中国城市建成区绿化覆盖率变化特征及影响因素分析

Changes in Green Coverage Rate of Urban Built-up Areas in Chinaand Influencing Factors

城市建成区绿地建设有利于改善城市环境,提高人居适宜度,优化城市生态系统服务功能。基于2002—2018年建成区绿化覆盖率及影响因子数据分析了中国城市建成区绿化覆盖率变化特征及其主要影响因素,结果表明,(1)中国建成区绿化覆盖率在2018年达到了41.11%,相比2002年增加了11.36%,2018年绿化覆盖率达到了35.0%以上的城市占全国城市的93.55%。(2)中国建成区绿化覆盖率存在明显的区域差异。按照华北、东北、华东、中南、西南和西北六个地区划分中国城市区域,华东地区的城市建成区绿化覆盖率最高,中南地区次之,其余四个地区为华北地区>东北地区>西北地区>西南地区;各地区建成区绿化覆盖率随时间发生显著变化(P<0.05),华北地区绿化覆盖率发生显著变化的城市占比最高达94.60%,中南地区最低为65.88%。(3)建成区绿化覆盖率与城市化指标(地区生产总值GDP、地区人均生产总值PGDP、绿化投入LP、建成区面积BUA、城区面积百分比UAP、建成区面积百分比BUAP、总人口TP、城市人口密度UPD、城区人口UP、建成区人口BUP、城区人口百分比UPP、建成区人口百分比BUPP)和气候因子(年平均温度YT、年平均湿度YH和年降雨量YW)均呈极显著正相关关系(P<0.01),其中PGDP、LI、BUAP、UAP、UPD、BUPP和YT、YW、YH是影响建成区绿化覆盖率的最主要因子。本研究结果可为中国未来城市绿地建设均衡发展提供重要的理论参考依据。

Construction of green space in urban built-up areas improves the urban environment by increasing the living environment for humans and improving urban ecosystem services provision.Based on the data on green coverage rate,urbanization factors,and climate factors in the period 2002‒2018,this study analyzed variations in green coverage rate and the main influencing factors in urban built-up areas in China.The results showed that,(1)The green coverage rate in built-up areas reached 41.11%in 2018,an 11.36%increase compared with 2002,and 93.55%of cities had≥35.0%urban green coverage by 2018.(2)There were marked regional differences in green coverage rate in urban built-up areas in the six different official regions of China(North China,Northeast China,East China,Central-south China,Southwest China and Northwest China).The rate was highest in East China,followed by Centralsouth China,and then North China,Northeast China,Northwest China,and Southwest China.Green coverage rate of built-up areas changed significantly(P<0.05)over time in all regions,affecting from around 94.60%of cities(North China)to 65.88%(Central-south China).And(3)green coverage rate in built-up areas was significantly positively correlated(P<0.01)with urbanization indicators(regional gross domestic product(GDP),regional per capital gross product(PGDP),landscaping investment(LI),urban built-up area(BUA),urban area percentage(UAP),built-up area percentage(BUAP),total population(TP),urban population density(UPD),urban population(UP),built-up population(BUP),urban population percentage(UPP),built-up area population percentage(BUPP))and with climate factors(annual mean temperature(YT),annual mean humidity(YH),annual rainfall(YW)).Of these,PGDP,LI,BUAP,UAP,UPD,BUPP,and the three climate factors were identified as most important in affecting green coverage rate of built-up areas.These results provide an important theoretical basis for the future balanced development of urban green space construction in China.