After the completion of Beijing New Airport, air-rail intermodality will become an important means of internal and external links in Jing-Jin-Ji Region. Jing-Jin-Ji Air-Rail Intermodality System is built and 7 sub-sys...After the completion of Beijing New Airport, air-rail intermodality will become an important means of internal and external links in Jing-Jin-Ji Region. Jing-Jin-Ji Air-Rail Intermodality System is built and 7 sub-systems are divided based on user demand analysis. Refer to the passenger process, the business process of the system is planned and the sub-systems are described using data flow diagram. The system provides theoretical support for the development of air-rail intermodal in Jing-Jin-Ji region.展开更多
Research into urban expansion patterns and their driving forces is of great significance for urban agglomeration development planning and decision-making.In this paper,we reveal the multi-dimensional characteristics o...Research into urban expansion patterns and their driving forces is of great significance for urban agglomeration development planning and decision-making.In this paper,we reveal the multi-dimensional characteristics of urban expansion patterns,based on the intensity index of the urban expansion,the differentiation index of the urban expansion,the fractal dimension index,the land urbanization rate,and the center of gravity model,by taking the Beijing-Tianjin-Hebei(Jing-Jin-Ji)urban agglomeration as an example.We then build the center of gravity-geographically and temporally weighted regression(GTWR)model by coupling the center of gravity model with the GTWR model.Through the analysis of the temporal and spatial patterns and by using the center of gravity-GTWR model,we analyze the driving forces of the urban land expansion and summarize the dominant development modes and core driving forces of the Jing-Jin-Ji urban agglomeration.The results show that:1)Between 1990 and 2015,the expansion intensity of the Jing-Jin-Ji urban agglomeration showed a down-up-down trend,and the peak period was in 2005-2010.Before 2005,high-speed development took place in Beijing,Tianjin,Baoding,and Langfang;after 2005,rapid development was seen in Xingtai and Handan.2)Although the barycenter of cities in the Jing-Jin-Ji urban agglomeration has shown a divergent trend,the local interaction between cities has been enhanced,and the driving forces of urban land expansion have shown a characteristic of spatial spillover.3)The spatial development mode of the Jing-Jin-Ji urban agglomeration has changed from a dual-core development mode to a multi-core development mode,which is made up of three functional cores:the transportation core in the northern part,the economic development core in the central part,and the investment core in the southern part.The synergistic development between each functional core has led to the multi-core development mode.4)The center of gravity-GTWR model combines the analysis of spatial and temporal nonstationarity with urban spatial interaction,and analyzes the urban land expansion as a space-time dynamic system.The results of this study show that the model is a feasible approach in the analysis of the driving forces of urban land expansion.展开更多
Potential evapotranspiration(ET_0) is vital for hydrologic cycle and water resource assessments as well as crop water requirement and irrigation demand assessments. The Beijing-Tianjin-Hebei region(Jing-Jin-Ji)–an im...Potential evapotranspiration(ET_0) is vital for hydrologic cycle and water resource assessments as well as crop water requirement and irrigation demand assessments. The Beijing-Tianjin-Hebei region(Jing-Jin-Ji)–an important, large, regional, economic community in China has experienced tremendous land use and land cover changes because of urbanisation and ecological restoration, affecting the hydrologic cycle and water resources of this region. Therefore, we analysed ET_0 in this region using climate data from 22 meteorological stations for the period 1991–2015 to understand this effect. Our findings show that ET_0 increased significantly at a rate of 7.40 mm per decade for the region. Based on the major land use type surrounding them, the meteorological stations were classified as urban, farmland, and natural stations using the 2015 land use dataset. The natural stations in the northern mountainous area showed a significant increase in ET_0, whereas most urban and farmland stations in the plain area showed a decrease in ET_0, with only a few of the stations showing an increase. Based on the different ET_0 trends for different land use types, these stations can be ranked as follows: urban stations(trend value:-4.663 to-1.439) > natural stations(trend value: 2.58 to 3.373) > farmland stations(trend value:-2.927 to-0.248). Our results indicate that land use changes affect meteorological parameters, such as wind speed and sunshine duration, which then lead to changes in ET_0. We noted that wind speed was the dominant parameter affecting ET_0 at all the natural stations, and wind speed and sunshine duration were the dominant parameters affecting ET_0 at most of the urban stations. However, the main controlling parameters affecting ET_0 at the farmland stations varied. These results present a scope for understanding land use impact on ET_0, which can then be applied to studies on sustainable land use planning and water resource management.展开更多
文摘After the completion of Beijing New Airport, air-rail intermodality will become an important means of internal and external links in Jing-Jin-Ji Region. Jing-Jin-Ji Air-Rail Intermodality System is built and 7 sub-systems are divided based on user demand analysis. Refer to the passenger process, the business process of the system is planned and the sub-systems are described using data flow diagram. The system provides theoretical support for the development of air-rail intermodal in Jing-Jin-Ji region.
基金National Natural Science Foundation of China,No.41571384Land Resources Survey and Evaluation Project of Ministry of Land and Resources of China,No.DCPJ161207-01+2 种基金Fund for Fostering Talents in Basic Science of National Natural Science Foundation of China,No.J1103409Key Program of National Natural Science Foundation of China,No.71433008Programme of Excellent Young Scientists of the Institute of Geographic Sciences and Natural Resources Research,CAS。
文摘Research into urban expansion patterns and their driving forces is of great significance for urban agglomeration development planning and decision-making.In this paper,we reveal the multi-dimensional characteristics of urban expansion patterns,based on the intensity index of the urban expansion,the differentiation index of the urban expansion,the fractal dimension index,the land urbanization rate,and the center of gravity model,by taking the Beijing-Tianjin-Hebei(Jing-Jin-Ji)urban agglomeration as an example.We then build the center of gravity-geographically and temporally weighted regression(GTWR)model by coupling the center of gravity model with the GTWR model.Through the analysis of the temporal and spatial patterns and by using the center of gravity-GTWR model,we analyze the driving forces of the urban land expansion and summarize the dominant development modes and core driving forces of the Jing-Jin-Ji urban agglomeration.The results show that:1)Between 1990 and 2015,the expansion intensity of the Jing-Jin-Ji urban agglomeration showed a down-up-down trend,and the peak period was in 2005-2010.Before 2005,high-speed development took place in Beijing,Tianjin,Baoding,and Langfang;after 2005,rapid development was seen in Xingtai and Handan.2)Although the barycenter of cities in the Jing-Jin-Ji urban agglomeration has shown a divergent trend,the local interaction between cities has been enhanced,and the driving forces of urban land expansion have shown a characteristic of spatial spillover.3)The spatial development mode of the Jing-Jin-Ji urban agglomeration has changed from a dual-core development mode to a multi-core development mode,which is made up of three functional cores:the transportation core in the northern part,the economic development core in the central part,and the investment core in the southern part.The synergistic development between each functional core has led to the multi-core development mode.4)The center of gravity-GTWR model combines the analysis of spatial and temporal nonstationarity with urban spatial interaction,and analyzes the urban land expansion as a space-time dynamic system.The results of this study show that the model is a feasible approach in the analysis of the driving forces of urban land expansion.
基金National Key Research and Development Program of China,No.2016YFC0401407National Natural Science Foundation of China,No.51379216+1 种基金National Science Foundation for Distinguished Young Scholars,No.51625904International Science&Technology Cooperation Program of China,No.2016YFE0102400
文摘Potential evapotranspiration(ET_0) is vital for hydrologic cycle and water resource assessments as well as crop water requirement and irrigation demand assessments. The Beijing-Tianjin-Hebei region(Jing-Jin-Ji)–an important, large, regional, economic community in China has experienced tremendous land use and land cover changes because of urbanisation and ecological restoration, affecting the hydrologic cycle and water resources of this region. Therefore, we analysed ET_0 in this region using climate data from 22 meteorological stations for the period 1991–2015 to understand this effect. Our findings show that ET_0 increased significantly at a rate of 7.40 mm per decade for the region. Based on the major land use type surrounding them, the meteorological stations were classified as urban, farmland, and natural stations using the 2015 land use dataset. The natural stations in the northern mountainous area showed a significant increase in ET_0, whereas most urban and farmland stations in the plain area showed a decrease in ET_0, with only a few of the stations showing an increase. Based on the different ET_0 trends for different land use types, these stations can be ranked as follows: urban stations(trend value:-4.663 to-1.439) > natural stations(trend value: 2.58 to 3.373) > farmland stations(trend value:-2.927 to-0.248). Our results indicate that land use changes affect meteorological parameters, such as wind speed and sunshine duration, which then lead to changes in ET_0. We noted that wind speed was the dominant parameter affecting ET_0 at all the natural stations, and wind speed and sunshine duration were the dominant parameters affecting ET_0 at most of the urban stations. However, the main controlling parameters affecting ET_0 at the farmland stations varied. These results present a scope for understanding land use impact on ET_0, which can then be applied to studies on sustainable land use planning and water resource management.
