow regime, causes short cutting, and makes the membrane dryer. Due to these multiple effects on gas permeation, there is an optimum operational condition concerning the vacuum pressure and the air flow rate. Under the optimum operational condition, the residence time within the hollow-fibre membrane to achieve 99% removal of TCE was 5.25 minutes. The log (removal rate) was linearly correlated with the average hydraulic residence time within the membrane, and 1 mg/L of TCE can be reduced to 1 μg/L (99.9% removal).

scholarly journals Urban Policies and Large Projects in Central City Areas: The Example of Madrid (Spain)

Urban Science ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 42
Author(s):  
Dolores Brandis García
Keyword(s):  
Urban Planning ◽  
20Th Century ◽  
Large Scale ◽  
Central City ◽  
Global Market ◽  
Late 20Th Century ◽  
Public And Private ◽  
Urban Policies ◽  
Starting Point ◽  
The City

Since the late 20th century major, European cities have exhibited large projects driven by neoliberal urban planning policies whose aim is to enhance their position on the global market. By locating these projects in central city areas, they also heighten and reinforce their privileged situation within the city as a whole, thus contributing to deepening the centre–periphery rift. The starting point for this study is the significance and scope of large projects in metropolitan cities’ urban planning agendas since the final decade of the 20th century. The aim of this article is to demonstrate the correlation between the various opposing conservative and progressive urban policies, and the projects put forward, for the city of Madrid. A study of documentary sources and the strategies deployed by public and private agents are interpreted in the light of a process during which the city has had a succession of alternating governments defending opposing urban development models. This analysis allows us to conclude that the predominant large-scale projects proposed under conservative policies have contributed to deepening the centre–periphery rift appreciated in the city.

scholarly journals Accessible Routes Integrating Data from Multiple Sources

2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Miguel R. Luaces ◽  
Jesús A. Fisteus ◽  
Luis Sánchez-Fernández ◽  
Mario Munoz-Organero ◽  
Jesús Balado ◽  
...  
Keyword(s):  
Information System ◽  
Data Model ◽  
Large Scale ◽  
Heterogeneous Data ◽  
Multiple Sources ◽  
Heterogeneous Data Sources ◽  
Different Types ◽  
Software Sensors ◽  
The City

Providing citizens with the ability to move around in an accessible way is a requirement for all cities today. However, modeling city infrastructures so that accessible routes can be computed is a challenge because it involves collecting information from multiple, large-scale and heterogeneous data sources. In this paper, we propose and validate the architecture of an information system that creates an accessibility data model for cities by ingesting data from different types of sources and provides an application that can be used by people with different abilities to compute accessible routes. The article describes the processes that allow building a network of pedestrian infrastructures from the OpenStreetMap information (i.e., sidewalks and pedestrian crossings), improving the network with information extracted obtained from mobile-sensed LiDAR data (i.e., ramps, steps, and pedestrian crossings), detecting obstacles using volunteered information collected from the hardware sensors of the mobile devices of the citizens (i.e., ramps and steps), and detecting accessibility problems with software sensors in social networks (i.e., Twitter). The information system is validated through its application in a case study in the city of Vigo (Spain).

scholarly journals A Digital Framework to Predict the Sunshine Requirements of Landscape Plants

2021 ◽  
Vol 11 (5) ◽  
pp. 2098
Author(s):  
Heyi Wei ◽  
Wenhua Jiang ◽  
Xuejun Liu ◽  
Bo Huang
Keyword(s):  
Solar Radiation ◽  
Plant Species ◽  
Large Scale ◽  
Normal Growth ◽  
Adaptive Selection ◽  
Landscape Plant ◽  
Landscape Plants ◽  
The Stability ◽  
Stability And Accuracy ◽  
The City

Knowledge of the sunshine requirements of landscape plants is important information for the adaptive selection and configuration of plants for urban greening, and is also a basic attribute of plant databases. In the existing studies, the light compensation point (LCP) and light saturation point (LSP) have been commonly used to indicate the shade tolerance for a specific plant; however, these values are difficult to adopt in practice because the landscape architect does not always know what range of solar radiation is the best for maintaining plant health, i.e., normal growth and reproduction. In this paper, to bridge the gap, we present a novel digital framework to predict the sunshine requirements of landscape plants. First, the research introduces the proposed framework, which is composed of a black-box model, solar radiation simulation, and a health standard system for plants. Then, the data fitting between solar radiation and plant growth response is used to obtain the value of solar radiation at different health levels. Finally, we adopt the LI-6400XT Portable Photosynthetic System (Li-Cor Inc., Lincoln, NE, USA) to verify the stability and accuracy of the digital framework through 15 landscape plant species of a residential area in the city of Wuhan, China, and also compared and analyzed the results of other researchers on the same plant species. The results show that the digital framework can robustly obtain the values of the healthy, sub-healthy, and unhealthy levels for the 15 landscape plant species. The purpose of this study is to provide an efficient forecasting tool for large-scale surveys of plant sunshine requirements. The proposed framework will be beneficial for the adaptive selection and configuration of urban plants and will facilitate the construction of landscape plant databases in future studies.

Sex in the City that Peter Built: The Demimonde and Sociability in Mid-Eighteenth Century St. Petersburg

Slavic Review ◽  
2017 ◽  
Vol 76 (4) ◽  
pp. 907-930
Author(s):  
Igor Fedyukin
Keyword(s):  
Eighteenth Century ◽  
Public Sphere ◽  
Large Scale ◽  
Historical Context ◽  
Reading Public ◽  
Associational Life ◽  
The Public ◽  
The World ◽  
The Public Sphere ◽  
The City

This article uses the materials of the Drezdensha affair, a large-scale investigation of “indecency” in St. Petersburg in 1750, to explore unofficial sociability among the Imperial elite, and to map out the institutional, social, and economic dimensions of the post-Petrine “sexual underworld.” Sociability and, ultimately, the public sphere in eighteenth century Russia are usually associated with loftier practices, with joining the ranks of the reading public, reflecting on the public good, and generally, becoming more civil and polite. Yet, it is the privately-run, commercially-oriented, and sexually-charged “parties” at the focus of this article that arguably served as a “training ground” for developing the habits of sociability. The world of these “parties” provides a missing link between the debauchery and carousing of Peter I's era and the more polite formats of associational life in the late eighteenth century, as well as the historical context for reflections on morality, sexual licentiousness, foppery, and the excesses of “westernization.”

Changes in Residence Time due to Large-Scale Infrastructure in a Coastal Plain Estuary

2017 ◽  
Vol 33 (4) ◽  
pp. 815-828 ◽  
Author(s):  
Steven D. Meyers ◽  
Amanda J. Moss ◽  
Mark E. Luther
Keyword(s):  
Residence Time ◽  
Coastal Plain ◽  
Large Scale ◽  
Coastal Plain Estuary

Form Follows Experience - Notes on the Functionality of Footbridges

2021 ◽  
Author(s):  
Michel Schreinemachers ◽  
Wiebe Strick
Keyword(s):  
The Netherlands ◽  
Large Scale ◽  
Water Levels ◽  
Added Value ◽  
Highway Bridge ◽  
Or Efficiency ◽  
Pedestrian Bridges ◽  
The City ◽  
Prime Location ◽  
Natural Way

<p>Should a bridge always be functional and accessible? Should it always fulfil its purpose? This seemingly self- evident question is a key question in footbridge design that is oriented towards creating experiences.</p><p>Footbridges are able to successfully enriches our experience of a certain context or landscape, it cannot be functional all the time, under all environmental conditions, weather and seasons. A good example is the Zalige bridge designed as part of the Room for the River, a large-scale national program for inland flood- protection in the Netherlands. Build upon the floodplains within a newly created river-park by the city of Nijmegen, the Zalige bridge’s curved shape stands in direct relationship to the fluctuating water levels of the river. When water levels rise, the bridge partially submerges, becoming only accessible through steppingstones. At peak heights, the bridge disappears completely, becoming a metaphor for our relationship to the water.</p><p>“Building a bridge that fails to fulfil its sole purpose of containing the water; this can only be pulled off in the Netherlands.” – jury Dutch Design Awards about the Zalige bridge.</p><p>The loss of functionality is directly related to the creation of an experience. When the water levels rose in January 2018, the bridge became the prime location to experience the changing landscape. It shows that engineering a bridge is not solely focussed on the most efficient engineering, but for the purpose it fulfils as for society. For most pedestrian bridges where the perception of the user is on a different level as for a highway bridge, functionality provides more than just cost driven or efficiency driven parameters. It is more related to the added value for the community. When design not solemnly derives from the sheer taste and predilection of the designer but is based on the user’s experience, it generates a durable relation with a feeling of ownership of its users. The key is to create this experience in an elegant and natural way and not forced or dictated. It should be people's own unique discovery and should not be imposed.</p>

Oosterweel – from an underground and even underwater road infrastructure plan to an urban transformation project

2021 ◽  
Author(s):  
Luc Hellemans
Keyword(s):  
Traffic Flow ◽  
Large Scale ◽  
Good Reason ◽  
Urban Transformation ◽  
Construction Site ◽  
Successful Completion ◽  
Road Infrastructure ◽  
Living Space ◽  
The City ◽  
Made In

<p>For the coming ten years, the heart of Europe will turn into a gigantic construction site for works on one of the largest hubs of the continent: Antwerp. The Oosterweel Link is the project whereby the motorway ring around Antwerp is undergoing a metamorphosis to reinvigorate traffic flow and add living space to the City. The project had come to a standstill for several years as a result of protests by assertive citizens, but was given a second lease of life following a large-scale participation project.</p><p>To ensure its successful completion, unparalleled efforts are being made in the field and in the area of digitization. It is therefore with good reason that in Belgium the project is referred to as “the construction site of the century”.</p>

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