URBAN GREEN SPACES: TRENDS & SCENaRIO-BASED SIMULATION
CONTEXT
Cities, home to over half the global population, consume 75% of the world's energy and emit a significant portion of greenhouse gases. As urban expansion continues, sustainable development is crucial for managing climate change. The UN's 11th Sustainable Development Goal aims to create inclusive, safe, resilient, and sustainable cities by 2030. However, the recent IPCC report highlights the increasing vulnerability of urban communities, particularly the underprivileged, to climate change-related disasters. The report suggests that the implementation of nature-based solutions (NBS) with equitable access could address these issues.
NBS, such as green roofs, parks, and street trees, provide numerous benefits in promoting sustainable urban environments, including ecosystem services, protection from floods and coastal hazards, and recreational opportunities. However, quantifying NBS benefits at a city scale remains challenging, as most studies focus on small or medium-scale areas and often overlook the impact of land use and land cover (LULC) changes. Additionally, research tends to focus on cities in developed countries, neglecting the rapidly growing cities in developing nations.
The proposed study aims to assess the expected future benefits of NBS using a scenario approach, allowing policymakers to compare the potential gains, including economic value, health benefits, and access equity to urban natural infrastructure, from the deployment of different NBS. The study's originality lies in its (1) quantification of ecosystem services provided by NBS at a city scale, considering economic valuation, health benefits, and access equity; (2) incorporation of future LULC change scenarios based on different planning scenarios; and (3) comparative analysis of NBS benefits across cities with varying characteristics in both developing and developed countries, which often have contrasting urbanization trends.
OBJECTIVES
The main objective of this research is to develop a spatial-based methodological framework for evaluating the current and future potential benefits of NBS and spatial access equity to them based on current and scenario-based future LULC. To achieve this main objective, the study will focus on four specific objectives:
First, it will extract past, current, and scenario-based future LULC in the target cities, simulating future LULC trends based on four planning scenarios and investigating spatial and temporal insights on accessibility to green spaces.
Second, it will define scenarios for implementing NBS based on LULC transition rules, generating LULC maps representing all possible NBS scenarios for 2021, 2030, and 2050, including a baseline scenario, a scenario removing all nature, and four sub-scenarios prioritizing different NBS combinations.
Third, the study will conduct a spatial/statistical assessment of implemented NBS in terms of economic value, health benefits, and spatial equity of access to greenspaces by population. This will involve extracting current and future ecosystem services (ESs) of urban natural infrastructure for each planning-NBS scenario, categorizing ESs into four categories (environment quality, disaster mitigation, recreation, health, and habitat), and analyzing the spatial and statistical aspects of the extracted ESs.
Finally, the proposed approach will be applied to eight cities (FIG. 1) located in the Global North and South, with distinct characteristics. The results obtained from the application of the framework will be analyzed to select the optimal NBS scenarios that promote better sustainability in each of the target cities, considering their specific characteristics and needs.
The study will utilize GIS and remote sensing data and techniques, deep learning methods, and spatial/statistical analysis to achieve these objectives and provide evidence-based recommendations for implementing NBS that optimize economic value, health benefits, and spatial equity of access to green spaces, promoting sustainable urban development.
FIG 1. Target cities
OUTPUT (last updated: May 16th, 2024)
Academic Papers:
Derdouri, A., Murayama, Y., Morimoto, T., Wang, R., & Aghasi, N. (2024). Urban Green Spaces in Transition: A Cross-Continental Perspective from Eight Global North and South Cities. Landscape and Urban Planning (Under Review as of May 16th, 2024)
Conference Presentations:
Derdouri, A., Murayama, Y. & Morimoto, T. (2024, April 20). Predicting Greenspace Changes in Casablanca under Climate Change Scenarios: An IPCC-Informed Approach. [Oral Presentation]. American Association of Geographers 2024, Honolulu, USA (2024, April 16-20).
Derdouri, A., Murayama, Y. & Morimoto, T. (2023, December 14). Tracing 30-Year Greenspace Evolution and Human Exposure Inequalities in Global Cities. [Oral Presentation]. American Geoscience Union Meeting 2023, San Fransisco, USA (2023, December 11-15).
Derdouri, A., Murayama, Y. & Morimoto, T. (2023, October 28). Comparative Analysis of Urban Greening Evolution and Implications in Global North and South Cities over a 30-Year Period. [Oral Presentation]. The 32nd Annual Conference of the Geographic Information System Association 2023, Tokyo, Japan (2023, October 28-29).
acknowledgement
This study is gratefully being supported by the Japan Society for the Promotion of Science (JSPS) through the KAKENHI Grant Numbers 22KF0054 and 22F22303 (2022). All contributors would like to express their sincere appreciation for JSPS's generous funding, which has made this research possible.