Balancing Growth and Conservation: The potential of Density Transfer Modelling in Bowen Island's Urban Planning

The rapid population growth in British Columbia has led to the necessity of innovative housing solutions. Local municipalities in BC, such as Bowen Island, are exploring the implementation of Density Transfer Modelling (DTM) as a planning tool to address these challenges. The study examines Density Transfer Modelling by Geographic Information System (GIS) application on Bowen Island, managed under the Islands Trust Act, to balance development with ecological preservation. This involves identifying \"donor\" sites (areas of high ecological value with existing development) to transfer development rights from, and \"receiver\" sites (areas suitable for increased urban density) using the Normalized Difference Built-up Index and residential density classifications. Two main Comprehensive Development Areas (CDAs) on Bowen Island, Arbutus Ridge and Snug Cove are highlighted. The DTM calculates that this area supports the development of up to 30 additional detached homes in Arbutus Ridge Development Area. The Snug Cove Comprehensive Development Area (Snug Cove CDA) has been identified as a key area for increased residential development with a focus on increasing affordability and creating a pedestrian-friendly environment. According to DTM calculations Snug Cove Residential Area supports the development of 2186 dwelling units. The goal of the Snug Cove Development Area is to build a variety of housing types, including duplexes, triplexes, and multi-unit buildings, clustered near essential services and transportation hub(ferry). Both CDAs exemplify how density transfer modellings can be effectively utilized within designated development areas to support sustainable urban planning goals.加拿大不列颠哥伦比亚省（British Columbia，简称BC）人口快速增长，催生了创新性住房解决方案的迫切需求。该省地方市政当局——如鲍恩岛（Bowen Island）——正探索将密度转移模型（Density Transfer Modelling, DTM）作为规划工具，以应对此类住房挑战。本研究针对受《岛屿信托法》（Islands Trust Act）管辖的鲍恩岛，探讨地理信息系统（Geographic Information System, GIS）在密度转移模型中的应用路径，以期在开发建设与生态保护之间实现平衡。研究需识别“出让地块”（即具备高生态价值且已有开发活动的区域）以转出开发权，并借助归一化建筑指数（Normalized Difference Built-up Index）与住宅密度分类方法，筛选出“接收地块”（即适宜提升城市开发密度的区域）。鲍恩岛有两处重点综合开发区（Comprehensive Development Areas, CDAs），分别为香柏岭（Arbutus Ridge）与斯纳格湾（Snug Cove）。密度转移模型测算结果显示，香柏岭开发区可额外容纳至多30栋独立住宅的开发建设。而斯纳格湾综合开发区（Snug Cove CDA）已被确定为扩大住宅开发规模的核心区域，其核心目标为提升住房可负担性，并打造步行友好型环境。据密度转移模型测算，斯纳格湾居住区可开发建设2186套住宅单元。斯纳格湾开发区的建设愿景为打造多元化住宅类型，包括双联住宅、三联住宅及多单元建筑，并将其集中布局在基础服务设施与交通枢纽（轮渡码头）周边。两处综合开发区均印证了，密度转移模型可在指定开发区内得到有效应用，为可持续城市规划目标的实现提供支撑。