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The Path of Improving China Water Environment Through Green Infrastructures and Ecological Engineering Facilities
Yin Wenchao,
Liu Yongwang,
Yi Wenting,
Xiong Dicheng,
Lu Xingchao,
Zhao Xin,
Zhao Li
Issue:
Volume 4, Issue 3, September 2018
Pages:
50-65
Received:
14 August 2018
Accepted:
10 September 2018
Published:
10 October 2018
Abstract: In recent years, ecological progress has been promoted and given high priority by Chinese government. The improvement of urban water environment, as an important part of urban construction, should also be included in the ecological progress. This paper focuses on upgrading the quality of urban water environment in China. The study introduces the requirements of the ecological progress, and analyses the problems of water environment caused by urban development. A large number of research and case studies have been done to explore the paths, models and methods which improves urban water environment from both meso-scope and micro-scope. The analysis shows that urban water environment can be improved through three innovations-theoretical innovation, technological innovation and management mechanism innovation. The meso-scope model of ecological urban water system is proposed as a theoretical innovation. Technological innovations such as hybrid ecological pond, in-situ purification of contaminated water and low carbon treatment for the integrated drainage system have been confirmed to be effective on improving the water quality and environment. As the management and mechanism innovation, clear responsibility division of government, social organization and individuals and new business models are also useful. It is suggested that the innovations in three fields discussed above should be gradually decomposed and implemented at the micro level, so as to develop the path of urban water environment improvement, which suitable for China.
Abstract: In recent years, ecological progress has been promoted and given high priority by Chinese government. The improvement of urban water environment, as an important part of urban construction, should also be included in the ecological progress. This paper focuses on upgrading the quality of urban water environment in China. The study introduces the re...
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Numerical Modelling of Waves from the 1991 Cyclone in the Bay of Bengal (Bangladesh)
Mohammad Akhtaruzzaman Sarker
Issue:
Volume 4, Issue 3, September 2018
Pages:
66-74
Received:
30 July 2018
Accepted:
14 September 2018
Published:
17 October 2018
Abstract: Cyclones cause significant loss of life and damage to properties, marine structures/facilities and ecosystems. Cyclone modelling results are used for deriving robust design conditions for coastal and marine structures and facilities. They are also used for emergency planning and decision-making to estimate potential loss of life, damage to properties and marine facilities and to develop rescue and mitigation measures and plan clean-up operations. Royal HaskoningDHV (hereafter RHDHV) has set up a regional wave model covering the Bay of Bengal and its wider surroundings to address these issues. A list of major cyclones in Bay of Bengal that have affected the Bangladeshi coastline since 1970 was initially identified. The 1991 Cyclone (22-30 April 1991) was found to be the second strongest cyclone affecting the coastal areas of Bangladesh since 1945 (after the Bhola Cyclone on 7-13 November 1970). This paper concentrates on the 1991 Cyclone to illustrate the use of numerical modelling to simulate waves generated by cyclones. The MIKE21 Spectral Wave Model of DHI was used in the study. Sample results of waves from the modelling study are presented in this paper for illustration purposes. The model could be used to simulate any cyclone originating in the Bay of Bengal and its surroundings. The methodology described in this paper for modelling cyclone waves in the Bay of Bengal could also be applied to simulate cyclones at other sites around the world.
Abstract: Cyclones cause significant loss of life and damage to properties, marine structures/facilities and ecosystems. Cyclone modelling results are used for deriving robust design conditions for coastal and marine structures and facilities. They are also used for emergency planning and decision-making to estimate potential loss of life, damage to properti...
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Optimization of Anaerobic Granular Sludge by Removing Biogas
Issue:
Volume 4, Issue 3, September 2018
Pages:
75-79
Received:
25 September 2018
Accepted:
10 October 2018
Published:
25 October 2018
Abstract: The loss of granular sludge and acidification of sludge are common problems in highly efficient anaerobic reactors in operation at present, which results in that the reactors cannot reach the design COD removal rates. The problems must be solved for the widespread use of the highly efficient anaerobic reactors. There are many different studies on the formation and loss of granular sludge in an anaerobic reactor, however, the researchers ignore the effects of the gas-producing and biogas-off process of granular sludge on the formation mechanism of granular sludge. The sedimentation and buoyancy phenomena of the granular sludge cultured by self-made transparent reactor were observed in the lab and their relative velocities were measured by photos. Granular sludge and their biogas are coexistent, that is, any size particles of granular sludge can form high floating speed when granular sludge particles contain a lot of bubbles and the granular sludge particles can precipitate well when the air bubbles of granular sludge particles are released in time. So the water test on the sedimentation rate of granular sludge is insufficient. Unified consideration of granular sludge and biogas is beneficial to solve the loss of granular sludge and acidation of sludge in anaerobic reactors and to ensure the normal operation of anaerobic reactors. The biogas-off of biogas produced by anaerobic sludge has essential effects on the granulation of granular sludge. It is conducive to highly efficient anaerobic reactors and three phase separator to reconstruct.
Abstract: The loss of granular sludge and acidification of sludge are common problems in highly efficient anaerobic reactors in operation at present, which results in that the reactors cannot reach the design COD removal rates. The problems must be solved for the widespread use of the highly efficient anaerobic reactors. There are many different studies on t...
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Morphometric Analysis of Kito and Awetu Sub Basins Jimma, Ethiopia
Fayera Gudu Tufa,
Tolera Abdissa Feyissa
Issue:
Volume 4, Issue 3, September 2018
Pages:
80-90
Received:
10 September 2018
Accepted:
22 October 2018
Published:
14 November 2018
Abstract: Morphometric analysis is very important to evaluate watershed characteristics. Watershed characteristics are essential in watershed management, site selection for water resource projects, groundwater evaluation and proposing flood control measures. The present study aimed the morphometric analysis of Kito and Awetu sub-basins which drain into Kito and Awetu Rivers. Both rivers merge into a single river in Jimma town which is subjected to flood and sediment generated from both sub-basins. Topographic map of scale 1:50,000 was obtained from Ethiopian National Mapping Agency and satellite image of digital elevation model of fine resolution (12.5m x12.5m) was downloaded and used for morphometric analysis. GIS and remote sensing technique have been employed to generate and quantify morphometric parameters. Twenty-six parameters under linear aspects, areal aspects, and relief aspects were evaluated to characterize both Kito and Awetu sub-basins. Kito and Awetu Sub basins have both 5th order stream and the 1st order encompasses 78% and 77% of total stream number respectively which indicates the presence of flashy flood. The drainage area, basin perimeter, stream length and weighted mean bifurcation is 113.21km2, 82.65km, 270.33km, and 4.51 respectively for Kito sub-basin and 77.17km2, 73.58km, 192.45km, and 4.45 respectively for Awetu sub-basin. The values indicate that both sub-basins are characterized by mountainous, steep slope and mostly homogeneous geologic materials. The elongation ratio of Kito and Awetu sub-basins are 0.62 and 0.64 respectively. Kito and Awetu sub-basins are both elongated and the rivers have slow hydrograph for a long time. Relatively, Awetu sub-basin is more elongated than Kito sub-basin. The study reveals that both sub-basins are susceptible to surface runoff and soil erosion but the rivers are long and easy to manage flood occurrence.
Abstract: Morphometric analysis is very important to evaluate watershed characteristics. Watershed characteristics are essential in watershed management, site selection for water resource projects, groundwater evaluation and proposing flood control measures. The present study aimed the morphometric analysis of Kito and Awetu sub-basins which drain into Kito ...
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