Temporal and spatial impact of lockdown during COVID-19 on air quality indicators in Haryana, India

[ad_1]

Table of Contents

Research area

The present study was conducted in Haryana state located between 27°39′ to 30°35′ N latitude and 74°28′ and 77°36′ E longitude as shown in Figure 1 . Haryana is a landlocked state in northern India. The study area comprises 22 districts of the state with a total area of 44,212 km² That is 1.3% of the total area of the country. Eastern region includes Panchkula, Ambala, Yamunanagar, Kurukshetra, Karnal, Kaithal, Panipat, Sonipat, Faridabad and parts of Jind, Rohtak, Jhajjar and Gurgaon districts. It covers about 49 percent area of the state which consists of Gurgaon tract, Rohtak tract, central plains and hilly areas. Western region includes Sirsa, Hisar, Bhiwani, Fatehabad, Mahendragarh, Rewari districts and parts of Jind, Rohtak, Jhajjar and Gurgaon. Industry, transport and economy developed rapidly. But the air pollution that comes from development has become a serious issue. Air quality in the state varies from good to severe during different months and seasons of the year. Current investigation and analysis of temporal and spatial characteristics of air pollutants is therefore important for improving air quality in Haryana.

Data sources

The monitoring station data used in this study was obtained from the CPCB (Central Pollution Control Board) site and included six air pollutants, namely, coarse particulate matter (PM).₁₀), fine particulate matter (PM_2.5), ozone (O₃), nitrous oxide (NO_X), sulfur dioxide (SO₂) and carbon monoxide (CO).²⁰. Data is retrieved every 1 hour, which is calculated as the average of measurements taken every 24 hours. Data not available for one or two districts i.e. Charkhi Daderi (2019), Mewat (2019 and 2020), Kaithal.

AQI is a dimensionless index that quantitatively describes air quality. According to the Central Control Pollution Board, the air quality standards implemented by the Ministry of Environment, Forests and Climate Change and the AQI was calculated by the AQI calculator provided by the CPCB site using various factors (PM).₁₀P.M_2.5And₃no_Xso₂and CO).

When the AQI is greater than 50 it represents increased major pollutant concentrations. There are six AQI categories and their ranges are 0–50, 51–100, 101–200, 201–300, 301–400 and 401–500. The respective pollution levels are good, satisfactory, moderate, poor, very poor and severe respectively. The higher the AQI, the worse the air quality.

The mathematical equation for calculating the sub-index of AQI is as follows:

$${\text{Ip }} = \frac{{\left( {{\text{IHI }}{-}{\text{ ILO}}} \right)}}{{\left( {{\text {BPHI }}{-}{\text{ BPLO}}} \right)}} \, \times \, \left( {{\text{CP }} – {\text{ BPLO}}} \right) \ , + {\text{ILO}}$$

where IP is the AQI for pollutant “P” (rounded to the nearest integer), CP is the actual ambient concentration of pollutant “P”, BPHI is the upper-end breakpoint concentration that is greater than or equal to CP, BPLO is the lower-end breakpoint concentration that is CP Less than or equal to, ILO sub-index or AQI value corresponding to BPLO, AQI value corresponding to IHI sub-index or BPHI²¹.

Data processing

Data analysis was done by keeping daily data of various pollutants in MS-Excel. Averages of daily data were converted to monthly individual pollutants to calculate the air quality index. Statistical analysis and Arc GIS were used to explore the temporal and spatial extent of air pollution. For spatial analysis, ARC GIS software (version 10.4 available in Geoinformatics Lab, Dept. of Agrometeorology, Chaudhary Charan Singh, Haryana Agricultural University, Hisar, Haryana. Environmental Systems Research Institute (ESRI), Redlands, California, USA)²².

[ad_2]

Source link