Urban-suburban-rural(U-S-R)zones exhibit distinctive transitional characteristics in interaction between human and nature.U-S-R transition zones(U-S-RTZ)are also highlighting the function diversity and landscape heter...Urban-suburban-rural(U-S-R)zones exhibit distinctive transitional characteristics in interaction between human and nature.U-S-R transition zones(U-S-RTZ)are also highlighting the function diversity and landscape heterogeneity across territorial spaces.As a super megacity in western China,Chengdu’s rapid urbanization has driven the evolution of U-S-R spaces,resulting in a sequential structure.To promote the high-quality spatial development of urban-rural region in a structured and efficient manner,it is essential to con-duct a scientific examination of the multidimensional interconnection within the U-S-RTZ framework.By proposing a novel identifica-tion method of U-S-RTZ and taking Chengdu,China as a case study,grounded in a blender of natural and humanistic factors,this study quantitatively delineated and explored the spatial evolutions of U-S-RTZ and stated the optimization orientation and sustainable devel-opment strategies of the production-living-ecological spaces along the U-S-R gradients.The results show that:1)it is suitable for the quantitative analysis of U-S-RTZ by established three-dimensional identification system in this study.2)In 1990-2020,the urban-sub-urban transition zones(U-STZ)in Chengdu have continuously undergone a substantial increase,and the scale of the suburban-rural transition zones(S-RTZ)has continued to expand slightly,while the space of rural-ecological transition zones(R-ETZ)has noticeably compressed.3)The landuse dynamics within U-S-RTZ has gradually increased in 1990-2020.The main direction of landuse transition was from farmland to construction land or woodlands,with the expansion of construction land being the most significant.4)R-ETZ primarily focus on ecological functions,and there is a trade-off relationship between the production-ecological function within the S-RTZ,and in the U-STZ,production-living composite functions are prioritized.This study emphasizes the importance of elastic planning and precise governance within the U-S-RTZ in a rapid urbanization region,particularly highlighting the role of suburbs as landscape corridors and service hubs in urban-rural integration.It elucidates to the practical implications for achieving high-quality development of integrated U-S-R territorial spaces.展开更多
A subsurface flow wetland(SSFW)was simulated using a commercial computational fluid dynamic(CFD)code.The constructed media was simulated using porous media and the liquid resident time distribution(RTD)in the SSFW was...A subsurface flow wetland(SSFW)was simulated using a commercial computational fluid dynamic(CFD)code.The constructed media was simulated using porous media and the liquid resident time distribution(RTD)in the SSFW was obtained using the particle trajectory model.The effect of wetland configuration and operating conditions on the hydraulic performance of the SSFW were investigated.The results indicated that the hydraulic performance of the SSFW was predominantly affected by the wetland configuration.The hydr...展开更多
The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles a...The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles and procedures are presented in this paper. Indicators and methods for IEA may vary from case to case, but guidelines for selection of indicators and methods may be applicable for a specific case, so they are also introduced. Although great progress has been made in IEA, there is still a lot for future development. Prospects are presented as follows: (1) IEA at strategic level; (2) mechanisms for public involvement; (3) post project analysis; (4) cumulative impact assessment; and (5) application of new approaches such as expert system and GIS in IEA.展开更多
Responding to concerns raised by the Bhopal accident, more and more attention has been paid to local emergency, especially chemical emergency, prevention and planning worldwide, and many chemical emergency response sy...Responding to concerns raised by the Bhopal accident, more and more attention has been paid to local emergency, especially chemical emergency, prevention and planning worldwide, and many chemical emergency response systems for public response personnel have been built. With the successful application of geographical information system (GIS) technology in many fields, GIS can be an efficient tool for effective response to chemical emergencies. The purpose of this paper is to introduce the application of GIS technology in emergency response. Typical GIS technology is simply introduced and some of its existing applications to emergency, mainly natural disaster, response are summarized. Spatial data and spatial analysis requirements for chemical monitoring and emergency response are also discussed in detail. Finally a chemical monitoring and emergency response system under development by combining GIS and expert system for both chemical distribution centers and public response personnel is presented.展开更多
Climate change(CC)and human activities(HA)are the main reasons for the restoration/degradation of the Qinghai-Tibet Plateau(QTP)grassland.Many related studies have been conducted thus far,but the impact mechanism of C...Climate change(CC)and human activities(HA)are the main reasons for the restoration/degradation of the Qinghai-Tibet Plateau(QTP)grassland.Many related studies have been conducted thus far,but the impact mechanism of CC coupled with HA on QTP remains unclear.We summarized the two main coupling factors in recent years(specifically,in the past five years)and obtained the following conclusions.(1)CC and HA have positive and negative effects on the QTP grassland ecosystem.CC primarily affects grassland ecology through temperature,humidification,and extreme climate,and HA mainly affects ecosystems through primary,secondary,and tertiary industries and restoration measures.(2)CC coupled with HA affects soil,plants,animals,and fungi/microbes.CC makes the snow line rise by increasing the temperature,which expands the zone for HA.CC also restricts HA through hydrological changes,extreme climate,and outbreak of pikas and pests.Simultaneously,measures are implemented through HA to control and adapt to CC.Hence,the grassland ecosystem is comprehensively influenced by CC and HA.(3)The grassland ecosystem dynamically adapts to the disturbance caused by CC and HA by changing its physiological characteristics,distribution range,diet structure,community structure,and physical state.Simultaneously,it responds to environmental changes through desertification,poisonous weeds,rodent outbreak,release of harmful gases,and other means.This work can be used as a reference for the sustainable development of the QTP grassland.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41930651)Sichuan Science and Technology Program(No.2023NSFSC1979)。
文摘Urban-suburban-rural(U-S-R)zones exhibit distinctive transitional characteristics in interaction between human and nature.U-S-R transition zones(U-S-RTZ)are also highlighting the function diversity and landscape heterogeneity across territorial spaces.As a super megacity in western China,Chengdu’s rapid urbanization has driven the evolution of U-S-R spaces,resulting in a sequential structure.To promote the high-quality spatial development of urban-rural region in a structured and efficient manner,it is essential to con-duct a scientific examination of the multidimensional interconnection within the U-S-RTZ framework.By proposing a novel identifica-tion method of U-S-RTZ and taking Chengdu,China as a case study,grounded in a blender of natural and humanistic factors,this study quantitatively delineated and explored the spatial evolutions of U-S-RTZ and stated the optimization orientation and sustainable devel-opment strategies of the production-living-ecological spaces along the U-S-R gradients.The results show that:1)it is suitable for the quantitative analysis of U-S-RTZ by established three-dimensional identification system in this study.2)In 1990-2020,the urban-sub-urban transition zones(U-STZ)in Chengdu have continuously undergone a substantial increase,and the scale of the suburban-rural transition zones(S-RTZ)has continued to expand slightly,while the space of rural-ecological transition zones(R-ETZ)has noticeably compressed.3)The landuse dynamics within U-S-RTZ has gradually increased in 1990-2020.The main direction of landuse transition was from farmland to construction land or woodlands,with the expansion of construction land being the most significant.4)R-ETZ primarily focus on ecological functions,and there is a trade-off relationship between the production-ecological function within the S-RTZ,and in the U-STZ,production-living composite functions are prioritized.This study emphasizes the importance of elastic planning and precise governance within the U-S-RTZ in a rapid urbanization region,particularly highlighting the role of suburbs as landscape corridors and service hubs in urban-rural integration.It elucidates to the practical implications for achieving high-quality development of integrated U-S-R territorial spaces.
基金The authors are grateful to"Chemical Grid Project"of Beijing University of Chemical Technology for providingthe computer facilities.
文摘A subsurface flow wetland(SSFW)was simulated using a commercial computational fluid dynamic(CFD)code.The constructed media was simulated using porous media and the liquid resident time distribution(RTD)in the SSFW was obtained using the particle trajectory model.The effect of wetland configuration and operating conditions on the hydraulic performance of the SSFW were investigated.The results indicated that the hydraulic performance of the SSFW was predominantly affected by the wetland configuration.The hydr...
文摘The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles and procedures are presented in this paper. Indicators and methods for IEA may vary from case to case, but guidelines for selection of indicators and methods may be applicable for a specific case, so they are also introduced. Although great progress has been made in IEA, there is still a lot for future development. Prospects are presented as follows: (1) IEA at strategic level; (2) mechanisms for public involvement; (3) post project analysis; (4) cumulative impact assessment; and (5) application of new approaches such as expert system and GIS in IEA.
文摘Responding to concerns raised by the Bhopal accident, more and more attention has been paid to local emergency, especially chemical emergency, prevention and planning worldwide, and many chemical emergency response systems for public response personnel have been built. With the successful application of geographical information system (GIS) technology in many fields, GIS can be an efficient tool for effective response to chemical emergencies. The purpose of this paper is to introduce the application of GIS technology in emergency response. Typical GIS technology is simply introduced and some of its existing applications to emergency, mainly natural disaster, response are summarized. Spatial data and spatial analysis requirements for chemical monitoring and emergency response are also discussed in detail. Finally a chemical monitoring and emergency response system under development by combining GIS and expert system for both chemical distribution centers and public response personnel is presented.
基金National Natural Science Foundation of China,No.41930651,No.41701100Applicationof Sichuan Science and Technology Department,No.2017JY0155。
文摘Climate change(CC)and human activities(HA)are the main reasons for the restoration/degradation of the Qinghai-Tibet Plateau(QTP)grassland.Many related studies have been conducted thus far,but the impact mechanism of CC coupled with HA on QTP remains unclear.We summarized the two main coupling factors in recent years(specifically,in the past five years)and obtained the following conclusions.(1)CC and HA have positive and negative effects on the QTP grassland ecosystem.CC primarily affects grassland ecology through temperature,humidification,and extreme climate,and HA mainly affects ecosystems through primary,secondary,and tertiary industries and restoration measures.(2)CC coupled with HA affects soil,plants,animals,and fungi/microbes.CC makes the snow line rise by increasing the temperature,which expands the zone for HA.CC also restricts HA through hydrological changes,extreme climate,and outbreak of pikas and pests.Simultaneously,measures are implemented through HA to control and adapt to CC.Hence,the grassland ecosystem is comprehensively influenced by CC and HA.(3)The grassland ecosystem dynamically adapts to the disturbance caused by CC and HA by changing its physiological characteristics,distribution range,diet structure,community structure,and physical state.Simultaneously,it responds to environmental changes through desertification,poisonous weeds,rodent outbreak,release of harmful gases,and other means.This work can be used as a reference for the sustainable development of the QTP grassland.
