Surface Urban Heat Islands Dynamics in Response to LULC and Vegetation across South Asia (2000–2019)

Remote Sensing

Talha Hassan¹  Jiahua Zhang¹  Til Prasad Pangali Sharma¹  Foyez Ahmed Prodhan¹  Barjeece Bashir² 

[1] Key Laboratory of Digital Earth Sciences, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100094, China;University of Chinese Academy of Sciences, Beijing 100049, China;

关键词: surface urban heat island;    land use land cover;    land surface temperature;    normalized difference vegetation index;    urbanization;   

DOI  :  10.3390/rs13163177

来源: DOAJ

【 摘 要 】

Urbanization is an increasing phenomenon around the world, causing many adverse effects in urban areas. Urban heat island is are of the most well-known phenomena. In the present study, surface urban heat islands (SUHI) were studied for seven megacities of the South Asian countries from 2000–2019. The urban thermal environment and relationship between land surface temperature (LST), land use landcover (LULC) and vegetation were examined. The connection was explored with remote-sensing indices such as urban thermal field variance (UTFVI), surface urban heat island intensity (SUHII) and normal difference vegetation index (NDVI). LULC maps are classified using a CART machine learning classifier, and an accuracy table was generated. The LULC change matrix shows that the vegetated areas of all the cities decreased with an increase in the urban areas during the 20 years. The average LST in the rural areas is increasing compared to the urban core, and the difference is in the range of 1–2 (°C). The SUHII linear trend is increasing in Delhi, Karachi, Kathmandu, and Thimphu, while decreasing in Colombo, Dhaka, and Kabul from 2000–2019. UTFVI has shown the poor ecological conditions in all urban buffers due to high LST and urban infrastructures. In addition, a strong negative correlation between LST and NDVI can be seen in a range of −0.1 to −0.6.

【 授权许可】

Unknown