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Li L.-G.,Institute of Atmospheric Environment | Xu S.-L.,Tsinghua Holdings Human Settlements Environment Institute Co. | Wang H.-B.,Institute of Atmospheric Environment | Zhao Z.-Q.,Institute of Atmospheric Environment | And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2013

Based on the remote images in 2001 and 2010, the source and sink areas of urban heat island (UHI) in Shenyang City, Northeast China were determined by GIS technique. The effect of urban regional landscape pattern on UHI effect was assessed with land surface temperature (LST), area rate index (CI) of the source and sink areas and intensity index (LI) of heat island. The results indicated that the land use type changed significantly from 2001 to 2010, which significantly changed the source and sink areas of UHI, especially in the second and third circle regions. The source and sink areas were 94.3% and 5. 7% in the first circle region, 64.0% and 36.0% in the third circle region in 2001, while they were 93.4% and 6.6%, 70.2% and 29.8% in 2010, respectively. It suggested that the land use pattern extended by a round shape in Shenyang led to the corresponding UHI pattern. The LST in the study area tended to decrease from the first circle region to the third. The UHI intensity was characterized with a single center in 2001 and with several centers in 2010, and the grade of UHI intensity was in a decreasing trend from 2001 to 2010.The absolute value of CI increased from the first circle region to the third, and the LI was close to 1, suggesting the change in land use pattern had no significant influence on UHI in Shenyang. Source


Wang H.-B.,Institute of Atmospheric Environment | Li L.-G.,Institute of Atmospheric Environment | Zhao Z.-Q.,Institute of Atmospheric Environment | Zhao X.-L.,Institute of Atmospheric Environment | And 5 more authors.
3rd International Workshop on Earth Observation and Remote Sensing Applications, EORSA 2014 - Proceedings | Year: 2014

Base on the Landsat TM/ETM+ data on August of 2001 and 2010, the surface urban heat island (SUHI) intensity on prevailing wind direction belt using three sampling belts with 1 km width within the third circle freeway of Shenyang were calculated, and its relationships with land use types, source-sink distribution, normal differential vegetation index (NDVI), normal differential built-up index (NDBI), modified normal differential water index (MNDWI) were analyzed. The results show that land surface temperature (LST) and SUHI intensity increases from southeast to northwest for 3 belts. The mean LST on 3 belts is greater in 2010 than in 2001. The LST value and ratio of SUHI source areas on 3 belts are greater in 2010 than that in 2001, while SUHI decreases in 2010 compared with in 2001. There is a significant positive correlation between SUHI and NDBI in all 3 belts, and the correlation coefficients are 0.9123 in 2001 and 0.9103 in 2010. There is also a significant positive correlation between SUHI and SUHI sources area ratio in all 3 belts, the correlation coefficient is 0.9618 in 2001 and 0.9588 in 2010. However, there are no significant correlation relationships between SUHI and NDVI, SUHI and MNDWI, SUHI and source-sink boundary length, SUHI and each land use types. © 2014 IEEE. Source


Li L.-G.,Institute of Atmospheric Environment | Wang H.-B.,Institute of Atmospheric Environment | Zhao Z.-Q.,Institute of Atmospheric Environment | Cai F.,Institute of Atmospheric Environment | And 2 more authors.
3rd International Workshop on Earth Observation and Remote Sensing Applications, EORSA 2014 - Proceedings | Year: 2014

Based on the Landsat TM image on August 12, 2010, a 4 × 4 fishnet with 16 grids was built, and each grid was 3.5 km× 3.5 km. The changes of the LST (land surface temperature), urban heat island (UHI) source and sink areas and their corresponding percentages in the 16 grids were analyzed in order to find the optimum configuration of source and sink areas. The relationships between LST and remote sensing indices such as NDVI, NDBI and MNDWI, LST and LI (UHI intensity index), LI and remote sensing indices were discussed. The results indicated that the percentage of UHI source area is greater than that of UHI sink area in each grid. The 16 grids are divided into 5 groups according to the percentage of source area. There are 7 grids in the first group with greater 90.00%, 3 grids in the second group with 80.00%-89.99%, 2 grids in the third group with 70.00%-79.99%, 3 grids in the fourth group with 60.00%-69.99%, 1 grid in the fifth group with fewer 60.00%. The mean LST in the source area, sink area and the whole grid decreases with the decreasing of source area percentage, especially for LST in the sink area. The NDVI and NDBI values in each grid are fewer than 0.100 and greater than 0.100 of the first and second groups respectively, and their corresponding LI values are lower than 1.00. It suggests that they can enhance the urban heat island effect. The NDVI values in the two grids with 70.84% and 78.11% are greater than 0.100, the NDBI values are 0.030 and 0.106, and the corresponding LI values are 1.05 and 0.94. The effects of the third group on urban heat island are complex. The percentage of source area is fewer than 70% in the fourth and fifth groups, and their corresponding LI values are greater 1.00, which suggests that they can reduce the UHI effect. Analysis of relationships between indices showed that the relation of the LST is in a negative correlation with NDVI and is in a positive correlation with NDBI, while that of the LI is positive with NDVI and is in a negative correlation with NDBI. The MNDWI has no significant correlations with LST and LI. According to the above analysis, the study plot can reduce or enhance the UHI effect when the percentage of UHI source area is fewer or greater than the 70%, while it neither reduce nor enhance the UHI effect when the percentage of UHI source area is about 70%. Thus, the 70% of the UHI source area should be considered as a reference for urban planning in order to reduce the UHI effect. © 2014 IEEE. Source

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