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 usin展开更多
Mechanism of satellitic thermo-infrared brightness temperature and temperature increasing is studied. Experiments are made with a gas sample taken around the epicenter area. The gas sample is proved to contain green h...Mechanism of satellitic thermo-infrared brightness temperature and temperature increasing is studied. Experiments are made with a gas sample taken around the epicenter area. The gas sample is proved to contain green house gases such as CH4 and CO2 which have increased by tens of thousands of times. In addition, lab research also proves that CH4 and CO2 can obtain energy under the action of transient electric field and release heat, thus resulting in a temperature increase of 2-6℃ . Also a brief account of practices since 1990 is given; altogether 40 short-term and impending earthquake predictions have been made, with 9 precise ones whose three main factors of an earthquake are clearly depicted, and 12 fairly good ones. These predictions include 3 earthquakes of Ms≥7, 4 of M8≥6.0 and the rest are around MS5.0. Yet there are earthquakes left out of prediction. Finally the evolutionary processing characters of satellitic thermo-infrared brightness temperature and temperature increase before the Lijiang earthquake on Feb. 3, 1996 and Tangshan earthquake on April 14, 1998 are introduced in detail. The conclusion makes a study on the regularities of connection among time, space and stress when there appears the satellitic thermal-infrared brightness temperature and temperature increasing anomaly.展开更多
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 usin
基金Project supported by the State 863 High-Tech Project (Grant No. 863-2-7-4-18).
文摘Mechanism of satellitic thermo-infrared brightness temperature and temperature increasing is studied. Experiments are made with a gas sample taken around the epicenter area. The gas sample is proved to contain green house gases such as CH4 and CO2 which have increased by tens of thousands of times. In addition, lab research also proves that CH4 and CO2 can obtain energy under the action of transient electric field and release heat, thus resulting in a temperature increase of 2-6℃ . Also a brief account of practices since 1990 is given; altogether 40 short-term and impending earthquake predictions have been made, with 9 precise ones whose three main factors of an earthquake are clearly depicted, and 12 fairly good ones. These predictions include 3 earthquakes of Ms≥7, 4 of M8≥6.0 and the rest are around MS5.0. Yet there are earthquakes left out of prediction. Finally the evolutionary processing characters of satellitic thermo-infrared brightness temperature and temperature increase before the Lijiang earthquake on Feb. 3, 1996 and Tangshan earthquake on April 14, 1998 are introduced in detail. The conclusion makes a study on the regularities of connection among time, space and stress when there appears the satellitic thermal-infrared brightness temperature and temperature increasing anomaly.
