Climatic factors dominate the spatial patterns of urban green space coverage in the contiguous United States

Abstract

Urban green space (UGS) is directly or indirectly related to the human well-being of urban inhabitants, information on the availability or quantity of UGS is thus very fundamental for policy-makers to conduct sustainable land management. Analysis of UGS patterns and their influencing factors at large scales using high-resolution remotely sensed imagery is still understudied. Our study aimed to map the spatial patterns of UGS coverage (UGSC) in all (i.e., 3,535) urban areas of the contiguous US (CONUS) and uncover the main influencing factors that dominate the spatial patterns. We mapped the UGS cover of each urban area using the one-meter high-resolution remote sensing images provided by the National Agriculture Imagery Program (NAIP) of the US on the Google Earth Engine platform. Then we calculated the UGSC of each urban area and quantified the spatial patterns of UGSC for the CONUS urban areas. We established a random forests model to quantify the impact of the influencing factors on UGSC. The results showed that: (1) UGSC in the CONUS urban areas varied largely from 2.2% in Kayenta, AZ to 89.36% in Ocala Estates, FL, with a mean UGSC of 39.43% (SD = 18.19%); (2) UGSC in humid Eastern US was much higher than that in urban areas with hyper-arid or arid climate classes in Western or Central regions of the US. Yet, UGSC of urban areas with different city sizes dose not vary largely; (3) the climatic factors were the main influencing factors that dominate the spatial patterns of UGSC in urban areas of the CONUS, while the socio-economic and terrain factors play relatively less important roles in shaping the UGSC pattern.