期刊文献+
共找到12,730篇文章
< 1 2 250 >
每页显示 20 50 100
Evaluation of water resources conserved by forests in the Hani rice terraces system of Honghe County,Yunnan,China:an application of the fuzzy comprehensive evaluation model 被引量:10
1
作者 LI Jing MIN Qingwen +3 位作者 LI Wenhua BAI Yanying YANG Lun Dhruba Bijaya G C 《Journal of Mountain Science》 SCIE CSCD 2016年第4期744-753,共10页
The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in... The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in the sustainable development of this system. The value of water conserved by the forest is influenced by natural, economic and social factors. In this paper, the water quality, per capita water resources, per capita GDP and population density are chosen as indices to construct an index system for a comprehensive evaluation of water resources value. The weights of these indices are 0.443, 0.31, 0.141 and 0.106 respectively, which are determined by the analytic hierarchy process(AHP) method. The water resources value has been assessed by the fuzzy comprehensive evaluation model. The results show that the water resources value in the Hani Rice Terraces System is 4.25 RMB/m^3. Evaluating the value of water resources in the Hani Rice Terraces System can provide a reference for ecological compensation, for raising public awareness of the importance of protecting the system, and ultimately achieving its sustainable development. 展开更多
关键词 Fuzzy comprehensive evaluation model water resources Hani Rice Terrace water value Globally Important Heritage systems(GIAHS)
下载PDF
Design and Implementation of Aquaculture Pond Water Quality Assessment System Based on Fuzzy Mathematics 被引量:2
2
作者 王瑞梅 傅泽田 何有缘 《Agricultural Science & Technology》 CAS 2010年第7期171-175,共5页
The aquaculture pond water quality was taken as research objects,based on the general analysis of factors influencing the pond water quality,the system of index estimation and assessment standard were established afte... The aquaculture pond water quality was taken as research objects,based on the general analysis of factors influencing the pond water quality,the system of index estimation and assessment standard were established after sorting by importance of the factors by means of Delphi and expert investigation.In this study,index weight was confirmed according to the importance of the factors and relative membership grade of the measured values,thus and the fuzzy comprehensive evaluation model of aquaculture pond water quality was constructed,and the fuzzy comprehensive evaluation system of freshwater aquaculture pond water quality was designed and implemented.The application of this system in the assessment of aquaculture pond water quality by a company had achieved better result. 展开更多
关键词 PonD AQUACULTURE water quality Fuzzy comprehensive evaluation
下载PDF
Evaluation index system for positive operation of water conservancy projects 被引量:3
3
作者 Qing-yuan ZHU Guo-hua FANG 《Water Science and Engineering》 EI CAS 2009年第4期110-117,共8页
The conditions for the positive operation of water conservancy projects are described in this paper. A scientific and effective evaluation index system was established based on frequency analysis, theoretical analysis... The conditions for the positive operation of water conservancy projects are described in this paper. A scientific and effective evaluation index system was established based on frequency analysis, theoretical analysis, and expert consultation. This evaluation index system can be divided into six first-level indices: the degree to which facilities are intact and functionality standards are reached, the status of operation and management funds, the rationality and degree of advancement of the management team structure, the adaptability and rationality of the water conservancy project management system, the degree of automatization and informationization of the management techniques, and the conduciveness of the exterior environment. The weights for evaluation indices were obtained through the analytic hierarchy process method with consideration of the difference between public welfare and profit-oriented water conservancy projects. This study provides a scientific method for evaluating the positive operation of water conservancy projects. 展开更多
关键词 water conservancy project positive operation evaluation index system analytic hierarchy process WEIGHT
下载PDF
Fuzzy Comprehensive Evaluation for Decision Making of Water Saving Irrigation System 被引量:3
4
作者 Luo Jin\|yao, Qiu Yuan\|feng College of Water Resources and Hydropower Engineering , Wuhan University, Wuhan 430072, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03A期837-841,共5页
A model of fuzzy comprehensive evaluation for water saving irrigation system (WSIS) decision making is proposed based on establishing an index system affected by six kinds of basic factors including qualitative and qu... A model of fuzzy comprehensive evaluation for water saving irrigation system (WSIS) decision making is proposed based on establishing an index system affected by six kinds of basic factors including qualitative and quantitative indexes. The object function of WSIS is set up by using the concept of fuzzy membership degree, it is to transform characteristic vector matrix into unify membership matrix and extending the least square method to the least of weighted distance square. The optimum weighted membership degree and the inferior weighted membership degree are used to solve the object function. This method effective solves the problem of classify for fuzzy attributive indexes and the problem of optimum for the set of different attributive indexes. A case study shows that the fuzzy comprehensive evaluation model is reasonable and effective in decision making for water saving irrigation system planning. 展开更多
关键词 water saving irrigation system (WSIS) decision making fuzzy comprehensive evaluation (FCE) index system fuzzy membership degree
下载PDF
Assessing adaptability of the water resource system to social-ecological systems in the Beijing-Tianjin-Hebei region:Based on the DPSIR-TOPSIS framework 被引量:3
5
作者 Dan Wu Mengyao Liu 《Chinese Journal of Population,Resources and Environment》 2022年第3期261-269,共9页
To optimize the overall layout of water resource allocation in the Beijing-Tianjin-Hebei region,the adaptabil‐ity of the water resource system to the regional social-ecological systems has to be enhanced.Based on the... To optimize the overall layout of water resource allocation in the Beijing-Tianjin-Hebei region,the adaptabil‐ity of the water resource system to the regional social-ecological systems has to be enhanced.Based on the driver-pressure-state-impact-response(DPSIR)framework,this study constructs an evaluation index system to analyze the adaptability mechanisms of Beijing-Tianjin-Hebei’s water resource system according to the three major constituent social-ecological systems(i.e.,economic,social,and ecological systems).Moreover,it adopts the technique of order preference similarity to the ideal solution(TOPSIS)to comprehensively evaluate the adaptability of Beijing-Tianjin-Hebei’s water resource system based on three constituent social-ecological systems(i.e.,economic,social,and ecological systems)and identifies the spatiotemporal differentiation char‐acteristics of the region.Our results showed that,①from 2000 to 2020,the adaptability of Beijing-Tianjin Hebei’s water resource system,as a whole,significantly improved.In terms of stages,from 2000 to 2007,the adaptability of the water resource social system was significantly higher than that of economic and ecological systems in the region.From 2008 to 2015,by accelerating the transformation and upgrading of industrial structures,improving the efficiency of economic water utilization,and strengthening the governance of the water ecosystem,the adaptability of water resource economic and ecological systems rapidly improved;how‐ever,that of the water resource ecological system was still the lowest.Additionally,the adaptability of the wa‐ter resource economic system exceeded that of the social system.From 2016 to 2020,the gap in adaptability of the water resource system to all three major constituent systems gradually narrowed.By 2020,the three sys‐tems entered a relatively balanced development stage,with the adaptability of the entire water resource system and the three major constituent systems maintaining a high level.②The economic system was significantly af‐fected by per capita GDP,per capita water resources,and the efficiency of economic water utilization.Addition‐ally,the social system was significantly affected by water consumption per unit of irrigation area.Meanwhile,the ecological system was significantly influenced by precipitation,water pollution discharge performance indi‐cators,and the structure optimization indicators of water supply.According to the evaluation results,we pro‐pose countermeasures and provide recommendations to optimize the overall layout of water resource alloca‐tion and promote the coordinated management of water resources in the Beijing-Tianjin-Hebei region. 展开更多
关键词 Beijing-Tianjin-Hebei region water resource system Social-ecological systems ADAPTATIon Mechanism evaluation
下载PDF
Benefits Evaluation of Water Resources Used for Ecosystem in Shiyang River Basin of Gansu Province 被引量:1
6
作者 粟晓玲 康绍忠 +2 位作者 李伏生 张橹 佟玲 《Transactions of Tianjin University》 EI CAS 2009年第2期108-112,共5页
Among the numerous inland river basins in the arid northwest China,Shiyang River basin is known for its most serious water shortage that constrains its social and economic developments and for some of the worst ecolog... Among the numerous inland river basins in the arid northwest China,Shiyang River basin is known for its most serious water shortage that constrains its social and economic developments and for some of the worst ecological and environmental deterioration in China.The research on the value of water resources used for ecosystem is the basis for reasonable allocation of water resources between users of ecosystem and economic system.In this paper the concept of dynamic value for the ecosystem services is proposed.A modified coefficient for the ecosystem service value per unit area is proposed according to the cover degrees of biomes combined with expert consultation.Based on the developmental stage coefficient and scarcity of ecological resources,a dynamic evaluation method is proposed.The theoretical formula and simple calculation formula of the sharing benefits coefficient and benefits per unit ecological water utilization are proposed.The result shows that the benefit of unit ecological water utilization in the lower reach was greater than that in the upper reach in the Shiyang River basin. 展开更多
关键词 benefits evaluation ecosystem services water resources ecological water utilization
下载PDF
Response Mechanism of Water Ecosystem under the Influence of Urbanization: A Case Study of the Connection Zone between Shenyang and Fushun
7
作者 Zhang Runjie Gu Chunyu +3 位作者 Zuo Shiwen Qi Yue Tong Lili Fu Baorong 《Meteorological and Environmental Research》 CAS 2018年第5期15-18,共4页
Taking the connection zone between Shenyang and Fushun as an example,urbanization indicator system was established from the aspects of population,economy,space and society,and the comprehensive evaluation indicator sy... Taking the connection zone between Shenyang and Fushun as an example,urbanization indicator system was established from the aspects of population,economy,space and society,and the comprehensive evaluation indicator system of water ecological environment was also established from the aspects of water ecological environmental pressure,state and response. Based on the evaluation of comprehensive level of urbanization and the comprehensive quality of water ecological environment,their changing trends during 2000-2014 were analyzed,and the response model between them was established. The composite index of urbanization in the connection zone between Shenyang and Fushun always increased from 2000 to 2014,and urbanization developed rapidly after 2004. The comprehensive quality of water ecological environment decreased firstly and then increased during 2000-2014. The response relationship between urbanization comprehensive index and water ecological comprehensive index during 2000-2014 could be expressed by a cubic curve. 展开更多
关键词 URBANIZATIon water ECOLOGICAL environment Response the ConNECTIon ZonE BETWEEN Shenyang and Fushun
下载PDF
Application of a Groundwater Classification System and GIS Mapping System for the Lower Ruby Valley Watershed, Southwest Montana
8
作者 Scott M. Payne Ian A. Magruder William W. Woessner 《Journal of Water Resource and Protection》 2013年第8期775-791,共17页
Classification of groundwater conditions at the watershed scale synthesizes landscape hydrology, provides a mapped summary of groundwater resources, and supports water management decisions. The application of a recent... Classification of groundwater conditions at the watershed scale synthesizes landscape hydrology, provides a mapped summary of groundwater resources, and supports water management decisions. The application of a recently developed watershed-scale groundwater classification methodology is applied and evaluated in the 100,000 hectare lower Ruby Valley watershed of southwestern Montana. The geologic setting, groundwater flow direction, aquifer productivity, water quality, anthropogenic impact to water levels, depth to groundwater, and the degree of connection between groundwater and surface water are key components of the classification scheme. This work describes the hydrogeology of the lower Ruby Valley watershed and illustrates how the classification system is applied to assemble, analyze, and summarize groundwater data. The classification process provides information in summary tables and maps of seamless digital overlays prepared using geographical information system (GIS) software. Groundwater conditions in the watershed are classified as low production bedrock aquifers in the mountainous uplands that recharge the moderate productivity basin-fill sediments. Groundwater levels approach the surface near the Ruby River resulting in sufficient groundwater discharge to maintain stream flow during dry, late summer conditions. The resulting classification data sets provide watershed managers with a standardized organizational tool that represents groundwater conditions at the watershed scale. 展开更多
关键词 Aquifers HYDROGEOLOGY waterSHED GROUNDwater Management GEOGRAPHICAL Information systems Rivers/Streams Surface water/Groundwater Connection Land Use
下载PDF
A novel experimental system for performance evaluation of water powered percussive rock drill
9
作者 李夕兵 李志国 +1 位作者 周梓荣 刘希灵 《Journal of Central South University》 SCIE EI CAS 2011年第6期1902-1909,共8页
A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, e... A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, electronic control system, test and data acquisition system, and assistant devices, such as guideway and drilling bench. Parameters of the water powered percussive rock drill can be obtained by analyzing testing data, which contain impact energy, front and back cavity pressure, pressure and flow in each working part, drilling velocity, frequency and energy efficiency etc. The system is applied to test the self-designed water powered percussive rock drill SYYG65. The parameters of water powered percussive rock drill with impact pressure of about 8.9 MPa are 58.93 J for impact energy, and 8.97% for energy efficiency, which prove the effectiveness of system. 展开更多
关键词 water powered percussive rock drill performance test water powered excavation comprehensive evaluation
下载PDF
High-quality Development Evaluation System of Water Parks
10
作者 Yongshen TANG Hailong ZHANG Lei ZHANG 《Asian Agricultural Research》 2023年第1期16-22,共7页
Based on the connotation of high-quality development of water parks,this study established an evaluation system from distinctive water conservancy characteristics,excellent ecological environment,strong cultural atmos... Based on the connotation of high-quality development of water parks,this study established an evaluation system from distinctive water conservancy characteristics,excellent ecological environment,strong cultural atmosphere,strong development momentum,safe and efficient management,and significant comprehensive benefits,including 23 main contents and 52 evaluation indicators.Delphi method was used to score,and the evaluation results were divided into 3 levels,thus forming the evaluation system of high-quality development of water parks.This evaluation system has been preliminarily applied to the collection and selection of typical cases of the first national high-quality development of water parks.A total of 30 typical cases of high-quality development of water parks in China were collected and selected,and the first batch of 10 benchmark scenic spots were announced for key recommendation,and considerable application results have been achieved. 展开更多
关键词 water parks High-quality development Main characteristics evaluation system
下载PDF
Entropy method for determination of weight of evaluating indicators in fuzzy synthetic evaluation for water quality assessment 被引量:218
11
作者 ZOU Zhi-hong YUN Yi SUN Jing-nan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第5期1020-1023,共4页
Considering the difficulty of fuzzy synthetic evaluation method in calculation of the multiple factors and ignorance of the relationship among evaluating objects, a new weight evaluation process using entropy method w... Considering the difficulty of fuzzy synthetic evaluation method in calculation of the multiple factors and ignorance of the relationship among evaluating objects, a new weight evaluation process using entropy method was introduced. This improved method for determination of weight of the evaluating indicators was applied in water quality assessment of the Three Gorges reservoir area. The results showed that this method was favorable for fuzzy synthetic evaluation when there were more than one evaluating objects. One calculation was enough for calculating every monitoring point. Compared with the original evaluation method, the method predigested the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable. 展开更多
关键词 water quality evaluation FUZZY weight of evaluating indicator entropy method
下载PDF
Water quantity-quality combined evaluation method for rivers' water requirements of the instream environment in dualistic water cycle: A case study of Liaohe River Basin 被引量:2
12
作者 WANG Xiqin ZHANG Yuan LIU Changming 《Journal of Geographical Sciences》 SCIE CSCD 2007年第3期304-316,共13页
In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relatio... In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river requirements, the efficiency of water resource usage, the consumption coefficient, and the concentration of waste water elimination, the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed, and the criteria for environmental flows of river requirements are established, and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized Taking the Liaohe River as a model, the environmental flows of river requirements for Xiliao River, Dongliao River, mainstream Liaohe River, Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated, each taking up 39.3%, 63.0%, 43.9%, 43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow, the results show that: except Xiliao River is "median", the rest are all upon "good", the Dongliao River is even "very good". The corresponding results in dualistic water cycle are that, the proportion of natural flows for each river is 57.5%, 74.1%, 60.8%, 60.3% and 60.4%; while the combined evaluation results show that: considering "quantity", except Xiliao River, the rest rivers can all achieve the "quantity" criteria of the en- vironmental flows of river requirements, but if considering the aspect of "quality", only Dongliao River can reach the "quality" standard. By water quantity-quality combined evaluation method, only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem demands. 展开更多
关键词 dualistic water cycle RIVERS environmental flows of river requirements water quantity water quality evaluation Liaohe River
下载PDF
Fuzzy Synthetic Evaluation of Water Quality of Naoli River Using Parameter Correlation Analysis 被引量:14
13
作者 WANG Jianhua LU Xianguo +1 位作者 TIAN Jinghan JIANG Ming 《Chinese Geographical Science》 SCIE CSCD 2008年第4期361-368,共8页
In order to improve the effectiveness of Fuzzy Synthetic Evaluation (FSE) models, a Parameter Correlation Analysis (PCA) was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang ... In order to improve the effectiveness of Fuzzy Synthetic Evaluation (FSE) models, a Parameter Correlation Analysis (PCA) was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang Plain, Northeast China. The basic principle of the PCA is that the pairs of parameters which are highly correlated and linear with each other would contribute the same information to an assessment and one of them should be eliminated. The method of the PCA is that a correlation relationship among candidate parameters is examined before the FSE. If there is an apparent nonlinear or curvilinear relationship between two parameters, then both will be retained; if the correlation is significant (p<0.01), and the scatter plot suggests a linear relationship, then one of them will be deleted. However, which one will be deleted? For solving this problem, a sensitivity test was conducted and the higher sensitivity parameters remained. The results indicate that the original data should be preprocessed through the PCA for redundancy and variability. The study shows that introducing the PCA into the FSE can simplify the FSE calculation process greatly, while the results have not been changed much. 展开更多
关键词 Parameter Correlation Analysis (PCA) Fuzzy Synthetic evaluation (FSE) surface water quality Naoli River Sanjiang Plain
下载PDF
Chemical kinetics evaluation and its application of natural gas generation derived from the Yacheng Formation in the deep-water area of the Qiongdongnan Basin,China 被引量:2
14
作者 SU Long ZHANG Dongwei +4 位作者 YANG Haizhang CHEN Ying CHEN Guojun ZHENG Jianjing XU Yongchang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第1期50-59,共10页
The natural gas generation process is simulated by heating source rocks of the Yacheng Formation, including the onshore-offshore mudstone and coal with kerogens of Type II2-III in the Qiongdongnan Basin. The aim is to... The natural gas generation process is simulated by heating source rocks of the Yacheng Formation, including the onshore-offshore mudstone and coal with kerogens of Type II2-III in the Qiongdongnan Basin. The aim is to quantify the natural gas generation from the Yacheng Formation and to evaluate the geological prediction and kinetic parameters using an optimization procedure based on the basin modeling of the shallow-water area. For this, the hydrocarbons produced have been grouped into four classes(C1, C2, C3 and C4-6). The results show that the onset temperature of methane generation is predicted to occur at 110℃ during the thermal history of sediments since 5.3 Ma by using data extrapolation. The hydrocarbon potential for ethane, propane and heavy gaseous hydrocarbons(C4-6) is found to be almost exhausted at geological temperature of 200℃ when the transformation ratio(TR) is over 0.8, but for which methane is determined to be about 0.5 in the shallow-water area. In contrast, the end temperature of the methane generation in the deep-water area was over 300℃ with a TR over 0.8. It plays an important role in the natural gas exploration of the deep-water basin and other basins in the broad ocean areas of China. Therefore, the natural gas exploration for the deep-water area in the Qiongdongnan Basin shall first aim at the structural traps in the Ledong, Lingshui and Beijiao sags, and in the forward direction of the structure around the sags, and then gradually develop toward the non-structural trap in the deep-water area basin of the broad ocean areas of China. 展开更多
关键词 deep—water area geological prediction natural gas Yacheng Formation evaluation Qiongdongnan Basin
下载PDF
Evaluation of the water resources carrying capacity of Shandong peninsula, China 被引量:2
15
作者 WANG Kui-feng 《Journal of Groundwater Science and Engineering》 2016年第2期120-130,共11页
Research on the carrying capacity and security of water resources is vital for its contribution to implementing sustainable development goals. The limitation of water resources is one of the most important factors tha... Research on the carrying capacity and security of water resources is vital for its contribution to implementing sustainable development goals. The limitation of water resources is one of the most important factors that influence the sustainable utilization of resources. Studying the carrying capacity of water resources will not only facilitate monitoring and forecast of national resources and environmental carrying capacity, but also be valuable for building ecological civilization. According to the principles of evaluation system, the carrying capacity of water resources on Shandong peninsula is explored. A comprehensive evaluation model of the carrying capacity of water resources is constructed based on the carrying capacity of water resources index and the composite of water resources index. The results show that the capacity of water resources on Shandong peninsula is generally consistent with overexploitation, and that the development and utilization of water resources has reached a considerable scale under existing economic and technological conditions. The carrying capacity of water resources in this region is relatively small, and the contradiction between supply and demand of water resources is alarming. Relative countermeasures are put forward, to improve the water resources carrying capacity and to provide a basis for future sustainable development and utilization of water resources in this region. 展开更多
关键词 water resources carrying capacity Shandong peninsula evaluation water resources carrying capacity index
下载PDF
Quality Evaluation and Its Application to Surface Water Ecosystem Based on Maximum Flux Principle 被引量:3
16
作者 刘年磊 毛国柱 赵林 《Transactions of Tianjin University》 EI CAS 2010年第5期336-341,共6页
Based on the maximum flux principle(MFP),a water quality evaluation model for surface water ecosystem is presented by using self-organization map(SOM) neural network simulation algorithm from the aspect of systematic ... Based on the maximum flux principle(MFP),a water quality evaluation model for surface water ecosystem is presented by using self-organization map(SOM) neural network simulation algorithm from the aspect of systematic structural evolution.This evaluation model is applied to the case of surface water ecosystem in Xindu District of Chengdu City in China.The values reflecting the water quality of five cross-sections of the system at different developing stages are obtained,with stable values of 1.438,2.952,1.86... 展开更多
关键词 evaluation model maximum flux principle surface water ecosystem self-organization map
下载PDF
Determining the Quality of Mine Gushing and Mixed Water Using Coupled AHP and Fuzzy Comprehensive Evaluation Methods 被引量:1
17
作者 Junzhi Wang Wei Zhao +3 位作者 Xinyi Wang Naima A. M. Hersi Pingqing Zhang Xiangyang Sang 《Journal of Water Resource and Protection》 2018年第12期1185-1197,共13页
This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using ... This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using a combination of the three-scale AHP and fuzzy evaluation methods for the comprehensive evaluation of water quality. Ion chromatography (ICS 1100) has been used to analyze the content of the water sample while portable pH/EC/TDS/Tem- perature meters (SX 811 and SX 813) were used to test physical-chemical parameters. The results of this study show that chemistry of in No.11 gushing mine is dominated by HCO3-Na and HCO3-Ca, and had a pH between 7.1 and 8.00, belonging to neutral or slightly alkaline water. In addition, water were found to have the hardness between 18 mg/L and 542.5 mg/L. Results also show that the TDS of the roof sandstone and goaves water are higher than Cambrian limestone water, while the turbidity of the mixed water is 20 NTU in the sump, again higher than in other samples such as Cambrian limestone water. Total dissolved solids and the total hardness of Cambrian limestone groundwater mainly depend on the content of K+ + Na+, Ca2+, B={b1,b2,…,bj} and SO2-4. Thus, chemical composition changes remarkably after mine water mixing. Results showed that the coal roof sandstone water is class V while that in the sump is class III, and the Cambrian limestone groundwater is class I. In gushing, the quality of water can vary greatly;thus, water from the coal face roof sandstone and the Cambrian limestone should be stored and treated separately before being utilized. 展开更多
关键词 MINE water Chemical Characteristics AHP Method Fuzzy COMPREHENSIVE evaluation Method water QUALITY COMPREHENSIVE evaluation
下载PDF
An evaluation of the simulations of the Arctic Intermediate Water in climate models and reanalyses 被引量:1
18
作者 LI Xiang SU Jie ZHAO Jinping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第12期1-14,共14页
The simulations of the Arctic Intermediate Water in four datasets of climate models and reanalyses, CCSM3, CCSM4, SODA and GLORYS, are analyzed and evaluated. The climatological core temperatures and depths in both CC... The simulations of the Arctic Intermediate Water in four datasets of climate models and reanalyses, CCSM3, CCSM4, SODA and GLORYS, are analyzed and evaluated. The climatological core temperatures and depths in both CCSM models exhibit deviations over 0.5°C and 200 m from the PHC. SODA reanalysis reproduces relatively reasonable spatial patterns of core temperature and depth, while GLORYS, another reanalysis, shows a remarkable cooling and deepening drift compared with the result at the beginning of the dataset especially in the Eurasian Basin (about 2°C). The heat contents at the depth of intermediate water in the CCSM models are overestimated with large positive errors nearly twice of that in the PHC. To the contrary, the GLORYS in 2009 show a negative error with a similar magnitude, which means the characteristic of the water mass is totally lost. The circulations in the two reanalyses at the depth of intermediate water are more energetic and realistic than those in the CCSMs, which is attributed to the horizontal eddy-permitting reso-lution. The velocity fields and the transports in the Fram Strait are also investigated. The necessity of finer horizontal resolution is concluded again. The northward volume transports are much larger in the two re-analyses, although they are still weak comparing with mooring observations. Finally, an investigation of the impact of assimilation is done with an evidence of the heat input from assimilation. It is thought to be a reason for the good performance in the SODA, while the GLORYS drifts dramatically without assimilation data in the Arctic Ocean. 展开更多
关键词 Arctic Intermediate water model evaluation Arctic modeling impact of data assimilation
下载PDF
Quality Evaluation of Lake Water and Sediment Based on Multilevel Fuzzy Theory 被引量:4
19
作者 FENG Su-zhen ZHANG Zhi-shu 《Meteorological and Environmental Research》 2012年第8期24-27,35,共5页
[ Objective ] The study aimed to assess the pollution of water and sediment in Wuliangsuhai Lake based on multilevel fuzzy theory. [ Method] On the basis of measured and survey data, the quality of water and sediment ... [ Objective ] The study aimed to assess the pollution of water and sediment in Wuliangsuhai Lake based on multilevel fuzzy theory. [ Method] On the basis of measured and survey data, the quality of water and sediment in six representative sites of Wuliangsuhai Lake was evalu- ated by using multilevel fuzzy theory. [ Result] Water quality of Wuliangsuhai Lake was different in space, that is, the water quality closer to outfalls was poor, but the water quality became better from north to south with the direction of water flow. Sediment near the water exit was at Grade IV, while it was at GradeV in other sites. From the evaluation results of water and sediment, we could see that Wuliangsuhai Lake was suffering serious pollution, and eutrophication process was aggravating, so it is extremely urgent to control and restore Wuliangsuhai Lake. [Conclusion] The re- search could provide scientific references for controlling the pollution of Wuliangsuhai Lake. 展开更多
关键词 Wuliangsuhai Lake water SEDIMENT Quality evaluation China
下载PDF
Species richness and biodiversity significance of alpine micro-waterbody systems in Gaoligong Mountain, Northwest Yunnan, China 被引量:1
20
作者 LIU Shuo-Ran Davide FORNACCA +8 位作者 YANG Dao-De TAN Lu LI Xian-Fu REN Guo-Peng SUN Jun HE Xiao-Yang YANG Wen-Shu CAI Qing-Hua XIAO Wen 《Journal of Mountain Science》 SCIE CSCD 2020年第4期907-918,共12页
Water quality, size, connectivity and other physical properties of hydrological systems might have different functions in the formation and maintenance of biodiversity, but this remains mostly unclear due to the lack ... Water quality, size, connectivity and other physical properties of hydrological systems might have different functions in the formation and maintenance of biodiversity, but this remains mostly unclear due to the lack of undisturbed sites for experimental modelling. Alpine freshwater habitats such as micro-waterbodies(MWB) represent a kind of natural system suitable for biodiversity research. In order to assess potential linkages between environmental factors, connectivity of MWBs and aquatic species richness, we conducted a pilot study in two separated MWB systems located in Gaoligong Mountain, northwest Yunnan province, China. A total of 27 MWBs have been analyzed, including 22 connected and 5 isolated bodies. 13 conventional environmental factors were tested while all kinds of aquatic macro-organisms were collected and classified. Results showed a high environmental heterogeneity among MWBs and significant differences between the two systems but only a few environmental variables such as the depth of soil bottom, total Nitrogen and altitude were related to species richness and the formation of the community structure. As a benefit from the high environmental heterogeneity, the cascaded MWB systems provided divergent habitats able to support species richness at a higher level than the same number of randomly selected MWBs. This finding supports the idea that habitat connectivity matters also in extremely small aquatic ecosystems. Moreover, although still a preliminary result, a polarization effect within connected chains where edge MWBs host higher taxa and endemic taxa richness as well as larger populations, was detectable. This study gives interesting insights on the spatial processes driving community structure and a new prospective for biodiversity conservation. Since alpine MWBs have significant effects on the maintenance of watershed biodiversity, further research on such small and crucial ecosystems is encouraged. 展开更多
关键词 HABITAT connectivity High MOUNTAIN Extreme fine scale Cascaded water system Richness maintenance Polarized dispersal
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部