Impervious Areas

The Impervious Feature Class was created by combining the Debris Management Study and the PDD % Impervious Study. The Debris Management Study was done in order to identify possible impervious surfaces that were within Public Owned Properties that could be used in case of a disaster striking and debris needing to be moved from roads, sidewalks and private properties and on to a surface that wouldn't be affected. The PDD % Impervious Study was designed to map impervious surfaces of sample sets of taxlots from primary land use/plan designations that were developed from 2001 to 2012 and calculate the average percent of impervious surfaces for the taxlots within each land use/plan designation. The percentages were then compared with previous ISAs (from 1990s) referenced in the City's Stormwater Basin Plans. Four different surface types were chosen to differentiate between surfaces: parking, driveway, sidewalk, and miscellaneous. In 2022, runway was added as a surface type.

不透水面要素类（Impervious Feature Class）由杂物管理研究与PDD不透水面占比研究合并创建。杂物管理研究旨在识别公共所有土地内的潜在不透水面，用于灾害发生时，将道路、人行道与私人地块上的杂物转移至不受灾害影响的不透水面场地。PDD不透水面占比研究旨在针对2001至2012年间划定的主要土地利用/规划指定类型的税地块（taxlots）样本集绘制不透水面分布图，并计算每一类土地利用/规划指定类型下税地块的不透水面平均占比。随后将该占比数据与该市雨水流域规划中引用的1990年代的不透水面面积（ISA）数据进行对比。研究选取了四种地表类型以区分不同地表：停车场、车道、人行道及杂项地表。2022年新增跑道作为地表类型类别。