YI Wei, YANG Dong, LI Xirong

（College of Geography and Environmental Science, Northwest Normal University, Lanzhou, 730070, China）

Abstract: Constructing a model for the relationship between PM2.5 concentration and related factors has been regarded as one effective means to obtain the continuously PM2.5 concentration data in the economic zone of arid regions. In this study, the Economic Zone in Northern Tianshan Mountain Slope was taken as the research object. Based on the data of monitored PM2.5 concentration, aerosol optical depth(AOD) acquired by the moderate-resolution imaging spectroradiometer(MODIS) and the meteorological data, the geographically weighted regression model (GWR) was used to invert the PM2.5 concentration in the study area from March to November in 2018, furthermore, the spatiotemporal variation characteristics was analyzed. The results showed that: (1) compared with the multiple linear regression model(MLR), the inversion effect of PM2.5 concentration by using the GWR model in the Economic Zone of Northern Tianshan Mountain Slope illustrated a better result, and the coefficient of determination R2, mean absolute error (MAE) and the root mean square error (RMSE) were 0.897, 4.569 μg/m3 and 5.627 μg/m3, respectively, which were remarkably better than 0.819, 5.825 μg/m3 and 7.731 μg/m3 of MLR model; (2) the PM2.5 concentration in the Economic Zone of Northern Tianshan Mountain Slope indicated a concave type for the monthly time-scale, with the highest in November (59.50 μg/m3), then followed by March and October, and the lowest in September (17.92 μg/m3). For different seasons, it decreases in the order of autumn (September-November)>spring(March-May)>summer(June-August), and a characteristic of fluctuation with downward trend in spring, stable at a low level in summer, sharply increase in autumn, was observed; (3) in terms of spatial distribution, the PM2.5 concentration in the study area displayed the characteristics of "higher in the east and lower in the west", and the peak value appeared near Urumqi, indicating that the PM2.5 pollution in the eastern part of the economic belt was relatively serious, especially in Urumqi.

Key words: geographically weighted regression model; the Economic Zone of Northern

EARTH AND ENVIRONMENT Vol.49, No.1, Tot No.339, 2021, Page 51-58