Changes in the attraction area and network structure of recreation flows in urban green, blue and grey spaces under the impact of the COVID-19 pandemic

Despite increasing attention to the impact of the COVID-19 pandemic on outdoor recreation, there is limited knowledge about its effects on visitor travel across cities for recreation and changes in the recreation response of blue, green and grey spaces within cities. This study examines changes in the attraction area of inter-city recreation flows within Wuhan, China, before and after the COVID-19 pandemic. The results showed a significant decrease in average attraction distance from 861.74 km to 787.77 km after the pandemic, while attraction directions remained stable. Intra-city recreation routes tend to be simplified, with average length decreasing from 40.86 km to 30.52 km and node number of recreation routes reducing from 7.02 to 5.00. However, the proportion of blue nodes in recreation routes increased significantly from 17.45 % to 23.25 %, while the proportion of grey nodes decreased noticeably from 57.36 % to 52.75 %. The proportion of green nodes did not show a significant change, but when the number of nodes exceeded 6.18, the proportion of green nodes slightly decreased below pre-pandemic levels. With the increase in the length of recreation routes, the proportion of grey nodes gradually converged to around 42 % from around 54 % before the pandemic. The total proportion of agglomeration and diffusion nodes increased from 13.71 % to 20.01 %, while the balanced nodes decreased from 8.87 % to 6.93 % after the pandemic. Notably, 35.71 % of the functional nodes before the pandemic remained their original functional type after the pandemic, but 7.14 % of functional nodes converted to weak function. These findings can assist tourism departments and scenic spot managers in developing strategies that balance pandemic control and recreation needs.