During the COVID-19 emergency, cities around the world introduced measures to guarantee physical distancing that restricted access to urban parks and green areas, with potentially negative effects on citizens’ health and wellbeing. This study aims at providing insights to manage access to urban green space in physical distancing times, when the risk of crowding should be avoided. Using the city of Trento (Italy) as a case study, the study simulates policy scenarios corresponding to different restrictions and assesses their effects on green space access and crowding. Policy scenarios are obtained by combining different distances that people are allowed to travel, different types of green areas available for public use (only urban parks or parks and schoolyards), and different target populations (all residents or only people with no private gardens). The results unveil the trade-off between access and crowding of green areas, and can be used to suggest policy interventions and regulations that can be adopted in an emergency. Particularly, the study shows that: i) The relationship between distance threshold and the percentage of people with access to green areas is non-linear, and this should be carefully considered when proposing travel restrictions; ii) Changing the maximum travel distance does not produce major effects on the number of crowded green areas, hence additional or alternative measures need to be adopted; iii) Off-the-shelf measures, such as opening schoolyards, are beneficial and can be implemented rapidly in an emergency. Finally, the study reveals “hotspots” of green space deprivation/overcrowding in the city that should be addressed by urban planning to ensure that green space continues to benefit citizens also during emergency conditions.

在 COVID-19 紧急情况期间，世界各地的城市采取了保证身体距离的措施，限制了进入城市公园和绿地，这可能对公民的健康和福祉产生负面影响。这项研究旨在提供见解，以管理在保持物理距离的情况下进入城市绿地的机会，同时应避免拥挤的风险。该研究以特伦托市（意大利）为案例研究，模拟了不同限制对应的政策情景，并评估了其对绿地准入和拥挤的影响。政策情景是通过结合允许人们出行的不同距离、可供公众使用的不同类型的绿地（仅城市公园或公园和校园）以及不同的目标人群（所有居民或仅没有私人花园的人群）来获得的。结果揭示了绿地的通行和拥挤之间的权衡，并可用于建议在紧急情况下可以采取的政策干预和法规。特别是，研究表明：i）距离阈值与进入绿地的人数百分比之间的关系是非线性的，在提出旅行限制时应仔细考虑这一点； ii) 改变最大行驶距离不会对拥挤绿地的数量产生重大影响，因此需要采取额外或替代措施； iii) 现成的措施，例如开放校园，是有益的，并且可以在紧急情况下迅速实施。最后，该研究揭示了城市绿地剥夺/过度拥挤的“热点”，应通过城市规划来解决，以确保绿地在紧急情况下也能继续造福公民。