Page 42 - Msingi Afrika Magazine Issue 25
P. 42
The En vir onment
The Environment
The annual mean temperature including rivers, streams,
in Nairobi has increased by and green spaces, have been
approximately 1.4°C over the disrupted or paved over to
past few decades due to the make way for roads, buildings,
intensification of UHIs. and parking lots. These natural
During the daytime, UHI drainage systems served
effects has led to land surface as critical mechanisms for
temperature differences of 2°C water absorption and runoff
Ronald Mbiu as exhibited in the graph below management, reducing the risk
I offer sustainable design and construction services between the period of 2000 to of flooding during heavy rains.
as a construction project manager and quantity
surveyor. I focus on using sustainable materials 2010 and 2010 to 2020 using
for building. You can reach me on the NASA ARSET’s MODIS. The construction of
rnmbiu1@gmail.com
Likewise, Nairobi’s nighttime impermeable surfaces and
LSTs are rising as well, with haphazard storm water
has not always been given differential temperature of management have led to
due consideration in urban 0.5°C exhibited within the surface water runoff that
planning. same duration periods and overwhelms the city’s drainage
Rising Urban Heat shown in the graph below. infrastructure. As a result,
Temperatures: Furthermore, the construction Nairobi faces increased
of tall buildings often creates instances of flash floods,
One of the most noticeable “urban canyons” that trap heat waterlogging, and erosion
consequences of the and limit airflow, exacerbating during rainy seasons. These
construction boom in Nairobi the warming effect. This rise drainage problems not only
is the increase in urban heat in urban heat temperatures is disrupt daily life but also pose
temperatures. Urban Heat not merely a matter of comfort; threats to public health and
Islands (UHIs), which are it has significant health safety.
areas of elevated temperatures implications, particularly for
within cities, have become vulnerable populations, as heat- The Need for a Balanced
more pronounced. The removal related illnesses become more Approach:
of greenery, such as grassy common. While the construction boom is
lawns and trees, has resulted undoubtedly driving economic
in greater absorption of solar Drainage Problems in growth and urban development
radiation by concrete and Nairobi: in Nairobi, it is essential to
asphalt. These heat-absorbing adopt a balanced approach that
surfaces then release heat Nairobi has experienced a takes into account the value of
slowly, causing higher daytime surge in drainage issues as a nature-based solutions.
and nighttime temperatures. direct result of the construction
To put this into perspective, boom. The city’s once-effective Sustainable urban development
let’s examine some figures: natural drainage systems, can coexist with green spaces,
42 | we tell the true afrikan story
