Water quantity planning and management require understanding of spatial variations of water catchment availability. Several environmental indicators are associated with water quantity such as flood occurrence, drought...Water quantity planning and management require understanding of spatial variations of water catchment availability. Several environmental indicators are associated with water quantity such as flood occurrence, drought severity, seasonal supply and groundwater stress. Analyzing water stress at national geographic scale is crucial to detect and explore geographic shortage of water resources at national scale. In this study, Geographical Information Systems (GIS) techniques were employed to analyze the spatial variations of water scarcity across Sultanate of Oman provinces. For this main objective, various spatial and attribute datasets were prepared. Many variables were selected based on their importance and correlation with water quantity. GIS overlay function then was used to produce maps for each water indicator. This was followed by employing raster zonal statistics to aggregate the values of each catchment area within each province. The findings of this analysis indicated that significant spatial variation was found among Omani provinces in terms of water quantity stress and its determinants. The most important factors affecting the water quantity stress were drought severity and flood occurrence. Furthermore, physical risk of water quantity was higher in Mascut and Dhofar provinces while it was moderate in Al-Batinah, A’Dakhiliyah and Al-Wusta. Lower risk of water quantity was observed in A’Sharqiyah, Masandam, and A’Dhahriah provinces. Thus, in order to mitigate the impacts of water scarcity on agriculture, cultivation and domestic usages, policy makers in water sector should include spatial strategies for water resource maintain and allocation.展开更多
Using the characteristic of addition of information quantity and the principle of equivalence of information quantity, this paper derives the general conversion formulae of the formation theory method conversion (synt...Using the characteristic of addition of information quantity and the principle of equivalence of information quantity, this paper derives the general conversion formulae of the formation theory method conversion (synthesis) on the systems consisting of different success failure model units. According to the fundamental method of the unit reliability assessment, the general models of system reliability approximate lower limits are given. Finally, this paper analyses the application of the assessment method by examples, the assessment results are neither conservative nor radical and very satisfactory. The assessment method can be popularized to the systems which have fixed reliability structural models.展开更多
The study was undertaken to evaluate the collectable and usable volume of existing straw resources,its suitability for different ways of utilization and fully reorganization of its development potential in China.Based...The study was undertaken to evaluate the collectable and usable volume of existing straw resources,its suitability for different ways of utilization and fully reorganization of its development potential in China.Based on the results on the stubble heights of major crops in the Huang-Huai-Hai area(the area along the Yellow River,Huai River,and Hai River),the evaluation of the collectable and usable coefficients,and the collectable and usable volumes of various straw resources in China were worked out during 2005.The respective collectable and usable volumes of straw resources were worked out on the basis of suitability as fuel,feed,fertilizer,and base material for edible mushrooms.The total collectable and utilizable quantity of straw in China was 685950000 t,and the mean collection coefficient was 0.81 during 2005.The quantity of straw residue and wasted straw accounted for 19%.The collectable and utilizable quantities of grain,cash crop,and other crop straw were 492310000,162610000,and 31030000 t which accounted for 71.77,23.71,and 4.52%,respectively of the total collectable and utilizable quantity of straw.The quantity of straw which could be used as fuel was 635000000 t,which accounted for 92.63%of total quantity of the straw in the country during 2005.Among the total quantity of collectable and utilizable straw in China during 2005,the quantities of straw suitable and unsuitable for being processed as feedstuff were 587640000 and 98310000 t,which accounted for 85.67 and 14.33%,respectively.The quantity of straw residue returned to the field and collectable and utilizable straw for direct field restoration was 616000000 t,which accounted for about three-fourths of the total straw yield,while the quantity of straw for cultivation of edible mushrooms and industrial processing was about 587000000 t,which accounted for more than 85%of the total collectable and utilizable straw.The evaluation results indicate that the collectable and utilizable quantity of straw in China is abundant and suitable for many purposes.展开更多
The water cycle and water resources within river basins under changing environmental conditions undergo profound changes, which have significant effects on the water environment of the river. Owing to the water resour...The water cycle and water resources within river basins under changing environmental conditions undergo profound changes, which have significant effects on the water environment of the river. Owing to the water resources demanded for economic and social development, water quantity and quality are becoming the core constraints of water resources development and utilization. In this paper, the dual attributes of water resources, progress into research regarding water quantity and quality joint assessment and simulation and the shortcomings associated with these techniques are summarized and described with respect to water quantity and quality. The results indicated that under the current environmental conditions, the method used for traditional water quality assessment of single water bodies cannot meet the requirements for water resources management. Moreover, a coupled hydrodynamic and water quality numerical model for river networks and lakes that applies to the river water environment system was developed for the river network flow and pollutant migration and transformation process and validated. This validation revealed that the error between the simulated values calculated by the model and the monitored values was small, meeting the application requirements and realizing the integrated and dynamic simulation of water quantity and quality of the river water environmental system. On this basis, the integrated simulation model was applied to the Luanhe River Basin.展开更多
文摘Water quantity planning and management require understanding of spatial variations of water catchment availability. Several environmental indicators are associated with water quantity such as flood occurrence, drought severity, seasonal supply and groundwater stress. Analyzing water stress at national geographic scale is crucial to detect and explore geographic shortage of water resources at national scale. In this study, Geographical Information Systems (GIS) techniques were employed to analyze the spatial variations of water scarcity across Sultanate of Oman provinces. For this main objective, various spatial and attribute datasets were prepared. Many variables were selected based on their importance and correlation with water quantity. GIS overlay function then was used to produce maps for each water indicator. This was followed by employing raster zonal statistics to aggregate the values of each catchment area within each province. The findings of this analysis indicated that significant spatial variation was found among Omani provinces in terms of water quantity stress and its determinants. The most important factors affecting the water quantity stress were drought severity and flood occurrence. Furthermore, physical risk of water quantity was higher in Mascut and Dhofar provinces while it was moderate in Al-Batinah, A’Dakhiliyah and Al-Wusta. Lower risk of water quantity was observed in A’Sharqiyah, Masandam, and A’Dhahriah provinces. Thus, in order to mitigate the impacts of water scarcity on agriculture, cultivation and domestic usages, policy makers in water sector should include spatial strategies for water resource maintain and allocation.
文摘Using the characteristic of addition of information quantity and the principle of equivalence of information quantity, this paper derives the general conversion formulae of the formation theory method conversion (synthesis) on the systems consisting of different success failure model units. According to the fundamental method of the unit reliability assessment, the general models of system reliability approximate lower limits are given. Finally, this paper analyses the application of the assessment method by examples, the assessment results are neither conservative nor radical and very satisfactory. The assessment method can be popularized to the systems which have fixed reliability structural models.
基金supported and financed by the Basic R&D Operation Special Fund for the Central Level,Non-Profit,Scientific Research Institutes,China(2008-15)
文摘The study was undertaken to evaluate the collectable and usable volume of existing straw resources,its suitability for different ways of utilization and fully reorganization of its development potential in China.Based on the results on the stubble heights of major crops in the Huang-Huai-Hai area(the area along the Yellow River,Huai River,and Hai River),the evaluation of the collectable and usable coefficients,and the collectable and usable volumes of various straw resources in China were worked out during 2005.The respective collectable and usable volumes of straw resources were worked out on the basis of suitability as fuel,feed,fertilizer,and base material for edible mushrooms.The total collectable and utilizable quantity of straw in China was 685950000 t,and the mean collection coefficient was 0.81 during 2005.The quantity of straw residue and wasted straw accounted for 19%.The collectable and utilizable quantities of grain,cash crop,and other crop straw were 492310000,162610000,and 31030000 t which accounted for 71.77,23.71,and 4.52%,respectively of the total collectable and utilizable quantity of straw.The quantity of straw which could be used as fuel was 635000000 t,which accounted for 92.63%of total quantity of the straw in the country during 2005.Among the total quantity of collectable and utilizable straw in China during 2005,the quantities of straw suitable and unsuitable for being processed as feedstuff were 587640000 and 98310000 t,which accounted for 85.67 and 14.33%,respectively.The quantity of straw residue returned to the field and collectable and utilizable straw for direct field restoration was 616000000 t,which accounted for about three-fourths of the total straw yield,while the quantity of straw for cultivation of edible mushrooms and industrial processing was about 587000000 t,which accounted for more than 85%of the total collectable and utilizable straw.The evaluation results indicate that the collectable and utilizable quantity of straw in China is abundant and suitable for many purposes.
基金supported by the National Basic Research Program of China (2006CB403404 and 2010CB951102)the Funds for Creative Research Groups of China (51021066)the National Natural Science Foundation of China (51009150,40830637)
文摘The water cycle and water resources within river basins under changing environmental conditions undergo profound changes, which have significant effects on the water environment of the river. Owing to the water resources demanded for economic and social development, water quantity and quality are becoming the core constraints of water resources development and utilization. In this paper, the dual attributes of water resources, progress into research regarding water quantity and quality joint assessment and simulation and the shortcomings associated with these techniques are summarized and described with respect to water quantity and quality. The results indicated that under the current environmental conditions, the method used for traditional water quality assessment of single water bodies cannot meet the requirements for water resources management. Moreover, a coupled hydrodynamic and water quality numerical model for river networks and lakes that applies to the river water environment system was developed for the river network flow and pollutant migration and transformation process and validated. This validation revealed that the error between the simulated values calculated by the model and the monitored values was small, meeting the application requirements and realizing the integrated and dynamic simulation of water quantity and quality of the river water environmental system. On this basis, the integrated simulation model was applied to the Luanhe River Basin.
