Identification

Title

Efficacy of possible strategies to mitigate the urban heat island based on urbanized high-resolution land data assimilation system (u-HRLDAS)

Abstract

Summer heat waves are a significant public health threat in China. This paper took Wuhan (one of the four hottest furnace cities in China) as an example to explore several strategies for mitigating the surface urban heat island (UHI), measured by the land surface temperature, including green roofs, cool roofs, bright pavements, and altered urban building patterns. The offline urbanized High-Resolution Land Data Assimilation System (u-HRLDAS) was used to conduct 1-km resolution numerical simulations, which also accounts for the effects of Wuhan's abundant lakes on UHI evolution, with a dynamic lake model. The diurnal cycle and spatial distribution of simulated UHI were analyzed under different mitigation strategies. Results show that considering lake effects reduces daytime (nighttime) UHI intensity by about 1.0 K (0.5 K). Green roofs and cool roofs are more effective in mitigating daytime UHI than bright pavements. The maximum UHI reduction is about 2.1 K at 13:00 local time by replacing 80 % of conventional roofs with green roofs. The UHI mitigation efficiency increases with larger fractions of green roofs, and increased albedo of roofs and roads. In contrast to green roofs, cool roofs and bright pavements are ineffective during nighttime, changing the urban building pattern to mitigate UHL is effective throughout the day. "Height-driven building structure changing" (raising the building height while changing the fraction of impervious surface in each grid to keep the total building volume intact) can reduce surface UHF intensity by 0.4-0.9 K, and "density-driven building structure changing" (distributing building density uniformly and modifying the building height to make the total building volume unchanged) reduces UHI by 1.2-2.6 K. These results showed new insights in mitigating UHIs for mega cities, like Wuhan, and provides a practical guideline for policymakers to offer more habitable cities.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7x63r6h

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2019-01-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact