Urban Climate News - FAU

Urban Projects 1
Table 1: Summary of site characteristics.
Station Site Lat. (N) Long. (E) Elev. (m) LCZ Description
1 Oja Oba 07 o 15.250’ 005 o 11.672’ 347 2 Compact midrise
2 Airport 07 o 14.881’ 005 o 18.001’ 329 10 Sparsely built
3 Ijapo Est 07 o 15.983’ 005 o 12.512’ 342 6 Open-set lowrise
4 NTA Ondo Rd 07 o 15.030’ 005 o 07.940’ 373 14 Bush/scrub
5 Aratusin 07 o 14.546’ 005 o 10.682’ 347 6 Open-set lowrise
6 Ayedun 07 o 15.708’ 005 o 11.149’ 351 3 Compact lowrise
7 Oshinle 07 o 14.156’ 005 o 11.442’ 361 3 Compact lowrise
8 Ijoka 07 o 12.093’ 005 o 12.030’ 359 3 Compact lowrise
9 Ala Qtrs 07 o 14.181’ 005 o 12.480’ 369 6 Open-set lowrise
10 Alagbaka Park (Deciduous) 07 o 15.018’ 005 o 12.444’ 367 16 Close-set trees
11 Alagbaka GO (Asphalt) 07 o 14.479’ 005 o 12.994’ 367 5 Open-set midrise
12 Alagbaka Est 07 o 14.252’ 005 o 13.495’ 367 6 Open-set lowrise
13 Oba ile 07 o 15.343’ 005 o 14.841’ 367 6 Open-set lowrise
14 FUTA lawn 07 o 18.234’ 005 o 08.181’ 367 5 Open-set midrise
15 FUTA tree (Evergreen) 07 o 18.222’ 005 o 08.173’ 367 15 Open-set trees
16 FUTA Obk (Concrete) 07 o 17.586’ 005 o 08.975’ 367 3 Compact lowrise
17 Shagari Est 07 o 17.290’ 005 o 11.601’ 367 6 Open-set lowrise
The climatic condition of Akure follows the pattern
of southwestern Nigeria where the climate is influenced
mainly by the rain-bearing southwest monsoon winds
from the ocean and the dry northwest winds from the
Sahara Desert. Akure experiences a warm humid tropical
climate, with two distinct seasons, the rainy and dry
seasons. The rainy season lasts for about seven months,
April to October. It records an average rainfall of about
1500 mm per annum.
Annual average temperatures range between 21.4 o C
and 31.1 o C, and the mean annual relative humidity is
about 77% (based on 1980-2010 data from the Nigerian
Meteorological Agency). Vegetation is of the tropical
rainforest type. Akure lies on a relatively flat plain of
about 360 m above sea level within the Western Nigerian
plains.
Methodology
The analysis of LULCC is predicated basically on the
use of remote sensing and GIS techniques. The study
utilizes diverse forms of data. Remotely sensed data −
Landsat TM satellite imageries of Akure in 1986, 2002
and 2007 were obtained from the Global Land Cover
Facility. A year-long dataset from in situ measurements
of air temperature and humidity, sampled at 5 minute
intervals, was obtained from shielded portable Lascar
EL-USB-2 temperature / humidity data loggers that were
mounted on lamp posts above head height (3 m) at anurban
site and a rural reference site.
The spatio-temporal variability of the canopy-level
urban heat island (UHI) of Akure is examined on the basis
of observations using shielded thermochron i-button
temperature loggers. Temperature data obtained from
the seventeen selected sites, which include different urban
areas (Central Business District-CBD, high-density
and low-density housing) are compared with ‘rural’ reference
data and analysed with respect to meteorological
variables and differences in land use. The land use
classification followed the urban climate zone scheme of
Stewart and Oke (2010), as shown in Table 1.
ISSUE NO. 46 DECEMBER 2012 INTERNATIONAL ASSOCIATION FOR URBAN CLIMATE