Most of the world＇s cities are concentrated in coastal areas. As a special geographical component of the coastal system, island urban spatial expansion is the outcome of interactions between city development and the ...Most of the world＇s cities are concentrated in coastal areas. As a special geographical component of the coastal system, island urban spatial expansion is the outcome of interactions between city development and the physical environment. This paper takes Xiamen Island, located in Southeastern China, as an example to analyze island urban spatial expansion and its determinants by combining an analysis of the literature on urban development policies, urban overall plans, population growth and industrial development, with geographical information analysis using historical maps and remote sensing photographs. Firstly, we reviewed the history of the Xiamen City development during the last 100 years, which can be divided into four periods： the embryonic modern city and early development from 1908 to 1949; administrative boundary expansion and infrastructure development from 1950 to 1979; special economic zone construction and rapid urbanization from 1980 to 2003; and Bay City construction since 2003. The dynamic changes to the coastline, island shape, built-up area, transportation, administrative division, and major land use type conversion which occurred during approximately the past 100 years were analyzed and the characteristics of the island urban spatial expansion were concluded： early expansion from a central point, followed by expansion along a section of coastline, and expansion from the coastline inland. Secondly, we discussed the potential determinants of island urban spatial expansion including administrative division adjustment, urban master planning revision, industrial development, topographical factors, coastal area reclamation, transportation expansion, and population growth. Finally, the effects of each potential determinant on island urban spatial expansion were concluded. Island urban spatial expansion is the result of a synthesis of natural and socio-economic factors which are not independent but interacting. Built-up area expansion is the major driver of island land cover and land use changes. By this paper, we hope to provide a scientific reference contributing to the rational understanding of island and coastal sustainable urbanization in China, and the world beyond.展开更多
World-wide urbanization has significantly modified the landscape, which has important climatic implications across all scales due to the simultaneous removal of natural land cover and introduction of urban materials. ...World-wide urbanization has significantly modified the landscape, which has important climatic implications across all scales due to the simultaneous removal of natural land cover and introduction of urban materials. This resulted in a phenomenon known as an urban heat island(UHI). A study on the UHI in Xiamen of China was carried out using remote sensing technology. Satellite thermal infrared images were used to determine surface radiant temperatures. Thermal remote sensing data were obtained from band 6 of two Landsat TM/ETM\++ images of 1989 and 2000 to observe the UHI changes over 11-year period. The thermal infrared bands were processed through several image enhancement technologies. This generated two 3-dimension-perspective images of Xiamen's urban heat island in 1989 and 2000, respectively, and revealed heat characteristics and spatial distribution features of the UHI. To find out the change of the UHI between 1989 and 2000, the two thermal images were first normalized and scaled to seven grades to reduce seasonal difference and then overlaid to produce a difference image by subtracting corresponding pixels. The difference image showed an evident development of the urban heat island in the 11 years. This change was due largely to the urban expansion with a consequent alteration in the ratio of sensible heat flux to latent heat flux. To quantitatively compare UHI, an index called Urban-Heat-Island Ratio Index(URI) was created. It can reveal the intensity of the UHI within the urban area. The calculation of the index was based on the ratio of UHI area to urban area. The greater the index, the more intense the UHI was. The calculation of the index for the Xiamen City indicated that the ratio of UHI area to urban area in 2000 was less than that in 1989. High temperatures in several areas in 1989 were reduced or just disappeared, such as those in old downtown area and Gulangyu Island. For the potential mitigation of the UHI in Xiamen, a long-term heat island reduction strategy of planting shade trees and using light-colored, highly reflective roof and paving materials should be included in the plans of the city planers, environmental managers and other decision-makers to improve the overall urban environment in the future.展开更多
Using relative humidity data from two meteorological stations in Xiamen and absolute humidity calculated from temperature and water vapor,the annual,seasonal and monthly change characteristic of relative humidity and ...Using relative humidity data from two meteorological stations in Xiamen and absolute humidity calculated from temperature and water vapor,the annual,seasonal and monthly change characteristic of relative humidity and absolute humidity were comprehensive analyzed.Then the dry island effect of Xiamen city was studied.The result demonstrated that because of unique geographical features,the air humidity showed different change rules between urban and suburb.There was no obvious dry island effect in urban and suburb at last century.The change trend of average air humidity was unapparent before 90th of last century.From early 90th of last century,the air humidity in suburb began to decrease obviously.There was dry mutation for these two stations in 1993 and 2004 respectively.From the beginning of early of this century,both areas became dry obviously.The seasonal average relative humidity of Tongan station decreased each season,but what in Xiamen station changed unapparent.The seasonal average absolute humidity of Tongan station decreased apparently in spring and summer,but what did not change obviously in autumn and winter.The seasonal average absolute humidity of Xiamen station decreased apparently in summer,but what did not change apparently in other seasons.As respect from climate change of air humidity of each time,it decreased obviously at all four times at Tongan station.Relative humidity diminished most apparently at 8 and 20 o'clock.Absolute humidity diminished most apparently at 14 o'clock.For Xiamen station,relative humidity diminished most apparently at 14 o'clock.Absolute humidity diminished most apparently at 2 and 20 o'clock.展开更多
基金Knowledge Innovation Programs of the Chinese Academy of Sciences, No.KZCX2-YW-450 No.0714121d10, National Natural Science Foundation of China, No.40901243 Natural Science Foundation of Fujian Province of China, No.2010J05100
文摘Most of the world＇s cities are concentrated in coastal areas. As a special geographical component of the coastal system, island urban spatial expansion is the outcome of interactions between city development and the physical environment. This paper takes Xiamen Island, located in Southeastern China, as an example to analyze island urban spatial expansion and its determinants by combining an analysis of the literature on urban development policies, urban overall plans, population growth and industrial development, with geographical information analysis using historical maps and remote sensing photographs. Firstly, we reviewed the history of the Xiamen City development during the last 100 years, which can be divided into four periods： the embryonic modern city and early development from 1908 to 1949; administrative boundary expansion and infrastructure development from 1950 to 1979; special economic zone construction and rapid urbanization from 1980 to 2003; and Bay City construction since 2003. The dynamic changes to the coastline, island shape, built-up area, transportation, administrative division, and major land use type conversion which occurred during approximately the past 100 years were analyzed and the characteristics of the island urban spatial expansion were concluded： early expansion from a central point, followed by expansion along a section of coastline, and expansion from the coastline inland. Secondly, we discussed the potential determinants of island urban spatial expansion including administrative division adjustment, urban master planning revision, industrial development, topographical factors, coastal area reclamation, transportation expansion, and population growth. Finally, the effects of each potential determinant on island urban spatial expansion were concluded. Island urban spatial expansion is the result of a synthesis of natural and socio-economic factors which are not independent but interacting. Built-up area expansion is the major driver of island land cover and land use changes. By this paper, we hope to provide a scientific reference contributing to the rational understanding of island and coastal sustainable urbanization in China, and the world beyond.
文摘World-wide urbanization has significantly modified the landscape, which has important climatic implications across all scales due to the simultaneous removal of natural land cover and introduction of urban materials. This resulted in a phenomenon known as an urban heat island(UHI). A study on the UHI in Xiamen of China was carried out using remote sensing technology. Satellite thermal infrared images were used to determine surface radiant temperatures. Thermal remote sensing data were obtained from band 6 of two Landsat TM/ETM\++ images of 1989 and 2000 to observe the UHI changes over 11-year period. The thermal infrared bands were processed through several image enhancement technologies. This generated two 3-dimension-perspective images of Xiamen's urban heat island in 1989 and 2000, respectively, and revealed heat characteristics and spatial distribution features of the UHI. To find out the change of the UHI between 1989 and 2000, the two thermal images were first normalized and scaled to seven grades to reduce seasonal difference and then overlaid to produce a difference image by subtracting corresponding pixels. The difference image showed an evident development of the urban heat island in the 11 years. This change was due largely to the urban expansion with a consequent alteration in the ratio of sensible heat flux to latent heat flux. To quantitatively compare UHI, an index called Urban-Heat-Island Ratio Index(URI) was created. It can reveal the intensity of the UHI within the urban area. The calculation of the index was based on the ratio of UHI area to urban area. The greater the index, the more intense the UHI was. The calculation of the index for the Xiamen City indicated that the ratio of UHI area to urban area in 2000 was less than that in 1989. High temperatures in several areas in 1989 were reduced or just disappeared, such as those in old downtown area and Gulangyu Island. For the potential mitigation of the UHI in Xiamen, a long-term heat island reduction strategy of planting shade trees and using light-colored, highly reflective roof and paving materials should be included in the plans of the city planers, environmental managers and other decision-makers to improve the overall urban environment in the future.
文摘Using relative humidity data from two meteorological stations in Xiamen and absolute humidity calculated from temperature and water vapor,the annual,seasonal and monthly change characteristic of relative humidity and absolute humidity were comprehensive analyzed.Then the dry island effect of Xiamen city was studied.The result demonstrated that because of unique geographical features,the air humidity showed different change rules between urban and suburb.There was no obvious dry island effect in urban and suburb at last century.The change trend of average air humidity was unapparent before 90th of last century.From early 90th of last century,the air humidity in suburb began to decrease obviously.There was dry mutation for these two stations in 1993 and 2004 respectively.From the beginning of early of this century,both areas became dry obviously.The seasonal average relative humidity of Tongan station decreased each season,but what in Xiamen station changed unapparent.The seasonal average absolute humidity of Tongan station decreased apparently in spring and summer,but what did not change obviously in autumn and winter.The seasonal average absolute humidity of Xiamen station decreased apparently in summer,but what did not change apparently in other seasons.As respect from climate change of air humidity of each time,it decreased obviously at all four times at Tongan station.Relative humidity diminished most apparently at 8 and 20 o'clock.Absolute humidity diminished most apparently at 14 o'clock.For Xiamen station,relative humidity diminished most apparently at 14 o'clock.Absolute humidity diminished most apparently at 2 and 20 o'clock.
