NKOMATI ANTHRACITE (PTY) LIMITED - Sentula Mining

Environmental Impact Assessment Report: Nkomati Anthracite (Pty) Limited,
Madadeni Opencast Mining Project Page 15
August 19.6 28.3 11.0 39.3 20.1
September 21.9 29.6 14.2 46.7 22.8
October 24.4 31.6 17.2 44.8 27.5
November 25.3 31.9 18.9 44.8 27.8
December 26.7 33.2 21.2 47.7 27.8
Average 23.1 30.4 15.8 47.7 27.8
3 . 1 . 2 . 4 W i n d D i r e c t i o n a n d S p e e d a t t h e M i n e
The nearest wind recording station for which data is available is situated at Nelspruit. Records have
been kept for the period 1959 to 1988 regarding direction, frequency and velocity for each of the eight
main directions. This is indicated in Table 6.
Month
NKOMATI ANTHRACITE (PTY) LIMITED
Table 6: Average wind speed and direction
N NE E SE S SW W NW
n v n v n v n V n v n v n v n v
Jan 17 2.6 160 3.6 66 3.7 84 4.3 5 3.7 26 3.8 23 3.0 38 3.6
Feb 16 2.4 142 3.4 76 3.6 92 4.1 7 2.9 34 3.5 27 2.7 33 3.1
Mar 18 2.7 123 3.4 60 3.5 93 3.9 4 3.2 27 3.6 30 2.7 42 3.0
Apr 15 2.4 112 3.3 45 3.0 69 3.9 4 2.9 31 3.7 39 2.8 51 3.3
May 17 2.7 96 3.3 45 3.4 68 4.0 3 2.8 37 3.8 63 3.2 93 3.4
Jun 16 2.7 86 3.2 43 3.0 60 3.8 6 3.4 60 4.2 51 3.2 102 3.2
Jul 17 3.0 102 3.5 45 3.1 70 4.2 5 3.2 49 3.6 47 3.0 81 3.3
Aug 18 3.3 146 3.7 75 3.9 70 4.3 5 4.0 39 4.0 47 3.1 78 3.3
Sept 25 3.3 226 3.9 79 3.8 70 4.5 3 4.6 37 3.8 37 2.9 50 3.2
Oct 25 3.6 207 4.0 76 4.1 84 4.5 6 3.7 22 3.4 19 3.6 28 3.2
Nov 18 2.9 191 3.7 78 3.9 89 4.0 9 3.5 29 3.9 17 3.5 25 3.5
Dec 16 2.7 172 3.6 81 3.7 86 4.3 10 3.0 29 3.8 20 2.9 28 3.5
Avg 18 2.9 147 3.6 64 3.6 78 4.1 6 3.4 35 3.8 35 3.1 54 3.3
3 . 1 . 2 . 5 M e a n M o n t h l y E va p o r at i o n
The gross annual “A” pan evaporation recorded at Piet Retief is 1 635 mm. It is evident that there is a
monthly moisture deficit throughout the year; this results in an average annual deficit of 870 mm.
Furthermore it is also observed that the maximum potential water loss occurs during August,
September and October.
Table 7: Mean monthly evaporation for the region
MONTH Evaporation (mm)
January 182
February 156
March 151
April 117
May 97
June 82
July 92
August 119
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