Response of urban heat island to future urban expansion over the Beijing–Tianjin–Hebei metropolitan area

TLDR: In this paper, the responses of urban heat islands to urban expansion in the past decades were simulated using the coupled weather research forecast/urban canopy model (WRF/UCM) system from the 1980s to 2005 and in the future in 2050 embedded with the fine spatial resolution land use/land cover (LULC) datasets over the Beijing-Tianjin-Hebei (BTH) metropolitan area.

About: This article is published in Applied Geography.The article was published on 2016-05-01 and is currently open access. It has received 86 citations till now. The article focuses on the topics: Urban climate & Urban climatology.

Figures

Fig. 4. Surface skin temperature (TSK) at 02:00, 08:00, 14:00, and 20:00 (from top to bottom). Left: January; Right: July.

Fig. 5. Diurnal variation in simulated 2-m air UHII (AUHII) and surface UHII (SUHII) in July 2005.

Fig. 9. Heat fluxes in July 1980s, 2005, and 2050 over newly developed urban areas in 2005.

Fig. 1. Study area and the two nested domains in WRF simulations.

Fig. 7. Relative frequency distribution curves for daily mean (above row), maximum (middle row), and minimum (below row) surface skin temperature over newly developed urban areas in the 1980s (left column), 2005 (middle column), and 2050 (right column).

Table 1 Physical parameterization schemes used in this study.

Frequently asked questions

Q1. What are the contributions in "Response of urban heat island to future urban expansion over the beijing-tianjin-hebei metropolitan area" ?

In this study, the responses of UHI to the urban expansion in the past decades were simulated using the coupled weather research forecast/urban canopy model ( WRF/UCM ) system from the 1980s to 2005 and in the future in 2050 embedded with the fine spatial resolution land use/land cover ( LULC ) datasets over the BeijingeTianjineHebei ( BTH ) metropolitan area. With the urban expansion, the validations suggested that the designed models in this research can well simulate the generation and development of UHI. 

Q2. What is the effect of urbanization on the surface temperature?

The urban surface had much higher sensible heat flux and much lower latent heat flux than rural areas due, in part, to lower evaporation over the urban surface. 

Q3. What is the effect of the low sky view factor on the temperature of urban areas?

The low sky view factor also delayed the loss of heat through multiple reflections and the trapping of nearsurface air in urban areas (Argüeso, Evans, Fita, & Bormann, 2013). 

Q4. What datasets were used to derive the explanatory factors?

The datasets, which were used to derive the explanatory factors, were obtained from the DSIESS, CAS, including road, population density, and digital elevation data. 

Q5. What are the main characteristics of the UHI?

Statistical models, in particular correlation and regression, have been employed widely to determine the effect of urbanization on surface UHI (SUHI). 

Q6. What were the two experiments used as the compared experiments?

The experiments in the 1980s and 2050 were used as the compared experiments presenting the early and future urbanization simulations, respectively. 

Q7. What data were used in this research?

Reanalysis data used in this research were obtained from the “National Centers for Environmental Prediction/Global Forecast System (NCEP/GFS)” (http://www.nco.ncep.noaa.gov/pmb/products/ gfs/). 

Q8. How was the correlation coefficient between the observed and simulated values in January?

In January, the correlation coefficient (CC) between the observed and simulated values was significant at the 0.001 level (CC: 0.84 for the temperature and 0.86 for the wind speed). 

Q9. How was the simulated average of the two meteorological stations in the study area?

A simulated average of 2-m temperature and 10-m wind speed was achieved within the 3 3 pixels surrounding each meteorological station. 

Q10. What were the different types of urbanerural maps used in the 1980s and 2005?

To produce the dependent urbanerural map in the 1980s and 2005, the urban built-up areas were reclassified as the “urban” category, the seas and deserts were reclassified as “others”, and all the other types were reclassified as the “rural” category.