Simulation and Analysis of the Topographic Effects on Snow-Free Albedo over Rugged Terrain

作者:Hao, DL (Hao, Dalei)[ 1,2 ] ; Wen, JG (Wen, Jianguang)[ 1,2,3 ] ; Xiao, Q (Xiao, Qing)[ 1,2 ] ; Wu, SB (Wu, Shengbiao)[ 1,2 ] ; Lin, XW (Lin, Xingwen)[ 1,2 ] ; Dou, BC (Dou, Baocheng)[ 1 ] ; You, DQ (You, Dongqin)[ 1 ] ; Tang, Y (Tang, Yong)[ 1 ]

REMOTE SENSING

卷: 10  期: 2

文献号: 278

DOI: 10.3390/rs10020278

出版年: FEB 2018

文献类型:Article

摘要

Topography complicates the modeling and retrieval of land surface albedo due to shadow effects and the redistribution of incident radiation. Neglecting topographic effects may lead to a significant bias when estimating land surface albedo over a single slope. However, for rugged terrain, a comprehensive and systematic investigation of topographic effects on land surface albedo is currently ongoing. Accurately estimating topographic effects on land surface albedo over a rugged terrain presents a challenge in remote sensing modeling and applications. In this paper, we focused on the development of a simplified estimation method for snow-free albedo over a rugged terrain at a 1-km scale based on a 30-m fine-scale digital elevation model (DEM). The proposed method was compared with the radiosity approach based on simulated and real DEMs. The results of the comparison showed that the proposed method provided adequate computational efficiency and satisfactory accuracy simultaneously. Then, the topographic effects on snow-free albedo were quantitatively investigated and interpreted by considering the mean slope, subpixel aspect distribution, solar zenith angle, and solar azimuth angle. The results showed that the more rugged the terrain and the larger the solar illumination angle, the more intense the topographic effects were on black-sky albedo (BSA). The maximum absolute deviation (MAD) and the maximum relative deviation (MRD) of the BSA over a rugged terrain reached 0.28 and 85%, respectively, when the SZA was 60 degrees for different terrains. Topographic effects varied with the mean slope, subpixel aspect distribution, SZA and SAA, which should not be neglected when modeling albedo.

通讯作者地址: Wen, JG (通讯作者)

Chinese Acad Sci, Inst Remote Sensing & Digital Earth, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China.

通讯作者地址: Wen, JG (通讯作者)

Univ Chinese Acad Sci, Beijing 100049, Peoples R China.

通讯作者地址: Wen, JG (通讯作者)

JCGCS, Beijing 100875, Peoples R China.

地址:

[ 1 ] Chinese Acad Sci, Inst Remote Sensing & Digital Earth, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China

[ 2 ] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[ 3 ] JCGCS, Beijing 100875, Peoples R China