Impact of Land Cover Changes on Land Surface Temperature and Human Thermal Comfort in Dhaka City of Bangladesh

Abstract

Urbanization leads to the construction of various urban infrastructures in the city area for residency, transportation, industry, and other purposes, which causes major land use change. Consequently, it substantially affects Land Surface Temperature (LST) by unbalancing the surface energy budget. Higher LST in city areas decreases human thermal comfort for the city dwellers and affects the urban environment and ecosystem. Therefore, a comprehensive investigation is needed to evaluate the impact of land use change on the LST. Remote Sensing (RS) and Geographic Information System (GIS) techniques were used for the detailed investigation. RS data for the years 1993, 2007 and 2020 during summer (March–May) in Dhaka city were used to prepare land cover maps, analyze LST, generate hazard maps and relate the land cover change with LST by using GIS. The results show that the built-up area in Dhaka city increased by 67% from 1993 to 2020 by replacing lowland mainly, followed by vegetation, bare soil and water bodies. LSTs found in the study area were ranged from 23.26 to 39.94 °C, 23.69 to 43.35 °C and 24.44 to 44.58 °C for the years 1993, 2007 and 2020, respectively. The increases of spatially distributed maximum and mean LST were found 4.62 °C and 6.43 °C, respectively, for the study period of 27 years while the change in minimum LST was not substantial. LST increased by around 0.24 °C per year and human thermal discomfort shifted from moderate to strong heat stress for the total study period due to the increase of built-up and bare lands. This study also shows that normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) were negatively correlated with LST while normalized difference built-up Index (NDBI) and normalized difference built-up Index (NDBAI) were positively correlated with LST. The methodology developed in this study can be adapted to other cities around the globe.

Remote Sensing and Geospatial Models to Simulate Land Use and Land Cover and Estimate Water Supply and Demand for Water Balancing in Phuket Island, Thailand

“…Phuket Island's urban and built-up areas have been primarily expanded by converting perennial trees and orchards and idle land. This finding is consistent with previous studies [54,55], which stated that most agricultural land and vegetation areas were transformed into urban and built-up areas to meet people's demands, leading to the LULC change.…”

Geomorphologic Change in Nagavali River Basin: Geospatial Approach

“…The overall accuracy of the LULC maps of these maps achieved with minor error percentage. Error percentage caused due to wrong color detection while creating training samples, which lead to change in area of LULCC [41,42].…”

Examining the relationship between land surface temperature and landscape features using spectral indices with Google Earth Engine

“…Furthermore, Figure 6 (i, n, p) demonstrates a positive trend, whereas Figure 6 (m, o) demonstrates a decreasing trend and Figure 6 (j, k, l) demonstrates no trend. Some studies also found that NDBI and NDBAI had a positive correlation with LST, while NDWI had a negative correlation with LST [ 71 ].

Figure 5 Scatter plot for NDVI and LST (a–d); NDBI and LST (e–h).

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