Hochschule Rhein-Waal Rhine-Waal University of Applied Sciences Faculty of Communication and Environment

Prof. Dr. Ute Hansen Dr. Maheswar Rupakheti

IMPACT OF COVID-19 LOCKDOWN ON PARTICULATE MATTER (PM) CONCENTRATION IN ’S AMBIENT AIR

MASTER THESIS

By

SHIRISH MAHARJAN

Hochschule Rhein-Waal Rhine-Waal University of Applied Sciences Faculty of Communication and Environment

Prof. Dr. Ute Hansen Dr. Maheswar Rupakheti

IMPACT OF COVID-19 LOCKDOWN ON PARTICULATE MATTER (PM) CONCENTRATION IN NEPAL’S AMBIENT AIR

A Thesis submitted in Partial Fulfilment of the Requirements of the Degree of

Master of Science In Information Engineering and Computer Science

by Shirish Maharjan Nohlstr. 134 46045 Oberhausen

Matriculation Number: 24906

Submission Date: 24.11.2020 ii

ACKNOWLEDGMENTS

First of all, I would like to thank my professor who has helped me analyze the data and has helped me entirely through this master thesis. I would like to express my gratitude to my professor Prof. Dr. Ute Hansen for guiding me to complete this thesis. Without her help and guidance, this thesis wouldn’t have completed. Secondly, I would like to thank Dr. Maheswar Rupakheti (Ph.D.; Institute for Advanced Sustainability Studies (IASS)) for his precious and important guidelines through this entire thesis. This thesis would not have been possible without his timely guidance and advice. I am deeply thankful to my two supervisors for guiding me and help me complete my master thesis.

Secondly, I want to thank the Government of Nepal, Department of Environment Air Quality Monitoring, and NASA Prediction of Worldwide Energy Resources for providing me meteorological data of Nepal during this particular period. Without these data, the analysis would not have been completed and I am very much thankful to them for providing these necessary data to complete this thesis.

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ABSTRACT

The pandemic COVID-19 has drastically changed the lives of every human being in most of the countries in the world. Lockdown has been implemented in various countries to prevent the virus. Lockdown has prohibited people to go outside of their houses, closed industries and factories restricted the free movement of public and private vehicles, air transportation whereas emergency vehicles and flights were allowed. On the optimistic side, lockdown might have a beneficial impact on Nepal’s ambient air quality as there has been less consumption of fossil fuels during the lockdown period. This study evaluated air quality data provided by the authorities of Nepal and analyzed the monthly mean PM2.5 concentration detected in the ambient air of 7 major cities of Nepal during March, April, and May of the year 2020 and compared these with respective months of the year 2019 in order to figure out how COVID-19 lockdown has affected Nepal’s ambient air. Similarly, this study compared the monthly mean PM2.5 levels to air quality standards of no concern published by the WHO for the particulate matter. Furthermore, meteorological data were evaluated in order to investigate how meteorological conditions have affected Nepal’s ambient air quality during the lockdown period. Beside monthly averages, line charts of 24h mean values of PM2.5 concentrations and meteorological data have been plotted to visualize characteristics of the variation with time. The PM2.5 concentration during March, April, and May 2020 was found to be lower in nearly all of the 7 cities of Nepal as compared to March, April, and May 2019. The highest PM2.5 concentration decrement was found in Nepalgunj (72.78%) followed by (46.2%) during May 2020 as compared to May 2019. To some extent, at a given level of precipitation, the PM2.5 concentration tended to be lower in 2020 than in 2019. COVID-19 lockdown might have contributed to lower the PM2.5 concentration in some extent. In accordance with this the h