TITLE:
Assessing the Diurnal and Spatial Role of Greenspaces and Concrete Landscapes in Regulating Urban Microclimate
AUTHORS:
Fardina Jahid Tahia, Eyanur Hossain, Anika Tahsin Odri, Ummeh Saika
KEYWORDS:
Urban Microclimate, Greenspaces, Concrete Landscapes, Temperature and Humidity Regulation, Diurnal Variation, Spatial Analysis
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.1,
January
30,
2025
ABSTRACT: Amidst Dhaka city’s rapidly growing urban fabric, Dhanmondi Lake is one of the few remaining natural features that directly impacts the area’s microclimate, which is especially relevant to combating the increasing urban heat island phenomenon. This research investigates the lake’s diurnal and spatial impact on local temperature and humidity variations between greenspaces and concrete landscapes. Data from 14 monitoring points, collected over two months (March-April 2024), were analyzed using descriptive statistics (mean, median, standard deviation) and inferential statistics (Pearson’s correlation coefficient), alongside spatial analysis through Inverse Distance Weighting (IDW) to visualize microclimate patterns. The results demonstrate that during the daytime, temperatures are higher in concrete areas and lower near the lake, with a strong positive correlation between distance from the lake and temperature across the lake (r = 0.933, p = 0.002). Conversely, at night, temperature decreases as the distance from the lake increases, with a strong negative correlation between them (r = −0.983, p = 0.000). The recorded nighttime temperature was relatively stable with a small variation (mean = 28.47˚C, SD = 0.21˚C) across the lake, suggesting the lake’s ability to retain heat at night. In contrast, the average temperature in the areas near the lake was relatively more stable (mean = 28.59˚C, SD = 0.06˚C). Humidity consistently showed a strong negative correlation with distance from the lake both day (r = −0.993, p = 0.000) and night (r = −0.977, p = 0.000), with higher humidity levels near the lake and lower concrete areas. These findings emphasize that distance from the lake and greenspace is a key factor influencing microclimate. The results lead to policy recommendations highlighting integrating natural elements into urban planning to mitigate urban heat island (UHI) effects and enhance thermal comfort.