Sand barriers are the most widely used mechanical implements for wind-blown sand control and desertification prevention.However,there is no standard quantitative cost analysis of the sizes and materials required for s...Sand barriers are the most widely used mechanical implements for wind-blown sand control and desertification prevention.However,there is no standard quantitative cost analysis of the sizes and materials required for sand barriers.In this study,based on the original land grid division model for optimal resource utilization,we calculated the total side lengths of square and regular hexagonal sand barriers with the sizes of 1.0 m×1.0 m,2.0 m×2.0 m,and 3.0 m×3.0 m in a desertified region of the Shapotou area on the southeastern edge of the Tengger Desert,China.Then,through literature review and social survey,we obtained the material cost and material utilization amount of sand barriers with different materials and sizes.Finally,we calculated the costs of square and regular hexagonal sand barriers comprised of wheat straw,corn stalk,Salix mongolica,poly lactic acid,magnesium cement,and high-density polyethylene,with the sizes of 1.0 m×1.0 m,2.0 m×2.0 m,and 3.0 m×3.0 m.The results show that the material cost of regular hexagonal corn stalk sand barriers with the size of 3.0 m×3.0 m is the lowest,while the material cost of square magnesium cement sand barriers with the size of 1.0 m×1.0 m is the highest.When using the same material,the cost of regular hexagonal sand barriers is lower than that of square sand barriers with the same size.When using the same size,the cost of sand barriers with corn stalk material is lower than that of sand barriers with other materials.Based on the above analysis,we can conclude that the economic benefits of regular hexagonal sand barriers are greater than those of square sand barriers.This study provides a theoretical basis for accurately calculating the material cost of sand barriers,particularly for the estimated cost of mechanized sand barrier engineering projects.展开更多
In this article, the distribution of cultivated land, the changes ofcultivated land productivity, and regional differentiation of the Change forpresent productivity in the Farming-Pastoral Zone, Inner Mongolia aredis...In this article, the distribution of cultivated land, the changes ofcultivated land productivity, and regional differentiation of the Change forpresent productivity in the Farming-Pastoral Zone, Inner Mongolia arediscussed. Then, the close relationship between dynamic characterlsticsdivision and atmospheric circulation systems is revealed. Finally, based ondynamic characteristics, four regions are divided, including thenortheastem area, the eastern area, the western area, and the middle area.展开更多
Constant divisions of rural land rights and contract renegotiations are the hallmark of China’s collective ownership system.Rural land ownership,property and operation systems in China have experienced four stages of...Constant divisions of rural land rights and contract renegotiations are the hallmark of China’s collective ownership system.Rural land ownership,property and operation systems in China have experienced four stages of evolution:(i)The People’s Communes,which served administrative and economic functions,exercised integrated collective land ownership,property,and operation rights.(ii)Under the system of“threetier ownership with production teams as basic accounting units,”production teams exercised the ownership right over land plots with greater autonomy and were responsible for organizing farm work.(iii)The household contract system has entitled farmers to claim surplus products and turned farm households into the basic unit of agricultural production.Subsequently,the reform of collective ownership has further enhanced farmers’contract rights and separated their operation rights from contract rights.The separation of rural land ownership,contract and operation rights marks a top-down design of the structure of China’s rural land rights after the collective ownership system and the reform of household contract system.By recognizing separate contract and operation rights without changing collective ownership,the separation aims to protect rural land contract and operation rights in accordance with the law.As in the four case studies,Chongzhou,Songjiang,Meitan and Liupanshui have experienced a restructuring of collective ownership,contract and operation rights.Their experience foretells complexities in the future evolution of rural land rights in China.展开更多
The social and environmental demands in Brazilian cities are usually neglected by the local municipal powers due to a heavy bias toward speculative capital. The main issue is a public administration that benefits the ...The social and environmental demands in Brazilian cities are usually neglected by the local municipal powers due to a heavy bias toward speculative capital. The main issue is a public administration that benefits the private initiative instead of popular and environmental values and needs. Despite federal efforts at the end of the 20th and beginning of the 21 st century, water resources and urban reform policies are not able to ensure a connection between these two issues in the urban environment. Aiming at showing a new approach of citizenship and environmental rights in a developing country, Bauru, a Brazilian city located in the state of S^o Paulo, was used as a study case. In this scenario, the research is based on the action research method, in which a dynamic profile of the researchers was adopted in order to solidify environmental and social issues in the urban planning process. This article shows the advantages in using the river basin as an urban planning territory in the city master plan, and providing continuous technique support to the citizen, through the role played by the researcher-planner between government and population, as a way to possibly reach social and environmental interests. The territorial perception of the river basin by citizens brings effective environmental and social results.展开更多
基金supported by the Research Program of Technology and Demonstration of Desert Margin Expansion Zone Stabilization for Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences(XDA23060201)。
文摘Sand barriers are the most widely used mechanical implements for wind-blown sand control and desertification prevention.However,there is no standard quantitative cost analysis of the sizes and materials required for sand barriers.In this study,based on the original land grid division model for optimal resource utilization,we calculated the total side lengths of square and regular hexagonal sand barriers with the sizes of 1.0 m×1.0 m,2.0 m×2.0 m,and 3.0 m×3.0 m in a desertified region of the Shapotou area on the southeastern edge of the Tengger Desert,China.Then,through literature review and social survey,we obtained the material cost and material utilization amount of sand barriers with different materials and sizes.Finally,we calculated the costs of square and regular hexagonal sand barriers comprised of wheat straw,corn stalk,Salix mongolica,poly lactic acid,magnesium cement,and high-density polyethylene,with the sizes of 1.0 m×1.0 m,2.0 m×2.0 m,and 3.0 m×3.0 m.The results show that the material cost of regular hexagonal corn stalk sand barriers with the size of 3.0 m×3.0 m is the lowest,while the material cost of square magnesium cement sand barriers with the size of 1.0 m×1.0 m is the highest.When using the same material,the cost of regular hexagonal sand barriers is lower than that of square sand barriers with the same size.When using the same size,the cost of sand barriers with corn stalk material is lower than that of sand barriers with other materials.Based on the above analysis,we can conclude that the economic benefits of regular hexagonal sand barriers are greater than those of square sand barriers.This study provides a theoretical basis for accurately calculating the material cost of sand barriers,particularly for the estimated cost of mechanized sand barrier engineering projects.
文摘In this article, the distribution of cultivated land, the changes ofcultivated land productivity, and regional differentiation of the Change forpresent productivity in the Farming-Pastoral Zone, Inner Mongolia arediscussed. Then, the close relationship between dynamic characterlsticsdivision and atmospheric circulation systems is revealed. Finally, based ondynamic characteristics, four regions are divided, including thenortheastem area, the eastern area, the western area, and the middle area.
文摘Constant divisions of rural land rights and contract renegotiations are the hallmark of China’s collective ownership system.Rural land ownership,property and operation systems in China have experienced four stages of evolution:(i)The People’s Communes,which served administrative and economic functions,exercised integrated collective land ownership,property,and operation rights.(ii)Under the system of“threetier ownership with production teams as basic accounting units,”production teams exercised the ownership right over land plots with greater autonomy and were responsible for organizing farm work.(iii)The household contract system has entitled farmers to claim surplus products and turned farm households into the basic unit of agricultural production.Subsequently,the reform of collective ownership has further enhanced farmers’contract rights and separated their operation rights from contract rights.The separation of rural land ownership,contract and operation rights marks a top-down design of the structure of China’s rural land rights after the collective ownership system and the reform of household contract system.By recognizing separate contract and operation rights without changing collective ownership,the separation aims to protect rural land contract and operation rights in accordance with the law.As in the four case studies,Chongzhou,Songjiang,Meitan and Liupanshui have experienced a restructuring of collective ownership,contract and operation rights.Their experience foretells complexities in the future evolution of rural land rights in China.
文摘The social and environmental demands in Brazilian cities are usually neglected by the local municipal powers due to a heavy bias toward speculative capital. The main issue is a public administration that benefits the private initiative instead of popular and environmental values and needs. Despite federal efforts at the end of the 20th and beginning of the 21 st century, water resources and urban reform policies are not able to ensure a connection between these two issues in the urban environment. Aiming at showing a new approach of citizenship and environmental rights in a developing country, Bauru, a Brazilian city located in the state of S^o Paulo, was used as a study case. In this scenario, the research is based on the action research method, in which a dynamic profile of the researchers was adopted in order to solidify environmental and social issues in the urban planning process. This article shows the advantages in using the river basin as an urban planning territory in the city master plan, and providing continuous technique support to the citizen, through the role played by the researcher-planner between government and population, as a way to possibly reach social and environmental interests. The territorial perception of the river basin by citizens brings effective environmental and social results.
