摘要
基于Landsat遥感影像分析1986~2020年青海湖流域植被覆盖度时空变化特征,结合多元线性回归和地理探测器,考虑气候、地表及人类足迹的影响,阐明时间和空间尺度下植被覆盖度变化的机制,并探讨空间粒度对驱动因素及其相对贡献的影响.结果表明:(1)近35年来青海湖流域植被状况整体改善,表现为中等、中高覆盖度植被面积增加,其中环青海湖东北部及布哈河上游植被覆盖度呈显著增加趋势;(2)时间尺度上,流域平均植被覆盖度变化受气候暖湿化和生态恢复工程驱动;(3)空间尺度上,植被覆盖度变化由气候、地形、植被和土壤控制,解释力较大因素为气温(0.41),高程(0.34)和降水(0.30).气候、地形和人为因素对植被覆盖度的影响存在交互增强效应,气温、高程对交互效用具有控制作用,其中气温与距水系距离、降水和人类足迹的交互较为显著;(4)空间粒度对植被覆盖度空间变化驱动因素的贡献具有显著影响,考虑气候、地表和人为因素交互作用时青海湖流域植被覆盖度空间变化最佳研究粒度为6km.
This study utilized Landsat images to analyse spatiotemporal variations of FVC in QHLB from 1986 to 2020.The driving mechanisms of the FVC changes at temporal and spatial scales was investigated,taking into account the influences of climate,surface conditions,and human activity by employing multiple linear regression and geodetector.Additionally,the mechanism of change was discussed,and the impact of spatial granularity on driving factors and their relative contributions was explored.The results shows that:(1)the vegetation conditions in the QHLB have improved overall in the past 35 years,marked by an increase in vegetation types of medium and moderate height,along with a notable rise in FVC around the Qinghai Lake and the upper reaches of the Buha River;(2)On temporal scale,changes in FVC were primarily influenced by climate warming,humidification and ecological restoration initiatives;(3)On spatial scale,changes in FVC were controlled by climate,topography,vegetation,and soil,and the factor with greater explanatory power was temperature(0.41),elevation(0.34)and precipitation(0.30).Furthermore,the influence of climate,topography,and human activity exhibits a synergistic interaction,with temperature and elevation playing a controlling role in these interactions.Among these,the interaction between and factors such as water systems,precipitation,and human activities were particularly significant;(4)The spatial scale proved to be a critical factor influencing the contributions of driving factors.Therefore,taking into consideration the interaction of climate,surface conditions,and human factors,the optimal scale for investigating the FVC changes in QHLB was determined to be 6km.
作者
周美林
刘家宏
刘希胜
王亚琴
ZHOU Mei-lin;LIU Jia-hong;LIU Xi-sheng;WANG Ya-qin(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Institute of Geographic Sciences and Natural Resources Research,Beijing 100101,China;Key Laboratory of River Basin Digital Twinning of Ministry of Water Resources,Beijing 100038,China;Qinghai Hydrological and Water Resources Survey and Report Center,Xining 810001,China;China Institute of Geo-Environment Monitoring,Beijing 100081,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2024年第3期1497-1506,共10页
China Environmental Science
基金
青海省重点研发与转化计划项目(2022-SF-143)。
关键词
植被覆盖度
时空变化
气候变化
人类活动
地理探测器
空间粒度
青海湖流域
fractional vegetation cover(FVC)
spatio-temporal variations
climate change
human activities
geodetector
spatial scale
Qinghai Lake Basin