Azura-Edo Independent Power Plant Environmental Impact ... - IFC

climate but straddles the Tropical Wet and Dry climate (Aw) climate where
rainfall is a key climatic variable. The two key air masses are the dry Tropical
Continent air mass originating from the Sahara in the north, and the moist
Tropical Maritime from the Atlantic Ocean in the south. The two air masses are
separated by an Inter-Tropical Discontinuity (ITD) zone. This zone is
characterised by high levels of rainfall which move north and south with the
seasonal movements of the sun.
There are four characteristic seasons that are generally observed across Nigeria:
• An extended dry season from mid December to late March;
• An extended wet season from early April to the end of July;
• A short dry season running from late July to late August; and
• A short wet season running from September to November.
Nigeria’s climate varies across the country with tropical humidity in the centre,
an equatorial climate across the south, and arid areas in the north. Edo State is
characterised by a humid tropical climate in the south, and sub-humid climates
in the north (Uyigue and Agho, 2006). The in situ weather parameters were
sampled at ten sampling locations (A1 – A10) during the wet season using a
handheld Kestrel (4500NV model) weather meter (Table 4.1).
Table 4.1
Wet Season Measurement of Weather Parameters
Parameters A1 A2 A3 A4 A5 A6 A7 A8 A9 A10
Sampling Date 25-07 25-07 25-07 25-07 25-07 25-07 25-07 26-07 26-07 26-07
(dd/mm/2011)
Ambient Air 26.0 25.2 26.2 24.9 25.0 24.2 25.0 24.8 25.5 26.5
Temperature ( 0 C)
Humidity (%) 83.3 92.3 83.0 96.5 93.0 87.6 74.2 98.1 99.4 99.3
Wind speed (m/s) 0.2 0.3 0.2 0.9 2.8 4.7 2.8 3.0 2.1 2.0
Heat Index ( 0 C) 27.8 28.1 28.0 26.2 26.7 26.0 30.6 27.3 22.8 25.1
Dew point ( 0 C) 23.1 24.6 23.1 23.5 24.1 24.3 24.6 24.3 22.8 23.1
Wet bulb ( 0 C) 23.5 23.4 25.1 24.9 25.0 25.1 24.8 24.5 23.1 23.1
Altitude (ft) 352 351 335 353 356 365 370 343 353 378
4.3.1 Temperature
The results of the wet season sampling were supported by the literature review,
as discussed below.
The key factors that influence temperature in the area are the movement of the
sun, wind speed and direction, and land configuration. During 2011 (thus far)
the average temperature reached a maximum of 30.6 °C and a minimum of 24.8
(1) The IFC requires an assessment of air quality impacts to 10km from the proposed Project site. Given the stack height and
plant design, however, the maximum impacts will occur at a maximum of 1-2 km from the plant and thus setting the receptor
grid at 5km from the plant is adequate to ensure that the maximum impacts are assessed.
AZURA EDO IPP
4-2
DRAFT EIA REPORT