基于Landsat 8 OLI和Sentinel-2A的南京市各城区绿化差异分析

Difference analysis of the greenlands of the urban districts in Nanjing City based on Landsat OLI imagery

遥感作为多时空技术在全面调查城市绿化现状方面具有优势,遥感在城市绿地调查中的应用也随着遥感技术的发展和遥感影像质量及精度的提高越来越广泛。该研究基于Sentinel-2A和Landsat 8影像将南京市区域地块分类为绿地、建筑地、农业用地(包括耕种期的农田和非耕种期的裸地)和水体,并针对南京市不同的分区计算人均绿地和绿化率,及其与城市发展之间的关系。结果显示,南京各区绿地率分别为:江宁区22%,溧水区27%,浦口区35%,六合区28%,栖霞区24%,雨花台区33%,建邺区20%,玄武区42%,鼓楼区17%,秦淮区18%,高淳区20%;各区人均绿化面积为:江宁区377 m2/人,溧水区716 m2/人,浦口区606 m2/人,六合区697 m2/人,栖霞区222 m2/人,雨花台区173 m2/人,建邺区67 m2/人,玄武区63 m2/人,鼓楼区9 m2/人,秦淮区13 m2/人,高淳区362 m2/人。数据反映了绿地率与人均绿化面积可能与不同行政区的规划以及城市化程度有联系。

Along with fast pace of urban sprawl in Nanjing City,Jiangsu Province,urban green ratio(green area ratio to impervious area in a city)and the average green area per person change gradually.Remote sensing,with various spatial and temporal information,has been widely applied in investigating urban greenland.In this study,both Sentinel-2 and Landsat 8 images were used to classify Nanjing City into four classes,i.e.,green land,impervious area,agricultural fields(including farmland and bareland)and water body,and then green ratio and average green area per person were compared among 11 districts of Nanjing City.The results showed that green ratio of 11 districts in Nanjing was as follows,22%in Jiangning District,27%in Lishui District,35%in Pukou District,28%in Luhe District,24%in Qixia District,33%in Yuhuatai District,20%in Jianye District,42%in Xuanwu District,18%in Qinhuai District,20%in Gaochun District,17%in Gulou District;and average green area per person of 11 districts in Nanjing was as follows,337 m^2/person in Jiangning District,716 m^2/person in Lishui District,606 m^2/person in Pukou District,697 m^2/person in Luhe District,222 m^2/person in Qixia District,173 m 2/person in Yuhuatai District,67 m^2/person in Jianye District,63 m^2/person in Xuanwu District,13 m^2/person in Qinhuai District,362 m^2/person in Gaochun District,9 m^2/person in Gulou District.The data reflects that the green ratio and average green area per person may be related to the planning of different administrative regions and the degree of urbanization.