The solution to cooling the intense heat in urban areas might be found in the surrounding rural regions, according to a new study by scientists from the University of Surrey and Southeast University in China.
Using two decades of data, the researchers demonstrated how rural areas can significantly reduce city temperatures, offering valuable insights that could be particularly beneficial for rapidly urbanizing countries like Nigeria.
Rural Influence on Urban Heat Islands
Urban heat islands (UHIs) occur when cities experience higher temperatures than their rural surroundings due to human activities and dense infrastructure. This phenomenon is prevalent in Nigerian cities like Lagos, Abuja, and Port Harcourt, where rapid urbanization exacerbates heat retention.
The study revealed that the most substantial cooling effects happen when the rural areas around a city extend for at least half the city’s diameter.
Professor Shi-Jie Cao, the lead author and visiting professor at the University of Surrey’s Global Centre for Clean Air Research (GCARE), explained the findings: “While we often focus on urban green spaces, wetlands, or waterways to cool down cities, our study shows that the land use outside a city can significantly affect downtown temperatures.”
Practical Recommendations for Nigerian Urban Planners
The researchers found that urban overheating was best mitigated by:
- Connecting Patches of Rural Land: Ensuring that rural areas around cities are continuous rather than fragmented.
- Scattered Woodland: Planting woodlands around cities rather than concentrating them in one area.
- Larger Lakes: Prioritizing fewer, larger lakes over many small bodies of water.
These strategies can be tailored to Nigeria’s unique geographical and climatic conditions, offering a sustainable approach to cooling urban areas.
How Rural Land Cools Cities
As warm air rises in a city, it creates a low-pressure layer close to the ground, drawing cooler air from the surrounding rural areas. This cooling process is influenced by the city’s size and the nature of the neighboring rural land.
By comparing satellite data from 30 Chinese cities between 2000-2020, scientists could see how ground temperature and land use patterns contributed to cooling.
Professor Prashant Kumar, another author of the study and co-director of Surrey’s Institute of Sustainability, stated, “Our detailed analysis confirms that belts of rural land can help cool urban centers. We hope planners and governments can use our findings to make urban communities more resilient against rising global temperatures.”
Implications for Nigeria
Nigeria’s urban centers, which are rapidly growing, face significant challenges related to UHI effects. Implementing the study’s findings could have several benefits:
- Health Benefits: Reduced temperatures can lower the incidence of heat-related illnesses.
- Energy Savings: Cooler urban areas require less energy for air conditioning, leading to reduced greenhouse gas emissions.
- Improved Livability: Lower temperatures can enhance the overall quality of life in urban areas.
Related Article: Nigeria’s Hot Cities: Can Cooler Roofs Make a Difference?
Bottom Line
By adopting a holistic approach that integrates urban and rural planning, Nigerian cities can become more sustainable and resilient to climate change. The insights from this study provide a valuable roadmap for Nigerian policymakers, urban planners, and environmentalists working to mitigate the adverse effects of urban heat
Research Article Source: Nature Cities
