Journal of Geographical Sciences ›› 2020, Vol. 30 ›› Issue (12): 2015-2032.doi: 10.1007/s11442-020-1825-5

• Research Articles • Previous Articles     Next Articles

Monitoring thermal field, humidity field and energy balance over heterogeneous surfaces in the typical valley-city

LI Guodong1,2(), ZHANG Junhua1,2,*(), MIRZAEI Parham A.3, DING Shengyan1,2, DING Yapeng1, LIU Man1   

  1. 1. College of Environment and Planning, Henan University, Kaifeng 475004, Henan, China
    2. Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, Kaifeng 475004, Henan, China
    3. Department of Architecture and Built Environment, The University of Nottingham, Nottingham NG7 2RD, UK
  • Received:2020-03-09 Accepted:2020-07-23 Online:2020-12-25 Published:2021-01-05
  • Contact: ZHANG Junhua E-mail:liguodonghd@163.com;zhangjunhua@henu.edu.cn
  • About author:Li Guodong, Associate Professor, specialized in urban climate and land surface processes. E-mail: liguodonghd@163.com
  • Supported by:
    National Natural Science Foundation of China(U1404401);National Natural Science Foundation of China(41771202);Natural Science Foundation of Henan Province(182300410129);Open Fund of Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security(20170201)

Abstract:

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.

Key words: thermal field, humidity field, energy balance, heat fluxes, LULC, valley-city