Predicting PM_2.5 levels over the north of Iraq using regression analysis and geographical information system (GIS) techniques

Figures & data

Figure 1. Location of the study area; (a) Iraq, (b) the borders of the two provinces in northern Iraq including train and test points, (c) the experimental area, (d) the experimental and test area including 20 test points (5.6 km²).

Figure 2. The procedures employed in the research.

Figure 3. The air quality multimeter.

Table 1. Daily PM_2.5 and PM₁₀ levels μg/m³ (U.S. Environmental Protection Agency).

PM2.5(μg/m^3)	PM10(μg/m^3)	Air Quality
0 − 12.0	0-54	Good
12.1-35.4	55-154	Moderate
35.5 − 55.4	155-254	Unhealthy to sensitive groups of people
55.5 − 150.4	255-354	Unhealthy air
150.5 − 250.4	355-424	Very unhealthy air
250.5 − 500.4	425-504	Hazard

Figure 4. IDW outputs of July 2019 datasets for (a) PM_2.5, (b) PM₁₀, (c) Temperature, (d) Humidity, (e) Wind.

Figure 5. The PM_2.5 distribution map based on the MODIS image.

Table 2. Regression outputs of July 2019 dataset.

Parameters	Intercept Coefficient	Parameters Coefficients	P-value	Standard Error
PM10	−25.6878	0.276	0.002228	0.082956
Temperature		1.405	2.52E-05	0.284294
Humidity		0.123	0.011793	0.046197
Wind		−5.563	0.000939	1.521399

Table 3. Regression outputs of February 2020 dataset.

Parameters	Intercept Coefficient	Parameters Coefficients	P-value	Standard Error
PM10	−124.074	1.754	0.002082	0.478542
Temperature		− 1.798	0.008828	0.603418
Humidity		1.016	0.000699	0.242964

Figure 6. (a) Prediction map of PM_2.5 in Kirkuk and Sulaymaniyah provinces of July 2019. (b) Prediction map in Kirkuk at an area of 5.6 km² of July 2019. (c) Prediction map in Kirkuk at an area of 5.6 km² of February 2020.

Figure 7. PM2.5 cross-validation, (a) Predication validation at 5.6 km2 of July 2019, (b) Predication validation north of Iraq of July 2019, (c) Predication validation at 5.6 km2 of February 2020.

Figure 8. Model-validation in Kirkuk at 5.6 km² of; (a) July 2019 (b) February 2020.

Data availability statement

The data that support the findings of this study are available from the corresponding author, Bahareh Kalantar, upon reasonable request.