Land use and land cover(LULC)alteration has changed original energy balance and heat fluxes between land and atmosphere,and thus affects the structure characteristics of temperature and humidity fields over urban hete...Land use and land cover(LULC)alteration has changed original energy balance and heat fluxes between land and atmosphere,and thus affects the structure characteristics of temperature and humidity fields over urban heterogeneous surfaces in different spatio-temporal scales.Lanzhou is the most typical river valley city of China,it is chosen as the case study.Typical river valley terrain,rapid urbanization and severe air pollution have caused unique urban climate and urban heat island(UHI)effects in Lanzhou.Firstly,the spatial structure characteristics and dynamic evolution of temperature and humidity fields in autumn are simulated by mobile measurement experiment and GIS spatial analysis method.The results show that temperature and humidity fields have significant dynamic change within a day,and have multiple center and multiple intensity level characteristics.Then,LULC and normalized difference vegetation index(NDVI)are extracted from remote sensing images,the distribution patterns of temperature and humidity fields have close relationships with LULC and NDVI.Moreover,there is a significant positive correlation between impervious surface area and thermal field intensity.A positive correlation between NDVI value and humidity field intensity has been found as well as a negative correlation between NDVI value and thermal field intensity.Finally,heat fluxes and energy balance characteristics between ground and atmosphere are analyzed based on the Bowen-ratio System experiments.This study could provide theoretical support and practical guidance for urban planning,urban eco-environment construction and air pollution prevention of river valley city.展开更多
Accompanied with the acceleration of urbanization and industrialization,the large and medium-scale valley-cities in the western China are facing environmental problems at respective levels in common. The urban environ...Accompanied with the acceleration of urbanization and industrialization,the large and medium-scale valley-cities in the western China are facing environmental problems at respective levels in common. The urban environmental pollution causes economic losses,and also brings out negative effects on urban society. Based on the social investigation method,this paper aims to study the harms to urban society brought by environmental pollution. After the investigation to the inhabitants of six typical valley-cities:Lanzhou,Xining,Chongqing,Baiyin,Luzhou and Zigong,we found that the urban environmental pollution has resulted in negative influences with different levels on residents' physical,psychological,work,recreations,studies and social activities. The problem of environmental pollution has become a serious restriction to sustainable development of cities mentioned above. Herewith,it has become urgent to strengthen the government regulations for controlling urban environmental pollution.展开更多
基金National Natural Science Foundation of China,No.U1404401,No.41771202Natural Science Foundation of Henan Province,No.182300410129Open Fund of Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security,No.20170201。
文摘Land use and land cover(LULC)alteration has changed original energy balance and heat fluxes between land and atmosphere,and thus affects the structure characteristics of temperature and humidity fields over urban heterogeneous surfaces in different spatio-temporal scales.Lanzhou is the most typical river valley city of China,it is chosen as the case study.Typical river valley terrain,rapid urbanization and severe air pollution have caused unique urban climate and urban heat island(UHI)effects in Lanzhou.Firstly,the spatial structure characteristics and dynamic evolution of temperature and humidity fields in autumn are simulated by mobile measurement experiment and GIS spatial analysis method.The results show that temperature and humidity fields have significant dynamic change within a day,and have multiple center and multiple intensity level characteristics.Then,LULC and normalized difference vegetation index(NDVI)are extracted from remote sensing images,the distribution patterns of temperature and humidity fields have close relationships with LULC and NDVI.Moreover,there is a significant positive correlation between impervious surface area and thermal field intensity.A positive correlation between NDVI value and humidity field intensity has been found as well as a negative correlation between NDVI value and thermal field intensity.Finally,heat fluxes and energy balance characteristics between ground and atmosphere are analyzed based on the Bowen-ratio System experiments.This study could provide theoretical support and practical guidance for urban planning,urban eco-environment construction and air pollution prevention of river valley city.
基金Under the auspices of National Natural Science Foundation of China (No. 40201016)
文摘Accompanied with the acceleration of urbanization and industrialization,the large and medium-scale valley-cities in the western China are facing environmental problems at respective levels in common. The urban environmental pollution causes economic losses,and also brings out negative effects on urban society. Based on the social investigation method,this paper aims to study the harms to urban society brought by environmental pollution. After the investigation to the inhabitants of six typical valley-cities:Lanzhou,Xining,Chongqing,Baiyin,Luzhou and Zigong,we found that the urban environmental pollution has resulted in negative influences with different levels on residents' physical,psychological,work,recreations,studies and social activities. The problem of environmental pollution has become a serious restriction to sustainable development of cities mentioned above. Herewith,it has become urgent to strengthen the government regulations for controlling urban environmental pollution.
