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71.
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Caikun GAO Huakun DU Jingtian TANG Kangxiu WU Chang'an XIAO Shiping WANG 《东北亚地学研究》2008,11(3):191-196
Integrated geophysical interpretation is a method of combinating different geophysics prospecting methods based on different physical properties of accumulation. As different geophysical methods own different interpretations and varying detection accuracies, the key issue becomes how to integrate the results of several geophysical methods to corrently carry out a comprehensive explanation. Based on different geophysical results, the authors proposed an integrated geophysical explanation method and successfully applied it in practical engineering problems. 相似文献
73.
Thanh Duc Dang Thomas A. Cochrane Mauricio E. Arias Pham Dang Tri Van Tonny T. de Vries 《水文研究》2016,30(21):3824-3838
The Mekong floodplains, which encompasses the region from Kratie Township in Central Cambodia to the Vietnamese East Sea, is a region of globally renown agricultural productivity and biodiversity. The construction of 135 dams across the Mekong basin and the development of delta‐based flood prevention systems have caused public concern given possible threats on the stability of agricultural and ecological systems in the floodplains. Mekong dams store water upstream and regulate flow seasonality, while in situ flood prevention systems re‐distribute water retention capacity in the floodplains. The main aim of this paper is to evaluate possible impacts of the recent development of both hydropower dams and flood prevention systems on hydrological regimes in the Mekong floodplains. An analysis of measured daily and hourly water level data for key stations in the Mekong floodplains from Kratie to the river mouth in Vietnam was conducted. Hydropower dam information was obtained from the hydropower database managed by the Mekong River Commission, and the MODIS satellite imagery was used to detect changes in flooding extent related to the operation of flood prevention systems in the Vietnam Mekong Delta. Results indicate that the upper part of the floodplains, the Cambodian floodplains, may buffer upstream dam impacts to the Vietnam Mekong Delta. Flood prevention up to date has had the greatest effect on the natural hydrological regime of the Mekong floodplains, evidenced by a significant increase of water level rise and fall rates in the upper delta and causing water levels in the middle delta to increase. The development of flood prevention systems has also effected spatial distribution of flooding as indicated via a time series analysis of satellite imagery. While this development leads to increase localized agricultural productivity, our historical data analysis indicates that development of one region detrimentally affects other regions within the delta, which could increase the risk of future conflicts among regions, economic sectors and the ecological value of these important floodplains. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Mohr-Coulomb屈服准则在岩土工程中的应用 总被引:1,自引:0,他引:1
对Tresca屈服准则、Mises屈服准则、双剪屈服准则及Mohr-Coulomb屈服准则的屈服线、屈服应力进行分析比较,找出了各种屈服准则之间的差异。探讨Mohr-Coulomb屈服准则与其他屈服准则的关系,并确定Mohr-Coulomb屈服准则在岩土工程中的安全性及岩土体破坏时的破裂面位置与滑移线之间的关系。以亚碧罗水电站实测地应力为例,对实测地应力用不同的屈服准则进行分析,论证了Mohr-Coulomb屈服准则的安全性及剪切破裂面与滑移线的差异。 相似文献
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Thierry Ranchin Mélodie Trolliet Lionel Ménard Lucien Wald 《International Journal of Digital Earth》2020,13(2):253-261
ABSTRACTEssential Variables are defined as a minimal set of variables that explain the state of the system. They are crucial for predicting its developments, and support metrics that measure its evolution. The variables should be relevant to meet requirements of stakeholders and be technically and economically feasible for systematic observation. A definition of Essential Renewable Energies Variables is proposed linked with their identification in several domains in renewable energy using a bottom-up and user-driven approach, and spanning over several years of documented interaction with stakeholders. Lists of variables are proposed in hydropower, solar, wind, and marine energies. It does not comprise the variables relating to social and economic aspects supporting decision making in investment nor those relating to civil engineering that are needed to erect a plant or farm. 相似文献
77.
基于集对分析理论的水电站中长期风险调度问题研究 总被引:1,自引:0,他引:1
解决水电站中长期风险调度问题,在电力市场环境下显得尤为必要。在纵观国内外水电站中长期风险调度问题研究现状的基础上,应用集对分析理论对市场环境下水电站中长期调度的风险问题进行具体分析,对径流、发电用水和电价进行同异反描述,建立了基于集对分析理论的中长期风险调度模型,并用一次二阶矩法进行求解,可以提供效益与风险的定量关系。同时,对中长期风险调度进行了基于不确定数i的敏感性分析,给出了风险因子变化时所引起的发电收入变化幅度。实例研究表明了该方法的可行性与有效性。 相似文献
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Haakon Lein 《GeoJournal》2004,61(2):155-162
The furrow irrigation systems of Kilimanjaro were first described by European explorers coming to the area by the end of the
19th century. Although being impressed, the German and later the British colonial powers soon came to see the system as wasteful
and in need of improvement. Despite several attempts to control water use among the ‘natives’ in the highlands, the furrow
system has remained fairly intact and still plays a key role in the local farming systems.
However, the utilisation of available water resources is still a highly controversial political issue and in this paper three
major challenges to traditional water use are discussed: (i) hydropower development, (ii) construction of large-scale irrigation
projects, and (iii) implementation of economic and institutional reforms. All this has led to renewed and intensified conflicts
over the use of water on Kilimanjaro as well as in the Pangani river.
At one level, the situation can be described as a conflict over access to a scarce resource. However, beyond this perception,
the controversies over water are also based on more fundamental ideological conflicts and competing ways of thinking about
both development and water management.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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