Urban Greening and Public Health: A Study on Heat-Related Illness in Low-Income Neighborhoods of Rajshahi City
Abstract
Urbanization and global climatic change have intensified urban heat stress and created immense challenges for global public health, especially for cities that are developing rapidly. In this context, cities such as Rajshahi, Bangladesh have recognized that Green Infrastructure will be central to reducing urban heat island effect as well as protecting health This research assessed the role of Green Infrastructure (GI) with respect to urban heat stress across three neighborhoods of Rajshahi City Corporation, Bangladesh. The research utilized a semi-structured questionnaire survey and filed observation checklist mixed methods design to assess household survey to collect necessary data, spatial information, and a logistic regression model to clarify the relationship between vegetation cover, household income and size, proximity to GI, vulnerable members, and perceived heat stress. Results demonstrated a significant, inverse relationship between perceived heat stress at various distances from GI (r = -0.72), indicating that households with higher income had less heat stress due to enhanced access to GI and/or adaptive practices. In Choto Bonogram, only 35% of respondents reported awareness of green infrastructure benefits; this contrasts with 58% in Chalk Kristan Para, which indicates a substantial knowledge discrepancy. Moreover, 72% of low-income respondents identified space to access vegetative shade as a barrier to utilizing GI. Mediation and interaction analyses indicated that access to GI significantly mediated the income–heat stress relationship and generated larger GI benefits for households with vulnerable individuals. These findings have important implications on the geographical distribution of GI and access for communities, the climate and GI education and engagement of communities, and the way planning processes in cities recognize the role of GI and the design and implementation of GI in rapidly growing urban areas.
Conclusion
The research explored the association between green infrastructure (GI) and perceived heat stress in three neighborhoods in Rajshahi City Corporation: Chalk Kristan Para, Choto Bonogram, and Baze Kazla. Utilizing statistical modelling and qualitative elements, the study yielded a diverse and comprehensive understanding of how urban vegetation, socioeconomic status, and behavior, in the context of neighborhoods, influenced heat vulnerability. Every neighborhood indicated a consistent association between perceived heat stress and GI. Chalk Kristan Para had lower levels of heat stress with greater access to GI and a higher average income. The neighborhood Choto Bonogram with the highest perceived thermal discomfort had the highest density and lower income, as well as with little vegetation. Baze Kazla, in the middle of these two neighborhoods, with moderate GI access and perceived heat stress. Statistical modelling revealed an important negative correlation of heat stress with GI proximity (r = -0.72) and household income (r = -0.53). The current study therefore highlighted the protective nature of green cover and ability to economically buffer urban heat at the neighborhood level. Behavioral and perceptual insights distinguished differences in behavior functions. The residents in all three neighborhoods indicated that 1 PM to 4 PM comprised the most uncomfortable period. It was evident that residents in Chalk Kristan Para were the most likely (frequently) to use vegetative shade. The level of awareness regarding GI benefits and support for tree planting was notably higher in Chalk Kristan Para (58%) compared to Choto Bonogram (35%), where residents were similarly constrained spatially and not sufficiently aware of green solutions to launch community engagement. Logistic regression assured that distance to the nearest GI, the frequency of GI usage, and perceived shading, decreased the odds of reporting high heat stress levels, whereas the vulnerability of household members significantly increased the likelihood of reporting high heat stress. Mediation analysis confirmed that income decreases heat stress by increasing access to GI and showed an interaction effect in terms of frequent GI usage was beneficial especially for households with elder and chronically ill members. These findings have substantial implications for policy. First and foremost, to support equitable distribution and consideration of distributed green infrastructure (GI) in urban adaptation policy, particular attention needs to be placed on how we equip the most populous and lowest income neighborhoods with GI interventions. Secondly, and directly related to the first point, we need to emphasize public education related to GI with a community capacity building approach at the outset of GI interventions. Thirdly, it should be an important element for public policy - beyond just municipal guidelines - to incentivize vertical greening, rooftop gardening, and small-scale urban forestry, especially where open space is limited [10], [16].. Lastly, since low-income residents in urban centers are disproportionately affected by heat stress, urban planning efforts must prioritize these vulnerable populations through targeted green infrastructure expansion, equitable access to cooling, and inclusive design of adaptation strategies. In summary, this study supports our conclusion that GI is beneficial as a spatial management tool to reduce urban heat stress. However, GI effectiveness is reliant on considerations related to social inequities, spatial distribution, and community engagement/support. Therefore, GI is a potential foundation for creating inclusive and sustainable urban development when taken to a whole-system, contextually sensitive, inclusive and participatory approach to urban planning.