摘要
为阐明祁连山区草地退化的时空分布特征,并评估其退化趋势,本文采用Landsat 8 OLI影像数据,结合地理国情监测成果,通过计算2013—2020年的归一化植被指数(NDVI)和草地退化指数(GDI),量化分析了该地区草地覆盖度和退化的时空变化格局。结果显示:①祁连山地区草地覆盖面积为121039.75 km^(2),约占总面积的79.15%,其中高覆盖度草地占28.25%;②祁连山区草地退化指数从2014年的1.59降至2020年的1.27,表明草地退化情况整体呈现改善趋势;③退化草地的空间分布表现出显著的异质性,西部地区退化较为集中,而中部和东部地区退化状况不明显。不同流域的草地退化指数变化趋势差异显著,湟水/大通河外流区和河西走廊内流区草地退化指数呈波动下降,而柴达木盆地内流区则在2018年后有所上升。研究结果为评估祁连山地区草地退化和植被恢复提供了科学依据,对区域生态保护和可持续发展具有重要意义。
To clarify the spatio-temporal distribution characteristics of grassland degradation in the Qilian Mountain area and to assess its degradation trends,this study uses Landsat 8 OLI image data in conjunction with geographical national condition monitoring results.By calculating the normalized difference vegetation index(NDVI)and grassland degradation index(GDI)from 2013 to 2020,a quantitative analysis of the spatial and temporal changes in grassland coverage and degradation in the area is conducted.The results show that:①The grassland coverage area in the Qilian Mountain area is 121039.75 km^(2),accounting for 79.15%of the total area,with high coverage grasslands accounting for 28.25%.②The grassland degradation index in the Qilian Mountain area decreases from 1.59 in 2014 to 1.27 in 2020,indicating an overall improvement in the temporal trend.③The spatial distribution of degraded grasslands shows significant heterogeneity,with more concentrated degradation in the western region,while the central and eastern regions show no significance.The change trends in the grassland degradation index vary significantly among different watersheds,with the Huangshui/Datong River and Hexi Corridor areas showing a fluctuating downward trend,while the Qaidam Basin area has risen after 2018.The findings provide a scientific basis for assessing grassland degradation and vegetation restoration in the Qilian Mountain area,which is of great significance for regional ecological protection and sustainable development.
作者
田丹
白晓
秦坤
TIAN Dan;BAI Xiao;QIN Kun(First Institute of Photogrammetry and Remote Sensing,Ministry of Natural Resources,Xi'an 710054,China;College of Geomatics,Xi'an University of Science and Technology,Xi'an 710054,China)
出处
《测绘通报》
北大核心
2025年第4期152-157,共6页
Bulletin of Surveying and Mapping
基金
国家自然科学基金(42307407)
陕西省教育厅科学研究计划(23JK0540)。
关键词
草地退化
生态遥感
时空变化
祁连山区
Landsat
8
OLI
grassland degradation
remote sensing in ecology
spatio-temporal analysis
Qilian Mountain area
Landsat 8 OLI
