The Utilization of Normalized Difference Vegetation Index to Map Habitat Quality in Turin (Italy)

Analysis of the impact of green urban areas in historic fortified cities using Landsat historical series and Normalized Difference Indices

Urban green areas minimize the negative effects of climatic change and improve the sustainability of historic cities. Despite this, green areas have traditionally been considered a threat to heritage buildings because they cause humidity changes, that accelerate degradation processes. Within this context, this study evaluates the trends in the inclusion of green areas in historic cities and the effects it causes on humidity and conservation of earthen fortifications. To achieve this goal, vegetative and humidity information has been obtained since 1985 from Landsat satellite images. The historical series of images has been statistically analysed in Google Earth Engine to obtain maps that show the means, 25th, and 75th percentiles of the variations registered in the last 35 years. The results allow visualizing spatial patterns and plotting the seasonal and monthly variations. In the decision-making process, the proposed method allows to monitor whether the presence of vegetation is an environmental degradation agent in the nearby earthen fortifications.The analysis of the historic fortified cities of Seville and Niebla (Spain) shows a gradual increase in green areas and an interest in locating them near the earthen fortifications. The impact on the fortifications is specific to each type of vegetation and can be positive or negative. In general, the low humidity registered indicates low danger, and the presence of green areas favours drying after heavy rains. This study suggests that increasing green spaces to historic cities does not necessarily endanger the preservation of earthen fortifications. Instead, managing both heritage sites and urban green areas together can encourage outdoor cultural activities, reduce the impacts of climate change, and enhance the sustainability of historic cities.

Designing Urban Green Infrastructures Using Open-Source Data—An Example in Çiğli, Izmir (Turkey)

The city of Izmir (Turkey) has experienced one of the most rapid and fastest urbanization processes in the last thirty years; more than 33 thousand hectares of agricultural and seminatural land have been transformed into urban areas, leading to a drastic reduction of biodiversity and hard deployments of the ecosystem service supply. In this perspective, the potential definition of methodologies to design multifunctional green infrastructures is extremely important to challenge the effects of climate change. The aim of this study is to propose an easy and replicable methodology to design a Green Infrastructure at the neighbourhood level in one of the most important districts of Izmir: Çiğli. To this end, we combined historical land-use change analysis (based on Urban Atlas, Copernicus Land Monitoring Service) with environmental and ecosystem mapping in a Geographic Information System environment (ESRI ArcMap 10.8.1) while creating a composite layer based on unweighted overlays of Imperviousness, Tree Cover Density, and Habitat Quality. Results were used to design the Green Infrastructure of Çiğli and suggest context-based strategies for urban adaptation, including Nature-Based Solutions for core, edge, and urban links.

Designing with Ecosystem Modelling: The Sponge District Application in İzmir, Turkey

Climate change is threatening coastal cities affected by multiple hazards worldwide. Due to the increase in extreme weather events and the low capacity of cities to adapt to these odds, losses, exposure, and fatalities arise with the occurred events. Besides, traditional hazard mapping and risk planning techniques often fall behind when facing a climate crisis since extreme changes in quantity, frequency, and distribution of meteorological phenomena are observed. Specific and localized flood vulnerability mitigation strategies need to be developed, particularly for settlements on coastal and sloppy areas with a high risk of stream accumulation during rainfall days. This paper uses the urban flood risk mitigation of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) generated within the Natural Capital Project to determine İzmir’s cloudburst vulnerability level. The city has experienced several cloudbursts in the last couple of months which inundated densely populated areas. The soil’s hydrologic conductibility and the land use/land cover (LULC) map were required as main inputs. The LULC map was produced on the basis of surface imperviousness. The model calculates the run-off volume and how much is retained by soil and vegetation. Outputs were used to concretely apply the sponge district concept while designing performance-based ecosystem solutions. In the light of the findings, the new performance-based design demonstrated how digital ecosystem modelling could support the urban design decision-making process.

Integrating Ecosystem Vulnerability in the Environmental Regulation Plan of Izmir (Turkey)—What Are the Limits and Potentialities?

The land-use regulatory framework in Turkey is composed of several hierarchical plans. The Environmental Regulation Plan pursues comprehensive planning management, which ranges between 1/100,000 and 1/25,000 and defines the framework for local master plans. Unfortunately, there is scarce knowledge of how these plans effectively protect the environment. Besides, these plans have poor consideration of socio-economic dynamics and the ecosystem vulnerability, while evaluating the actual conflicts or synergies within the localization of ecological conservation and settlement expansion areas. In this work, an ecosystem-based geodatabase was created for the western Izmir area (Turkey). The dataset has been created by employing a supervised classification sampling of Sentinel-2 images acquired on 28 March 2021, while accessing ONDA-DIAS services to L2C products. Then, the InVEST software was used to map the Habitat Quality and the Habitat Decay, while the ArcMap raster analysis tool was employed to generate the Normalized Difference Vegetation Index. The results were used to classify the ecosystem vulnerability of the western metropolitan area of Izmir and then superimposed to the Environmental Regulation Plan of the city of Izmir (2021), thus evaluating synergies and conflicts. Although integration of the ecosystem services approach into spatial planning is lacking in the planning practice of Turkey, the paper provides an operative methodology to integrate ecosystem evaluation in environmental planning as a basic strategy to support sustainable development.

Going Green and Going Dense: A Systematic Review of Compatibilities and Conflicts in Urban Research

The dilemma of simultaneously promoting the advantages of urban densification and urban liveability, namely the environmental and social benefits of urban green spaces, has been widely acknowledged in the research literature. This paper aims to provide an overview of the current state of evidence on benefits, conflicts and challenges emerging from fostering both urban densification and urban greening aims. A systematic review following the PRISMA guidelines was conducted. Searches for peer-reviewed papers were conducted in Scopus and Web of Science. Our search yielded an initial 357 papers, which were then further sorted and screened to the 117 manuscripts retained and included in this review. The authors systematized the multiple perspectives in which the interactions between urban densification and urban greening have been explored. Moreover, the results revealed a lack of clear agreement about the existence or not of conflicts emerging from fostering both urban densification and urban greening aims, suggesting that the positive or negative interactions are not absolute but depend on the scale or the context on which the studies are conducted. Further research should explore multiple potential mediating variables (e.g., the mediator effect of scale and context) to deepen our understanding of interactions between density and greening.

The Utilization of Supervised Classification Sampling for Environmental Monitoring in Turin (Italy)

In a world threatened by climate change, the need to observe the land transformation is crucial to set environmental policies. One of the most prominent issues of environmental monitoring is the availability of updated and reliable land use data. The last land-use release in Piedmont Region (Italy) is in 2010, while the most updated Normalized Difference Vegetation Index is in 2016. To overcome this limit, in this study, a supervised classification sampling has been applied on a Sentinel-2 image produced by the Copernicus Program on 29 September 2020, using Esri ArcGIS (ver.10.8 Redlands, California, US) by accessing via ONDA-DIAS services to L2A products. After land classification, three maps were generated—the Habitat Quality, the Habitat Decay, and the Normalized Difference Vegetation Index. This study aimed at classifying the environmental status in five classes ranging from “critical” to “health” with a double perspective—(i) to make a comparative metropolitan assessment between municipalities and (ii) to evaluate the quality of urban public green areas in the city of Turin while defining a different kind of intervention. Results indicate that products derived from supervised classification sampling can be applied in a wide range of applications while reaching seasonal monitoring of the environmental status and delivering just-in-time solutions.