【摘要】 以4期Landsat TM/OLI为遥感数据源,采用像元二分模型估算植被覆盖度,运用转移矩阵、地学信息图谱和重心迁移模型分析1993—2016年沁河流域植被覆盖的时空演变特征;并结合地形数据分析海拔、坡度和坡向上植被覆盖度的空间响应规律。结果表明:沁河流域植被覆盖度呈北高南低的空间分布特征,且高等级覆盖的植被主要由低等级覆盖的植被转化而来; 1993—2016年,沁河流域植被覆盖度呈不显著波动上升趋势,显著改善(55.99%)和轻微改善(10.13%)之和远大于显著退化(7.31%)和轻微退化(4.59%)之和,反映了良好的植被状况;沁河流域植被覆盖度重心整体表现为向南偏东迁移2.05 km,其中较高和高植被覆盖迁移最为明显;沁河流域植被覆盖度与海拔、坡度呈显著正相关,显著改善面积占比随高程、坡度的增加呈先增加后减小趋势,坡向在东北、西北和西南方向为优势地形位。研究结果有助于为该流域水土流失治理和生态环境的恢复提供决策依据。更多还原

【Abstract】 With four images of Landsat TM/OLI as data sources,fractional vegetation coverage(FVC) in Qinhe Basin was estimated by dimidiating pixel model,and the spatiotemporal changes of vegetation patterns from 1993 to 2016 were analyzed using transition matrix,geo-spectrum and center of gravity migration model.The spatial variation of FVC at different attitudes,slopes,and aspects were explored based on topographic factors.The results showed that,spatially,FVC was higher in the north and lower in the south,and the vegetation with higher FVC was mainly transformed from those with lower FVC.During 1993-2016,the FVC in the Qinhe Basin showed an increasing trend with no significant fluctuation.The sum of areas with significant improvement(55.99%) and slight improvement(10.13%) were greater than that of areas with significant degradation(7.31%) and slight degradation(4.59%),reflecting good vegetation conditions.The center of gravity for FVC was migrated toward the southeast with 2.05 km,with the migrations of higher and highest FVC being the most obvious.FVC values were significantly positively correlated with elevation and slope.The area with remarkable improvement increased and then decreased with elevation and slope.The favorable terrain of vegetation in aspect was the area of the northeast,northwest and southwest.Our results will be helpful to the control of soil and water losses and ecological restoration in the study area.更多还原