期刊文献+
共找到4,192篇文章
< 1 2 210 >
每页显示 20 50 100
Optimal Operation for Baoying Pumping Station in East Route Project of South-to-North Water Transfer 被引量:7
1
作者 FENG Xiaoli QIU Baoyun +2 位作者 CAO Haihong WEI Qianglin TENG Haibo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第1期78-83,共6页
Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjus... Baoying pumping station is a part of source pumping stations in East Route Project of South-to-North Water Transfer in China. Aiming at the characteristics of head varying, and making use of the function of pump adjustable blade, mathematical models of pumping station optimal operation are established and solved with genetic algorithm. For different total pumping discharge and total pumping volume of water per day, in order to minimize pumping station operation cost, the number and operation duties of running pump units are respectively determined at different periods of time in a day. The results indicate that the saving of electrical cost is significantly effected by the schemes of adjusting blade angles and time-varying electrical price when pumping certain water volume of water per day, and compared with conventional operation schemes (namely, the schemes of pumping station operation at design blade angles based on certain pumping discharge), the electrical cost is saved by 4.73%-31.27%. Also, compared with the electrical cost of conventional operation schemes, the electrical cost is saved by 2.03%-5.79% by the schemes of adjusting blade angles when pumping certain discharge. 展开更多
关键词 south-to-north water transfer Baoying pumping station optimal operation adjusting blade angle time-varying electrical price
下载PDF
Critical discharge at Datong for controlling operation of South-to-North Water Transfer Project in dry seasons 被引量:3
2
作者 Wang Yigang Huang Huiming Li Xi 《Water Science and Engineering》 EI CAS 2008年第2期47-58,共12页
Previous research shows that there is a strong correlation between saltwater intrusion in the Yangtze Estuary and discharge at Datong. In the near future, the discharge of the Yangtze River during dry seasons will dec... Previous research shows that there is a strong correlation between saltwater intrusion in the Yangtze Estuary and discharge at Datong. In the near future, the discharge of the Yangtze River during dry seasons will decrease due to the construction and operation of large water diversion projects, including the South-to-North Water Transfer Project, which will further exacerbate saltwater intrusion in the estuary. In this paper, a nested 1D river network model and a 2D saltwater numerical model are used to associate saltwater intrusion in the Yangtze Estuary with different values of discharge at Datong. It is concluded that 13 000 m3/s is the critical discharge at Datong for preventing saltwater intrusion and controlling the volume of water transferred by the South-to-North Water Transfer Project. Furthermore, based on the analysis of river discharge from Datong to Xuliujing and in consideration of the influence of all of the water diversion projects, operation schemes are proposed for the Eastern Route of the South-to-North Water Transfer Project for different hydrological years. 展开更多
关键词 saltwater intrusion critical discharge at Datong water diversion the south-to-north water transfer Project
下载PDF
Research on Expansive Soils Encountered in Middle Route Project of South-to-north Water Transfer Canal 被引量:2
3
作者 GONG Bi-weiSenior Engineer, Yangtze River Scientific Research Institute, Changjiang Water Resources Commission, Wuhan, 430010, China ZHOU Xiao-wenSenior Engineer, Yangtze River Scientific Research Institute, Changjiang Water Resources Commission, Wuhan, 430010, China BAO Chen-gangProfessor-Senior Engineer, Yangtze River Scientific Research Institute, Changjiang Water Resources Commission, Wuhan, 430010, China 《人民长江》 北大核心 2002年第S1期36-39,共4页
The main canal of the Middle Route Project of South-to-North Water Transfer totals more than 1 240 km in length. In Henan Province and Hebei Province, there will be a section of more than 120 km passing through an exp... The main canal of the Middle Route Project of South-to-North Water Transfer totals more than 1 240 km in length. In Henan Province and Hebei Province, there will be a section of more than 120 km passing through an expansive soils area. Expansive soils is a special kind of tenacious clay, which swells when meeting with water and shrinks when losing water. With complicated mechanical properties, it changes with the variation of water content. As a result, expansive soils become the key object of study on unsaturated soils mechanics for the project. From the status of study on unsaturated soils at home and abroad, this paper covers an analysis on stability analysis method of expansive soils slope, determination of expansive soils strength, rational design of canal slope ratio and support, and forecast of landslide for the Middle Route Project of South-to-North Water Transfer. 展开更多
关键词 Unsaturated SOILS Expansive SOILS Suction the south-to-north water transfer CANAL
下载PDF
Evolution trend of the water quality in Dongping Lake after South-North Water Transfer Project in China 被引量:2
4
作者 HU Zun-fang KANG Feng-xin +4 位作者 ZOU An-de YU Lin-song LI Yang TIAN Tong-liang KANG Gui-ling 《Journal of Groundwater Science and Engineering》 2019年第4期333-339,共7页
To investigate the evolution trend of water quality in Dongping Lake after South-North Water Transfer Project operation as well as to ensure the safe usage of the water receiving areas, water samples were collected an... To investigate the evolution trend of water quality in Dongping Lake after South-North Water Transfer Project operation as well as to ensure the safe usage of the water receiving areas, water samples were collected and determined before and after water delivery in different hydrological seasons. Then, comprehensive pollution index method, comprehensive nutrition state index method and health risk assessment model were utilized to evaluate the quality, nutrition, and health risk of Dongping Lake water. Results showed that the quality of Dongping Lake water still met level Ⅲ (light pollution) no matter before or after water delivery. The nutrition state was improved from light eutropher before water delivery to mesotropher after water delivery. The health risk level was reduced from high-medium before water delivery to medium level after water delivery. In summary, the operation of the eastern route of South-North Water Transfer Project is beneficial for water environment improvement of Dongping Lake. 展开更多
关键词 south-north water transfer Project Dongping LAKE water quality NUTRITION Health risk
下载PDF
Forecasting Loss of Ecosystem Service Value Using a BP Network: A Case Study of the Impact of the South-to-north Water Transfer Project on the Ecological Environmental in Xiangfan, Hubei Province, China 被引量:1
5
作者 YUN-FENG CHEN, JING-XUAN ZHOU, JIE XIAO, AND YAN-PING LIEnvironmental Science and Engineering College, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2003年第4期379-391,共13页
Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific... Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific countermeasures. Methods A three-layer BP network was built to simulate topology and process of the eco-economy system of Xiangfan. Historical data of ecological environmental factors and socio-economic factors as inputs, and corresponding historical data of ecosystem service value (ESV) and GDP as target outputs, were presented to train and test the network. When predicted input data after 2001 were presented to trained network as generalization sets, ESVs and GDPs of 2002, 2003, 2004... till 2050 were simulated as output in succession. Results Up to 2050, the area would have suffered an accumulative total ESV loss of RMB 104.9 billion, which accounted for 37.36% of the present ESV. The coinstantaneous GDP would change asynchronously with ESV, it would go through an up-to-down process and finally lose RMB89.3 billion, which accounted for 18.71% of 2001. Conclusions The simulation indicates that ESV loss means damage to the capability of socio-economic sustainable development, and suggests that artificial neural networks (ANNs) provide a feasible and effective method and have an important potential in ESV modeling. 展开更多
关键词 Artificial neural network BP Ecosystem service value south-to-north water transfer Project
下载PDF
Geological conditions and key rock mechanics issues in the Western Route of South-to-North Water Transfer Project 被引量:2
6
作者 XuechaoWang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第3期234-243,共10页
In terms of special geological conditions of the Western Route of South-to-North Water Transfer Project, the classification method for surrounding rocks is discussed by combining with the construction method of tunnel... In terms of special geological conditions of the Western Route of South-to-North Water Transfer Project, the classification method for surrounding rocks is discussed by combining with the construction method of tunnel boring machine (TBM). The classification standard of surrounding rocks is put forward on the basis of physical simulations and engineering practices. Damage, deformation and evolution of surrounding rocks induced by TBM excavation are discussed. Meanwhile, the long-term deformation mechanisms and stability of surrounding rocks are also studied. On this basis, a three-dimensional constitutive model for interbedded sandstone slate and a fiat shell-joint element-foundation system for calculating internal forces of segment lining are established. The deformation features of surrounding rocks of deep and steep interbedded sandstone slate and their influences on internal forces of segment lining are presented. Finally, the design methods of segment lining constructed in deep and steep flysch are proposed. 展开更多
关键词 the Western Route of south-to-north water transfer Project rock mechanics issues classification of surrounding rocks stability of surrounding rocks excavation-induced damage lining design
下载PDF
Eco-environmental benefit assessment of China's South-North Water Transfer Scheme——the middle route project
7
作者 DUANGuang-ming ZHAOJing-zhu LIUGuo-hua KEBing XIAOHan WUGang DENGHong-bing 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第2期308-315,共8页
This paper assess the eco-environmental benefits that may come from the middle route project of China's South-North Water Transfer Scheme(SNWT) with principles and methods of eco-economics and planning reports of ... This paper assess the eco-environmental benefits that may come from the middle route project of China's South-North Water Transfer Scheme(SNWT) with principles and methods of eco-economics and planning reports of SNWT's middle route project. Some benefits were calculated in monetary units. To make sure that the results can be comparable with normal monetary indices, concrete assessment objects and the parameters are prudently selected according to the major characteristics of the project and its water import region. Primary assessment revealed that in different project construction stages, the benefit could be more than 13 07 billion RMB Yuan in 2010 and 19 79 billion RMB Yuan in 2030, respectively. The monetary value tends to increase with social-economic development. To realize these potential benefits, however, calls for more endeavors. 展开更多
关键词 China's south-north water transfer Scheme(SNWT) the middle route project of south-north water transfer(MRPSNWT) assessment ecosystem services monetary indices
下载PDF
Asynchronism-synchronism of regional precipitation in South-to-North Water Transfer planned areas
8
作者 ZHENG Hong-xing, LIU Chang-ming (Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2001年第2期161-169,共9页
This paper proposes a method on analyzing the asynchronism-synchronism of precipitation of different hydrological regions regarding the S-to-N water transfer areas of eastern China. The general process of the analysis... This paper proposes a method on analyzing the asynchronism-synchronism of precipitation of different hydrological regions regarding the S-to-N water transfer areas of eastern China. The general process of the analysis includes three steps. Firstly, we created the rainfall series of the region concerned by calculating the regional average rainfall of the stations in the area with the help of the classical Thiessen Polygon method. Secondly, the standards of assessment indices for wetness or dryness are set according to Gamma distribution function with a certain probability P 37.5% or 62.5% given respectively. Finally, the frequency of nine combinations are counted as the quantitative feature of asynchronism and synchronism in three time scales, that is the yearly, seasonal and monthly scales. The asynchronism-synchronism of two region pairs has been estimated. The results show that the frequency of precipitation asynchronism in 1957–1998 is larger than the synchronism frequency for both the North China-middle and lower Yangtze River pair and for the North China-upper Hanjiang River pair. As for the synchronism phenomena, the frequency of Nd?Sd is rather low. As the combinations that are suitable for water transfers are Nd?Sw, Nn?Sw, Nd?Sn and Nn?Sn, the total frequency of these combinations for North China-middle and lower Yangtze River is 40% on an annual basis, but only 28% in spring when water shortages are most likely to occur. The total frequency of these combinations for North China-upper Hanjiang River is about 24% on an annual basis, but 35% in spring and winter. It should be noted that if future precipitation patterns are similar to that of the period 1957–1998, it is very important to change the natural character of asynchronism-synchronism by enhancing the capability of hydro-projects regulation and improving management of the water transfer project. 展开更多
关键词 synchronous frequency asynchronous frequency south-to-north water transfer
下载PDF
Price Analysis of Water Supply for South-to-North Water Transfer Project
9
作者 QIU Zhong enProfessor, Design Institute, Changjiang Water Resources Commission, Wuhan 430010, China Tan Chang liSenior Engineer, Design Institute, Changjiang Water Resources Commission, Wuhan 430010, China ZHU Qin Engineer, Design Institute, Chan 《人民长江》 北大核心 2001年第S1期29-32,共4页
The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from ... The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from the viewpoint of economic policies. It is considered that if the project is assigned as a profitable one and built depending on commercial loan from bank completely or mostly, the water price will be too high to be undertaken by users,and if the project places the public good at first while considering the economic benefit, its investment mainly relies on the state (national or local governments) appropriation and self-raised funds and a little from the bank loan on favorable terms, the price determined according to the principle of satisfying the cost and reasonable profit will be relatively lower and can be undertaken by the users in the North China where water shortage is serious. The problem of higher water price of agricultural irrigation to the north of the Yellow River can be tackled by taking measures such as "compensating agriculture by industry" according to foreign practical experiences and relevant suggestions. 展开更多
关键词 PRICE of water supply water PRICE estimation FUND RAISING schemes water transfer cost Middle-Route Project of south-to-north water transfer
下载PDF
LONG AND DEEP DIVERSION TUNNELS OF 1^(ST) STAGE PROJECT IN WEST ROUTE OF SOUTH-NORTH WATER TRANSFER PROJECT
10
作者 Shen Fengsheng,Liu Xin (Reconnaissance,Planning,Design and Research Institute,Yellow River Construction Commission, Ministry of Water Resources, Zhengzhou 450003 China) 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2003年第9期1527-1532,共6页
West Route of South-North Water Transfer Project,situated in southeastern Qinghai-Tibet Plateau,is a giant project,which will deliver 17 billion m3 of water from the main stream and tributaries upstream of the Yangtze... West Route of South-North Water Transfer Project,situated in southeastern Qinghai-Tibet Plateau,is a giant project,which will deliver 17 billion m3 of water from the main stream and tributaries upstream of the Yangtze River to the upper reaches of the Yellow River. It is to be constructed in 3 stages, of which the 1st stage project includes delivering 4 billion m3 of water by gravity from two tributaries of Yalong River and three tributaries of Dadu River. The project consists of 5 dams,7 tunnels and a channel in series,with the dam height of 63~123 m and water transfer length of 260.3 km,of which the tunnels measure 244.1 km. The special climatic,environmental and geologic conditions make the project much more complicated in construction,especially 3 tunnels with the length longer than 50 km each create challenges to the technical requirements of engineering survey,design and construction. 展开更多
关键词 南水北调工程 西线工程 引水隧洞 TBM
下载PDF
Impact of the eastern water diversion from the south to the north project on the saltwater intrusion in the Changjiang Estuary in China 被引量:10
11
作者 XU Kun ZHU Jianrong GU Yuliang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第3期47-58,共12页
The south to the north project (WDP) on the saltwater intrusion in the Changjiang Estuary is studied by the improved three-dimensionai (3D) numerical model.The net unit width flux in the Changjiang Estuary as well as ... The south to the north project (WDP) on the saltwater intrusion in the Changjiang Estuary is studied by the improved three-dimensionai (3D) numerical model.The net unit width flux in the Changjiang Estuary as well as the sectional salt flux is calculated in the North Branch (NB),the South Branch (SB),the North Channel (NC),the South Channel (SC),the North Passage (NP) and the South Passage (SP),respectively.The net seaward water flux in the SB is reduced,and the net water flux spilling over from the NB to the SB is enhanced after the eastern WDP.Under the mean river discharge condition in the dry season,the net salt flux spilling over from the NB to the SB is increased by 2.09 t/s and 0.52 t/s during the spring and neap tides,respectively,due to the eastern WDP.The saltwater intrusion in the Changjiang Estuary is enhanced by the eastern WDP.Compared with that during the spring tide,the net water diversion ratio during the neap tide in the NC is smaller,and thus the enhancement of the saltwater intrusion by the eastern WDP is smaller in the NC,and larger in the NP and the SP.The tidally averaged surface salinity at the water intakes of the Dongfengxisha Reservoir,the Chenhang Reservoir and the Qingcaosha Reservoir rises both during the spring and neap tides. 展开更多
关键词 eastern water diversion from the south to the north project saltwater intrusion Changjiang Estuary numerical calculation the water resource
下载PDF
The destiny of the North Pacific Intermediate Water in the South China Sea 被引量:2
12
作者 LAN Jian ZHANG Ningning WANG Caixia 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第5期41-45,共5页
The previous studies show that the spreading path of the subtropical salinity minimum of the North Pacific Intermediate Water (NPIW) is southwestward pointing to the Luzon Strait. Based on the P -vector method and g... The previous studies show that the spreading path of the subtropical salinity minimum of the North Pacific Intermediate Water (NPIW) is southwestward pointing to the Luzon Strait. Based on the P -vector method and generalized digital environmental model (GDEM) data, the volume transport of NPIW through Luzon Strait and the upward transport on the NPIW lower and upper boundaries are calculated to examine the destiny of NPIW in the South China Sea (SCS). On the annual mean, the estimation of NPIW transport into the SCS through the Luzon Strait is 1.72 Sv (1Sv=10 6 m 3 /s). The upward transport over the SCS is 0.31 Sv on the NPIW upper boundary and 1.31 Sv on the NPIW lower boundary. There is no strait or passage deeper than the surface for the NPIW to extend, except for the Luzon Strait. For the volume balance in the SCS NPIW, the volume transport of 2.72 Sv has to flow out of the SCS NPIW layer through the Luzon Strait. 展开更多
关键词 north Pacific Intermediate water south China Sea P -vector method
下载PDF
Optimization and coordination of South-to-North Water Diversion supply chain with strategic customer behavior 被引量:4
13
作者 Zhi-song CHEN Hui-min WANG 《Water Science and Engineering》 EI CAS 2012年第4期464-477,共14页
The South-to-North Water Diversion (SNWD) Project is a significant engineering project meant to solve water shortage problems in North China. Faced with market operations management of the water diversion system, th... The South-to-North Water Diversion (SNWD) Project is a significant engineering project meant to solve water shortage problems in North China. Faced with market operations management of the water diversion system, this study defined the supply chain system for the SNWD Project, considering the actual project conditions, built a decentralized decision model and a centralized decision model with strategic customer behavior (SCB) using a floating pricing mechanism (FPM), and constructed a coordination mechanism via a revenue-sharing contract. The results suggest the following: (1) owing to water shortage supplements and the excess water sale policy provided by the FPM, the optimal ordering quantity of water resources is less than that without the FPM, and the optimal profits of the whole supply chain, supplier, and external distributor are higher than they would be without the FPM; (2) wholesale pricing and supplementary wholesale pricing with SCB are higher than those without SCB, and the optimal profits of the whole supply chain, supplier, and external distributor are higher than they would be without SCB; and (3) considering SCB and introducing the FPM help increase the optimal profits of the whole supply chain, supplier, and external distributor, and improve the efficiency of water resources usage. 展开更多
关键词 south-to-north water Diversion supply chain strategic customer behavior floatingpricing mechanism
下载PDF
North-south difference of water mass properties across the Lembeh Strait, North Sulawesi, Indonesia 被引量:2
14
作者 WANG Weibo PAN Aijun +2 位作者 EDI Kusmanto MUH Hasanudin DENY Sutisna 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第12期1-8,共8页
Two field observations were conducted around the Lembeh Strait in September 2015 and 2016, respectively.Evidences indicate that seawater around the Lembeh Strait is consisted of North Pacific Tropical Water(NPTW),Nort... Two field observations were conducted around the Lembeh Strait in September 2015 and 2016, respectively.Evidences indicate that seawater around the Lembeh Strait is consisted of North Pacific Tropical Water(NPTW),North Pacific Intermediate Water(NPIW), North Pacific Tropical Intermediate Water(NPTIW) and Antarctic Intermediate Water(AAIW). Around the Lembeh Strait, there exist some north-south differences in terms of water mass properties. NPTIW is only found in the southern Lembeh Strait. Water mass with the salinity of 34.6 is only detected at 200–240 m between NPTW and NPTIW in the southern Lembeh Strait, and results from the process of mixing between the saltier water transported from the South Pacific Ocean and the lighter water from the North Pacific Ocean and Sulawesi Sea. According to the analysis on mixing layer depth, it is indicated that there exists an onshore surface current in the northern Lembeh Strait and the surface current in the Lembeh Strait is southward.These dramatic differences of water masses demonstrate that the less water exchange has been occurred between the north and south of Lembeh Strait. In 2015, the positive wind stress curl covering the northern Lembeh Strait induces the shoaling of thermocline and deepening of NPIW, which show that the north-south difference of airsea system is possible of inducing north-south differences of seawater properties. 展开更多
关键词 water mass Lembeh Strait north-south difference
下载PDF
Critical chain construction with multi-resource constraints based on portfolio technology in South-to-North Water Diversion Project 被引量:3
15
作者 Jing-chun FENG Lei LI +4 位作者 Nan YANG Yu-zhen HONG Min PANG Xiong YAO Li-cheng WANG 《Water Science and Engineering》 EI CAS 2011年第2期225-236,共12页
Recently, the critical chain study has become a hot issue in the project management research field. The construction of the critical chain with multi-resource constraints is a new research subject. According to the sy... Recently, the critical chain study has become a hot issue in the project management research field. The construction of the critical chain with multi-resource constraints is a new research subject. According to the system analysis theory and project portfolio theory, this paper discusses the creation of project portfolios based on the similarity principle and gives the definition of priority in multi-resource allocation based on quantitative analysis. A model with multi-resource constraints, which can be applied to the critical chain construction of the A-bid section in the South-to-North Water Diversion Project, was proposed. Contrast analysis with the comprehensive treatment construction method and aggressive treatment construction method was carried out. This paper also makes suggestions for further research directions and subjects, which will be useful in improving the theories in relevant research fields. 展开更多
关键词 multi-resource constraints south-to-north water Diversion Project project portfolio critical chain
下载PDF
Reliability model of organization management chain of South-to-North Water Diversion Project during construction period 被引量:3
16
作者 Feng Jingchun Zhou Yang +2 位作者 Hong Yuzhen Zhao Shixin Ren Xiaoqiang 《Water Science and Engineering》 EI CAS 2008年第4期107-113,共7页
In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project (SNWDP), two basic forms (series connection state and mixed state of both series connectio... In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project (SNWDP), two basic forms (series connection state and mixed state of both series connection and parallel connection) of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up. 展开更多
关键词 south-to-north water Diversion Project reliability model management chain parallel connection series connection
下载PDF
Land Cover Changes and Drivers in the Water Source Area of the Middle Route of the South-to-North Water Diversion Project in China from 2000 to 2015 被引量:3
17
作者 GAO Wenwen ZENG Yuan +2 位作者 ZHAO Dan WU Bingfang REN Zhiyuan 《Chinese Geographical Science》 SCIE CSCD 2020年第1期115-126,共12页
The Middle Route of the South-to-North Water Diversion Project(MR-SNWDP)in China,with construction beginning in 2003,diverts water from Danjiangkou Reservoir to North China for residential,agriculture and industrial u... The Middle Route of the South-to-North Water Diversion Project(MR-SNWDP)in China,with construction beginning in 2003,diverts water from Danjiangkou Reservoir to North China for residential,agriculture and industrial use.The water source area of the MR-SNWDP is the region that is most sensitive to and most affected by the construction of this water diversion project.In this study,we used Landsat Thematic Mapper(TM)and HJ-1 A/B images from 2000 to 2015 by an object-based approach with a hierarchical classification method for mapping land cover in the water source area.The changes in land cover were illuminated by transfer matrixes,single dynamic degree,slope zones and fractional vegetation cover(FVC).The results indicated that the area of cropland decreased by 31%and was replaced mainly by shrub over the past 15 years,whereas forest and settlements showed continuous increases of 29.2% and 77.7%,respectively.The changes in cropland were obvious in all slope zones and decreased most remarkably(–43.8%)in the slope zone above 25°.Compared to the FVC of forest and shrub,significant improvement was exhibited in the FVC of grassland,with a growth rate of 16.6%.We concluded that local policies,including economic development,water conservation and immigration resulting from the construction of the MR-SNWDP,were the main drivers of land cover changes;notably,they stimulated the substantial and rapid expansion of settlements,doubled the wetlands and drove the transformation from cropland to settlements in immigration areas. 展开更多
关键词 remote sensing land cover change object-based classification Middle Route of the south-to-north water Diversion Project(MR-SNWDP) China
下载PDF
Penalty model for delay of bidding section construction period in South-to-North Water Diversion Eastern Route Project from perspective of programs 被引量:2
18
作者 Jing-chun FENG Ya-fang REN +2 位作者 Zhong-nan DUAN Zhan-jun LIU Hai-yang LI 《Water Science and Engineering》 EI CAS 2012年第3期350-360,共11页
According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculatio... According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculation of penalty for delay of the bidding section construction period with the critical path method, we studied the effects of contractor-induced delay of the bidding section construction period in detail, including the effects on the construction period of the bidding section itself, the earliest start times of the next bidding section and other subsequent bidding sections, and the construction period of the program, and then constructed a penalty model for delay of the bidding section construction period from the perspective of programs. Using the penalty model, we conducted a practical analysis of penalty for delay of the construction period of the Baoying station program in the South-to-North Water Diversion Project. The model can help determine the amount of penalty for delay of the construction period in bidding sections scientifically and reasonably, 展开更多
关键词 program establishment program management bidding section construction period critical path method (CPM) penaly model south-to-north water Diversion Project
下载PDF
IMPACTS OF THE SOUTH-TO-NORTH WATER DIVERSION PROJECTS (MIDDLE ROUTE)ON THE WATER ENVIRONMENT OF THE MIDDLE AND LOWER REACHES OF THE HANJIANG RIVER
19
作者 FAN Bei-Lin, WAN Jian-Rong, ZHANG Jie and LIN Qiu-Sheng (Yangtze River Scientific Research Institute,River Research Deparment, Wuhan 430010,China) 《水生生物学报》 CAS CSCD 北大核心 2006年第6期643-646,共4页
In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well... In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang River. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang River will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation. 展开更多
关键词 south-to-north water Diversion Project River regime water environment Mathematical model
下载PDF
The variation of DOM during long distance water transport by the China South to North Water Diversion Scheme and impact on drinking water treatment 被引量:1
20
作者 Hankun Yang Yujuan Li +6 位作者 Hongyu Liu Nigel J.D.Graham Xue Wu Jiawei Hou Mengjie Liu Wenyu Wang Wenzheng Yu 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2024年第5期85-100,共16页
In this study,samples were taken from three locations,upstream to downstream,along the central route project of the China South to North Water Diversion(SNWD)scheme in summer and winter.These were used to reveal the v... In this study,samples were taken from three locations,upstream to downstream,along the central route project of the China South to North Water Diversion(SNWD)scheme in summer and winter.These were used to reveal the variations of dissolved organic matter(DOM)during the water transfer process,and the effects of these variations on drinking water treatment and disinfection by-products formation potential(DBPs-FP).The results showed that polysaccharides accumulate in summer and reduce in winter with flow distance,which has an important effect on the overall properties of DOM,as well as on the performance of coagulation,ultrafiltration,and the formation of DBPs.Humic substances,and their hydrophilic content,also increased in summer and decreased in winter with flow distance.In contrast,the concentration of small organic substances(MW≤1000 Da)increased in both summer and winter with flow distance,which affected both nanofiltration(NF)membrane fouling and DBPs-FP.The results provide a useful case study of spatial and temporal changes in raw water DOM during long distance water transfer and their impact on the treatment and quality of drinking water from the SNWD. 展开更多
关键词 Long-distance water transfer The China south to north water Diversion Scheme COAGULATION Membrane filtration Disinfection by-products
原文传递
上一页 1 2 210 下一页 到第
使用帮助 返回顶部