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Identification and Evolution of Groundwater Chemistry in the Ejin Sub-Basin of the Heihe River, Northwest China

Pedosphere 2007年第3期17卷 331-342页

作者： SU Yong-Hong FENG Qi ZHU Gao-Feng SI Jian-Hua ZHANG Yan-Wu Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou730000 （China） School of Mathematics and Statistics Lanzhou University Lanzhou 730000 （China）

Hydro-chemical characteristics of groundwater and their changes as affected by human activities were studied in the Ejin Sub-Basin of the Inner Mongolia Autonomous Region, China, to understand the groundwater evolution, to identify the predominant geochemical processes taking place along the horizontal groundwater flow path, and to characterize anthropogenic factors affecting the groundwater environment based on previous data. The concentrations of major ions and total dissolved solids （TDS） in the groundwater showed a great variation, with 62.5% of the samples being brackish （TDS ≥ 1 000 mg L^-l）. The groundwater system showed a gradual hydro-chemical zonation composed of Na^＋ -HCO3^-, Na^＋ -Mg^2＋ -SO4 ^2 -Cl^-, and Na^＋ -Cl^-. The relationships among the dissolved species allowed identification of the origin of solutes and the processes that generated the observed water compositions. The dissolution of halite, dolomite, and 2- gypsum explained, in part, the presence of Na^＋, K^＋, Cl^-, SO^4 , and Ca^2＋, but other processes, such as mixing, Na^＋ exchange for Ca^2＋ and Mg^2＋, and calcite precipitation also contributed to the composition of water. Human activity, in particular large-scale water resources development associated with dramatic population growth in the last 50 years, has led to tremendous changes in the groundwater regime, which reflected in surface water runoff change, decline of groundwater table and degeneration of surface water and groundwater quality. Solving these largely anthropogenic problems requires concerted, massive and long-term efforts.

关键词： Ejin Sub-Basin groundwater quality Heihe River human impact water resources development

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The economic impact of schistosomiasis

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Infectious Diseases of Poverty 2021年第6期10卷 106-106页

作者： Daniele Rinaldo Javier Perez‑Saez Penelope Vounatsou Jürg Utzinger Jean-Louis Arcand Department of Economics and Land EnvironmentEconomics and Policy Institute(LEEP)University of ExeterExeterEngland 不详

Background:The economic impact of schistosomiasis and the underlying tradeofs between water resources devel‑opment and public health concerns have yet to be *** exerts large health,social and fnan‑cial burdens on infected individuals and *** irrigation schemes are one of the most important policy responses designed to reduce poverty,particularly in sub-Saharan Africa,they facilitate the propagation of schistoso‑miasis and other ***:We estimate the economic impact of schistosomiasis in Burkina Faso via its efect on agricultural produc‑*** create an original dataset that combines detailed household and agricultural surveys with high-resolution geo-statistical disease *** develop new methods that use the densities of the intermediate host snails of schis‑tosomiasis as instrumental variables together with panel,spatial and machine learning ***:We estimate that the elimination of schistosomiasis in Burkina Faso would increase average crop yields by around 7%,rising to 32%for high infection *** schistosomiasis unchecked,in turn,would correspond to a loss of gross domestic product of approximately 0.8%.We identify the disease burden as a shock to the agricultural productivity of *** poorest households engaged in subsistence agriculture bear a far heavier disease burden than their wealthier counterparts,experiencing an average yield loss due to schistosomiasis of between 32 and 45%.We show that the returns to water resources development are substantially reduced once its health efects are taken into account:villages in proximity of large-scale dams sufer an average yield loss of around 20%,and this burden decreases as distance between dams and villages ***:This study provides a rigorous estimation of how schistosomiasis afects agricultural production and how it is both a driver and a consequence of *** further quantifes the tradeof between the economics of wa

关键词： Schistosomiasis Neglected Tropical Diseases Sub-Saharan Africa Agriculture water resources development Poverty

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water Supply Route Optimization for Reservoir Emergency Based on Improved Ant Colony Algorithm

Water Supply Route Optimization for Reservoir Emergency Base...

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第26届中国控制与决策会议

作者： Du Xiang-run ZHANG Jian-long Feng Min-quan Institute of water Conservancy and Hydroelectric Power Xi'an University of Technology Shanxi Province water conservancy construction and development centers

In order to improve water supply in the path optimization problems, an improved Ant Colony based on the mathematical model of water supply is put forward to figure out optimization algorithm. Using the improved ant colony algorithm research water supply pipe network optimization problems. The inspire information was normalized process and the global strategy preferred node probability select based on the the introduced virtual path distance to the initial node in telection strategy. In the tpdate strategy, used local and global pheromone update and combined adaptive adjustment of the ants number and increased random interference improvement. The results show that the improved ant colony algorithm calculated better than basic ant colony algorithm from the each indicators. It can be seen the improved algorithm can improve the global search ability and convergence speed, can be quickly and effectively to solve the optimal solution path or near optimal solution of water supply. It can provide reference for the choice of the path of water supply.

关键词： water resources development path optimization Improved ant colony algorithms Ba Jiazui reservoir emergency water supply

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Environmental impacts in water resources planning

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丛书名： International series on progress in water resources,

2002年

作者： Yurdusev M. A.

来源：畅想之星图书光盘版（南... 评论

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