دانلود رایگان مقاله ارزیابی تنوع ذرات در طول 2011-2015 بر فراز ایستگاه گرمسیری آگرا

Abstract

Air quality over Agra is deteriorating and causing a serious threat to people residing in the city as well as to World heritage site- Tajmahal. In the present study, daily average concentrations of Suspended Particulate Matter (SPM) and Respirable Suspended Particulate Matter (RSPM) were analysed over a period of 2011–2015 at four stations in Agra city, namely: Taj, Itmad-Ud-Daula, Rambagh and Nunhai. The concentrations are above threshold values when compared to specify standards for a healthy environment (by India, US, WHO, EU and China - Class I and Class II) for all the seasons except monsoon and the values are highest in the month of November and lowest in the month of August and September. Variation of RSPM and SPM were found to be positively correlated with each other with values of 0.76 (Taj), 0.72 (Itmad-Ud-Daula), 0.69 (Rambagh), 0.77 (Nunhai). The study illustrates that the levels of SPM and RSPM are not showing any decreasing trend over Agra even after closing of industries and taking other precautions inside the city by Government of India. The study clearly identifies that local control of pollution sources are not enough and pollution is being transported from nearby regions to keep the daily pollution value higher than threshold. Source regions of transported pollutants over Agra have been analysed by using Weighted Potential Source Contribution Function (WPSCF) for both SPM and RSPM. Wavelet analysis of monthly averaged values of RSPM and SPM data sets has shown the existence of semi-annual and annual periodicity over the study region.

5. Conclusions

We have analysed the daily average concentration variations of RSPM and SPM over Agra for the period 2011e2015. Four stations Taj, Itmad-ud-Daula, Rambagh and Nunhai were considered to observe the daily average variation, seasonal variation of RSPM and SPM. The analysis depicted that the average annual concentrations of RSPM (164.9e245.08 mg/m3 ) and SPM (298.15e526.58 mg/m3 ) for the four sites were found to be very high when compared to the standards specified by Pollution Control Board of India. Higher values for daily average concentrations of RSPM have been observed in post monsoon and winter season, whereas for SPM higher values are persisting in pre monsoon and post monsoon season. Winter season is also accounting the high values of SPM, however, less than post monsoon values. Monsoon has been identified as the season with lowest values of RSPM and SPM at the study region. There is no trend existing in the time series of SPM and RSPM. The daily average values are still high at all stations and crossing threshold limits for the study period. The results are showing that even after taking measures to reduce pollution at the site by Government of India, high values are persisting over time.