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Discussion on Standardization and Automatic Flow Measurement of U-shaped Channel Water
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作者 Xiangkun Liu 《Journal of Electronic Research and Application》 2018年第6期5-9,共5页
In human life,water resources are inseparable.In recent years,China’s population growth has accelerated,and the industrial level has been continuously improved,resulting in the rapid use and waste of water resources.... In human life,water resources are inseparable.In recent years,China’s population growth has accelerated,and the industrial level has been continuously improved,resulting in the rapid use and waste of water resources.The protection and rational distribution of water resources are the most pressing issue in China’s water resources.At present,the water measuring facilities of the U-shaped channel mainly include a straight wall measuring pool,a parabolic throat measuring pool,and a long throat measuring pool.In view of the problems in irrigation measurement,the empirical water measurement of basic open-channel and automatic flow measurement system in irrigation district is summarized to improve the accuracy,fairness,and rationality of water measurement,and promote irrigation district management to a higher level. 展开更多
关键词 U-SHAPED CHANNEL water standardization AUTOMATED flow measurement
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The Study of the Standardization System for a Water-plan Database
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作者 Zhang Xin 《China Standardization》 2009年第2期27-32,共6页
In this paper,a detailed data list of water plan is given,based on its characteristics.This paper discusses the principles ofestablishing a system of standards for a water plan database,and amethod of modeling the wat... In this paper,a detailed data list of water plan is given,based on its characteristics.This paper discusses the principles ofestablishing a system of standards for a water plan database,and amethod of modeling the water plan data.The information is presentedin a standardization system graph. 展开更多
关键词 water plan database system standardization
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Evaluation Model of Carrying Capacity of Water Resources Based on Standardized Indices of Radial Basis Function
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作者 臧蕾 李祚泳 刘伟 《Agricultural Science & Technology》 CAS 2012年第6期1365-1367,共3页
[Objective] The aim was to study on RBF model about evaluation on carrying capacity of water resources based on standardized indices. [Method] The indices were transformed and the averages of standard values in differ... [Objective] The aim was to study on RBF model about evaluation on carrying capacity of water resources based on standardized indices. [Method] The indices were transformed and the averages of standard values in different levels were taken as the standardized values of components of central vectors for basic functions of RBF hidden nodes. Hence, the basic functions are suitable for most indices, simplifying expression and calculation of basic functions. [Result] RBF models concluded through Monkey-king Genetic Algorithm with weights optimization are used in evaluation on water carrying capacity in three districts in Changwu County in Shaanxi Province, which were in consistent with that through fuzzy evaluation. [Conclusion] RBF, simple and practical, is universal and popular. 展开更多
关键词 Indices standardization RBF water resource Carrying capacity Evaluation model
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Parasitic Contamination of Drinking Water and Egyptian Standards for Parasites in Drinking Water 被引量:2
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作者 Wafaa M. Hikal 《Open Journal of Ecology》 2020年第1期1-21,共21页
Water is life and access to clean drinking water is a fundamental human right. For human health, drinking water standards and guidelines have been developed to ensure their quality. Waterborne parasites are a great ch... Water is life and access to clean drinking water is a fundamental human right. For human health, drinking water standards and guidelines have been developed to ensure their quality. Waterborne parasites are a great challenge and cause many diseases for humans. Thus, continuous monitoring of drinking water from the competent authorities in search of pollutants is required. The safety of drinking water for the growing population can be ensured by the correct use of water treatment technologies. Cryptosporidium is the first parasite to cause concern to health officials in the world. Also, Naegleria fowleri causes fatal cerebral infection, Acanthamoeba species that cause both cerebral and corneal disease;and Giardia which has heightened world concerns because of its severity. This study is based on highlighting on drinking water quality guidelines and standards published by the World Health Organization and some countries, especially Egypt. A growing concern globally after the scientists revealed the effects of polluted drinking water. So, a large number of the population is at risk of water pollution for the purpose of human access to clean drinking water and other uses. 展开更多
关键词 Drinking water standardS ACANTHAMOEBA CRYPTOSPORIDIUM GIARDIA NAEGLERIA
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Development of an Ontology-Based Knowledge Network by Interconnecting Soil/Water Concepts/Properties, Derived from Standards Methods and Published Scientific References Outlining Infiltration/Percolation Process of Contaminated Water 被引量:1
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作者 Stephanos D. V. Giakoumatos Anastasios K. T. Gkionakis 《Journal of Geoscience and Environment Protection》 2021年第1期25-52,共28页
The present work deals with the development of an Ontology-Based Knowledge Network of soil/water physicochemical & biological properties (soil/water concepts), derived from ASTM Standard Methods (ASTMi,n) and rele... The present work deals with the development of an Ontology-Based Knowledge Network of soil/water physicochemical & biological properties (soil/water concepts), derived from ASTM Standard Methods (ASTMi,n) and relevant scientific/applicable references (published papers—PPi,n) to fill up/bridge the gap of the information science between cited Standards and infiltration discipline conceptual vocabulary providing accordingly a dedicated/internal Knowledge Base (KB). This attempt constitutes an innovative approach, since it is based on externalizing domain knowledge in the form of Ontology-Based Knowledge Networks, incorporating standardized methodology in soil engineering. The ontology soil/water concepts (semantics) of the developed network correspond to soil/water physicochemical & biological properties, classified in seven different generations that are distinguished/located in infiltration/percolation process of contaminated water through soil porous media. The interconnections with arcs between corresponding concepts/properties among the consecutive generations are defined by the relationship of dependent and independent variables. All these interconnections are documented according to the below three ways: 1) dependent and independent variables interconnected by using the logical operator “<em>depends on</em>” quoting existent explicit functions and equations;2) dependent and independent variables interconnected by using the logical operator “<em>depends on</em>” quoting produced implicit functions, according to Rayleigh’s method of indices;3) dependent and independent variables interconnected by using the logical operator “<em>related to</em>” based on a logical dependence among the examined nodes-concepts-variables. The aforementioned approach provides significant advantages to semantic web developers and web users by means of prompt knowledge navigation, tracking, retrieval and usage. 展开更多
关键词 INFILTRATION PERCOLATION ASTM standards Soil/water Contamination Knowledge Base Ontology Network Semantics Porous Media
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Drought trend analysis in a semi-arid area of Iraq based on Normalized Difference Vegetation Index, Normalized Difference Water Index and Standardized Precipitation Index 被引量:1
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作者 Ayad M F AL-QURAISHI Heman A GAZNAYEE Mattia CRESPI 《Journal of Arid Land》 SCIE CSCD 2021年第4期413-430,共18页
Drought was a severe recurring phenomenon in Iraq over the past two decades due to climate change despite the fact that Iraq has been one of the most water-rich countries in the Middle East in the past.The Iraqi Kurdi... Drought was a severe recurring phenomenon in Iraq over the past two decades due to climate change despite the fact that Iraq has been one of the most water-rich countries in the Middle East in the past.The Iraqi Kurdistan Region(IKR)is located in the north of Iraq,which has also suffered from extreme drought.In this study,the drought severity status in Sulaimaniyah Province,one of four provinces of the IKR,was investigated for the years from 1998 to 2017.Thus,Landsat time series dataset,including 40 images,were downloaded and used in this study.The Normalized Difference Vegetation Index(NDVI)and the Normalized Difference Water Index(NDWI)were utilized as spectral-based drought indices and the Standardized Precipitation Index(SPI)was employed as a meteorological-based drought index,to assess the drought severity and analyse the changes of vegetative cover and water bodies.The study area experienced precipitation deficiency and severe drought in 1999,2000,2008,2009,and 2012.Study findings also revealed a drop in the vegetative cover by 33.3%in the year 2000.Furthermore,the most significant shrinkage in water bodies was observed in the Lake Darbandikhan(LDK),which lost 40.5%of its total surface area in 2009.The statistical analyses revealed that precipitation was significantly positively correlated with the SPI and the surface area of the LDK(correlation coefficients of 0.92 and 0.72,respectively).The relationship between SPI and NDVI-based vegetation cover was positive but not significant.Low precipitation did not always correspond to vegetative drought;the delay of the effect of precipitation on NDVI was one year. 展开更多
关键词 climate change DROUGHT Normalized Difference Vegetation Index(NDVI) Normalized Difference water Index(NDWI) standardized Precipitation Index(SPI) delay effect
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Preliminary Study on Formulating Water Quality Standards for Estuaries of China
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作者 Wang Liping Liu Lusan Zheng Binghui 《Meteorological and Environmental Research》 CAS 2014年第3期37-41,45,共6页
In China,the water quality standards in operation include the Environmental Quality Standard for Surface Water(GB3838-2002)and Water Quality Standards for Seawater(GB3097-1997).However,these two standards are curr... In China,the water quality standards in operation include the Environmental Quality Standard for Surface Water(GB3838-2002)and Water Quality Standards for Seawater(GB3097-1997).However,these two standards are currently not suitable for the estuarial zones of China because of the unique properties of water environment in estuaries.We proposed preliminarily a basic idea and technical workflow in formulating water quality standards for the estuaries of China based on analyzing the water environment properties of estuaries comprehensively and comparing various parameters and their standard values mentioned in these two standards above.Issues pertinent to the formulation of the water quality standards for estuaries,e.g.nutrient,heavy metals and persistent organic pollutants(POPs),are highly concerned.The objective of this paper is to provide technical support for the formulation of scientific water quality standards and the assessment of water quality of the estuaries of China. 展开更多
关键词 ESTUARY water quality standards NUTRIENT Heavy metal Persistent organic pollutants(POPs) China
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Situation of China's solar water heater industry,related national standards,testing and the Golden Sun certification program
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作者 严军 H.Drück H.Müller-Steinhagen 《Journal of Chongqing University》 CAS 2008年第2期107-112,共6页
China is the largest solar water heater producer and market in the world.Despite the fast growth and an installed capacity that accounts for the majority of the global gross,China's per capita solar hot water capa... China is the largest solar water heater producer and market in the world.Despite the fast growth and an installed capacity that accounts for the majority of the global gross,China's per capita solar hot water capacity is still very low,implying a huge margin of market potential;and the recognition of the industry in the global market is handicapped by the scattered scale of production and inconsistent product quality.To ensure continued growth of China's solar water heating(SWH) industry,Chinese Government has established a series of national SWH standards,three national testing centers,and a certification program to lay the foundation for the development of the Golden Sun product labeling system.China General Certification Center(CGC) developed the Golden Sun product certification and labeling system on a pass/fail basis evaluating with established criteria.The system was designed to help manufacturers acclimate to explicit consistent requirements and to identify and fix the deficiencies in the design and execution of the program itself.Timely revision and integration of the national standards are recommended to accommodate the test procedures and requirements to new technologies and the evolving SWH market.Strict implementation of the Golden Sun certification and labeling system are suggested to avail improving the quality control and forging internationally reputable brands of Chinese solar water heating products. 展开更多
关键词 solar water heaters solar heating renewable energy resources national standards Golden Sun certification program
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Study on Shanghai Water Management Information Standard and its application
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作者 Wang Huajie Zheng Xiaoyang 《China Standardization》 2007年第2期6-11,共6页
In Shanghai, three trades including water conservancy, water supply and water drainage are managed integratively by Shanghai Water Authority. However, trade division is apparent among them, and information sharing nee... In Shanghai, three trades including water conservancy, water supply and water drainage are managed integratively by Shanghai Water Authority. However, trade division is apparent among them, and information sharing needs to be strengthened. Therefore, lack of information standard is becoming an urgent problem to be solved. According to the strategic objectives of "Golden Water Project" in China and "Digital City" in Shanghai, "Shanghai Water Management Information Standard" is made for normalizing information classifications, codes, terms, GIS symbols and attributed data structures. It not only coincides with national standards, ministerial standards and Shanghai local standards, but also embodies the characteristic of integrated water management in Shanghai. It provides "traffic rule" for resources integrating and information sharing. Some good research ideas such as omni-direction, multi-levels and facing application can be popularized in other provinces and municipalities of China. 展开更多
关键词 water management INFORMATION standard SHANGHAI
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Discussion on Top-level Design of the Environmental Monitoring Standard System Based on the Changes of 109 Method Standards for Surface Water
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作者 Haiqiong MAO Shuangye PAN +7 位作者 Huanyin FENG Yun XU Bijun SHEN Zhongquan CHEN Binjian YANG Kai CHEN Shayi WANG Jianxun SHI 《Meteorological and Environmental Research》 CAS 2022年第2期56-60,共5页
The changes of 109 analytical methods for surface water in the past 20 years since the implementation of Environmental Quality Standards for Surface Water(GB 3838-2002)were analyzed.Concidering with the analysis of sp... The changes of 109 analytical methods for surface water in the past 20 years since the implementation of Environmental Quality Standards for Surface Water(GB 3838-2002)were analyzed.Concidering with the analysis of specific items in the quality standard,it is suggested that the monograph method and the general method(the general method is moved to the standard collection of general rules and standards)can be combined when the analytical method is newly formulated and revised in the future;the limit table of the quality standard or pollution source emission standard is moved to the collection of general rules and standards,and the referenced analysis method standards are deleted.The description of analysis method standard is more succinct,and the structure of the whole ecological environment standard system is clearer. 展开更多
关键词 Surface water standard System
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Research Status of Water Quality Criteria and Standards and Analysis on the Transformation Methods
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作者 Cheng LI Yihong WU +1 位作者 Yang ZHAO Ruyu YUAN 《Meteorological and Environmental Research》 CAS 2023年第3期69-72,共4页
Under the vision of development for the new era,China has entered a stage of high-quality economic development and an important window period in which we have the conditions and ability to address the prominent issue ... Under the vision of development for the new era,China has entered a stage of high-quality economic development and an important window period in which we have the conditions and ability to address the prominent issue of economic development and ecological protection in a coordinated way.However,all kinds of environmental benchmark values in China are lacking and need to be constantly supplemented and improved.Therefore,exploring and putting forward a simple and efficient method for the transformation of environmental criteria into environmental standards is an important basis for the rapid establishment of relevant environmental criteria system and the effective promotion of the development of environmental standards system towards a scientific and reasonable direction.In this paper,the water environment is taken as the research object.By analyzing the research progress of environmental criteria and standards at home and abroad,and the foreign method of transforming environmental criteria into environmental standards,combined with the problems faced in the process of transforming environmental criteria into environmental standards in China,an effective method to transform China's environmental criteria into environmental standards is analyzed.After analysis and comparison,it is found that the pollution reduction accounting method could achieve their simple and efficient conversion.Under the premise of obtaining environmental criteria for certain pollutants,environmental criteria for certain pollutants could be obtained by distributing pollutants reduction costs,and accounting economic benefits after reaching standard,thus obtaining the environmental standard of this type of pollutant,which provides reference to determine the environmental standard limits of such pollutants. 展开更多
关键词 water quality criteria water quality standards Research status Transformation mechanism
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Development of emergency water quality standard for Cr^(6+) and Hg^(2+) in Liao River basin
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作者 Yan Zhenguang Zheng Xin +4 位作者 Ye Jing Wang Xiaonan Wu Jiangyue Liu Zhengtao Meng Wei 《Engineering Sciences》 EI 2014年第2期45-51,共7页
The acute toxicity data of Cr+ and Hg2+ to the aquatic organisms in Liao River basin was collected and screened. Calculated results of criteria values using popular species sensitivity distribution (SSD) methods w... The acute toxicity data of Cr+ and Hg2+ to the aquatic organisms in Liao River basin was collected and screened. Calculated results of criteria values using popular species sensitivity distribution (SSD) methods were evaluated through data analysis. The comprehensive methodology of emergency water quality standards (EWQSs) was established on the basis of the SSD method of Australia and New Zealand according to the evalu- ation results. The affected fractions of the aquatic organisms were set to be 5 %, 15 %, 30 % and 50 %, corre- sponding to the risk grades of Ⅰ,Ⅱ,Ⅲ and IV, and four-grade EWQSs, respectively. The EWQSs for Cr6+ and Hg2. in the Liao River were derived and the corresponding risk indicators were also proposed. The results showed that the four-grade EWQSs for Cr6+ were 2.85 μg/L, 21.0 μg/L, 161 μg/L and 797 μ/L, respec- tively, and the risk indicators were daphnia (grade Ⅱ ), shrimp (grade Ⅲ), and the bighead fish or tadpole (grade IV). The four-grade EWQSs for Hg2+ were 0.59 μg/L, 2.32 μg/L, 6.25 μg/L and 15.6 μg/L, respective- ly, and the risk indicators were crucian carp or daphnia (grade Ⅱ), shrimp (grade Ⅲ), and worm or crab (grade IV). The results provided valuable information for the risk analysis of sudden ambient water environmen- tal pollution accident. 展开更多
关键词 Liao River Cr6+ Hg2+ emergency water quality standards risk indicators
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Discussion about the standard system on urban domestic water saving technology in China
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作者 YANG Shujun, REN Xiaoli ,GAO Benhu 《China Standardization》 2007年第2期2-5,共4页
Standard is the technical foundation of national economic and social development, and it is the basic rule of establishing social regulation. Researching and constituting the standard system of urban domestic water sa... Standard is the technical foundation of national economic and social development, and it is the basic rule of establishing social regulation. Researching and constituting the standard system of urban domestic water saving technology is to offer important science basis for revising standard plan and standardize research plan. This paper introduces the present situation of our urban domestic water saving technical standard system, problem and the development direction in the future, as well as project planning of constructing urban domestic water saving technical standard system. 展开更多
关键词 standard system urban domestic water saving technology water shortage Project plan
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Overview of China's National Standards for Solar Water Heating
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作者 JIA Tieying 《China Standardization》 2007年第5期6-11,共6页
Energy supply is one of the major challenges facing China. The rate at which demand is outstripping supply led the Standing Committee of the National People's Congress to pass the Renewable Energy Law of the PRC a... Energy supply is one of the major challenges facing China. The rate at which demand is outstripping supply led the Standing Committee of the National People's Congress to pass the Renewable Energy Law of the PRC at its fourteenth session in February, 2005. The document points out that 'The law is legislated to promote exploitation and utilization of renewable energy, increase the supply of energy sources, improve the structure of energy sources, ensure the security of energy sources, protect the environment, and achieve the sustainable development of economy and society.' 'Renewable energy under the law is non-fossil energy, including wind, solar, water, biomass, geothermal, and ocean energies, etc.' 'The nation determines that the exploitation and utilization of renewable energy takes precedence in the development of energy sources, and propels the establishment and development of the renewable energy market.' 'The Standardization Administrative Department of the State Council should constitute and promulgate the national grid-connection standards for renew- able electricity, and other national technical standards that are related to renewable energy technology and products.' 展开更多
关键词 Overview of China’s National standards for Solar water Heating
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The Meeting for Promotion of the Standards for Water Saving Held in Beijing
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《China Standardization》 2005年第1期8-8,共1页
Jointly hosted by the Standardization Administration of China (SAC) and the National Development and Reform Commission, the Meeting for Promotion of the Standards for Water Saving was held in Beijing on Oct. 5th, 2004... Jointly hosted by the Standardization Administration of China (SAC) and the National Development and Reform Commission, the Meeting for Promotion of the Standards for Water Saving was held in Beijing on Oct. 5th, 2004, with the aim of promoting development of water intake technology, improving efficiency of water using and developing recycle economy. The meeting analyzed the current 展开更多
关键词 The Meeting for Promotion of the standards for water Saving Held in Beijing
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Surface Water Quality Profiling Using Physicochemical Parameters in Open Defecation Free and Non-Open Defecation Free Local Government Areas in Benue State, Nigeria
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作者 Moses T. Asoo Celestine U. Aguoru +1 位作者 Innocent O. Ogbonna Hyacinth O.A. Oluma 《Open Journal of Modern Hydrology》 CAS 2024年第3期174-191,共18页
Physicochemical parameters of surface water sources in the study of local government areas (LGAs) were assessed using standard procedures. The mean physicochemical parameters for pH (5.49), NO2 (0.23 mg/L), SO4 (0.77 ... Physicochemical parameters of surface water sources in the study of local government areas (LGAs) were assessed using standard procedures. The mean physicochemical parameters for pH (5.49), NO2 (0.23 mg/L), SO4 (0.77 mg/L), Na (28.72 mg/L), Ca (28.94 mg/L), Mg (17.50 mg/L), Cl (11.65 mg/L), TSS (6.27 mg/L), TDS (104.23 mg/L), BOD (2.83 mg/L) and F (0.87 mg/L) were below WHO standards irrespective of their defecation status. The values for electrical conductivity (EC) (2770.50 µs/cm, turbidity (481.24 NTU), dissolved oxygen (DO) (5.32 mg/L), chemical oxygen demand (COD) (445.50 mg/L), K (125.06 mg/L), PO4 (0.78 mg/L) and Fe (0.57 mg/L) were above the WHO limits for safe water. Higher EC and COD values obtained in the study is evidence of pollution of the water sources by organic matter. 展开更多
关键词 Open Defecation Surface water water Quality standard Physicochemical Parameters
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Analysis of the Quality of Physical and Chemical Parameters of Groundwater in Three Localities in the Sub-Prefecture of Zanzra (Ivory Coast)
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作者 Djedjess Essoh Jules-César Meledje Bi Irié Marc Gouli +3 位作者 Drissa Ouattara Kra Vanh Eric-Simon Zran Adjourma Konate Albert Trokourey 《Journal of Materials Science and Chemical Engineering》 2024年第4期1-17,共17页
The availability of groundwater of acceptable quality has become a difficult challenge to meet in many countries, particularly Côte d’Ivoire. The State of Côte d’Ivoire and rural populations are building h... The availability of groundwater of acceptable quality has become a difficult challenge to meet in many countries, particularly Côte d’Ivoire. The State of Côte d’Ivoire and rural populations are building hydraulic infrastructure for this purpose. However, the quality of water coming from these infrastructures remains to be determined. This study therefore aims to analyze certain physicochemical parameters of the groundwater of Gloazra, Kouezra and Trahonfla. These are temperature, pH, electrical conductivity, TDS, salinity level, hardness, alkalinity, chloride content and bicarbonate. To determine the pH, electrical conductivity, temperature, TDS, and salinity rate, an electrochemical analysis was carried out. The titrimetric analysis made it possible to determine the chloride and bicarbonate content, alkalinity, and hardness. The results indicate that the studied groundwater is soft and acidic with good mineralization. This water does not present a health hazard to consumers but can affect hydraulic equipment and household containers. 展开更多
关键词 Ivory Coast Gloazra Trahonfla Kouezra Physicochemical Parameters water WHO standards
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Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal
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作者 Abdou Khafor Ndiaye Falilou Coundoul +2 位作者 Abdoulaye Deme Antonina Torrens Armengol Abdoulaye Senghor 《Natural Resources》 2024年第1期1-16,共16页
In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed... In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability. 展开更多
关键词 Constructed Wetlands Horizontal Flow Reed Beds Wastewater Treatment Phragmites and Typha Plants Physicochemical Pollutant Removal Microbiological Indicators Fecal Coliforms and Helminth Eggs water Quality Improvement Senegal water Reuse standards Sustainable water Management Agricultural Irrigation Reuse Nutrient Removal Efficiency Environmental Engineering Ecological Sanitation Systems
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Diagnosing anomalous characteristics of atmospheric water cycle structure during seasonal-scale drought events:A case study in middle and lower reaches of Yangtze River 被引量:4
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作者 Hai He Rui Cao +3 位作者 Zhi-yong Wu Yuan Li Hao Yin Fei Yuan 《Water Science and Engineering》 EI CAS CSCD 2022年第2期103-113,共11页
Anomalous characteristics of the atmospheric water cycle structure are highly significant to the mechanisms of seasonal-scale meteorological droughts.They also play an important role in the identification of indicativ... Anomalous characteristics of the atmospheric water cycle structure are highly significant to the mechanisms of seasonal-scale meteorological droughts.They also play an important role in the identification of indicative predictors of droughts.To better understand the causes of seasonal meteorological droughts in the middle and lower reaches of the Yangtze River(MLRYR),characteristics of the atmospheric water cycle structure at different drought stages were determined using standardized anomalies.The results showed that the total column water vapor(TCWV)was anomalously low during drought occurrence periods.In contrast,there were no anomalous signals at the drought persistence and recovery stages in the MLRYR.Moreover,there was no significant temporal correlation between the TCWV anomaly and seasonal-scale drought index(the 3-month standardized precipitation index(SPI_(3))).During drought events,water vapor that mainly originated from the Bay of Bengal was transported southwest of the MLRYR.Meanwhile,the anomalous signal of water vapor transport was negative at the drought appearance stage.At the drought persistence stage,the negative anomalous signal was the most significant.Water vapor flux divergence in the MLRYR showed significant positive anomalous signals during drought events,and the signal intensity shifted from an increasing to a decreasing trend at different drought stages.In addition,a significant positive correlation existed between the anomaly of water vapor flux divergence and regional SPI_(3).Overall,water vapor flux divergence is more predictive of droughts in the MLRYR. 展开更多
关键词 water vapor transport water vapor flux divergence standardized anomalies Seasonal-scale drought process Middle and lower reaches of Yangtze River
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Using GIS and Remote Sensing in Assessment of Water Scarcity in Nakuru County, Kenya 被引量:1
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作者 Catherine Changwony Arthur W. Sichangi Moses Murimi Ngigi 《Advances in Remote Sensing》 2017年第1期88-102,共15页
Water is at the core of sustainable development and is critical for socio-economic development, healthy ecosystems and for human survival. This research study has been carried out in Nakuru County, a tropical region i... Water is at the core of sustainable development and is critical for socio-economic development, healthy ecosystems and for human survival. This research study has been carried out in Nakuru County, a tropical region in the Rift Valley of Kenya, bounded between latitude 0.28°N and 1.16°S, and longitude 36.27°E and 36.55°E. The objective of the study has been to use GIS and remote sensing in assessment of water scarcity using Land use Land cover area changes, standard precipitation index and crop yields. Landsat satellite images for the year 1985, 1995, 2005 and 2015 were used. Classification was done using maximum likelihood algorithm while classification accuracy assessment entailed the use of confusion matrix method and ground truth data. Post classification change detection results gave percentage cropland areas as 21% in 1985, 29% in 1995, 53% in 2005 and also 53% in 2015. Eleven (11) ground rainfall stations and TRMM satellite rainfall data from 1985 to 2015 has been used to show meteorological drought. Validation of rainfall data done using correlation coefficient (R2) and root mean square (RMS) methods showed that ground rainfall data and TRMM data correlate. Modelling of 3 months SPI for each of the three seasons (MAM, JJA and OND) has been done using interpolation distance weighted method (IDW). 3 months SPI time scales curves gave October 1987 May 1993, and July 2004 as water scarce and dry seasons and were categorized as either Normal, moderately dry, severely dry and extremely dry. Crop yield trends curves showed crop yield decrease in this identified water scarce and dry years. Conclusion reached is that crop yields is not dependent on size of land ploughed only but mostly on rainfall quantities. Therefore, the findings of this research can be used as drought monitoring tools. 展开更多
关键词 LAND Use LAND COVER (LULC) METEOROLOGICAL DROUGHT standard Precipitation Index (SPI) water SCARCITY
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