• 论文与研究报告 •

### 我国4个典型城市近30年绿色空间时空演变规律

1. 中国林业科学研究院林业研究所 国家林业和草原局林木培育重点实验室 国家林业和草原局城市森林研究中心 北京 100091
• 收稿日期:2018-05-04 出版日期:2020-03-25 发布日期:2020-04-08
• 通讯作者: 王成
• 基金资助:
中央级公益性科研院所基本科研业务费专项(CAFYBB2019SY004);林业公益性行业科研专项经费项目(201404301)

### Spatio-Temporal Patterns of Evolution Urban Greenspace during the Last Three Decades in Four Typical Cities of China

Jiali Jin,Cheng Wang*,Baoquan Jia

1. Urban Forest Research Centre, National Forestry and Grassland Administration Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration Research Institute of Forestry, CAF Beijing 100091
• Received:2018-05-04 Online:2020-03-25 Published:2020-04-08
• Contact: Cheng Wang

Abstract:

Objective: Changsha, Dalian, Nanchang and Shenzhen were selected to detect the spatio-temporal patterns of greenspace changes and main impact factors.This study aims to provide the new spatial data for the improvement of urban greenspace theories and models, and for the optimization of greenspace network. Method: Based on the time-series Landsat composites imagess, NDVI-thresholding technique was applied to reclassify greenspace into four categories and landscape indices were used to measure the characteristics of greenspace patterns. Temporal dynamics of greenspace was assessed using the Mann-Kendall trend test. Normalized distance index (NDI) was calculated to measure the urban-to-rural gradients. Dynamic time warping (DTW) was applied to detect the differences of long-term trends trajectories of landscape indices in four cities. Finally, maximum information-based non-parametric exploration method (MINE) was used to detect the pairwise relationships between the changes in greenspace patterns and main impact factors. Result: From 1985 to 2011, the percentage of dense vegetation in Changsha, Dalian, and Shenzhen had an average increase of 0.26% and the mean patch size of dense vegetation increased 0.11 hm2. The percentage of medium-dense vegetation in these three cities had an average decrease of 0.40%, while the mean patch size in Nanchang and Shenzhen increased 0.15, 0.04 hm2 respectively, however, Changsha and Dalian decreased 0.01, 0.08 hm2 respectively. The percentage and mean patch size of sparse vegetation in Changsha and Nanchang showed an increase trend. The percentage increased by 0.12% and 0.23%, the mean patch size increased by 0.04 and 0.01 hm2, respectively. To the contrary, the percentage of sparse vegetation in Dalian and Shenzhen decreased 0.22% and 0.63% while the mean patch size decreased 0.04 and 0.06 hm2.The urban-to-rural gradients of dense vegetation in Changsha and Nanchang had a ∩-shaped trajectory. Sparse vegetation in Changsha and Shenzhen had a monotonic decreasing trajectory, while Dalian, and Nanchang had a ∪-shaped trajectory. The changes in greenspace patterns had strong non-linear relationships with income, gross domestic product per person, proportion of urban population and proportion of city area. Conclusion: From 1985 to 2011, the dense vegetation in Changsha, Dalian and Shenzhen increased and the patches became more connected, contrasting to medium-dense vegetations. In the four selected cities, sparse vegetation increased in inland cities and the patterns became less fragmented, contrasting to the coastal cities. There are three trajectories of urban-to-rural gradients of greenspace, the first one is parabola-shaped trajectory ("∩or∪"), second is constant trajectory ("-"), third is monotonic increasing or decreasing trajectory. The greenspaces tended to have large changes in the city centers and suburb areas.