Spectroscopy and Spectral Analysis, Volume. 42, Issue 8, 2572(2022)
Retrieval of Dust Retention Distribution in Beijing Urban Green Space Based on Spectral Characteristics
As the political center of China and a super large city of Beijing, Tianjin and Hebei, the urbanization process of Beijing has been rapid in the past 40 years, and the pollution problems of atmospheric particles and dust particles are prominent. It is of great practical significance to play the role of green space dust retention. This paper combines hyperspectral technology and remote sensing technology to retrieve the urban scale green space dust distribution. This study selected Euonymus japonicus, a common green space vegetation in Beijing, as the research object. The dust retention capacity, spectral reflectance and leaf area of leaf samples were obtained through outdoor sampling and indoor experiments. The original spectral curve and the first derivative of reflectance before and after dust retention were compared, and the effects of different dust retention on spectral reflectance were analyzed, To explore the band which is highly sensitive to dust retention of leaves. Using the spectral response function, the narrow band spectral reflectance data collected on the ground are transformed into the wide band spectral reflectance data of remote sensing satellite. The regression model of vegetation index ratio and dust retention capacity of corresponding satellite band is established. The regression model with the best fitting effect is selected as the dust retention inversion model. Combined with the green space range extracted from the GF-2 image, the dust retention distribution of Beijing urban green space was obtained using the dust retention inversion model. The spatial autocorrelation model is used to test the spatial aggregation characteristics. The results show that: in the 740~1 870 nm band, the spectral reflectance after dust retention is significantly lower than before dust retention. Dust retention has no obvious effect on the position of the red edge, yellow edge and blue edge but has pronounced effect on the “red edge amplitude” and “red edge area”. EVI index calculated by Sentinel-2 image has the highest correlation with dust retention. The coefficients of determination (R2) of the linear and quadratic regression models are 0.705 and 0.751, respectively. Based on the Sentinel-2 images on April 7, 2021, and June 3, 2021, the distribution trend of green space dust retention in the Beijing urban area is as follows: the city center is higher than the suburbs, the north is higher than the south, and the East is higher than the West. The central, northern and eastern parts of Beijing are prone to dust pollution. The pollution distribution is aggregated and not completely random.
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Ge WANG, Qiang YU, Di Yang, Teng NIU, Qian-qian LONG, [in Chinese]. Retrieval of Dust Retention Distribution in Beijing Urban Green Space Based on Spectral Characteristics[J]. Spectroscopy and Spectral Analysis, 2022, 42(8): 2572
Category: Orginal Article
Received: Jul. 7, 2021
Accepted: --
Published Online: Mar. 17, 2025
The Author Email: WANG Ge (GlennW0912@bjfu.edu.cn)