气候变化与人类活动在四川植被覆盖度变化中的相对作用

Relative Effects of Climate Change and Human Activities on Vegetation Coverage Change in Sichuan

为了从宏观上评估气候变化和人类活动对植被覆盖度变化的影响,借助于Google Earth Engine平台,以MODIS-EVI和气象数据为基础,采用像元二分模型、趋势分析、相关分析和残差分析方法结合GIS空间分析定量评价气候变化与人类活动在四川省2000—2015年植被覆盖度变化中的相对作用。结果显示:(1)四川省植被覆盖度总体上呈现改善趋势,其改善趋势的面积占43.95%,退化趋势的面积占40.57%,基本不变的面积占15.48%;气候变化和人类活动对植被覆盖度变化产生抑制作用的面积分别占19.65%、50.01%,产生促进作用的面积分别占31.51%、42.31%。(2)在植被覆盖度改善变化中,气候变化和人类活动共同影响的面积占10.66%,单独影响的面积分别占9.36%、23.93%;在植被覆盖度退化变化中,气候变化和人类活动共同影响的面积占8.82%,单独影响的面积分别占4.87%、26.88%。(3)气候变化和人类活动对植被覆盖度变化的贡献率分别为27.83%、72.17%,在植被覆盖度改善变化中的贡献率分别为33.42%、66.58%,在植被覆盖度退化变化中的贡献率分别为21.86%、78.14%;在21个市(州)中,气候变化和人类活动对植被覆盖度变化的贡献率范围分别为13.12%~48.55%和51.45%~86.88%。研究结果表明人类活动是四川植被覆盖度变化的主要影响因素,在后续生态植被恢复中应更加注意人为因素作用。

In order to assess the impact of climate change and human activities on changes in vegetation coverage from a macro perspective,based on the MODIS-EVI from the Google Earth Engine remote sensing bid data cloud computing platform and climate data,this paper quantitatively studied the impact of climate change and human activities on the change in vegetation coverage in Sichuan Province from 2000 to 2015.The dimidiate pixel model,trend analysis,correlation analysis and residual analysis combined with GIS spatial analysis were used.The results showed that:(1)The vegetation coverage in Sichuan Province generally showed an improvement trend.The area of improvement trend accounted for 43.95%.The area of degraded trend accounted for 40.57%.The area basically unchanged was 15.48%.The area where climate change and human activities inhibited vegetation coverage changes accounted for 19.65% and 50.01%,respectively.The area where climate change and human activities promoted vegetation coverage changes accounted for 31.51% and 42.31%,respectively.(2)In the vegetation improvement,the area affected by climate change and human activities together accounted for 10.66%,and the area affected separately accounted for 9.36% and 23.93%,respectively.In the vegetation degradation,the area affected by climate change and human activities together accounted for 8.82%,and the area affected separately accounted for 4.87% and 26.88%,respectively.(3)The contribution of climate change and human activities to vegetation cover change were 27.83% and 72.17%,respectively.The contribution of climate change and human activities in vegetation improvement were 33.42% and 66.58%,respectively.The contribution of climate change and human activities in vegetation degradation were 21.86% and 78.14%,respectively.Among the 21 administrative regions,the contribution of climate change and human activities to vegetation cover changes ranged from 13.12% to 48.55% and 51.45% to 86.88%,respectively.The research indicated that human activities were the main influencing factors of vegetation cover changes in Sichuan,and more attention should be paid to the role of human factors in subsequent ecological vegetation restoration.