Abstract Both compact and dispersed green cities are considered sustainable urban forms, yet some developments accompanied with these planning paradigms seem problematic in times of urban growth. A compact city might lose urban green spaces due to infill and a dispersed-green city might lose green in its outskirts through suburbanisation. To study these storylines, we introduce an operationalised concept of contrasting changes in population density (shrinkage or growth) with vegetation density (sealing or greening) over time. These trends are ascribed to different land use classes and single urban development projects, to quantify threads and pathways for urban green in a densifying city. We mapped the development in vegetation density over 30 years as subpixel fractions based on a Landsat remote sensing time series (for 2015: MAE 0.12). The case study city Berlin, Germany, developed into a city that is both gaining in vegetation–greening–and population–growing–in recent years but featured highly diverse trends for both compact and green city districts before that. Pathways to achieve a greening-growing scenario in a compact city include green roofs, brownfield and industrial revitalisation, and bioswales in predominantly green city districts. A threat for compact cities pose infill developments without greening measures. A threat for dispersed-green cities is microsealing in private residential gardens–gravel gardens–or car parking infrastructure. We conclude that neither a compact nor a dispersed-green city form concept logically leads to a development towards more environmental quality–here vegetation density–in times of densification but rather context specific urban planning.

中文翻译：

---

绿色增长？基于 30 年 Landsat 时间序列的城市人口密度、土地利用和植被覆盖率之间的关系

摘要 紧凑型和分散型绿色城市都被认为是可持续的城市形式，但伴随这些规划范式的一些发展在城市发展时期似乎存在问题。紧凑型城市可能会因填充而失去城市绿地，而分散的绿色城市可能会因郊区化而失去郊区的绿色。为了研究这些故事情节，我们引入了一个可操作的概念，将人口密度（收缩或增长）与植被密度（密封或绿化）随时间的变化进行对比。这些趋势归因于不同的土地利用类别和单一的城市开发项目，以量化密集城市中城市绿化的线索和路径。我们根据 Landsat 遥感时间序列（2015 年：MAE 0.12）将 30 年来植被密度的发展绘制为亚像素分数。案例研究城市德国柏林近年来发展成为一个在植被绿化和人口增长方面都在增加的城市，但在此之前，紧凑型和绿色城区的趋势非常多样化。在紧凑型城市中实现绿化增长场景的途径包括屋顶绿化、棕地和工业振兴，以及在主要绿色城市地区的生物沼泽。没有绿化措施的紧凑型城市构成了填充式开发的威胁。对分散的绿色城市的威胁是私人住宅花园——砾石花园——或停车场基础设施中的微密封。我们得出的结论是，无论是紧凑的还是分散的绿色城市形式概念，都不会在逻辑上导致向更高的环境质量发展——这里是植被密度——在密集化时期，而是特定于背景的城市规划。