基于GEE和地理探测器的河南省不同流域植被变化及影响因素

Vegetation changes and influencing factors in different watersheds of Henan Province based on GEE and geographic detectors

厘清植被变化及驱动因素,可为生态修复和社会可持续发展提供参考。本研究基于Google Earth Engine平台获取2000—2020年河南省植被覆盖数据,并结合Theil-Sen Median趋势、Mann-Kendall检验和Hurst指数,揭示河南省及其流域分区(海河流域分区、黄河流域分区、淮河流域分区、长江流域分区)植被分布和变化趋势,并联合因子探测及因子交互,从不同尺度探究了自然和人文因素对植被的影响机制。结果表明:研究期间,河南省植被覆盖度(FVC)呈南高北低的分布格局,以中高植被覆盖为主,其中,长江流域分区最好。河南省及各分区FVC变化规律一致,呈波动上升趋势,均以明显改善为主,其中,长江流域分区的改善面积最大。基于Hurst指数,河南省未来植被状况除了淮河流域分区可能持续改善外,其他分区均表现为从改善转向退化。河南省及各分区植被变化是人文因子与自然因子综合作用的结果,因子影响力随时间而改变,主导因子存在地域差异,土地利用/覆盖类型和夜间灯光等人文因素的影响强于海拔、坡度、年均低温等自然因素。因素间的交互作用,尤其是人文与自然因素的交互作用,呈非线性增强关系。

Clarifying vegetation changes and the driving factors can provide references for ecological restoration and sustainable social development.We analyzed vegetation distribution and trend changes in Henan Province and its basin zoning(Haihe River basin zoning,Yellow River basin zoning,Huaihe River basin zoning,Yangtze River basin zoning),with fractional vegetation cover data from 2000 to 2020 based on the Google Earth Engine platform,and by combining Theil-Sen Median trend analysis,Mann-Kendall test,and Hurst index.We also utilized factor detection and factor interaction to explore the individual and mutual influences of natural and anthropogenic factors on vegetation at different scales.The results showed that the fractional vegetation cover(FVC)in Henan Province exhibited a distribution pattern of higher coverage in the south and lower in the north during the study period,predominantly characterized by moderate to high vegetation coverage.The Yangtze River basin zoning had the highest coverage.FVC in Henan Province and its zoning exhibited a consistent pattern of fluctuating upward trends,with all areas showing significant improvement.Particularly,the Yangtze River basin zoning had the largest area of improvement.According to the Hurst index,apart from the possibility of continued improvement in the Huaihe River basin zoning,other zoning would be likely to shift from improvement to degradation in the future.Vegetation changes in Henan Province and its zoning were the result of combined effects of anthropogenic and natural factors,with the influence of these factors changing over time and the dominant factors varying by region.Anthropogenic factors such as land use/cover type and nighttime lighting had a stronger impact on vegetation than natural factors like elevation,slope,and annual mean low temperature.The interaction between factors,particularly between anthropogenic and natural factors,exhibited a nonlinear enhancing pattern.