Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper...Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper is to review the current state of knowledge on stable isotopes of carbon, oxygen, and hydrogen in the research of crop carbon and water relations, such as carbon isotope discrimination （△^13C） during carbon fixation process by photosynthesis, application of △^13C in crop water use efficiency （WUE） and breeding programs, oxygen isotope enrichment during leaf water transpiration, CO2 fixation by photosynthesis and release by respiration, application of hydrogen isotope composition （619） and oxygen isotope composition （6180） for determination of water source used by a crop, stable isotope coupling Keeling plot for investigating the carbon and water flux in ecosystem, energy and material cycle in SPAC and correlative integrative models on stable isotope. These aspects contain most of the stable isotope researches on crop carbon and water relations which have been widely explored internationally while less referred in China. Based on the reviewed literatures, some needs for future research are suggested.展开更多
Water pollution is a steadily worsening problem because of growth in the chemical, pharmaceutical, leather, textile, and mining industries. In addition, municipal wastewater further contributes to polluting pure water...Water pollution is a steadily worsening problem because of growth in the chemical, pharmaceutical, leather, textile, and mining industries. In addition, municipal wastewater further contributes to polluting pure water sources. Hence, adequate treatment is essential before it released to avoid pollution of pure water sources. Chapter 3 describes guidelines for wastewater treatment taking into account its physical, chemical and mechanical nature. The guidelines are also helpful in maintaining the operational treatment facilities;it is estimated that 10 to 20 percent of wastewater treatment facilities even in developed countries are not operating properly. Treatment methods are divided into conventional and Natural biological processes and the advantages and drawbacks of each are clearly explained. The influential parameters are identified for the primary (settling to remove solid wastes), secondary (bacteria in removing pollutants) and tertiary (involving advanced techniques such as Biological Nutrient Removal) water purification methods, particularly municipal wastewater treatments. The biological treatment process via microorganisms is particularly suited for Lagoons, Ponds and wetlands because they avoid secondary by-products contaminants. Guidelines are given for the construction of artificial lakes and ponds to be used for wastewater treatment, and diagrams, designs, schemes, and mathematical models are provided. These can also be used for some difficult industrial wastewaters as well as for municipal water containing pharmaceuticals and personal care products. The author emphasized that wetland treatment is often the best choice for the pre-treatment of water and wastewater based on cost and the efficiency. This wastewater treatment chapter is very useful for environment researchers, and engineers, ecologist and the environmental education programs.展开更多
The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the coll...The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the collection of wastewater samples. Their analysis revealed specific pollutant loads, including loads of BOD5 3.6966 kgO<sub>2</sub>/day and COD of 12.8775 kgO<sub>2</sub>/day, which were central to the design phase. Following a rigorous assessment of the existing sanitation infrastructure, constructed wetland (CWs) emerged as the most appropriate ecological solution. This system, valued for its ability to effectively remove contaminants, was tailored to the specific needs of the site. Consequently, the final design of the filter extends over 217.16 m<sup>2</sup>, divided into two cells of 108.58 m<sup>2</sup> each, with dimensions of 12.77 m in length and 8.5 m in width. The depth of the filtering medium is approximately 0.60 m, meeting the standards while ensuring maximized purification. Typha, an indigenous and prolific plant known for its purification abilities, was selected as the filtering agent. Concurrently, non-crushed gravel was chosen for its proven filtration capacity. This study is the result of a combination of scientific rigor and design expertise. It provides a holistic view of sanitation for Ndiebene Gandiol. The technical specifications and dimensions of the constructed wetland filter embody an approach that marries indepth analysis and practical application, all aimed at delivering an effective and long-lasting solution to the local sanitation challenges. By integrating precise scientific data with sanitation design expertise, this study delivers a holistic solution for Ndiebene Gandiol. The detailed dimensions and specifications of the constructed wetland filter reflect a methodology that combines meticulous analysis with practical adaptation, aiming to provide an effective and sustainable response to the challenges of rural and school sanitation in the northern region of Senegal.展开更多
The terrestrial hydrological process is an essential but weak link in global/regional climate models. In this paper, the development status, research hotspots and trends in coupled atmosphere-hydrology simulations are...The terrestrial hydrological process is an essential but weak link in global/regional climate models. In this paper, the development status, research hotspots and trends in coupled atmosphere-hydrology simulations are identified through a bibliometric analysis, and the challenges and opportunities in this field are reviewed and summarized. Most climate models adopt the one-dimensional (vertical) land surface parameterization, which does not include a detailed description of basin-scale hydrological processes, particularly the effects of human activities on the underlying surfaces. To understand the interaction mechanism between hydrological processes and climate change, a large number of studies focused on the climate feedback effects of hydrological processes at different spatio-temporal scales, mainly through the coupling of hydrological and climate models. The improvement of the parameterization of hydrological process and the development of large-scale hydrological model in land surface process model lay a foundation for terrestrial hydrological-climate coupling simulation, based on which, the study of terrestrial hydrological-climate coupling is evolving from the traditional unidirectional coupling research to the two-way coupling study of "climate-hydrology" feedback. However, studies of fully coupled atmosphere-hydrology simulations (also called atmosphere-hydrology two-way coupling) are far from mature. The main challenges associated with these studies are: improving the potential mismatch in hydrological models and climate models; improving the stability of coupled systems; developing an effective scale conversion scheme; perfecting the parameterization scheme; evaluating parameter uncertainties; developing effective methodology for model parameter transplanting; and improving the applicability of models and high/super-resolution simulation. Solving these problems and improving simulation accuracy are directions for future hydro-climate coupling simulation research.展开更多
基金supported by the National Basic Re-search Program of China (973 Program) (2005CB121103)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-406KSCX1-YW-09-05)
文摘Crop carbon and water relations research is important in the studies of water saving agriculture, breeding program, and energy and material cycles in soil plant atmosphere continuum （SPAC）. The purpose of this paper is to review the current state of knowledge on stable isotopes of carbon, oxygen, and hydrogen in the research of crop carbon and water relations, such as carbon isotope discrimination （△^13C） during carbon fixation process by photosynthesis, application of △^13C in crop water use efficiency （WUE） and breeding programs, oxygen isotope enrichment during leaf water transpiration, CO2 fixation by photosynthesis and release by respiration, application of hydrogen isotope composition （619） and oxygen isotope composition （6180） for determination of water source used by a crop, stable isotope coupling Keeling plot for investigating the carbon and water flux in ecosystem, energy and material cycle in SPAC and correlative integrative models on stable isotope. These aspects contain most of the stable isotope researches on crop carbon and water relations which have been widely explored internationally while less referred in China. Based on the reviewed literatures, some needs for future research are suggested.
文摘Water pollution is a steadily worsening problem because of growth in the chemical, pharmaceutical, leather, textile, and mining industries. In addition, municipal wastewater further contributes to polluting pure water sources. Hence, adequate treatment is essential before it released to avoid pollution of pure water sources. Chapter 3 describes guidelines for wastewater treatment taking into account its physical, chemical and mechanical nature. The guidelines are also helpful in maintaining the operational treatment facilities;it is estimated that 10 to 20 percent of wastewater treatment facilities even in developed countries are not operating properly. Treatment methods are divided into conventional and Natural biological processes and the advantages and drawbacks of each are clearly explained. The influential parameters are identified for the primary (settling to remove solid wastes), secondary (bacteria in removing pollutants) and tertiary (involving advanced techniques such as Biological Nutrient Removal) water purification methods, particularly municipal wastewater treatments. The biological treatment process via microorganisms is particularly suited for Lagoons, Ponds and wetlands because they avoid secondary by-products contaminants. Guidelines are given for the construction of artificial lakes and ponds to be used for wastewater treatment, and diagrams, designs, schemes, and mathematical models are provided. These can also be used for some difficult industrial wastewaters as well as for municipal water containing pharmaceuticals and personal care products. The author emphasized that wetland treatment is often the best choice for the pre-treatment of water and wastewater based on cost and the efficiency. This wastewater treatment chapter is very useful for environment researchers, and engineers, ecologist and the environmental education programs.
文摘The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the collection of wastewater samples. Their analysis revealed specific pollutant loads, including loads of BOD5 3.6966 kgO<sub>2</sub>/day and COD of 12.8775 kgO<sub>2</sub>/day, which were central to the design phase. Following a rigorous assessment of the existing sanitation infrastructure, constructed wetland (CWs) emerged as the most appropriate ecological solution. This system, valued for its ability to effectively remove contaminants, was tailored to the specific needs of the site. Consequently, the final design of the filter extends over 217.16 m<sup>2</sup>, divided into two cells of 108.58 m<sup>2</sup> each, with dimensions of 12.77 m in length and 8.5 m in width. The depth of the filtering medium is approximately 0.60 m, meeting the standards while ensuring maximized purification. Typha, an indigenous and prolific plant known for its purification abilities, was selected as the filtering agent. Concurrently, non-crushed gravel was chosen for its proven filtration capacity. This study is the result of a combination of scientific rigor and design expertise. It provides a holistic view of sanitation for Ndiebene Gandiol. The technical specifications and dimensions of the constructed wetland filter embody an approach that marries indepth analysis and practical application, all aimed at delivering an effective and long-lasting solution to the local sanitation challenges. By integrating precise scientific data with sanitation design expertise, this study delivers a holistic solution for Ndiebene Gandiol. The detailed dimensions and specifications of the constructed wetland filter reflect a methodology that combines meticulous analysis with practical adaptation, aiming to provide an effective and sustainable response to the challenges of rural and school sanitation in the northern region of Senegal.
基金National Key R&D Program of China,No.2017YFA0603702National Natural Science Foundation of China,No.41571019,No.41701023,No.41571028China Postdoctoral Science Foundation,No.2017M610867
文摘The terrestrial hydrological process is an essential but weak link in global/regional climate models. In this paper, the development status, research hotspots and trends in coupled atmosphere-hydrology simulations are identified through a bibliometric analysis, and the challenges and opportunities in this field are reviewed and summarized. Most climate models adopt the one-dimensional (vertical) land surface parameterization, which does not include a detailed description of basin-scale hydrological processes, particularly the effects of human activities on the underlying surfaces. To understand the interaction mechanism between hydrological processes and climate change, a large number of studies focused on the climate feedback effects of hydrological processes at different spatio-temporal scales, mainly through the coupling of hydrological and climate models. The improvement of the parameterization of hydrological process and the development of large-scale hydrological model in land surface process model lay a foundation for terrestrial hydrological-climate coupling simulation, based on which, the study of terrestrial hydrological-climate coupling is evolving from the traditional unidirectional coupling research to the two-way coupling study of "climate-hydrology" feedback. However, studies of fully coupled atmosphere-hydrology simulations (also called atmosphere-hydrology two-way coupling) are far from mature. The main challenges associated with these studies are: improving the potential mismatch in hydrological models and climate models; improving the stability of coupled systems; developing an effective scale conversion scheme; perfecting the parameterization scheme; evaluating parameter uncertainties; developing effective methodology for model parameter transplanting; and improving the applicability of models and high/super-resolution simulation. Solving these problems and improving simulation accuracy are directions for future hydro-climate coupling simulation research.
