A Review on the Use of Geodesign Processes in Managing Flood Vulnerability

Abstract

The integration of geodesign with vulnerability analysis offers a novel approach to landscape, urban, and environmental planning challenges. The interdisciplinary nature, engaged processes, and advanced spatial analytics in geodesign provide important component pieces for identifying and addressing vulnerable places. A comparative case-study approach explores the geodesign process and its efficacy in addressing flooding issues in diverse settings. The objectives of this review include assessing geodesign processes in the development of vulnerability indices and assessments, exploring their effectiveness and limitations, and providing insights across different scales and contexts. The work seeks to contribute to the advancement of vulnerability assessment methodologies and their broader role in the fields of landscape design and urban and environmental planning. The findings of this study are expected to provide insights for researchers and practitioners looking to produce more effective, sustainable, and resilient planning and design outcomes.

1. Introduction

In the evolving landscape of urban planning and design, the multifaceted challenges of resilience and urban sustainability have come to the fore. Cities around the world are grappling with policy and design approaches for managing social, economic, and ecological infrastructure more sustainably while simultaneously trying to improve resilience against climate-driven disasters. One such common disaster, in particular, poses a significant threat to urban areas on a global scale. It has the potential to cause widespread damage to infrastructure, disrupt economic activity, and endanger numerous human lives: flooding. Flooding vulnerability is a problem that affects many urban areas around the world. It is influenced by a wide range of factors, including geographic location, socio-economic conditions, and the affected built environment. Assessing and mitigating flood vulnerability is crucial for developing effective strategies to enhance urban resilience and sustainability. In this paper, we argue that the integration of geodesign processes and vulnerability analysis represents a pioneering approach to assessing, planning, and designing for flood mitigation and adaptation. Geodesign and its associated processes for landscape analysis and design represent the merger of geographic, landscape, and urban design principles [1]. It provides an interdisciplinary framework for large-scale planning and design by incorporating advanced spatial analysis and geographic information systems (GIS) science. The methodology has been instrumental in bringing analytics to complex design solutions [2], assessing outcomes of various design interventions [3], and crafting sustainable solutions to environmental, social, and urban challenges [4]. Despite an increasing application across fields such as urban planning [5], landscape architecture [6], and environmental conservation [7,8], the use of geodesign processes in assessing the vulnerability of populations or geographies has been limited. The geodesign approach, however, leverages transdisciplinarity and spatial analytical approaches to facilitate a comprehensive understanding of the interplay between environmental, social, and built factors that contribute to flood vulnerability.

In terms of landscape design, urban planning, and environmental management, vulnerability can be characterized by the susceptibility of ecological, social, or infrastructural systems to stresses and shocks [9,10]. Cutter describes it as the degree to which a system is susceptible to a specific stress; this includes changes in environment and/or extreme events [9]. Similarly, Turner et al. [11] argue that vulnerability is not solely determined by exposure to hazards (perturbations and stresses) but also by the sensitivity and resilience of the system experiencing such hazards. In general, vulnerability refers to the propensity or predisposition to be adversely affected by external or internal factors, such as environmental hazards, economic shocks, social inequalities, or personal circumstances. It represents a state of susceptibility or exposure to harm, damage, or loss [12]. Vulnerability can be influenced by various factors, including socio-economic status, age, gender, disability, geographic location, and access to resources or support systems. For the most part, the literature emphasizes the importance of understanding vulnerability through a lens of exposure, sensitivity, and resilience.

While vulnerability highlights the potential for harm or negative consequences, resilience focuses on the capacity to overcome adversity and maintain or regain a state of equilibrium or functionality [13,14]. Individuals, communities, or systems with higher levels of resilience are better equipped to navigate through challenges, mitigate the impact of adverse events, and recover more quickly and effectively. If vulnerability is the condition of susceptibility, resilience is the ability to adapt, recover, and bounce back from adverse or susceptible situations, challenges, or disturbances.

It is important to note that vulnerability and resilience are not static or absolute states; rather, they exist on a continuum and can be influenced by various factors, including personal characteristics, social support systems, and access to resources [15]. Furthermore, vulnerability and resilience are interconnected, as high levels of vulnerability can diminish resilience while enhancing resilience can reduce vulnerability to future adversities.

According to Cutter et al. [16], understanding urban vulnerability (and its evolution toward resilience) requires a comprehensive and integrated approach that transcends traditional disciplinary boundaries. This is especially important within the realm of complex urban and landscape design problems [17]. Transdisciplinary processes, a notable component of geodesign, aim to create a holistic understanding of specific design issues by drawing insights from multiple disciplinary perspectives to produce a more holistic understanding of the interdependencies between natural and human systems [18]. Geodesign process provides a basis for transdisciplinary engagement, bridging the gap between data-driven analysis and creative problem-solving.

Geodesign principles can be effectively integrated into vulnerability assessments by leveraging the spatially explicit and transdisciplinary nature of the process. However, despite the growing recognition of geodesign’s potential in various fields, there is a lack of research specifically focusing on its application in vulnerability assessments. There is evidence in the literature on the theoretical benefits of integrating geodesign principles with vulnerability analysis, but there is a dearth of empirical studies that evaluate the effectiveness and limitations of the theoretical model in real-world contexts. Moreover, the existing literature does not adequately address the challenges and best practices associated with implementing the geodesign framework in vulnerability assessments across different scales and contexts. We aim to address this by critically evaluating comparative case studies with a particular focus on flooding. By examining the strengths, weaknesses, and lessons learned from these case studies, we hope to provide insights into the potential benefits and challenges of integrating geodesign into flood vulnerability assessments and to identify best practices and recommendations for future research and practice.

The primary objectives of this research are to (a) investigate how geodesign’s comprehensive and integrated approach can improve vulnerability indices and assessments; (b) explore the effectiveness and limitations of applying geodesign principles in real-world vulnerability assessment case studies; and (c) provide insights into the challenges and best practices associated with implementing the geodesign framework in vulnerability assessments across different scales and contexts. The work seeks to contribute to the advancement of vulnerability assessment methodologies and the broader fields of landscape design and urban and environmental planning. The findings of this study are expected to provide insights for researchers and practitioners looking to integrate geodesign principles into vulnerability assessment processes, ultimately leading to more effective, sustainable, and resilient planning and design outcomes.

This paper argues that the inclusion of vulnerability analysis within a geodesign process can enhance the way vulnerabilities are identified, assessed, and mitigated, leading to more informed, effective, and adaptive design strategies for reducing risk. To better understand the potential synergies between geodesign and vulnerability analysis and to identify the gaps in existing research, Section 2 provides a comprehensive review of the literature in these two fields. This review highlights the key contributions of previous studies and explores how geodesign can further inform vulnerability assessment and mitigation strategies, setting the stage for the present research. In Section 3, we outline our case study methodology, detailing parameters and evaluative framework used to examine the application of geodesign principles in addressing vulnerabilities with a specific focus on vulnerability to flooding. Section 4 describes our findings and discusses the impact of integrating geodesign on urban flood resilience. We discuss the broader implications of our study in Section 5, evaluating the utility of the methods described. The paper concludes with a summary of key insights and recommendations for advancing the application of geodesign in vulnerability assessments, along with a discussion of some next steps in Section 6.

2. Literature Review: Geodesign and Vulnerability

Geodesign. Geodesign, as defined by Steinitz [1], is a design and planning method that couples landscaped scaled design and design processes with impact simulations informed by analytically derived geographic contexts. Its interdisciplinary collaboration [6], stakeholder engagement [5], and spatial analysis [7] make it well-suited for assessing the multidimensional nature of vulnerability.

The literature on Geodesign suggests that geodesign principles and methods could enhance vulnerability assessments by providing a more integrated and spatially explicit approach [3], there is a lack of empirical studies demonstrating the effectiveness and limitations of this integration in practice. Geodesign principles can effectively enhance vulnerability assessments by providing a more integrated, spatially explicit, and transdisciplinary approach [3]. Traditional vulnerability assessment methods often struggle to capture the dynamic and multidimensional nature of the vulnerability, highlighting the need for more comprehensive and adaptive approaches [16]. Geodesign leverages the power of geospatial data, environmental factors, and stakeholder input to create a holistic understanding of the spatial distribution of vulnerability and identify targeted interventions [1]. By integrating advanced spatial analysis techniques, collaborative decision-making processes, and design thinking, geodesign offers a promising framework for addressing the complex challenges of vulnerability assessment and enhancing the resilience of urban systems [19]. This research aims to address this gap by critically evaluating the application of the geodesign framework in conducting vulnerability assessments through comparative case studies.

Vulnerability. Vulnerability in urban and environmental planning refers to the susceptibility of ecological, social, or infrastructural systems to stresses and shocks [9,10]. Key dimensions include physical exposure, socio-economic sensitivities, and adaptive capacity [12], with urbanization, climate change, and socio-economic disparities as major drivers [20,21]. Birkmann [12] suggests that it is essential to consider the physical, social, economic, and environmental dimensions of vulnerability when assessing the resilience of any urban systems [12]. Physical vulnerability refers to the potential for damage to infrastructure and the built environment, while social vulnerability considers the characteristics of populations that influence their capacity to anticipate, cope with, and recover from hazards. Economic vulnerability assesses the potential for losses and disruptions to economic activities, and environmental vulnerability examines the sensitivity of natural systems to human-induced stresses. Understanding these interconnected dimensions is crucial for developing comprehensive strategies to reduce vulnerability and enhance urban resilience.

To effectively assess and address vulnerability in urban planning, it is necessary to adopt a systems approach that considers the complex interactions and feedback between different components of urban systems [18]. This approach should also incorporate the knowledge and perspectives of diverse stakeholders, including local communities, policymakers, and experts from different disciplines [22]. However, traditional vulnerability assessment methods often struggle to capture the dynamic and multidimensional nature of vulnerability, highlighting the need for more integrated and adaptive approaches [16].

Vulnerability and Geodesign. The integration of geodesign principles and methods into vulnerability assessments offers a promising avenue for addressing the limitations of traditional approaches. Geodesign’s emphasis on interdisciplinary collaboration, stakeholder engagement, and spatial analysis [1] aligns well with the need for a systems approach to vulnerability assessment [18]. By incorporating geospatial data, environmental factors, and stakeholder input, geodesign can help planners and decision-makers better understand the spatial distribution of vulnerability and identify targeted interventions [3].

Despite the existence of studies exploring the potential for geodesign in resilience planning [3,23] and climate change adaptation [24], more systematic evaluations are needed to understand how geodesign can be integrated into vulnerability assessments effectively across different contexts and scales.

3. Materials and Methods

This study employs a comparative case study approach to evaluate the application of the geodesign framework in conducting vulnerability assessments with a specific focus on flooding. Comparative case studies are particularly useful for understanding complex phenomena in real-world contexts and for identifying patterns, similarities, and differences across different cases [25]. The approach can facilitate a deeper understanding of underlying issues by providing contextual diversity [26]. The methodological processes of comparative analysis include case study methods, social-science analytical methods, and methods using various scales of analysis [27]. Comparative methods have been found useful for gaining insight into the causal mechanisms of both urban and landscape-scaled phenomena [28]. According to Lange [27], the use of comparative case-study methods can help balance “ideographic and nomothetic explanations of empirical phenomena”. The approach has been used to compare nations [29], cities [30], and smaller landscapes [31]. Marsal-Llacuna [32] proposes the use of real-time data to construct smart-city indices, and Frey [33] uses a comparative framework to study sustainable urban form. Solecki et al. [34] use comparisons for urban climate change mitigation and adaptation analysis.

Comparative methods are not without limitation, however. Limitations identified in the literature include a lack of clear research questions [35], context-specificity [36], cultural biases [37], and limited applicability or understandability of the findings [38]. According to Timm [39], one major shortcoming of comparative methods is “a tendency to offer parallel descriptions of different places without a clear research question, hypothesis, or coherent system of comparison”.

Two case studies are selected for this comparative research that represent two different contextual applications of the geodesign process in flood-prone contexts in the US. They range from a data-rich urban setting (League City, TX, USA) to a data-scarce indigenous community (Tohono O’odham Nation, Arizona, USA). This diversity allows for a more comprehensive evaluation of the adaptability and transferability of the framework across scales, geographies, and social contexts.

The decision to employ only two case studies is justified by considerations of resource constraints, the need for focused investigation, theoretical relevance, methodological rigor, and practical feasibility. Conducting an urban analysis entails comprehensive data collection, synthesis, and interpretation, which can be resource-intensive in terms of time, finances, and manpower. By focusing on a limited number of case studies, we can allocate resources effectively, ensuring in-depth investigation and robust analysis. Selecting a smaller number of case studies also allows for a more concentrated examination of specific phenomena. Carefully selecting our two case studies to represent diverse urban typologies, socio-economic conditions, and policy contexts can enhance the generalizability and applicability of our findings to broader urban contexts [40]. Furthermore, limiting the number of case studies facilitates comparability and consistency in data collection, analysis, and reporting (see

Table 1. Evaluative Indicators and criteria.

Indicator	Criteria and Description
Spatial Analysis	Integration of relevant data layers: Incorporating diverse spatial data layers allows for a holistic analysis of physical, environmental, and social vulnerability factors. Use of spatial analysis techniques: Enables extraction of meaningful insights, identification of high-risk areas, and assessment of potential impacts. Generation of spatial outputs: Clear and informative spatial outputs communicate findings and support targeted mitigation strategies. Spatial resolution: High-resolution data improves reliability, enables the identification of localized vulnerabilities, and supports fine-grained decision-making.
Stakeholder Engagement	Types of stakeholders: Engaging diverse stakeholders captures unique perspectives, experiences, and needs, particularly of vulnerable or marginalized groups. Engagement methods: Multiple participatory methods cater to different preferences, uncover local knowledge, ensure accessibility, and enable broad participation. Incorporation of stakeholder input: Ensures findings are relevant, legitimate, and actionable.
Interdisciplinary Integration	Representation of relevant disciplines: Captures diverse drivers, impacts, and potential solutions related to vulnerability. Application of integrative methods and tools: Enables synthesis of knowledge and insights across disciplines.
Feedback Loops and Iterative Processes	Presence of monitoring and evaluation mechanisms: Allow tracking of performance, identification of gaps, and assessment of effectiveness in informing decisions. Evidence of iterative refinements: Demonstrate responsiveness to feedback, adaptability to new information, and the ability to remain relevant over time.
Resilience and Adaptability	Incorporation of resilience indicators: Measures assessing capacity to withstand, recover, and adapt to stresses and shocks. Use of adaptive design principles: Ensures proposed strategies are robust and adaptable to changing conditions. Consideration of long-term climate change impacts: Identifies potential future vulnerabilities and informs robust adaptation strategies.

).

Case Study Comparative Analysis. This study employs 2 contrasting cases to assess the adaptability and transferability of the geodesign framework across diverse contexts, scales, geographies, and social settings using flood vulnerability as a common factor.

The first case study, set in a data-rich urban context, allows for the evaluation of the framework’s effectiveness in spatial analysis, stakeholder engagement, interdisciplinary integration, and iterative processes. In contrast, the second case study, situated in a data-scarce indigenous community, enables the assessment of the framework’s adaptability, ability to integrate diverse data sources, and capacity to facilitate community-driven planning processes. The contrasting nature of these two cases provides insights into the strengths, weaknesses, and best practices for applying the geodesign framework in flood vulnerability assessments, contributing to a holistic understanding of its potential and limitations.

Evaluation Framework. From the literature, we identify five key variable categories to base our evaluation on: spatial analysis, stakeholder engagement, interdisciplinary integration, feedback and iterative processes, and resilience and adaptability. Spatial analysis evaluates the integration, sophistication, and relevance of spatial data and analytical methods. Stakeholder engagement refers to the extent and quality of participation by local communities, policymakers, designers, planners, and scientists in the assessment process. This variable is important for ensuring that the assessment incorporates a wide range of perspectives and knowledge bases [22]. Interdisciplinary integration is the extent to which the framework incorporates insights and methodologies from geography, urban planning, architecture, and environmental science into the analysis, design, and planning processes [41]. Iterative processes and feedback loops refer to the existence of mechanisms for continuous refinement of design decisions in response to new information, changing conditions, and ongoing monitoring of the system [1,42]. Finally, resilience and adaptability describe the framework’s ability to enhance the resilience and adaptability of communities, considering both immediate and long-term impacts [23,41].

We use this evaluative framework to study our 2 cases to understand the potential contribution of geodesign to urban resilience and flood risk management, as well as to assess the effectiveness of geodesign approaches in vulnerability assessment.

We use a systematic ‘document analysis’ methodological approach for our comparative case study research to generate insights, identify patterns, and construct narratives within and across case studies [43]. Textual materials provide valuable insights into the beliefs, values, norms, practices, decisions, and actions of individuals, groups, organizations, and institutions within specific socio-cultural, political, economic, and historical contexts [44]. For each case, we extensively review and analyze a diverse set of textual resources, including published papers, reports, official documents, and other published materials (newspaper, magazine articles, etc.). Our analysis focuses on extracting information from each document source related to our selection of indicator variables. For example, we examine plans and reports to identify spatial datasets and outputs connected to our flood vulnerability indicator.

4. Results

Each resulting case study is presented using our noted 5 evaluation criteria (see Table 2).

4.1. Case Study 1: “Integrating a Resilience Scorecard and Landscape Performance Tools into a Geodesign Process”

This study demonstrates an application of geodesign principles in League City, Texas. League City is a part of the Houston metro area in Southeast Texas on Galveston Bay and is considered highly urbanized. The case is aimed at urban flood resilience and employs an approach that combines a resilience planning scorecard, geodesign tools, and a landscape performance calculator to assess potential design interventions for sea-level rise vulnerabilities.

4.1.1. Spatial Analysis

In the League City case study, spatial analysis played a crucial role in delineating the ecological and social vulnerabilities at multiple scales by integrating diverse datasets within a GIS framework. In this context, to accurately identify the vulnerable area, the study integrates comprehensive data within GIS, including environmental, social, urban planning, and economic datasets. Researchers on the project followed a specific methodology as outlined in a reported “Methods” section [23]. First, to project the flood vulnerability, researchers utilized the FEMA 100-year flood elevations on Digital Flood Insurance Rates Maps and data derived from the US Army Corps of Engineers sea-level rise calculator to project the 100-year flood plain in 2100 at the site. As a result, the researchers have mapped the FEMA 100-year floodplain for 2100, identifying 3 levels of flood risk in the regional projection and 4 distinct flooding scenarios at the site level.

To address the social dimensions of vulnerability, in “Vulnerability projection”, the League City case study incorporated block-level socio-economic data into the spatial analysis, resulting in a comprehensive vulnerability map that classified the site as highly vulnerable. In addressing the social dimensions of vulnerability, the study integrated block-level social data into the suitability analysis. This included metrics such as percentage of individuals in poverty, per capita income in 2010, percentage of persons 65 years of age or older, percentage of persons 17 years of age or younger, percentage of minority, less than High School Diploma, High School Diploma, or Higher, and improvement values. Consequently, by integrating social and economic data into the geographic information system (GIS) at a regional scale, the researchers produced a final vulnerability map, depicted as “Figure 5 [23]. Hazard vulnerability outputs by census block in League City, TX, USA”. Through this comprehensive analysis, the site was classified as having a high level of vulnerability.

4.1.2. Stakeholder Engagement

The League City case study employed participatory methods to effectively engage stakeholders, integrating local insights and community feedback into the planning process to align the master plan with site-specific needs and aspirations. Under the “Master planning strategy-Community engagement and feedback” section, the study explains that the research and design efforts addressing those issues in the neighborhood adopted a participatory approach. This collaborative process involved local community members and senior planners from League City and included, “green infrastructure, open space planning, and community design scenarios developed through several engagement sessions assisted by community input”. This highlights that in this study, participatory methods were utilized to elicit community feedback on key issues such as green infrastructure, open space planning, and community design scenarios to enhance flood resilience. The research and design efforts within this neighborhood were conducted through a collaborative, participatory approach, engaging local community members and senior planners of League City. This approach facilitated the acquisition of local insights, which were subsequently integrated into the planning process. Evidence of this integration was manifest in the subsequent meetings between community members and the design teams. These sessions focused on providing feedback and critiquing the proposed design scenarios, leading to the iterative refinement of the community’s master plan, therefore aligning it more closely with the site-specific needs and aspirations identified through stakeholder engagement.

4.1.3. Interdisciplinary Integration

The League City case study demonstrates the value of interdisciplinary integration in comprehensively evaluating flood vulnerability. It employs a multifaceted approach that combines resilience planning scorecards, Geodesign tools, and landscape performance calculators. This approach showcases how integrating methods and tools from different disciplines can provide a more holistic understanding of flood vulnerability and inform effective mitigation strategies. Extracting from their conclusion, the resilience planning scorecard methodology, combined with policy analysis techniques, provided insights into the evaluation of existing local plans, regulations, and policies, determining their efficacy in mitigating vulnerabilities to hazards like flooding, sea-level rise, and other climate-related risks. Geodesign tools facilitated the integration of datasets from various fields, including social science (via the American Community Survey), geology, and environmental science (flood projections), enhancing the understanding of the city and site in both human and environmental aspects. Landscape performance calculators were employed as impact models to evaluate the flood attenuation capabilities of the site’s master plan, providing a quantitative measure of the landscape’s potential to mitigate flood impacts.

4.1.4. Feedback Loops and Iterative Processes

The participatory involvement featured feedback loops and iterative processes, which were initiated four times over 8 months. As evident from the quote, “a third and fourth meeting involved a feedback loop between community members and the design team in which a series of design scenarios were presented and critiqued by neighborhood members”. A total of 4 meetings were held, and the third and fourth meetings involved feedback from community members and the design team. During these meetings, the design team presented a series of design scenarios, which were then critiqued by neighborhood stakeholders and subsequently revised to reflect that feedback.

4.1.5. Resilience and Adaptability

The League City case study showcases the development of a data-driven, resilient community plan that incorporates a comprehensive array of flood attenuation strategies, ensuring the city’s capacity to withstand and recover from projected extreme conditions up to 2100. In this study, a data-driven community plan was developed for the city, designed to withstand the extreme conditions projected for 2100. The master plan incorporates a comprehensive array of flood attenuation mechanisms, drawing from both structural and non-structural strategies informed by resilient community design practices globally. These strategies are structured to be executed in three phases: retreat from flood-prone areas, flood mitigation, and flood control. Each phase is rigorously evaluated through cost-benefit analysis, employing landscape performance calculators to project their efficacy up to the year 2100, therefore ensuring a strategic approach to building resilience.

The League City case study demonstrates the potential of geodesign as a comprehensive, data-driven approach for analyzing and mitigating landscape vulnerabilities, particularly in the context of flood resilience planning. Through the integration of spatial analysis, stakeholder input, and resilience planning, geodesign facilitates a comprehensive and adaptive framework for managing and mitigating landscape vulnerabilities, highlighting its vital role in sustainable and resilient community planning.

4.2. Case Study 2: Resilience-Based Adaptation in Data-Scarce Areas: Flood Risk Assessment Using Geodesign in the Tohono O’odham Nation

The Sif Oidak District is a part of the greater Phoenix metropolitan statistical area in Arizona. Its case study showcases the application of Geodesign in developing a community-based, flood-resilient land-use plan for a data-limited Native American community facing significant flood risks. This community faces significant flood risks due to a combination of factors, including shallow soils, sparse vegetation, heavy rainfall, significant elevation changes, and traditional living patterns close to water sources. The study demonstrates the integration of qualitative, statistical, and spatial analysis with local insights to develop a strategy aimed at community resilience against flooding.

4.2.1. Spatial Analysis

In contrast to the League City case, the Sif Oidak District faced a scarcity of data for assessing flood vulnerability, lacking resources such as FEMA flood maps, flood zones, or county-level risk data. To address this challenge, the researchers employed a different approach, as detailed in the “Spatial Analysis of Flood Risk” section under “Research Design” in their study. They utilized remote sensing data in conjunction with a flood risk model to generate a flood risk map for the Sif Oidak District. The determination of flood risk values was based on a 10-m digital elevation model, which provided insights into slope, flow accumulation, and the drainage network. This alternative methodology allowed the researchers to overcome the data limitations and assess flood risk in the study area. Additionally, rainfall data for the basin was considered, while land-use cover and soil data were sourced from the U.S. Geological Survey and the United States Department of Agriculture (USDA) Natural Resource Conservation Service, respectively. The Sif Oidak District has been delineated into five distinct risk levels for flood vulnerability assessment: very low, low, medium, high, and very high risk.

4.2.2. Stakeholder Engagement

Given the scarcity of data, engaging stakeholders is crucial for identifying flood-prone areas in this project. A “Working with the Tohono O’odham Nation” section in their report documents the project’s collaboration with a diverse group of stakeholders. “Local community members, district council members, and officials from the Tohono O’odham Nation’s planning department” were involved in the process. For example, community members completed surveys to gather information on past flooding events and perceptions of flood risk and participated in the Geodesign workshop to create geospatial data mapping of known flood areas from the most recent and historical flood events. Through the use of mixed qualitative and quantitative methods, such as visioning sessions and Geodesign workshops, these stakeholders have actively participated, contributing their local knowledge and preferences to the planning process.

The comprehensive flood vulnerability assessment developed in the Sif Oidak District case study, which incorporates local input and knowledge, demonstrates the significant value added by stakeholder engagement in enhancing flood information and identifying risk reduction strategies. As a result, a thorough flood vulnerability assessment, “Mixed-Methods Flood Risk Map”, has been developed. It not only spatially identifies flood zones but also comprehends the frequency and locations of flood events within the community. Incorporating local input, it assesses the severity of damage and the frequency of displacement among community members, evaluates their perceptions of flood risk for both their community and the district, and identifies viable strategies to reduce flood risks. This study has underscored the significant enhancement of flood information in the district through stakeholder engagement.

4.2.3. Interdisciplinary Integration

The Sif Oidak District case study demonstrates the value of interdisciplinary integration in analyzing landscape vulnerabilities, although the lack of social vulnerability considerations highlights an area for improvement in the Geodesign approach. In the “Working with the Tohono O’odham Nation”—“Geodesign workshop” section, the report outlines the integration of geodesign through various methods. These include community-based participatory GIS, a pre-workshop visioning session, a geodesign workshop integrated with GIS practice, and surveys. This multifaceted approach allowed for the incorporation of geodesign principles and community input throughout the process.

4.2.4. Feedback Loops and Iterative Processes

The Sif Oidak District case study illustrates the importance of feedback loops and iterative processes in adapting to evolving conditions and community input, although the lack of future flood risk projections raises questions about the long-term reliability of the developed flood risk map. In this instance, a continuous feedback loop was implemented during community engagement to gather perceptions of flood risks before and after the workshops, allowing for adjustments in project strategies based on this feedback. As part of the Geodesign process, the community identified flood areas, weakened and aging berms, and land uses that could withstand flood damage, as well as areas of severe and minimal flooding. Consequently, the Sif Oidak District community was successful in developing a map depicting historical or known flood risk areas.

4.2.5. Resilience and Adaptability

The study demonstrates the practical value of flood risk assessments in enhancing resilience and adaptability despite its limited approach to incorporating resilience indicators. By focusing primarily on flood risk, the study may have overlooked other critical dimensions of resilience, missing opportunities to provide a more holistic understanding of the community’s capacity to cope with and adapt to stresses and shocks. Nonetheless, the case study showcases how flood risk assessments can inform land-use planning and guide development decisions to enhance community resilience. Leveraging local knowledge and scientific data, community members and researchers formulated flood-resilient land-use designations encompassing ten different land uses. The study’s adaptability is demonstrated by the initiation of housing developments in low-risk areas identified through community insights and spatial flood risk analysis. However, future studies could benefit from incorporating a broader range of social, economic, and environmental indicators to fully capitalize on the potential of resilience indicators in vulnerability assessments. By taking a more comprehensive approach to assessing resilience, vulnerability assessments can provide a more complete picture of a community’s capacity to withstand and recover from stresses and shocks and inform the development of targeted strategies to build resilience over time.

While the Sif Oidak District case study showcases the successful integration of community input and scientific research through the geodesign approach, it also reveals limitations in addressing future flood risks and incorporating iterative processes for land-use planning adaptations. This collaborative effort has successfully identified areas susceptible to severe and minimal flooding, deteriorating berms, and locations ideal for flood-resilient land use, thus promoting resilience in data-scare areas. The limitation of this study lies in the absence of iterative processes for future flood projections and the lack of feedback concerning proposed land-use planning adaptations based on future flood scenarios.

Table 2. Case Study Comparison.

Indicator	Case Study 1	Case Study 2
Spatial Analysis	Integration of relevant data layers: The study integrated diverse datasets within a GIS framework, including FEMA flood maps, sea-level rise projections, and socio-economic data.	Integration of relevant data layers: The study integrated a 10-m digital elevation model, rainfall data, land-use cover, and soil data to assess flood risk.
	Use of the spatial analysis techniques: Overlay analysis and vulnerability mapping	Use of the spatial analysis techniques: Flood risk modeling and GIS toolkits
	Generation of spatial outputs: Projection of FEMA 100-year flood plain; regional hazard vulnerability map; flood vulnerability maps, delineating areas of low, medium, and high vulnerability.	Generation of spatial outputs: A flood risk map delineating five distinct risk levels (very low, low, medium, high, and very high);
	Spatial resolution: Census block level for socio-economic vulnerability analysis, and municipal and local scales for future flood-prone area projection.	Spatial resolution: A 10-m digital elevation model for flood risk modeling.
Stakeholder Engagement	Types of stakeholders: Local community members and senior planners of League City.	Types of stakeholders: Local community members, district council members, and officials from the Tohono O’odham Nation’s planning department.
	Engagement methods: A collaborative, participatory approach, facilitating feedback and critique of proposed design scenarios.	Engagement methods: A mix of qualitative and quantitative methods, including surveys, visioning sessions, and Geodesign workshops, indicating a high level of participation and collaboration.
	Incorporation of stakeholder input: The planning process involved refining the community’s master plan based on “responses from the community to the design team”, which were “utilized to condense the scenarios into one unified revised master plan”.	Incorporation of stakeholder input: The mapping of “historical flood risk or known flood risk areas identified by Sif Oidak District community members” and the development of a flood vulnerability assessment through the “Sif Oidak Geodesign workshop to develop a community-based land-use plan”
Interdisciplinary Integration	Representation of relevant disciplines: The study combined resilience planning scorecards, geodesign tools, and landscape performance calculators.	Representation of relevant disciplines: The study employed Geodesign as a framework for integrating different methods and perspectives.
	Application of integrative methods and tools: The study employed a sequential approach, utilizing resilience scorecards for policy analysis, geodesign tools for data integration, and landscape performance calculators for impact assessment.	Application of integrative methods and tools: The study combined participatory GIS, visioning sessions, and Geodesign workshops to facilitate interdisciplinary integration.
Feedback Loops and Iterative Processes	Presence of monitoring and evaluation mechanisms: As evident from the quote (from results), this demonstrates the presence of feedback mechanisms during stakeholder engagement and the revision of the master plan.	Presence of monitoring and evaluation mechanisms: The study implemented a continuous feedback loop during community engagement to gather perceptions of flood risks before and after the workshops.
	Evidence of iterative refinements: The study showed evidence of iterative refinements through the creation and refinery of the master plan. However, it reveals a shortcoming in comprehensively testing the master plan against various future flood scenarios, indicating a need for more robust iterative processes.	Evidence of iterative refinements: The study showed evidence of iterative refinements through the identification of flood areas, weakened berms, and flood-resilient land uses based on community input. However, it lacked projections of future flood scenarios, potentially limiting its ability to handle emergent issues related to long-term flood risks.
Resilience and Adaptability	Incorporation of resilience indicators: The study developed a data-driven, resilient community plan incorporating a comprehensive array of flood attenuation strategies.	Incorporation of resilience indicators: The study considered flood risk as a key indicator for assessing resilience.
	Use of adaptive design principles: The master plan employs a phased approach, including retreat, flood mitigation, and flood control strategies, ensuring adaptability to future conditions.	Use of adaptive design principles: The study developed flood-resilient land-use designations based on community insights and spatial flood risk analysis.
	Consideration of long-term climate change impacts and uncertainties: The study evaluates the master plan’s performance up to the year 2100, considering projected extreme conditions and sea-level rise.	Consideration of long-term climate change impacts: The study did not explicitly address long-term climate change impacts or future flood risk projections.

Table 2. Case Study Comparison.

Indicator	Case Study 1	Case Study 2
Spatial Analysis	Integration of relevant data layers: The study integrated diverse datasets within a GIS framework, including FEMA flood maps, sea-level rise projections, and socio-economic data.	Integration of relevant data layers: The study integrated a 10-m digital elevation model, rainfall data, land-use cover, and soil data to assess flood risk.
	Use of the spatial analysis techniques: Overlay analysis and vulnerability mapping	Use of the spatial analysis techniques: Flood risk modeling and GIS toolkits
	Generation of spatial outputs: Projection of FEMA 100-year flood plain; regional hazard vulnerability map; flood vulnerability maps, delineating areas of low, medium, and high vulnerability.	Generation of spatial outputs: A flood risk map delineating five distinct risk levels (very low, low, medium, high, and very high);
	Spatial resolution: Census block level for socio-economic vulnerability analysis, and municipal and local scales for future flood-prone area projection.	Spatial resolution: A 10-m digital elevation model for flood risk modeling.
Stakeholder Engagement	Types of stakeholders: Local community members and senior planners of League City.	Types of stakeholders: Local community members, district council members, and officials from the Tohono O’odham Nation’s planning department.
	Engagement methods: A collaborative, participatory approach, facilitating feedback and critique of proposed design scenarios.	Engagement methods: A mix of qualitative and quantitative methods, including surveys, visioning sessions, and Geodesign workshops, indicating a high level of participation and collaboration.
	Incorporation of stakeholder input: The planning process involved refining the community’s master plan based on “responses from the community to the design team”, which were “utilized to condense the scenarios into one unified revised master plan”.	Incorporation of stakeholder input: The mapping of “historical flood risk or known flood risk areas identified by Sif Oidak District community members” and the development of a flood vulnerability assessment through the “Sif Oidak Geodesign workshop to develop a community-based land-use plan”
Interdisciplinary Integration	Representation of relevant disciplines: The study combined resilience planning scorecards, geodesign tools, and landscape performance calculators.	Representation of relevant disciplines: The study employed Geodesign as a framework for integrating different methods and perspectives.
	Application of integrative methods and tools: The study employed a sequential approach, utilizing resilience scorecards for policy analysis, geodesign tools for data integration, and landscape performance calculators for impact assessment.	Application of integrative methods and tools: The study combined participatory GIS, visioning sessions, and Geodesign workshops to facilitate interdisciplinary integration.
Feedback Loops and Iterative Processes	Presence of monitoring and evaluation mechanisms: As evident from the quote (from results), this demonstrates the presence of feedback mechanisms during stakeholder engagement and the revision of the master plan.	Presence of monitoring and evaluation mechanisms: The study implemented a continuous feedback loop during community engagement to gather perceptions of flood risks before and after the workshops.
	Evidence of iterative refinements: The study showed evidence of iterative refinements through the creation and refinery of the master plan. However, it reveals a shortcoming in comprehensively testing the master plan against various future flood scenarios, indicating a need for more robust iterative processes.	Evidence of iterative refinements: The study showed evidence of iterative refinements through the identification of flood areas, weakened berms, and flood-resilient land uses based on community input. However, it lacked projections of future flood scenarios, potentially limiting its ability to handle emergent issues related to long-term flood risks.
Resilience and Adaptability	Incorporation of resilience indicators: The study developed a data-driven, resilient community plan incorporating a comprehensive array of flood attenuation strategies.	Incorporation of resilience indicators: The study considered flood risk as a key indicator for assessing resilience.
	Use of adaptive design principles: The master plan employs a phased approach, including retreat, flood mitigation, and flood control strategies, ensuring adaptability to future conditions.	Use of adaptive design principles: The study developed flood-resilient land-use designations based on community insights and spatial flood risk analysis.
	Consideration of long-term climate change impacts and uncertainties: The study evaluates the master plan’s performance up to the year 2100, considering projected extreme conditions and sea-level rise.	Consideration of long-term climate change impacts: The study did not explicitly address long-term climate change impacts or future flood risk projections.

5. Discussion

Our case studies demonstrate the role of geodesign in assessing flood vulnerability. The findings reveal that geodesign serves as a useful tool in both data-rich and data-scarce contexts. In each of our five indicators—spatial analysis, stakeholder engagement, interdisciplinary integration, feedback loops and iterative processes, and resilience and adaptability—geodesign processes were proven to be vital components in assessing and addressing flood vulnerability.

The case studies presented explore the synergies between geodesign and vulnerability analysis to evaluate the effectiveness of integrating geodesign principles into vulnerability assessments across diverse contexts. The League City case study demonstrates the application of geodesign in a data-rich urban environment, while the Sif Oidak District case study describes a more rural, data-scarce environmental setting. Both case studies highlighted the critical roles of spatial analysis, stakeholder engagement, and interdisciplinary integration in enhancing flood resilience planning. However, they also revealed limitations in addressing social vulnerability, future flood risks, and the need for more robust feedback loops and iterative processes. In this discussion, we synthesize the key findings from these case studies and examine their broader implications for the integration of geodesign and vulnerability analysis in urban and environmental planning.

The comparative analysis of the two case studies emphasizes the importance of utilizing the geodesign approach and integrating comprehensive spatial analysis, stakeholder engagement, and interdisciplinary methods in flood vulnerability resilience planning. In League City, Texas, geodesign principles have been applied comprehensively to assess urban flood resilience in a data-rich environment. On the other hand, the case of Tohono O’odham Nation’s Sif Oidak District illustrates the unique challenges and innovative solutions that emerge when implementing geodesign strategies in data-limited environments. As a result of this comparison, it is evident that geodesign is adaptable and useful for enhancing flood resilience planning in various contexts.

Spatial Analysis: Both case studies highlight the indispensable role of spatial analysis in flood risk management. While League City leveraged detailed FEMA data and sea-level rise projections, Sif Oidak employed remote sensing and local knowledge to compensate for data scarcity. Spatial analysis techniques can adapt to varying data availability environments through these approaches. The League City case study demonstrates the effective delineation of ecological and social vulnerabilities at the municipal scale, although the analysis faced limitations in capturing fine-grained social vulnerability data for site-specific design and planning. They have pinpointed the flood-prone area with projections of the sea-level rise. Through the flood projections, they also critically evaluated the existing policy frameworks, assessing their efficacy in mitigating flood risks. Moreover, the articulated flood scenarios at the site-specific level provided essential insights, facilitating the refinement of land-use planning, community design, and landscape architecture initiatives. Nonetheless, the analysis faced challenges in addressing social vulnerability at the municipal scale. Despite utilizing block-scale census data, the resolution was inadequate for capturing the nuanced details of the site and its immediate surroundings, partly due to the data being aggregated into three broad categories. As a result, the study uniformly classified the entire site as having high social vulnerability, while the surrounding areas were categorized as medium to high vulnerability. The broad categorization of vulnerability constrained the data’s applicability for detailed design purposes, impeding the capacity for conducting accurate, site-specific analyses. This limitation is significant in the context of landscape architecture and urban planning, where detailed, nuanced information is crucial for informed decision-making and effective design implementation. The Sif Oidak District case study highlights the critical role of spatial analysis in identifying vulnerable areas by integrating remote sensing datasets and GIS toolkits, particularly in data-scarce contexts. Its strength lies in the integration of remote sensing datasets and GIS toolkits. It is a vital step in identifying vulnerable areas.

Stakeholder Engagement: The engagement of local communities and stakeholders proved vital in both contexts, enhancing the relevancy and acceptance of the planning processes. In League City, stakeholder feedback refined urban planning initiatives, while in the Sif Oidak District, it directly influenced the development of a flood risk map and land-use strategies. Nevertheless, both cases revealed gaps in documenting the extent to which stakeholder input impacted the final outcomes, pointing to a need for more transparent and detailed engagement records. While stakeholder engagement was crucial in shaping the League City master plan, the lack of detailed documentation of community members’ specific suggestions limits the ability to fully assess the impact of their contributions on the final design and planning outcomes. Its process ensured that the plan was reflective of the community’s needs and aspirations, therefore enhancing its relevance and effectiveness in addressing the site-specific challenges and opportunities. However, in this context, there is a limitation in the detailed documentation of community members’ specific suggestions, therefore restricting clarity on how their contributions tangibly shaped the planning outcomes. This gap hinders the ability to fully assess the impact of stakeholder engagement on the final design and planning process.

Interdisciplinary Integration: In addressing the complex nature of flood risks, these studies demonstrate the advantages of integrating interdisciplinary research. To conduct a comprehensive flood vulnerability assessment, it is necessary to combine various disciplines due to the complexity of natural and human systems. In the cases examined, the synthesis of design, Geographic Information Systems (GIS), geography, and urban planning was instrumental in delineating flood zones and formulating flood resilience strategies. Specifically, in League City, the adoption of additional methods, such as resilience scorecards and landscape performance tools, further enriched the analytical framework. In contrast, the Sif Oidak District benefitted from the incorporation of indigenous knowledge, which played a crucial role in comprehending areas susceptible to flooding. These examples illuminate the efficacy of interdisciplinary approaches in crafting holistic and sustainable solutions to flood risks, demonstrating their capacity to enhance resilience and adaptability in the face of environmental challenges. The sequential implementation of resilience planning scorecards, Geodesign tools, and landscape performance calculators in the League City case study facilitated a systematic and focused analysis of the city’s vulnerabilities and the effectiveness of proposed mitigation strategies. This process allowed for a systematic examination of League City’s susceptibility to flooding and other climate-related risks, followed by an assessment of the effectiveness of planning and mitigation strategies in addressing these identified risks. The sequential approach facilitated a focused and structured analysis, ensuring that each phase built upon the insights gained from the previous one, thus creating a comprehensive understanding of both the challenges faced and the potential effectiveness of the proposed solutions.

Although the League City case study initially considered social vulnerability, the master plan and subsequent evaluations primarily focused on flood mitigation, potentially overlooking the importance of social resilience and community needs. Despite the initial comprehensive considerations in policymaking and social vulnerability assessment, the context reveals that the master plan and its subsequent evaluations predominantly focused on flood mitigation, inadvertently sidelining social vulnerability issues. This suggests a potential imbalance in the approach, where the emphasis on physical and environmental resilience may have overshadowed the equally critical aspects of social resilience and community needs. To rectify this, it would be important for future revisions of the master plan to integrate social vulnerability considerations more thoroughly, ensuring that the strategies developed are holistic and address both environmental and social dimensions of resilience.

Similarly, the participatory GIS and Geodesign workshop are highlights of the Sif Oidak District case study, as they improve stakeholder engagement and expand access to geospatial data. Although this interdisciplinary approach helps with spatially identifying flood areas, there is no consideration of social vulnerability to floods. Social vulnerability is a critical aspect, as understanding the social dimensions of vulnerability, including factors like socio-economic status, age, disability, and access to resources, is essential for effective flood risk management. Addressing social vulnerability can ensure that flood management strategies are equitable and adequately protect the most at-risk populations. Integrating social vulnerability assessments into the GIS and Geodesign frameworks would be beneficial in enhancing this approach. This could involve collecting and analyzing data on the social, economic, and demographic characteristics of communities in flood-prone areas to identify vulnerable groups. By doing so, the strategy would be not only technically robust in identifying where floods might occur but also socially sensitive in understanding who is most at risk and why, allowing for more targeted and effective mitigation and response efforts.

Feedback. The significance of feedback loops and iterative processes in maintaining the effectiveness of flood resilience strategies over time is a key insight that emerges from the case studies. While current approaches have achieved improvements in flood resilience, the studies emphasize the need for more detailed scenarios and robust feedback mechanisms to facilitate systematic refinement of mitigation strategies in response to evolving flood scenarios. These findings underscore the importance of continuous evaluation and adaptation in ensuring the long-term relevance and effectiveness of flood risk plans. The League City case study demonstrates the importance of feedback loops and iterative processes in ensuring the adaptability and resilience of the master plan but also reveals a shortcoming in comprehensively testing the plan against various future flood scenarios. While feedback mechanisms were evident during stakeholder engagement and the revision of the master plan, the study failed to thoroughly evaluate the master plan’s performance under projected flood scenarios, such as the floodplain projections for 2025, 2050, and 2100 with sea-level rise, as well as the 100 year floodplain. This gap indicates a need for a more robust application of feedback loops and iterative processes to ensure that the master plan remains resilient and effective under a range of potential environmental changes and challenges, enhancing its ability to adapt to future conditions.

However, the Sif Oidak District case study demonstrates the lack of focus on feedback loops and iterative processes concerning future flood risks since no projections of future flood scenarios are provided. This results in questions regarding the feasibility and reliability of the flood risk map for future use in the district.

Resilience and Adaptability. The case studies highlight the importance of incorporating resilience and adaptability into flood risk management strategies. League City’s case study demonstrates the value of a strategic, long-term approach to building resilience. Similarly, the Sif Oidak District case study showcases how flood risk assessments can enhance resilience and adaptability by informing flood-resilient land-use designations and guiding practical applications. However, it also reveals limitations in addressing long-term resilience due to the lack of iterative processes for future flood projections and feedback on proposed land-use planning adaptations. To further enhance resilience and adaptability, future studies should consider integrating nature-based solutions and ecosystem-based approaches that recognize the critical role of ecosystems in providing essential services. These approaches can help identify strategies that work with nature, harnessing the resilience and adaptability of ecosystems to support human systems.

This work contributes to our understanding of vulnerability as it relates to landscape design processes. More specifically, it furthers knowledge of the integration of geodesign principles in flood risk and vulnerability assessments. Contributions include highlighting the role of spatial analysis in delineating ecological and social vulnerabilities at various scales, emphasizing the importance of stakeholder engagement in design initiatives, demonstrating the value of interdisciplinary integration in developing comprehensive flood resilience solutions, underscoring the significance of feedback loops and iterative processes in maintaining long-term effectiveness, and showcasing the potential of geodesign in informing flood-resilient land-use designations and guiding practical applications to enhance community resilience. Based on these findings, we have several (7) key planning and design recommendations. First, it is essential to invest in robust spatial data infrastructure including environmental, social, and economic datasets, to support comprehensive vulnerability assessments. In data-scarce contexts, exploring alternative data sources, such as remote sensing and local knowledge, can help overcome data limitations. Second, fostering active stakeholder engagement by involving a diverse set of stakeholders, including local community members, regional experts, and local decision-makers throughout the planning and design process is crucial. Developing transparent and detailed engagement records can help document the impact of stakeholder input on final outcomes. This helps justify the results and ease the transition from data to design decisions. Third, embrace interdisciplinary collaboration. Assembling multidisciplinary teams comprising experts from design, GIS, geography, urban planning, and other relevant fields can lead to the development of holistic, robust, defensible, and sustainable flood risk management strategies. Fourth, implementing iterative planning and design processes (like geodesign processes) that help establish mechanisms for continuous monitoring, evaluation, and refinement of flood resilience strategies based on evolving flood scenarios and stakeholder feedback is essential for long-term success. Fifth, integrate resilience and adaptability indicators that incorporate a broad range of social, economic, and environmental measures that can help assess community resilience and inform the development of targeted strategies for building long-term resilience. Sixth, explore nature-based solutions that integrate ecosystem-based approaches and that recognize the critical role of ecosystems in providing essential services for enhancing resilience. Finally, promote knowledge sharing and capacity building by encouraging the exchange of best practices and lessons learned to foster continuous improvement and innovation in design for flood risk management. By adopting these recommendations, planning professionals and authorities can harness the potential of geodesign to develop more effective, resilient, and adaptable flood risk management strategies that address the complex challenges posed by changing environmental conditions and social vulnerabilities.

6. Conclusions

This study questions the potential of integrating geodesign and vulnerability analysis to enhance resilience and sustainability in urban and environmental planning. The case studies of League City, Texas, and the Tohono O’odham Nation in Arizona provide insights into the application of the interdisciplinary approach across diverse contexts, highlighting the critical roles of spatial analysis, stakeholder engagement, and interdisciplinary integration in flood resilience planning and design.

Our investigation suggests that the integration of geodesign with vulnerability analysis can provide useful information for improving sustainable and resilient flood-based outcomes in terms of landscape design and urban and environmental planning. The interdisciplinary nature, engaged processes, and advanced spatial analytics in geodesign provide important components for identifying and addressing vulnerable places. The League City, Texas, and Tohono O’odham Nation case studies support its efficacy in improving flood resilience.

In League City, the integration of resilience planning scorecards, Geodesign tools, and landscape performance calculators allowed for a detailed assessment of flood vulnerabilities and design interventions. Conversely, the Tohono O’odham Nation study demonstrates the utility of geodesign in data-scarce environments, where community-based participatory methods were crucial in developing a flood resilience plan.

Both case studies underscore the importance of spatial analysis, stakeholder engagement, and interdisciplinary integration in crafting effective flood resilience strategies. However, they also revealed the need for more robust feedback and iterative processes to ensure the adaptability and long-term effectiveness of the resilience plans. The studies highlighted that while geodesign can significantly enhance the technical assessment of flood risks, integrating social vulnerability considerations remains essential for developing equitable and comprehensive strategies.

Future research should aim to fill the gap between technical assessments and social considerations. In addition, follow-up work should evaluate a more stringent and comprehensive scoring framework for determining whether design outcomes or plans truly reflect community needs and aspirations.