Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the r...Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the researcher first expounded the uncertainties of LUSO. Based on this, an interval programming model was developed, of which interval variables were to hold land use uncertainties. To solve the model, a heuristics based on Genetic Algorithm was designed according to Pareto Optimum principle with a confidence interval under given significance level to represent LUSO result. Proposed method was applied to a real case of Yangzhou, an eastern city in China. The following conclusions were reached. 1) Different forms of uncertainties ranged from certainty to indeterminacy lay in the five steps of LUSO, indicating necessary need of comprehensive approach to quantify them. 2) With regards to trade-offs of conflicted objectives and preferences to uncertainties, our proposed model displayed good ability of making planning decision process transparent, therefore providing an effective tool for flexible land use planning compiling. 3) Under uncertain conditions, land use planning effectiveness can be primarily enhanced by flexible management with reserved space to percept and hold uncertainties in advance.展开更多
Urban agglomeration is the main spatial organization mode used by the Chinese government to promote the policy of new urbanization strategy.Hence,a better understanding of the urban growth boundary(UGB)has profound th...Urban agglomeration is the main spatial organization mode used by the Chinese government to promote the policy of new urbanization strategy.Hence,a better understanding of the urban growth boundary(UGB)has profound theoretical and practical significance regarding sustainable urban development.This study devised a raster-based land use spatial optimization(LUSO)framework,and utilized ant colony optimization(ACO)algorithm to delimit the smart growth boundaries of the Changsha-Zhuzhou-Xiangtan city group(CZTCG)in China.The aim of this study is to design a LUSO model to explore an optimal pattern of urban agglomeration for sustainable growth.Multi growth scenario including a single development center,multipolar development and balanced development patterns are generated by the LUSO model for the year of 2050,and the optimum spatial pattern is chosen based on objectives comparison and the present stage of economic and social development in CZTCG.The main results are listed as the following.1)It is feasible to identify the growth boundaries of the urban agglomeration using the land use spatial optimization model,and the optimal form of the spatial pattern can be defined.2)With the growth trend of the urban agglomeration gradually spreads from a single center to multi-centers and even small towns,the total optimization target performance gradually increases,which means that the traditional pie-shaped development does not meet the maximum comprehensive benefit of the city group.3)Subject to the regional social and economic development stage,absolute fair development or simply developing the central city is not conducive to promoting the coordinated development of the urban agglomeration.Gradient equalization and gradual advancement are the best choice for UGB delineation of urban agglomeration.The findings of this study would be useful to identify the UGB in CZTCG for more sustainable urban development in the future.展开更多
This study analyses the possibilities for optimal land use structure in mountainous areas of rural Serbia, which is faced with problems such as unfavorable terrain characteristics and inadequate land use patterns caus...This study analyses the possibilities for optimal land use structure in mountainous areas of rural Serbia, which is faced with problems such as unfavorable terrain characteristics and inadequate land use patterns causing economic underdevelopment and increasing population migration. In the case of a small privately owned farm in Western Serbia, optimal land use pattern is determined using the linear programming model. The objective function-cost-effectiveness or soil erosion reduction, as well as constraints, are formulated using the benefit-cost ratio(BCR) for a 15-year production period and soil losses data calculated using the Universal Soil Loss Equation(USLE). The best results are achieved using the scenario with the aim to minimize soil erosion, considering the BCR in the constraints. This scenario is proposed since it was registered that the benefit for landowners would increase by five times, while the losses of land would decline about 80%. The sensitivity analysis of investments is performed to check whether the price variation affects the cost-effectiveness of proposed land use. Results show that market changes(nine cases are considered) do not lead to significant changes in land use allocation. Proposed land use pattern improves the environmental condition, strengthens the rural economy and thus offers the greatest potential for sustainable development of mountainous rural areas.展开更多
Land use and cover change(LUCC) is one of the important causes of the Earth’s carbon cycle imbalances resulting from failure in optimizing land use. The solution to this problem has been the hotspot of research in la...Land use and cover change(LUCC) is one of the important causes of the Earth’s carbon cycle imbalances resulting from failure in optimizing land use. The solution to this problem has been the hotspot of research in land and environmental science. We took 'low carbon', 'energy saving' and 'high-efficiency' as the goals of land use optimization,and integrated Markov-CA(Cellular Automaton),the Grid-Fractal model and GIS,in order to study carbon emission objective function,to establish a simulation method for land use spatial allocation optimization,to evaluate the effect of the method on carbon emissions. Regulation policy on three types of land use spatial allocation was proposed,including 'low-carbon type', 'low-carbon-economic type' and 'economic type'. We applied the method to analyze the land use spatial allocation in Taixing City of the 'Yangtze River Delta' regions in China,and obtained the following results:(i) The three optimization types would improve carbon emissions by 3. 21%,1. 80% and 0. 36% respectively in 2020,compared with 2010;(ii) The actual planning for 2020 was close to the 'low-carbon-economic type';(iii) The optimization method and regulation policy,combining local optimization and global control,could meet the sustainable multi-objective requirements for low-carbon constraints of land use spatial allocation. The result of this research could also serve as a reference for exploration into patterns of regional low-carbon land use and measures for energy saving and emission reduction.展开更多
Land is the foundation for human survival and development,and all human social and economic activities are inseparable from the land as a space carrier.With the continuous development of China's social economy,Chi...Land is the foundation for human survival and development,and all human social and economic activities are inseparable from the land as a space carrier.With the continuous development of China's social economy,China is facing new social development needs such as urban-rural integration and rural revitalization.At the same time,China starts to attach great importance to ecology and has proposed the concept that lucid waters and lush mountains are invaluable assets.In this situation,the rational use of land resources,the optimization of land use structure and layout are also facing new challenges and problems,and more comprehensive consideration is required to make relevant optimization.Using the method of literature comparative analysis,from the conceptual connotation,basic theory,method model,and specific practice of land use structure and layout optimization,this paper analyzed and summarized the current research situations and problems,and finally came up with recommendations for the future research.展开更多
Open space of metropolitan suburbs in mountain region, has been increasingly becoming the coupling mosaic structure of industrial actions and landscape behaviors. However, the local governments, when making land use p...Open space of metropolitan suburbs in mountain region, has been increasingly becoming the coupling mosaic structure of industrial actions and landscape behaviors. However, the local governments, when making land use planning, often aim at economic development, and rarely refer to the coordination of compatibilities and conflicts between industrial actions and landscape behaviors in the mosaic structure. In this study land use in the Jinyun Mountain and its surrounding area, Chongqing is adjusted by gray multi-objective programming approach and local-level decision-making process to cope with conflicts between objectives for human welfare and objectives for landscape conservation. The results indicate that: 1) the compatibilities and conflicts among different behavior characters and different landscape types result in the compatibilities of landscape to human behavior; 2) a land use planning in the study area is produced based on the sustainable land use and social-eco development, which pays more attention to the resources and environment constraints and economic objectives, and follows the distribution law of rare resources; 3) in the study area, cultivated land of 1,207.27 ha can meet the demands for food and byproducts by the residents there, orchard land and forestland of 632.55 ha, 2,276.61 ha, respectively can provide enough spaee for the local people to improve their living structure and meet their demands for reereational activities, and urban residential land, rural residential land, mining land and transportation land of 1107.60 ha, 120.27 ha, 162.48 ha, 100.91 ha, respeetively can satisfy the resident's eeonomie development and infrastructures; 4) the equilibrium among industrial actions, landscape accessibility and ecological conservation can be obtained by analyzing the possible impaets of human activities on landscape eeologieal proeess in open spaee of metropolitan suburbs in mountain areas.展开更多
Adjusting and optimizing land use structure is one of the essential approaches to solve the conflict between land supply and demand. In this study,an uncertain interval multi-objective linear programming model was est...Adjusting and optimizing land use structure is one of the essential approaches to solve the conflict between land supply and demand. In this study,an uncertain interval multi-objective linear programming model was established and applied to analyzing the suitability of land use structure in Pi County of Sichuan Province. An adjustment scheme for optimizing land use structure was proposed on the basis of development planning drawn up by the local government. The results are summarized as follows: 1) the optimal adjustment scope for cropland area ranges from 27 976.75 ha to 31 029.08 ha,and the current area is less than the lower limit of the scope; 2) the optimal adjustment scope for garden land area ranges from 4 736.49 ha to 12 967.11 ha,and the current area is less than the lower limit; 3) the optimal adjustment scope for construction land ranges from 7 761.95 ha to 10 393.18 ha,and the current area is greater than the upper limit; 4) the optimal adjustment scope for industry and mining land ranges from 557.29 ha to 693.54 ha,and the current area exceeds the upper limit; and 5) the areas of forest land,grassland and other agricultural land are within the optimal adjustment scope. In order to maximize comprehensive benefit with the limited resources and the demand of sustainable development,the areas of cropland and garden land are supposed to be expanded properly,while the construction land should be controlled and reduced gradually,and the forest land and other agricultural land can be maintained at the current level in short period.展开更多
Optimal allocation of land use is essential to promote regional economic and social development.However,research on such allocations in development zones is limited.This paper proposes a new land use allocation method...Optimal allocation of land use is essential to promote regional economic and social development.However,research on such allocations in development zones is limited.This paper proposes a new land use allocation method for development zones and tests its feasibility.Based on prior research,this study predicts the developmental stage of a development zone and sets the objective functions and constraint conditions accordingly.This paper then measures the conversion relationship between the land use types in an unit according to the land use suitability results and the vital mechanism theory and uses the ant colony algorithm to construct a land use optimization model on the basis of this conversion relatonship.The model is then applied successfully to a case study of the Liangjiang New Area,Chongqing,China.The results show that the vital mechanism theory better reflects the relationship between land use types.The economic benefits increase 3.5 times and compactness improves by 46.5%between the initial year(2009)and the optimized year(2020),after the proposed model is applied.展开更多
Oases are important habitats for human survival and development in northwest arid China;however, they are fragile. To realize ecological construction and sustainable development in northwest China, an analysis of the ...Oases are important habitats for human survival and development in northwest arid China;however, they are fragile. To realize ecological construction and sustainable development in northwest China, an analysis of the economic and ecological benefits of the oasis system with a focus on sustainability and land use optimization of oasis agro-economic systems are needed. This paper selects Fukang City as a study area. It is located on the northern slope of Mt Tianshan, Xinjiang Uygur Autonomous Region. The authors discuss the ecological and economic benefits of the oasis system, annual variation and establish an optimized allocation scheme of oasis land use structure in Fukang City based on emergy analysis and linear programming modeling. From 1996 to 2006 the oasis system was in a weak sustainable development state. Ecological and economic benefits analysis of the oasis system based on emergy analysis shows that the development of an oasis system in Fukang City is restricted by land, climate and water resources, being a typical example of the high-input and low-output type. The comparative advantage analysis of oasis cropping based on economics and ecological economics shows that the farming structure will vary across different goals. If the maximum ecological efficiency is pursued, farming structure is determined by emergy density;and if the maximum ecological and economic benefits with limited water resources are pursued, farming structure is determined by the emergy value per unit area of irrigation.展开更多
The delimitation of urban development boundaries plays an important role in optimizing the nation land space.“Double evaluation”is one of the important means to study and predict the scale of new construction land i...The delimitation of urban development boundaries plays an important role in optimizing the nation land space.“Double evaluation”is one of the important means to study and predict the scale of new construction land in the future and to determine the spatial distribution of urban construction land.This study combines the“double evaluation”with the FLUS(Future Land-Use Simulation)model to study the delimitation of the urban development boundary of Yichang.The results show that:(1)the“double evaluation”method comprehensively considers the carrying capacity of the resource environmental bear and the suitability of urban development;(2)the FLUS model can better couple the“double evaluation”method for Land Use/Land Cover(LULC)suitability evaluation,Land Use/land Cover Change(LUCC)simulation and urban development boundary delineation,and the overall accuracy of the simulation reaches 96%;(3)according to the requirements of relevant national policies,this study divides the urban development boundary of the study area into concentrated construction areas,elastic development areas and special purpose areas.This function-based division can meet the requirements of urban flexible development,ecological protection and urban safety.This research combines the FLUS model,which is widely used in the simulation of LUCC,with the double evaluation method used in China’s new round of land and space planning to obtain the result of the urban development boundary.This result is consistent with the existing plan of the study area.展开更多
Environmental and social problems caused by overfertilization,excessive pesticides,and encroachment on farmland are increasingly serious in agricultural settings,especially in suburban agricultural areas and highly in...Environmental and social problems caused by overfertilization,excessive pesticides,and encroachment on farmland are increasingly serious in agricultural settings,especially in suburban agricultural areas and highly intensive agricultural areas.Hence,modern agriculture not only pursues economic benefits,but it also pays more attention to ecological functions and social stability.This paper proposes a set of methods which are designed to realize optimal agricultural benefits and sustainable development by scientifically adjusting the land use structure.Taking Changsha County in South Central China as a case study,this paper first built an index system and adopted the information entropy-TOPSIS method to assess the economic,social,and ecological benefits of agricultural land use.Next,a coupled coordination model and an obstacle model were chosen to diagnose those factors that remained as obstacles to achieving the sustainable and coordinated development of the benefits of agricultural land use.Finally,based on the analysis of the changes in the benefits and obstacles over time,socio-economic and ecological constraints were established,and the multi-objective linear programming method(MOLP)was used to determine the comprehensive benefits and optimal land use structure.The results indicate that:(1)The agricultural benefits were stably increasing from 0.20 in 1996 to 0.79 in 2016.(2)The economic benefit index is no longer the main obstacle,while the social benefit index,which includes components such as the food security index,has become the principal influencing factor.(3)The optimal land use structure and comprehensive benefits were presented by taking into consideration the economic development,environmental protection,and social needs.This study emphasizes economic development,but it also seeks coordinated development with comprehensive benefits.The results of the study could provide scientific recommendations for optimizing the agricultural land use spatial patterns and sustainable land use.展开更多
This paper focuses on the prediction of the safe autorotation landing operations of a helicopter following engine failure.The autorotation landing procedure is formulated as a nonlinear optimal control problem based o...This paper focuses on the prediction of the safe autorotation landing operations of a helicopter following engine failure.The autorotation landing procedure is formulated as a nonlinear optimal control problem based on an augmented six-degree-of-freedom rigid-body flight dynamic model.First,the cost function and constraints are properly selected.The direct transcription approach is then employed to solve the optimal control problem.For a UH-60 helicopter,the optimal solutions with the rigid-body model are compared with those obtained using a two-dimensional point-mass model.It is found that the optimal solutions using the two different models show reasonably good agreement,and furthermore the optimal solutions using the rigid-body model involve the time histories of angular rates and attitudes,lateral velocity and position,as well as pitch controls.Finally the optimal control formulations with different cost functions are proposed for taking account of 1-s time delay and minimum touchdown speed.The calculated control strategies and trajectories are realistic.展开更多
The sustainable intensification of agriculture involves providing sufficient food and other ecosystem services without going beyond the limits of the earth’s system.Here a project management approach is suggested to ...The sustainable intensification of agriculture involves providing sufficient food and other ecosystem services without going beyond the limits of the earth’s system.Here a project management approach is suggested to help guide agricultural policy to deliver these objectives.The first step is to agree measurable outcomes,integrating formal policy goals with the often much less formal and much more diverse goals of individual farmers.The second step is to assess current performance.Ideally,this will involve the use of farm-scale metrics that can feed into process models that address social and environmental domains as well as production issues that can be benchmarked and upscaled to landscape and country.Some policy goals can be delivered by supporting ad hoc interventions,while others require the redesign of the farming system.A pipeline of research,knowledge and capacity building is needed to ensure the continuous increase in farm performance.System models can help prioritise policy interventions.Formal optimization of land use is only appropriate if the policy goals are clear,and the constraints understood.In practice,the best approach may depend on the scale of action that is required,and on the amount of resource and infrastructure available to generate,implement and manage policy.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41401627,41471144)Foundation Research Project of Jiangsu Province(No.BK20140236)
文摘Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the researcher first expounded the uncertainties of LUSO. Based on this, an interval programming model was developed, of which interval variables were to hold land use uncertainties. To solve the model, a heuristics based on Genetic Algorithm was designed according to Pareto Optimum principle with a confidence interval under given significance level to represent LUSO result. Proposed method was applied to a real case of Yangzhou, an eastern city in China. The following conclusions were reached. 1) Different forms of uncertainties ranged from certainty to indeterminacy lay in the five steps of LUSO, indicating necessary need of comprehensive approach to quantify them. 2) With regards to trade-offs of conflicted objectives and preferences to uncertainties, our proposed model displayed good ability of making planning decision process transparent, therefore providing an effective tool for flexible land use planning compiling. 3) Under uncertain conditions, land use planning effectiveness can be primarily enhanced by flexible management with reserved space to percept and hold uncertainties in advance.
基金Under the auspices of National Nature Science Foundation of China(No.41901311)。
文摘Urban agglomeration is the main spatial organization mode used by the Chinese government to promote the policy of new urbanization strategy.Hence,a better understanding of the urban growth boundary(UGB)has profound theoretical and practical significance regarding sustainable urban development.This study devised a raster-based land use spatial optimization(LUSO)framework,and utilized ant colony optimization(ACO)algorithm to delimit the smart growth boundaries of the Changsha-Zhuzhou-Xiangtan city group(CZTCG)in China.The aim of this study is to design a LUSO model to explore an optimal pattern of urban agglomeration for sustainable growth.Multi growth scenario including a single development center,multipolar development and balanced development patterns are generated by the LUSO model for the year of 2050,and the optimum spatial pattern is chosen based on objectives comparison and the present stage of economic and social development in CZTCG.The main results are listed as the following.1)It is feasible to identify the growth boundaries of the urban agglomeration using the land use spatial optimization model,and the optimal form of the spatial pattern can be defined.2)With the growth trend of the urban agglomeration gradually spreads from a single center to multi-centers and even small towns,the total optimization target performance gradually increases,which means that the traditional pie-shaped development does not meet the maximum comprehensive benefit of the city group.3)Subject to the regional social and economic development stage,absolute fair development or simply developing the central city is not conducive to promoting the coordinated development of the urban agglomeration.Gradient equalization and gradual advancement are the best choice for UGB delineation of urban agglomeration.The findings of this study would be useful to identify the UGB in CZTCG for more sustainable urban development in the future.
基金a part of the Project No.43007,subproject No.16 funded by the Ministry of Education,Science and Technological Development of the Republic of Serbia
文摘This study analyses the possibilities for optimal land use structure in mountainous areas of rural Serbia, which is faced with problems such as unfavorable terrain characteristics and inadequate land use patterns causing economic underdevelopment and increasing population migration. In the case of a small privately owned farm in Western Serbia, optimal land use pattern is determined using the linear programming model. The objective function-cost-effectiveness or soil erosion reduction, as well as constraints, are formulated using the benefit-cost ratio(BCR) for a 15-year production period and soil losses data calculated using the Universal Soil Loss Equation(USLE). The best results are achieved using the scenario with the aim to minimize soil erosion, considering the BCR in the constraints. This scenario is proposed since it was registered that the benefit for landowners would increase by five times, while the losses of land would decline about 80%. The sensitivity analysis of investments is performed to check whether the price variation affects the cost-effectiveness of proposed land use. Results show that market changes(nine cases are considered) do not lead to significant changes in land use allocation. Proposed land use pattern improves the environmental condition, strengthens the rural economy and thus offers the greatest potential for sustainable development of mountainous rural areas.
基金Supported by National Natural Science Foundation of China(71233004)Nonprofit Industry Financial Program of Ministry of Land and Resources of China(201111011)+1 种基金Project of Jiangsu Province Science and Technology(BE2016302)Humanities and Social Sciences Project of Nanjing Agricultural University(SKZK2015008)
文摘Land use and cover change(LUCC) is one of the important causes of the Earth’s carbon cycle imbalances resulting from failure in optimizing land use. The solution to this problem has been the hotspot of research in land and environmental science. We took 'low carbon', 'energy saving' and 'high-efficiency' as the goals of land use optimization,and integrated Markov-CA(Cellular Automaton),the Grid-Fractal model and GIS,in order to study carbon emission objective function,to establish a simulation method for land use spatial allocation optimization,to evaluate the effect of the method on carbon emissions. Regulation policy on three types of land use spatial allocation was proposed,including 'low-carbon type', 'low-carbon-economic type' and 'economic type'. We applied the method to analyze the land use spatial allocation in Taixing City of the 'Yangtze River Delta' regions in China,and obtained the following results:(i) The three optimization types would improve carbon emissions by 3. 21%,1. 80% and 0. 36% respectively in 2020,compared with 2010;(ii) The actual planning for 2020 was close to the 'low-carbon-economic type';(iii) The optimization method and regulation policy,combining local optimization and global control,could meet the sustainable multi-objective requirements for low-carbon constraints of land use spatial allocation. The result of this research could also serve as a reference for exploration into patterns of regional low-carbon land use and measures for energy saving and emission reduction.
文摘Land is the foundation for human survival and development,and all human social and economic activities are inseparable from the land as a space carrier.With the continuous development of China's social economy,China is facing new social development needs such as urban-rural integration and rural revitalization.At the same time,China starts to attach great importance to ecology and has proposed the concept that lucid waters and lush mountains are invaluable assets.In this situation,the rational use of land resources,the optimization of land use structure and layout are also facing new challenges and problems,and more comprehensive consideration is required to make relevant optimization.Using the method of literature comparative analysis,from the conceptual connotation,basic theory,method model,and specific practice of land use structure and layout optimization,this paper analyzed and summarized the current research situations and problems,and finally came up with recommendations for the future research.
基金supported by the Key Project of Science and Technology of the Ministry of Education(No.03111)Incubation Fund Project of Science and Technology Committee of Chongqing(No.017079)
文摘Open space of metropolitan suburbs in mountain region, has been increasingly becoming the coupling mosaic structure of industrial actions and landscape behaviors. However, the local governments, when making land use planning, often aim at economic development, and rarely refer to the coordination of compatibilities and conflicts between industrial actions and landscape behaviors in the mosaic structure. In this study land use in the Jinyun Mountain and its surrounding area, Chongqing is adjusted by gray multi-objective programming approach and local-level decision-making process to cope with conflicts between objectives for human welfare and objectives for landscape conservation. The results indicate that: 1) the compatibilities and conflicts among different behavior characters and different landscape types result in the compatibilities of landscape to human behavior; 2) a land use planning in the study area is produced based on the sustainable land use and social-eco development, which pays more attention to the resources and environment constraints and economic objectives, and follows the distribution law of rare resources; 3) in the study area, cultivated land of 1,207.27 ha can meet the demands for food and byproducts by the residents there, orchard land and forestland of 632.55 ha, 2,276.61 ha, respectively can provide enough spaee for the local people to improve their living structure and meet their demands for reereational activities, and urban residential land, rural residential land, mining land and transportation land of 1107.60 ha, 120.27 ha, 162.48 ha, 100.91 ha, respeetively can satisfy the resident's eeonomie development and infrastructures; 4) the equilibrium among industrial actions, landscape accessibility and ecological conservation can be obtained by analyzing the possible impaets of human activities on landscape eeologieal proeess in open spaee of metropolitan suburbs in mountain areas.
基金Under the auspices of National Key Technology R&D Program of China (No. 2006BAB04A08)
文摘Adjusting and optimizing land use structure is one of the essential approaches to solve the conflict between land supply and demand. In this study,an uncertain interval multi-objective linear programming model was established and applied to analyzing the suitability of land use structure in Pi County of Sichuan Province. An adjustment scheme for optimizing land use structure was proposed on the basis of development planning drawn up by the local government. The results are summarized as follows: 1) the optimal adjustment scope for cropland area ranges from 27 976.75 ha to 31 029.08 ha,and the current area is less than the lower limit of the scope; 2) the optimal adjustment scope for garden land area ranges from 4 736.49 ha to 12 967.11 ha,and the current area is less than the lower limit; 3) the optimal adjustment scope for construction land ranges from 7 761.95 ha to 10 393.18 ha,and the current area is greater than the upper limit; 4) the optimal adjustment scope for industry and mining land ranges from 557.29 ha to 693.54 ha,and the current area exceeds the upper limit; and 5) the areas of forest land,grassland and other agricultural land are within the optimal adjustment scope. In order to maximize comprehensive benefit with the limited resources and the demand of sustainable development,the areas of cropland and garden land are supposed to be expanded properly,while the construction land should be controlled and reduced gradually,and the forest land and other agricultural land can be maintained at the current level in short period.
文摘Optimal allocation of land use is essential to promote regional economic and social development.However,research on such allocations in development zones is limited.This paper proposes a new land use allocation method for development zones and tests its feasibility.Based on prior research,this study predicts the developmental stage of a development zone and sets the objective functions and constraint conditions accordingly.This paper then measures the conversion relationship between the land use types in an unit according to the land use suitability results and the vital mechanism theory and uses the ant colony algorithm to construct a land use optimization model on the basis of this conversion relatonship.The model is then applied successfully to a case study of the Liangjiang New Area,Chongqing,China.The results show that the vital mechanism theory better reflects the relationship between land use types.The economic benefits increase 3.5 times and compactness improves by 46.5%between the initial year(2009)and the optimized year(2020),after the proposed model is applied.
基金National Basic Research Program of China(2009CB421307)National Natural Science Foundation of China(40971282)
文摘Oases are important habitats for human survival and development in northwest arid China;however, they are fragile. To realize ecological construction and sustainable development in northwest China, an analysis of the economic and ecological benefits of the oasis system with a focus on sustainability and land use optimization of oasis agro-economic systems are needed. This paper selects Fukang City as a study area. It is located on the northern slope of Mt Tianshan, Xinjiang Uygur Autonomous Region. The authors discuss the ecological and economic benefits of the oasis system, annual variation and establish an optimized allocation scheme of oasis land use structure in Fukang City based on emergy analysis and linear programming modeling. From 1996 to 2006 the oasis system was in a weak sustainable development state. Ecological and economic benefits analysis of the oasis system based on emergy analysis shows that the development of an oasis system in Fukang City is restricted by land, climate and water resources, being a typical example of the high-input and low-output type. The comparative advantage analysis of oasis cropping based on economics and ecological economics shows that the farming structure will vary across different goals. If the maximum ecological efficiency is pursued, farming structure is determined by emergy density;and if the maximum ecological and economic benefits with limited water resources are pursued, farming structure is determined by the emergy value per unit area of irrigation.
基金Natural Science Foundation of Hubei Province(No.2021CFB402)Key Laboratory of National Geographic Census and Monitoring,Ministry of Natural Resources(No.2020NGCMZD03)。
文摘The delimitation of urban development boundaries plays an important role in optimizing the nation land space.“Double evaluation”is one of the important means to study and predict the scale of new construction land in the future and to determine the spatial distribution of urban construction land.This study combines the“double evaluation”with the FLUS(Future Land-Use Simulation)model to study the delimitation of the urban development boundary of Yichang.The results show that:(1)the“double evaluation”method comprehensively considers the carrying capacity of the resource environmental bear and the suitability of urban development;(2)the FLUS model can better couple the“double evaluation”method for Land Use/Land Cover(LULC)suitability evaluation,Land Use/land Cover Change(LUCC)simulation and urban development boundary delineation,and the overall accuracy of the simulation reaches 96%;(3)according to the requirements of relevant national policies,this study divides the urban development boundary of the study area into concentrated construction areas,elastic development areas and special purpose areas.This function-based division can meet the requirements of urban flexible development,ecological protection and urban safety.This research combines the FLUS model,which is widely used in the simulation of LUCC,with the double evaluation method used in China’s new round of land and space planning to obtain the result of the urban development boundary.This result is consistent with the existing plan of the study area.
基金The National Natural Science Foundation of China(41801216)The Fundamental Research Funds for the Central Universities of China(2018B20914)。
文摘Environmental and social problems caused by overfertilization,excessive pesticides,and encroachment on farmland are increasingly serious in agricultural settings,especially in suburban agricultural areas and highly intensive agricultural areas.Hence,modern agriculture not only pursues economic benefits,but it also pays more attention to ecological functions and social stability.This paper proposes a set of methods which are designed to realize optimal agricultural benefits and sustainable development by scientifically adjusting the land use structure.Taking Changsha County in South Central China as a case study,this paper first built an index system and adopted the information entropy-TOPSIS method to assess the economic,social,and ecological benefits of agricultural land use.Next,a coupled coordination model and an obstacle model were chosen to diagnose those factors that remained as obstacles to achieving the sustainable and coordinated development of the benefits of agricultural land use.Finally,based on the analysis of the changes in the benefits and obstacles over time,socio-economic and ecological constraints were established,and the multi-objective linear programming method(MOLP)was used to determine the comprehensive benefits and optimal land use structure.The results indicate that:(1)The agricultural benefits were stably increasing from 0.20 in 1996 to 0.79 in 2016.(2)The economic benefit index is no longer the main obstacle,while the social benefit index,which includes components such as the food security index,has become the principal influencing factor.(3)The optimal land use structure and comprehensive benefits were presented by taking into consideration the economic development,environmental protection,and social needs.This study emphasizes economic development,but it also seeks coordinated development with comprehensive benefits.The results of the study could provide scientific recommendations for optimizing the agricultural land use spatial patterns and sustainable land use.
文摘This paper focuses on the prediction of the safe autorotation landing operations of a helicopter following engine failure.The autorotation landing procedure is formulated as a nonlinear optimal control problem based on an augmented six-degree-of-freedom rigid-body flight dynamic model.First,the cost function and constraints are properly selected.The direct transcription approach is then employed to solve the optimal control problem.For a UH-60 helicopter,the optimal solutions with the rigid-body model are compared with those obtained using a two-dimensional point-mass model.It is found that the optimal solutions using the two different models show reasonably good agreement,and furthermore the optimal solutions using the rigid-body model involve the time histories of angular rates and attitudes,lateral velocity and position,as well as pitch controls.Finally the optimal control formulations with different cost functions are proposed for taking account of 1-s time delay and minimum touchdown speed.The calculated control strategies and trajectories are realistic.
文摘The sustainable intensification of agriculture involves providing sufficient food and other ecosystem services without going beyond the limits of the earth’s system.Here a project management approach is suggested to help guide agricultural policy to deliver these objectives.The first step is to agree measurable outcomes,integrating formal policy goals with the often much less formal and much more diverse goals of individual farmers.The second step is to assess current performance.Ideally,this will involve the use of farm-scale metrics that can feed into process models that address social and environmental domains as well as production issues that can be benchmarked and upscaled to landscape and country.Some policy goals can be delivered by supporting ad hoc interventions,while others require the redesign of the farming system.A pipeline of research,knowledge and capacity building is needed to ensure the continuous increase in farm performance.System models can help prioritise policy interventions.Formal optimization of land use is only appropriate if the policy goals are clear,and the constraints understood.In practice,the best approach may depend on the scale of action that is required,and on the amount of resource and infrastructure available to generate,implement and manage policy.