中国不同土地利用类型分光辐射地表反照率研究

选取2000～2015年遥感反演的地表反照率数据及2000和2015年两期土地利用数据,采用经典统计学方法分析不同土地利用类型分光辐射地表反照率的特征及其年际变化趋势。为了解土地利用类型的反照率特征、认知区域气候或陆面模式中能量模块的相关分光辐射变量的物理过程提供科学依据。结果表明:不同的土地利用类型具有差异明显的地表反照率特征,同种土地利用类型地表反照率的差异甚至超过了不同类别土地利用类型之间的差异,说明了地表反照率巨大的空间异质性;大部分土地利用类型在短波总辐射及分光辐射地表反照率满足:近红外>短波>可见光,说明短波地表反照率的上限值更大程度上取决于近红外波段的地表反照率;研究时段内,各土地利用类型在3个波段地表反照率分别呈现出了不同的变化趋势,但是大部分土地利用类型分光辐射地表反照率的年际变化速率较小,基本保持稳定。

Study on Surface Albedo of Spectral Radiation of Different Land Use Types in China

The change of surface albedo directly affects the radiation balance and surface heat budget,but it is limited by the lack of temporal and spatial discontinuity of remote sensing inversion data,the analysis of surface albedo on large-scale areas still faces many uncertainties.Moreover,the current researchesalways focus on short-wave albedo and few studies on surface albedo involving the visible and near-infrared bands.Select surface albedo data of 2000~2015 remote sensing inversion and land use data for 2000 and 2015,the classical statistical method was used to analyze the characteristics of surface albedo of different land use types and their inter-annual variation trend.Provide a scientific basis for understanding the albedo characteristics of land use types,the physical processes of the relevant spectral splitting variables of energy modules in cognitive regional climates or land surface models.The results show that different land use types have different surface albedo characteristics,and the difference in surface albedo of the same land use type even exceeds the difference between different types of land use types,indicating the spatial heterogeneity of the surface albedo sexuality.Most land use types meet the surface albedo of short-wave total radiation and spectral radiation: near-infrared>short-wave>visible,indicating that the upper limit of short-wave surface albedo depends more on the surface albedo in the near-infrared.During the period,the albedo of each land use type showed different trends in the three bands,but the annual inter-annual rate of surface albedo of most land use types was relatively small and remained basically stable.