EIA Studies of 3 Pre-Identified Hazardous Waste Disposal Sites in ...

Rapid EIA Studies of 3 Pre-identified Hazardous Waste Disposal Sites in NCT - Delhi:
Table 4.17: Average Wind Speed in NCT - Delhi
Months Mean wind speed (km/h)
January 8.3
February 10.1
March 10.7
April 11.2
May 12.8
June 13.7
July 9.9
August 8.3
September 8.9
October 6.1
November 6.1
December 7.4
Mean 9.5
The windrose diagram for NCT- Delhi is shown in Fig 4.26.
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It can be inferred from the above tables and windrose diagram, that wind speeds are
higher in summer and mid-monsoon, and are associated with higher mixing heights
providing high ventilation.
The most prevalent direction of wind is towards West and towards North-West
having average wind speed ranging from 9.5 Km.p.h.
4.7.6. Special Weather Phenomena
April to June is the period with the highest incidence of thunderstorms and duststorms.
Violent squalls (andhis) often accompany such storms. Where some of the
thunder storms are dry, others are accompanied with heavy rains and occasionally
with hail. In association with western disturbances a few thunderstorms occur in the
winter months also. Fogs occur sometimes in the winter season.
4.7.7 Ambient Air Quality
Secondary Data
Ambient air quality monitoring is being carried out regularly at nine stations in NCT -
Delhi. Out of these three stations viz, Ashok Vihar, Shahzada Bagh, Najafgarh road
falls within our study areas. The annual average ambient air quality at some of the
stations falling within the study area are given below in table 4.18 & 4.19 as given
below:
Table 4.18: Ambient Air Quality around site II: Wazirpur CETP Site
Station SPM, µg/m 3 SOx, µg/m 3 NOx, µg/m 3
Ashok Vihar 425 12 28
Najafgarh road 400 20 36
Shahzada Bagh 475 18 45
Source: State of Environment Report on Delhi 2001, Dept of Environment, NCT- Delhi.
Environment Division, National Productivity Council, New Delhi
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