McDonald et al. data on tree cover (2014-2016) at the US census block level for the 100 largest urbanized areas

This dataset is associated with the McDonald et al. paper, entitled "The urban tree cover and temperature disparity in US urbanized areas: Quantifying the effect of income across 5,723 communities". Urban tree cover provides benefits to human health and well-being, but previous studies suggest that tree cover is often inequitably distributed. Here, we use NAIP imagery to survey the tree cover inequality for Census blocks in US large urbanized areas, home to 167 million people across 5,723 municipalities and other places. We compared tree cover to summer surface temperature, as measured using Thematic Mapper imagery. In 92% of the urbanized areas surveyed, low-income blocks have less tree cover than high-income blocks. On average, low-income blocks have 15.2% less tree cover and are 1.5⁰C hotter (surface temperature) than high-income blocks. The greatest difference between low- and high-income blocks was found in urbanized areas in the Northeast of the United States, where low-income blocks often have at least 30% less tree cover and are at least 4.0⁰C hotter. Even after controlling for population density and built-up intensity, the association between income and tree cover is significant, as is the association between race and tree cover. We estimate, after controlling for population density, that low-income blocks have 62 million fewer trees than high-income blocks, a compensatory value of $56 billion dollars ($1,349/person). An investment in tree planting and natural regeneration of $17.6 billion would close the tree cover disparity for 42 million people in low-income blocks.

本数据集关联McDonald等人发表的题为《美国城市化区域的树木覆盖与气温差异：量化5723个社区的收入影响》的论文。城市树木覆盖可为人类健康与福祉带来诸多益处，但既往研究表明，树木覆盖的分布往往存在不公平性。本研究采用NAIP影像（美国国家农业影像计划，National Agriculture Imagery Program），针对覆盖1.67亿人口、涉及全美5723个市政管辖区及其他行政单元的大型城市化区域内的普查街区开展树木覆盖不平等状况调查。我们将树木覆盖情况与利用专题制图仪（Thematic Mapper）影像测得的夏季地表温度进行对比分析。结果显示，在92%的受访城市化区域中，低收入街区的树木覆盖率低于高收入街区。平均而言，低收入街区的树木覆盖率比高收入街区低15.2%，地表温度则高出1.5℃。美国东北部城市化区域的高低收入街区差异最为显著，当地低收入街区的树木覆盖率通常至少比高收入街区低30%，地表温度至少高出4.0℃。即便在控制人口密度与建成强度变量后，收入与树木覆盖之间的关联仍具有统计学显著性，种族与树木覆盖之间的关联亦是如此。经控制人口密度变量后，我们估算得出，低收入街区的树木总量较高收入街区少6200万棵，对应补偿价值达560亿美元（人均1349美元）。若投入176亿美元用于植树造林与自然更新，即可为低收入街区的4200万人口消除树木覆盖差异。