气候与土地利用变化对粤港澳大湾区增强型植被指数时空变化影响

Effects of climate change and land use and land cover change on the variation of enhanced vegetation index in Guangdong–Hong Kong–Macao Greater Bay Area

为了解粤港澳大湾区植被生长态势变化及气候与土地利用变化对植被生长的影响,基于MODIS-EVI数据、气候数据和土地利用类型数据,采用趋势分析、相关分析和响应分析,探讨粤港澳大湾区2001—2018年生长季植被EVI时空格局演变规律及其与平均气温、累积降雨量和土地利用变化的关系。结果表明:(1)2001—2018年粤港澳大湾区年EVI均值呈中心区和东南区向东北、西北和西南方向递增的趋势。年均增加速率约为0.003 EVI/年。从未来变化趋势看,大部分区域EVI在未来呈下降趋势;(2)EVI与平均气温和累积降雨量总体呈正相关关系,但EVI与降雨的相关性大于EVI与平均气温的相关性,EVI对气温和降雨总体呈正响应,其响应均值分别为0.009 EVI/℃和0.003 EVI/100 mm;(3)土地利用变化对EVI产生显著影响,其中城市扩张对EVI产生极显著负效应(P<0.0001),而生态恢复对EVI表现为极显著正效应(P<0.0001),且城市扩张对EVI的影响远高于生态恢复对EVI的影响。研究结果可为分析粤港澳大湾区生态系统变化、生态系统恢复、城市生态规划及生态文明建设提供参考。

In order to understanding the variation of vegetation growth and the impact of climate change and land use and land cover change on vegetation,spatiotemporal dynamics of enhanced vegetation index(EVI),and its correlation with mean temperature and cumulative precipitation of the growing season,and also,the relationship between EVI and land use and land cover change were analyzed in Guangdong–Hong Kong–Macao Greater Bay Area(GBA)during 2001-2018 based on MOIDS EVI data,climate data and land cover type data.Our results indicated that(1)mean EVI value increased from middle and southeast of the study area to northeast,northwest and southwest.EVI value displayed an increase trend during 2001-2018,and the rate was approximately 0.003 EVI per year.However,EVI in the GBA displays a decreasing trend in the future for most part of the region;(2)the correlations between EVI and mean temperature as well as cumulative precipitation were almost positive,but the mean coefficient between EVI and cumulative precipitation was larger than that of mean temperature;the responses of EVI to mean temperature and cumulative precipitation were almost positive,and the mean responses value were 0.009 EVI/℃and 0.003 EVI/100mm,respectively;(3)land use and land cover change has a significant impact on EVI.Urban sprawl has a significantly negative effect on EVI(P<0.0001),while restoration has a significantly positive impact on EVI(P<0.0001).However,the effect of urban sprawl on EVI was larger than that of restoration.Our results can provide a reference for ecosystem variation,ecosystem restoration,urban ecological planning and ecological civilization construction in the GBA.