胡焕庸线两侧气溶胶光学厚度时空分布特征及其与土地利用响应的研究

利用Aqua/MODIS C006大气气溶胶光学厚度(AOD)产品分析胡焕庸线两侧时空分布与变化特征,并结合2010年土地利用类型探究二者之间的响应.结果表明:(1)胡焕庸线一方面可作为中国气溶胶分布的重要分界线,两侧AOD呈现东高西低的特点;另一方面,亦可作为AOD成因的分界线,胡焕庸线东侧气溶胶主要以人为活动排放为主,胡焕庸线西侧气溶胶主要是以沙尘为主的自然气溶胶构成.(2)10年来,胡焕庸线东侧AOD以0.0768/10 a的速率下降,高值区面积也以6.41万km2·a-1的速率逐年萎缩;而胡焕庸线西侧只呈现微弱的下降趋势,高值区、低值区面积无显著变化.(3)胡焕庸线以东地区,土地覆盖类型为耕地和建设用地的区域AOD较高.而在胡焕庸线以西地区,AOD与未利用土地及其周边草地地区的响应较好.

Distributions and changes of aerosol optical depth on both sides of HU Huanyong Line and the response to land use and land cover

Aerosol optical depth (AOD) collection 6 products from Moderate Resolution Imaging Spectroradiometer (MODIS) of Aqua were used to analyse the spatiotemporal distribution and variation on both sides of Hu Huanyong line over China during June 2006 to December 2015. The response between AOD and land use and land cover (LUC) of China in 2010s was also studied. Results showed that the Hu Huanyong line can act as an important line for distinguishing AOD distribution patterns and aerosol contributing factors. AODs with high values in the east and low values in the west of Hu Huanyong line mainly attribute to the emission from human activity in the east side, while sand dust in the west side. In the past decades, AODs in the east side have declined by 0.0768/10 a and the areas of high values have also shrinked by 64.1 thousand km·a^-1. In the west side, by contrast, it showed slight decrease in AOD values and almost the same areas of both high and low values. Relationships between AOD and LUC indicate that arable land and construction areas are likely to associate with higher AOD in the eastern side whereas AODs have a good response to unused lands and grassland areas on the other side.