来自ASLA

Addressing Systemic Inequities in Neighborhood Greenspace: Leveraging Green Stormwater Infrastructure Design Elements to Enhance Well-being | Joan Nassauer, FASLA

项目概述

PROJECT STATEMENT

这项持续数年的跨学科研究以美国密歇根州底特律市为背景，探讨了在包含大量空置地产的社区中，绿地与居民福祉间的关系。研究团队借助供水部门提供的绿色雨水基础设施（GSI）资金创造新的社区绿地，深入考察了哪些设计元素对于创造幸福感不可或缺的，以及哪些元素对居民幸福感的影响程度最大。

和许多遗留城市一样，底特律也曾有过去工业化的历史、种族主义的住房政策以及多年缩减投资所导致的人口减少。贫困和地产空置尤其会对社区中的弱势群体带来消极影响，这样的经历对他们的幸福感、个人安全和财产价值都造成了损害。对空置的地产实施绿化或许能够提高幸福感，这取决于如何让居民体验到绿地景观的品质。不过，遗留城市的预算限制给空置场地的维护带来了挑战。考虑到这一原因，了解如何选择可以长期维护的、对居民福祉产生影响的GI设计元素，将对利用景观设计解决系统性的不平等问题起到至关重要的作用。

This multi-year transdisciplinary research project in Detroit, MI, USA, addressed the relationship between greenspace and residents’ well-being in neighborhoods struggling with widespread vacant property. Leveraging green stormwater infrastructure (GSI) investments by the water utility to create new neighborhood greenspaces, it investigated which design elements were essential to well-being, and which had the greatest effect on well-being of residents.

Detroit, like many legacy cities, has a history of deindustrialization, racist housing policies, and years of disinvestment contributing to depopulation. Poverty and property vacancy disproportionately affect disadvantaged residents in some neighborhoods. These residents’ experiences with vacant property undermine their well-being, personal safety and property values. Greening of vacant lots may promote well-being, depending upon how residents experience the qualities of greenspace landscapes. However, maintenance to ensure that vacant lots are well-cared-for is challenged by budgetary limitations of legacy cities. For this reason, understanding how to select GI design elements that can be maintained over time and that will make a difference in residents’ well-being is essential to landscape architecture’s capacity to address systemic inequities in legacy cities.

▲背景：遗留城市的地产空置现象不仅会降低社区绿地的质量，还会对弱势居民群体造成不良影响。该项目以密歇根州底特律市为实践背景，确定了能够通过解决社区绿地质量不平等问题来提升居民幸福感的设计方案。

BACKGROUND: Property vacancy in legacy cities disproportionately affects disadvantaged residents. Property vacancy in legacy cities degrades neighborhood greenspace, disproportionately affecting disadvantaged residents. This project in Detroit, MI, identified design choices that can support well-being by addressing inequities in the quality of greenspace in neighborhoods struggling with vacancy and poverty.

项目说明

PROJECT NARRATIVE

研究目标的重要性

研究的首要目标是为设计策略提供信息，以解决社区内绿地质量不平等的问题，尤其是在地产空置和缺乏维护等问题已经对遗留城市的街区景观带来改变的情况下。绿地的质量可能会影响居民的福祉：是否享有充足的绿地环境与居民的幸福感息息相关，而绿地分布的不公平状况则被认为是导致健康水平差异的重要因素。此次的健康差异研究并没有集中在绿地质量上，而是集中在景观设计师经常关注的小尺度设计元素上。在以大量空置地产为特征的社区语境中，小尺度设计元素是极为重要的，因为它们与居民的安全感有着紧密的联系。社区内部的景观质量会影响居民从家里向外望时的感受，以及他们在使用私人庭院或在附近散步时的体验。相比于大型的公共绿地，这些体验会让居民更加直观地感受到自身与其他社区之间的明显差异。该项目所建立的这种新的认知，将帮助景观设计师为解决类似的不平等现象做出有意义的贡献。

研究难点

此次研究的问题是，社区绿地中具有不同维护需求的小尺度设计元素会在多大程度上提高居民的幸福感？通过这种方式来界定问题，团队不仅可以更加关注居民的幸福感，同时也便于对研究结果进行调整，以解决遗留城市的维护挑战。

研究团队在两个互补的层面上对该问题做出了构想，这将从很大程度上决定本次研究在操作上的严谨性：1.以实践认知和本地经验为基础：一次跨学科的行动研究，为发展不力的社区带来直接的变化。该过程需要各方机构、非政府组织、社区居民和跨学科研究小组在七年时间内进行频繁且密切的合作。遗留城市的社区绿地应当由机构工作人员而非依靠志愿者来维护。在认识到遗留城市财政收入有限的事实的同时，研究团队围绕着一系列以维护效率为目标的设计选项提出了他们的研究问题。

2. 以学术理论为基础：以可复制的方式测试景观设计元素对居民幸福感的影响，具体的做法是对有关幸福感、选择偏好以及社区绿地感知的学术文献进行全面回顾。在建立幸福感方面，需要了解小尺度的景观元素如何对居民的心理和情感健康产生影响，以及他们可能影响健康的社会和身体行为。在关怀感和安全感方面，大量的学术文献表明对社区绿地的感知会影响遗留城市的居民的幸福程度，同时有许多研究确定了景观设计元素在提供关怀感和安全感方面的关键作用。不过，要解决社区绿地的不平等问题，需要将以上这些因素集中在一起考虑，以实验性的方式调整设计元素，从而对它们与选择偏好、认知以及幸福感之间的关联性进行量化。

研究问题

基于以上两个层面，研究团队深入分析了这些可能影响幸福感的设计元素，包括路桩、低矮的开花灌木和草本植物、成排的落叶树木以及经过修剪的草坪。

实际的操作从以下几个具体问题入手：• 居民们更希望附近空地上出现哪些元素的组合？

• 居民对于安全、关怀和吸引力的感知会如何影响他们的喜好？

• 居民对于不同的设计选项有何期待？这些选项将如何影响他们的幸福感，包括心理和情绪健康、与邻居的互动以及在附近散步的意愿程度？

• 鉴于需要尽可能地降低维护需求，哪些设计元素对于提升幸福感是不可或缺的？哪些元素对于幸福感的影响最大？

方法

研究范围和场地选择。

在底特律供水和污水处理部门（DWSD）优先采用绿色雨水基础设施（GSI）的地区，研究团队选择了间隔距离超过2415米的复证研究区域，以减少其产生的溢出效应。每个研究区都包含已入住的房屋和空置的地产，总体空置率为39%，且居民都是以黑人家庭和年收入低于2.5万美元（美国卫生与公众服务部制定的贫困准线）的家庭为主。

在每个研究区域内，研究团队在由底特律土地银行管理局（DLBA）管辖的空置地产上确定了潜在的GIS建造点，以及一个以“标准”方式管理的、作为对照组的空地。作为选址过程的一部分，团队与附近居民讨论了在每个场地上建造GIS的可能性。2015年，在每个研究区域的两个试点场地（由DWSD管辖）上，研究团队分别实施了两种不同的GIS设计。这些试点场地也是研究团队在2017年普查中测试设计方案的基础场地。

制定调查问卷和设计方案

为了解答研究问题，团队专门制定了一份调查问卷，其中包含10个设计方案的可视化解释（从为每个研究区域开发的15个方案中随机挑选），并列出了可能对关怀感、安全感、幸福感的认知以及居民对社区绿地的偏好产生影响的要素。根据居民向跨学科团队提出的见解，所有的设计方案均被赋予了朝向街道的

▲跨学科的行动研究：团队实施的跨学科行动研究过程将多个学科的学术知识和研究方法与社区和机构利益相关者的本地知识和经验相结合，最终带来了新颖的研究成果。

TRANSDISCIPLINARY ACTION RESEARCH. Our transdisciplinary action research process combined the scholarly knowledge and research methods of several disciplines with the local knowledge and practical insights of neighborhood and agency stakeholders to offer novel research results.

▲机会：利用雨水基础设施资源取得绿地效益。社区的空地被设计为新形式的绿色基础设施，在提升居民幸福感的同时还能实现街道径流的有效管理。通过这种方式，研究团队利用供水部门的资源为社区提供了更大的利益。

OPPORTUNITY: Leveraging stormwater infrastructure resources for greenspace benefits. By showing how vacant lots could be designed as new forms of green infrastructure that enhance well-being while also managing street run-off very effectively, we leveraged the water utility’s investment to deliver greater neighborhood benefits.

▲研究问题：哪些设计元素会提高居民的幸福感？研究团队选择了具有不同维护需求的景观设计元素，并假设安全感和关怀感会影响居民对社区空置地产改造的偏好以及他们对自身幸福的认知。

RESEARCH QUESTION: What design elements will enhance residents’ well-being? We selected elements with varying maintenance requirements, and hypothesized that residents’ perceptions of their safety and care would affect preferences for vacant property in their neighborhood, and their own well-being.

▲研究过程：在为期7年的项目中，研究团队在学术知识和方法，以及本地知识和实践经验之间反复检验，以建立可操作的新知识。该图展示了研究的一部分，它与上一张图所示的研究问题相关联。

RESEARCH PROCESS. We iterated between scholarly knowledge and methods, and local knowledge and practical insights to build actionable new knowledge in our seven-year project. Here, we focus on part of that research, which relates to our research question on image 4.

▲设计策略：借鉴学术研究和本地知识来选择设计元素。在调查问卷的设计上，团队根据过去的研究和本地知识提出了不同的设计元素，并假设这些元素会影响居民对关怀感和安全感的认知、幸福程度以及对附近空置地产的改造的偏好。

DESIGN STRATEGY: Draw on scholarship and local knowledge to select design elements. For the survey questionnaire design, we varied design elements suggested by past research and local knowledge that we hypothesized would affect residents’ perceptions of care and safety, their well-being and their preferences for transforming nearby vacant property.

▲方法：调查问卷和设计元素备选方案。团队的调查问卷中包含了10个设计方案的可视化阐述，它们是从为每个研究区开发的14个方案中随机挑选而出。这些方案是（如上一张图所示的）不同的设计元素以不同方式组合的结果。

METHOD: Questionnaire and design element alternatives. Our questionnaire included visualizations of 10 design alternatives, randomly selected from among 14 developed for each study area. They represented a factorial combination of the design elements we had varied, shown in image 6.

▲方法：试点场地的复证研究区域和居民普查。在供水部门采用绿色雨水基础设施（GSI）的地区，团队选择了一个总体地产空置率为39%的场地作为复证研究区域。随后，团队对底特律居民和前居民进行了培训，以安排他们对该区域的所有在住家庭逐一进行访问和调研。

METHOD: Replicate study areas for pilot sites and census survey. In an area designated for GSI implementation by the water utility, we selected replicate study areas with overall property vacancy of 39%. Then, we trained Detroit residents and former residents to conduct door-to-door interviews of all occupied households.

▲结论：谁参与了调查？本次普查的受访者以黑人和年收入低于2.7万美元的家庭为主，这与团队之前研究以及底特律市的人口普查统计数据相似，但与州和全国的统计数据存在较大差异。

RESULTS: Who was represented in the survey? Those interviewed were predominantly black and had household incomes below $27,000/year – similar to US Census statistics for our study area and the City of Detroit, but disproportionate with state and national statistics.

▲结论：谁应该维护社区绿地？受访者表示，依靠志愿者维护社区绿地并不是一个理想的解决方案，而是应当由市政府来维护。超过三分之一的人曾经参与过维护附近空置地产的工作。他们希望政府能够担负起这项责任。

RESULTS: Who should maintain neighborhood greenspaces? Respondents indicated that volunteering to maintain neighborhood greenspace was not a desirable solution, and the city should maintain neighborhood greenspace. More than 1/3 already filled gaps in maintenance of nearby vacant property. They wanted to see government take responsibility.

▲结论：哪些设计元素能够提高居民的幸福感？能够从多大程度上提高？考虑到需要尽可能地减少维护需求，修剪整齐的草坪成为了提高居民幸福感最基本的景观元素。不过，其他一些景观元素，尤其是低矮的开花灌木和草本植物，会比草坪更显著地提升幸福感。

RESULTS: What design elements enhance well-being? How much? Considering maintenance efficiencies, mown turf is the element most essential to well-being of residents, with significant improvements over infrequent mowing. However low-growing vividly flowering shrubs and herbs significantly enhance well-being compared with tree plantings or mown turf alone.

▲结论：居民的幸福感与拥有不同维护需求的特定设计元素相关联。除了对照组的空地之外，所有的设计方案都能非常有效地管理雨水。居民们强烈希望可以在自家附近的空地上种植灌木和鲜花，研究也证明这种方案能够带来最高的幸福感。

RESULTS: Well-being is associated with specific design elements that require different levels of maintenance. All designs manage stormwater very effectively. Since all alternatives except the control vacant lot managed stormwater very effectively, well-being could be decisive in design choices. Residents strongly preferred shrubs and flowers, associated with the highest well-being, for a vacant lot near their home.

▲结论：对设计的影响。利用雨水基础设施，景观设计师在小尺度设计元素上的选择会对贫困社区居民的幸福感产生显著的影响，并且有助于解决社区绿地质量的不平等问题。

CONCLUSIONS: Implications for design. Leveraging infrastructure investments, landscape architects’ choices of small-scale design elements can powerfully affect the well-being of people living in neighborhoods disadvantaged by property vacancy and poverty. This addresses greenspace inequities that contribute to health disparities.

▲分享知识，促进实践：图中展示了遗留城市的利益相关者人手一份的项目报告。在整个研究过程中，研究团队的首要任务是及时地与城市的利益相关者分享新知识，其中包括综合文献回顾（2017）和最终的综合评估（2019）。此外，团队还发表了数篇具有参考价值的学术论文，作为该项目的一部分。SHARING KNOWLEDGE FOR PRACTICE: Project reports used by legacy city stakeholders. Throughout our research, our first priority was to immediately share new knowledge with stakeholders in legacy cities – from synthetic literature reviews (2017) to our integrated assessment (2019). We also have produced refereed scholarly papers as part of this project.

▲价值：解决社区绿地中的系统性不平等问题。通过向跨学科团队中的机构决策者、社区领导以及焦点小组和受访居民学习，研究团队制定出了一系列小规模的设计元素，景观设计师可以采用这些元素来改善居民的福祉。

VALUE: Addressing systemic inequities in neighborhood greenspace. By learning from agency decisionmakers and neighborhood leaders in our transdisciplinary team and from residents in focus groups and our census survey, we identified small scale design elements that landscape architects can employ to make a difference in residents’ well-being.

PROJECT NARRATIVE

Importance of Research Goals

Our overarching goal was to inform design strategies that can address inequities in the quality of neighborhood greenspace, especially where property vacancies and inadequate maintenance have changed neighborhood landscapes in legacy cities. Quality of greenspace may affect the well-being of residents. Well-being is known to be associated with access to greenspace, and inequitable greenspace distribution is understood to be a driver of health disparities. However, health disparities research has not focused on greenspace quality: the small scale design elements that landscape architects routinely select. This is particularly important in neighborhoods characterized by widespread property vacancy, which undermines perceptions of safety and care. Neighborhood greenspace quality affects residents’ experiences as they look out the windows of their home, use their yard, or walk down their block. Compared with access to large public greenspaces, these experiences more immediately confront residents with glaring disparities between their neighborhoods and others’. This project built new knowledge to help landscape architects meaningfully contribute to resolving these inequities.

Research Problem

Our research problem was to identify how much small-scale design elements of neighborhood greenspace that presented different maintenance requirements could enhance residents’ well-being. Framing the problem in this way, we could focus on well-being of residents while also tuning results to address maintenance challenges of legacy cities.

We conceived of this problem on two complementary levels, both essential to the rigor of this actionable research:1. Basis in practical understandings and local knowledge: a transdisciplinary action research process that produced immediate change in a disadvantaged neighborhood. This required intensive iterative collaboration among agencies, NGOs, neighborhood residents and an interdisciplinary research team over seven years. It led us to understand that neighborhood greenspaces in legacy cities should be maintained by agency staff rather than relying on volunteers. Accepting the limited revenues of legacy cities, we framed our research questions around design alternatives that offered a range of maintenance efficiencies.

2. Basis in scholarly theory: testing the effects of landscape design elements on residents’ well-being in a replicable way that was informed by thorough review of the scholarly literature about well-being, preferences, and perceptions of neighborhood greenspace. Related to well-being, we identified a need to understand how small scale landscape elements might affect residents’ mental and emotional health, as well as their social and physical behavior that may affect health. Related to perceived care and safety, ample scholarly literature suggests that perceived care and safety of neighborhood greenspace affects well-being of residents of legacy cities, and many studies identify design elements that act as cues to care or safety. However, there is a need to put the pieces together to address inequity in neighborhood greenspaces – experimentally varying design elements to quantify their relationship to preferences, perceptions, and well-being.

Research Questions

Drawing on knowledge at both levels, we identified these design elements for investigation as cues to care or safety that could affect well-being: bollards, low-growing vividly flowering shrubs and herbs, deciduous trees in rows, mown turf.

We operationalized the research problem with these specific questions:• What combinations of these elements do residents most prefer for a nearby vacant lot?

• How does perceived safety, care, and attractiveness affect what residents prefer?

• How do residents expect different alternatives to affect their well-being, including mental or emotional health, interactions with neighbors, and likelihood to walk in their neighborhood?

• Considering the need to minimize maintenance requirements, which elements are essential to enhanced well-being? Which most greatly enhance well-being?

Methods

Study area and site selection. In an area that the Detroit Water and Sewerage Department (DWSD) had prioritized for GSI implementation, we selected replicate study areas separated by more than 2,415 m to reduce spillover effects across study areas. Each study area had a mix of occupied homes and vacant properties; overall vacancy was 39%. Each had majority black populations and a majority of households with incomes below $25,000/year (poverty level as per the US Department of Health and Human Services).

Within each study area our team identified potential sites for GSI construction on vacant properties owned by the Detroit Land Bank Authority (DLBA), and a control vacant lot for “typical” management. As part of site selection, the possibility of constructing GSI on each site was vetted with nearby neighbors. Then, in 2015 our team designed and constructed two different GSI designs on two pilot sites operated by the DWSD in each study area. These pilot sites were the base sites for design alternatives tested in the 2017 census survey that we report upon here.

Development of questionnaire and design alternatives. To answer our research questions, we developed a questionnaire including visualizations