Philadelphia land cover change data, 1970-2010: 2nd edition

These data represent land cover change in Philadelphia, Pennsylvania over 40 years, with land cover visually interpreted from aerial imagery in 1970, 1980, 1990, and 2000. Land cover classes were tree/shrub, herbaceous, other pervious, building, and other impervious at 10,000 random points. R code for visualization of transitions and multinomial logistic regression is also included.
Many cities in the United States and around the world have been assessing trends in urban tree canopy cover, and many municipal leaders have set goals for tree cover levels. However, there is a need for greater understanding of the socioecological dynamics of tree cover change over many decades, including varied trends within a city. These land cover change data were collected to assess the rates and drivers of tree cover change, using Philadelphia to investigate the processes of tree cover change in a post-industrial city.
For more information about these data, see Roman et al. (2021; https://doi.org/10.3390/land10040403). For more information about the analysis of these data, see Locke et al. (2023).

The first edition of these data (https://doi.org/10.2737/RDS-2021-0033) was made available on 04/09/2021. This second edition (https://doi.org/10.2737/RDS-2021-0033-2) was made available on 04/07/2023 and includes the data from the first edition in addition to the R code for visualization of transitions and multinomial logistic regression.

本数据集记录了宾夕法尼亚州费城40余年的土地覆被变化情况，其土地覆被类型通过1970年、1980年、1990年及2000年的航空影像目视解译得到。研究在10000个随机采样点上划分了五类土地覆被类型：乔木/灌丛、草本植被、其他透水地表、建筑用地以及其他不透水地表。本数据集还附带用于覆被变化转移可视化及多项逻辑回归分析的R代码。

当前，美国及全球诸多城市均在评估城市树冠覆被的变化趋势，不少市政管理者也制定了树冠覆盖率目标。然而，目前仍需深化对数十年间树冠覆被变化的社会生态动力学机制的理解，其中也包括城市内部的差异化变化趋势。本套土地覆被变化数据旨在通过费城这一后工业化城市样本，探究树冠覆被变化的速率与驱动因子，剖析其变化过程。

如需了解本数据集的更多细节，请参阅Roman等人（2021）的研究（https://doi.org/10.3390/land10040403）；若需了解本数据集的分析方法详情，请参阅Locke等人（2023）的研究。

本数据集的第一版（https://doi.org/10.2737/RDS-2021-0033）于2021年4月9日发布。第二版（https://doi.org/10.2737/RDS-2021-0033-2）于2023年4月7日发布，除包含第一版的全部数据外，还新增了用于土地覆被变化转移可视化及多项逻辑回归分析的R代码。