准噶尔盆地地表反照率时空变化特征及其影响因素分析

地表反照率变化影响地表辐射收支与能量平衡,从而对区域和全球气候产生影响.以准噶尔盆地为研究对象,利用MODIS卫星遥感数据产品MOD09A1反演地表短波反照率,结合气象数据和植被指数分析准噶尔盆地2001—2018年荒漠草地地表反照率时空变化特征及其影响因素.结果表明:准噶尔盆地地表反照率空间分布地域差异明显,地表反照...

Spatio-temporal variation characteristics of surface albedo and analysis of influential factors in the Junggar Basin

Surface albedo influences the balance between surface radiation and energy,affecting regional and global climates.The Moderate Resolution Imaging Spectroradiometer remote sensing data product MOD09A1 was used to retrieve surface short-wave albedo for the Junggar Basin.This was used to analyze the spatio-temporal variation and factors influencing the surface albedo of the desert grassland in the Junggar Basin during the period 2001-2018,based on meteorological data and the vegetation index.The results revealed evident differences in the spatial distribution of surface albedo across the study region,with an annual mean value of 0.303,high values in the northeast region and low values in the southwest region.The interannual variation of surface albedo showed a decreasing trend,with an average value of 1.4×10^?4.The decreased area accounted for approximately 52.8% of the total area,and its spatial distribution significantly varied across the four seasons.The spatial distributions in spring,summer,and autumn were similar,with the highest(0.551)and lowest(0.203)values observed in winter and summer,respectively.The surface albedo of the Altai Mountains in the northeast margin of the Junggar Basin drastically varied during the year:The normalized difference vegetation index(NDVI)value in the growing season was high in spring,significantly higher in autumn,and highest in summer.The surface albedo was negatively correlated with the NDVI and average temperature and positively correlated with precipitation in the majority of the study region.The correlation was as follows:Temperature>NDVI>precipitation.Further,there was a significant correlation between the retrieved results and measured values(R²=0.8908,P<0.01),and the root mean square error was 0.014.This study provides a theoretical basis for understanding the land-surface characteristics of the Junggar Basin in Northern Xinjiang,and it objectively evaluated the surface changes in arid regions and determined the positive and negative feedback response mechanisms under global climate change.