The Experts below are selected from a list of 34212 Experts worldwide ranked by ideXlab platform
Klement Tockner - One of the best experts on this subject based on the ideXlab platform.
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A global boom in hydropower Dam Construction
Aquatic Sciences, 2014Co-Authors: Christiane Zarfl, Alexander E. Lumsdon, Laura Tydecks, Jurgen Berlekamp, Klement TocknerAbstract:Human population growth, economic development, climate change, and the need to close the electricity access gap have stimulated the search for new sources of renewable energy. In response to this need, major new initiatives in hydropower development are now under way. At least 3,700 major Dams, each with a capacity of more than 1 MW, are either planned or under Construction, primarily in countries with emerging economies. These Dams are predicted to increase the present global hydroelectricity capacity by 73 % to about 1,700 GW. Even such a dramatic expansion in hydropower capacity will be insufficient to compensate for the increasing electricity demand. Furthermore, it will only partially close the electricity gap, may not substantially reduce greenhouse gas emission (carbon dioxide and methane), and may not erase interdependencies and social conflicts. At the same time, it is certain to reduce the number of our planet’s remaining free-flowing large rivers by about 21 %. Clearly, there is an urgent need to evaluate and to mitigate the social, economic, and ecological ramifications of the current boom in global Dam Construction.
Qinghe Zhao - One of the best experts on this subject based on the ideXlab platform.
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Determining the influencing distance of Dam Construction and reservoir impoundment on land use: A case study of Manwan Dam, Lancang River
Ecological Engineering, 2013Co-Authors: Qinghe Zhao, Shiliang Liu, Li Deng, Shikui Dong, Zhifeng Yang, Qi LiuAbstract:Abstract Based on Landsat MSS and TM images from 1974, 1988, and 2004, we conducted a case study of the Manwan Dam along the Lancang (Mekong) River to determine the influencing distance of Dam Construction and reservoir impoundment on land use. Spatio-temporal variation in land use was analyzed within 14 adjacent buffer zones around the Dam site (concentric rings) and in upstream and downstream areas along the riverway (linear tract). Grassland increased with the greatest dynamic degree in the 1974–1988 period, whereas water area increased extensively in the 1988–2004 period. The integrated dynamic degrees of forestland were low in both periods. The integrated land use dynamics in the 14 concentric rings showed that the impact of Dam Construction extended to a threshold distance of 5000–6000 m from the Dam site during the 1974–1988 period and to 2000–3000 m during the 1988–2004 period. The transformational patch density in the 14 linear buffer zones indicated that the impact of reservoir impoundment on land use conversion exhibited a threshold distance of 3000 m from the riverway. The impact intensity of Dam Construction in the concentric rings and linear buffer zones tended to decline with increasing distance from the Dam site or riverway. The impacts of Dam Construction and reservoir impoundment were larger in upstream locations than in downstream ones. Our results enhance our understanding of the threshold of Dam Construction and may guide the management of Dam Construction on a regional landscape level.
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landscape change and hydrologic alteration associated with Dam Construction
International Journal of Applied Earth Observation and Geoinformation, 2012Co-Authors: Qinghe Zhao, Li Deng, Shikui Dong, Zhifeng Yang, Juejie YangAbstract:Abstract Characterizing the landscape changes and hydrologic alterations associated with Dam Construction is very important for watershed management. This paper presents a case study of the Lancang River in Yunnan Province following Dam Construction. The landscape patterns and dynamics indicate the fragmentation, shape, and diversity of the river in 1980, 1990, and 2000. The Range of Variability Approach (RVA) is used to evaluate the degree of hydrologic alteration (DHA) using 44 years (1957–2000) of hydrologic data. The results indicate that the midstream and downstream landscapes were affected by Dam Construction, becoming more complex and fragmented during the 1980–2000 period; the upstream area was not influenced by Dam Construction and the reservoir impoundment exhibited less change. The variability in maximum runoff occurrence in the post-Dam period was less than that in the pre-Dam period. The integrated DHAs of the Jiuzhou (upstream), Gajiu (midstream), and Yunjinghong (downstream) stations were relatively low, reaching 26.28%, 33.40%, and 37.14%, respectively. However, the alteration became obvious in the midstream area, and the situation worsened when the river was simultaneously influenced by Dam Construction and other human activities (downstream). The results of the regression analysis show strong relationships of landscape metric changes with DHA, and the forestland and water areas with DHA. The DHA increased along with the aggravation of landscape fragmentation, the complexity of the landscape shape, and the diversification of the landscape.
Klaus Glenk - One of the best experts on this subject based on the ideXlab platform.
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Understanding Public Views on a Dam Construction Boom: the Role of Values
Water Resources Management, 2019Co-Authors: Christopher Schulz, Julia Martin-ortega, Klaus GlenkAbstract:Large numbers of Dams for hydroelectric power production are currently planned or under Construction in many areas around the world. While positive and negative social and environmental impacts of Dams are increasingly well understood, little is known about attitudes of the general public towards Dams, even though benefits to wider society are often cited to legitimise their Construction. In Brazil’s Upper Paraguay River Basin, more than 100 mostly small-scale hydropower Dams are planned or under Construction in what can be considered a regional Dam Construction boom. Here we analyse public preferences for strategies to manage Dam impacts in the area by investigating the value base that underpins such preferences, drawing on the recently proposed Value Landscapes Approach as our theoretical framework and data from a large representative household survey ( N = 1067). We find that contrasting attitudes towards Dams, expressed in preferences for economically or ecologically oriented water policies are informed by opposing underlying value landscapes, that is, groups of closely related funDamental, governance-related, and assigned (water) values. While such tensions between opposing values can never be fully eliminated, our research nevertheless gives insights to policy-makers seeking to minimise value conflict and to improve the political legitimacy of public decision-making on Dam Construction. Moreover, we find that a majority of members of the general public would prefer concentrating Dam Construction on some rivers while keeping others free-flowing, with direct implications for ecosystems and inland fisheries. This finding may guide policy-makers wishing to develop publicly supported water resources management strategies.
Sanghyun Lee - One of the best experts on this subject based on the ideXlab platform.
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integrated evaluation of cost schedule and emission performance on rock filled concrete Dam Construction operation using discrete event simulation
Winter Simulation Conference, 2013Co-Authors: Chunna Liu, Changbum R Ahn, Sanghyun LeeAbstract:Massive concrete Dam projects will be conducted in the next ten years to respond to the increasing demand for clean energy and water resources in developing countries. With more attention paid to environmental issues, there is an increasing need to develop a methodology for reliably predicting the integrated performance of cost, schedule and emission factors in the planning stage. In this paper, we propose a methodology for using discrete event simulation (DES) for Dam Construction processes to enhance the performance dynamically. A case study is conducted to demonstrate the effectiveness of the DES model, which is validated by the actual cumulative progress on the Construction site. The results indicate that the cost, schedule and emission performance are highly interactively correlated when using RFC in Dam projects. The promoted methodology could help Construction managers compare the integrated performance of different options in RFC Dam Constructions.
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life cycle assessment of concrete Dam Construction comparison of environmental impact of rock filled and conventional concrete
Journal of Construction Engineering and Management-asce, 2013Co-Authors: Chunna Liu, Changbum R Ahn, Sanghyun LeeAbstract:AbstractMassive concrete Dam projects will be constructed in the next 10 years to respond to the increasing demand for clean energy and water resources in developing countries. Because of their ample use of cement, these projects have a significant environmental impact, including the production of carbon dioxide (CO2) emissions. Rock-filled concrete (RFC) is an innovative Dam Construction method that promises better environmental performance than conventional concrete (CC) in the material production stage by saving a large amount of cement. However, the environmental loads throughout the entire life cycle of a Dam must be quantified. Thus, this paper aims to evaluate the environmental loads in the lifetime of a Dam and reveal the environmental impact of RFC relative to CC over the entire life cycle of a concrete Dam. Through reviewing the limitations of the existing life-cycle assessment (LCA) models, a hybrid LCA model is applied to achieve this goal. The results from a case study of a concrete Dam proje...
L I Xiuli - One of the best experts on this subject based on the ideXlab platform.
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modeling and rendering method for concrete Dams Construction process
Computer Simulation, 2010Co-Authors: L I XiuliAbstract:Along with the development of virtual reality technology,three-dimensional simulation system as a new perspective of management methods and technical means in the progress of the project management plays an increasingly important role.A new model and simulation method for concrete Dam Construction process was proposed.Unlike previous works which just create different models for different period manually,the Dam model of a certain period could be created by clipping the whole three-dimensional Dam model through Three-dimensional clip algorithm.To increase the efficiency for simulation,a real-time rendering framework was constructed based on Shader Model 4.0.And a simulation system for concrete Dam Construction process was designed and implemented based on proposed method.The results validate that the presented method can satisfy the requirement for project management.
