2000~2020年成渝双城经济圈植被生态质量变化及其对极端气候因子的响应

Changes of vegetation ecological quality in the Chengdu-Chongqing economic circle from 2000 to 2020 and its response to extreme climatic factor

成渝双城经济圈作为中国经济增长第四极,筑牢长江上游生态屏障对生态环境保护战略意义重大.以2000~2020年植被第一性生产力(NPP)和植被覆盖度(FVC)等多源遥感数据为基础,构建成渝双城经济圈植被生态质量(EQI),并分析了研究区的植被生态质量时空变化特征及极端气候因子的响应.结果表明:(1)2000~2020年间成渝双城经济圈的植被生态环境质量指数总体呈稳定和升降交替态势,多年平均植被生态环境质量值为63.96;(2)成渝双城经济圈生态环境质量呈中间低四周高的空间分布格局.平均生态环境质量指数高值区域主要集中分布于成渝城市群四周山区,渝东南地区也具有较高平均生态环境质量指数;中部地区平均生态环境质量指数年际间的分布相似,变化较小;(3)2000~2020年成渝双城经济圈生态环境质量斜率趋势整体呈向好发展的趋势.斜率最小等级(-3.17~-0.42)主要分布于成都以及重庆主城周边地区;成渝城市区东部和中部的生态环境质量趋势斜率均表现为增长趋势.(4)成渝双城经济圈植被生态质量与极端气候因子日最高气温>25℃的日数(SU)在0.01水平上显著正相关,与日最高气温高于90%分位数的日数(TX90P)、日最低气温<0℃的日数(FD)因子在0.05水平上正相关,与日最低气温高于90%分位数的日数(TN90P)因子在0.05水平上负相关;研究结果能为成渝双城经济圈植被生态环境质量变化及其对极端气候的响应过程提供依据.

As the fourth pole of China's economic growth,the Chengdu-Chongqing economic circle has great responsibility to build a solid ecological barrier in the upper reaches of the Yangtze River,which is of great significance to the strategy of ecological environmental protection.In this study,based on the NPP and vegetation coverage FVC data from 2000 to 2020 in the Chengdu-Chongqing urban area,the vegetation ecological quality index(EQI)was constructed,and the spatiotemporal variation characteristics of vegetation ecological quality and the response of extreme climatic factors were analyzed.The results showed that:(1)from 2000 to 2020,the EQI in Chengdu-Chongqing area was generally stable and alternately up-down,and the average value of vegetation ecological environment quality for many years was 63.96;(2)the EQI in Chengdu-Chongqing urban area showed a spatial distribution pattern of low in the middle and high in the surrounding areas.The areas with large values of the average ecological environment quality index were mainly concentrated in the mountainous areas around the Chengdu-Chongqing economic circle,and the southeast area of Chongqing also has a high average EQI.The distribution of the average ecological environment quality index in the central region was similar between years with a little change;(3)from 2000 to 2020,the slope of ecological environment quality in Chengdu-Chongqing economic circle showed a good development trend.The areas with the minimum slope grades(-3.17~-0.42)were mainly distributed in Chengdu and the surrounding areas of Chongqing main city.The slopes of the ecological environment quality trend in the eastern and central parts of the Chengdu-Chongqing urban area showed a growing trend;(4)in the Chengdu-Chongqing economic circle,there are the significantly positive correlations at 0.01level between the EQI and the number of days with daily maximum temperature>25℃(SU)in the extreme climate index,at 0.05level between the EQI and the number of days with daily maximum temperature higher than 90%of the quantile(TX90P),and at 0.05level between the EQI and the number of days with daily minimum temperature<0℃(FD).Whereas,the EQI is of negative correlation at 0.05level to the number of days with daily minimum temperature higher than 90%of the quantile(TN90P).The results can provide a basis for understanding the changes of vegetation habitat quality and its response to extreme climate in the Chengdu-Chongqing economic circle.