Effect of Atmospheric Haze Based on Multi-source Remote Sensing Data Considering the Size Effect of Landscape Sources and Sinks

Abstract

Based on a geo-weighted regression model, this study analyzes the relationship between the landscape patterns of sources and sinks in urban areas and atmospheric haze pollution. First, the classification result of the study area is divided into a number of square grids with side lengths of 2-9 km. Heterogeneity indices at different scales are calculated and compared to select an optimal scale for the following analysis. Then, the category level landscape indices, such as PLAND, PD, COHEDION, LPI, and FRAC_MN, are calculated in each grid. The aerosol optical thickness (AOD) of Wuhan is used to represent the degree of atmospheric haze pollution. Furthermore, the mean value of the pixels in each grid is regarded as the value of the grid's center. Next, the landscape sources and sinks of atmospheric haze pollution are selected based on the analysis of the correlation between landscape indices and AOD. To make the following analysis more efficient, the indices selected previously are determined using their correlation coefficients. Finally, the geo-weighted regression analysis model is used to analyze the relationship between the landscape indices of the category level and AOD. In addition, the influences of industrial, commercial, and residential areas on haze pollution are analyzed based on the result of the classification of urban functional areas. The results show that the heterogeneity of the whole landscape is most obvious at a 6 km scale, so 6 km is the optimal scale for the analysis. The landscape sources of atmospheric haze pollution are the buildings, and the landscape sinks are shrubs and woodland. Reducing the proportion of landscape source area and increasing the degree of fragmentation can cut down aerosol optical thickness. Distributing the landscape sources and sinks evenly and interspersedly could effectively reduce aerosol optical thickness, which represents atmospheric haze pollution. For Wuhan City, the main sources of haze pollution are commercial and residential areas in the city center, representing public sources. Since it is not easy to adjust existing facilities and infrastructure, adjusting built-up areas slightly and planning reasonably for those areas that are not yet built up can reduce atmospheric haze pollution.