Evaluation of urban green infrastructure in the context of ecosystem services and urban resilience: the case of Van metropolitan area

This research analyzes the impacts of rapid urban spatial change in the Van metropolitan area between 1990 and 2024 on the Urban Green Infrastructure (UGI) system, the degradation of its ecosystem services capacity, and the consequences within the context of urban resilience. A multi-layered methodology based on Geographic Information Systems (GIS) and Remote Sensing (RS) was adopted in this study. Macro-scale land cover change during the 1990-2018 period was analyzed using CORINE data; Urban Heat Island (UHI) and Normalized Difference Vegetation Index (NDVI) dynamics for the 2013-2024 period were analyzed using Landsat 8 satellite imagery; and the 2018 urban fabric was analyzed using Urban Atlas and MAKS data. The quantitative assessment of ecosystem services was conducted using a Literature-Based Coefficient Model; the past and present state of climate change was examined using temperature and precipitation data from the 1938-2020 period; and future climate pressures were investigated using RCP4.5 and RCP8.5 projections. The findings revealed that there was a 104.8% increase in artificial surfaces in the central districts of Van between 1990 and 2018. The most devastating impact of this growth was observed in wetlands, with a 50.7% loss, and in forest/semi-natural areas, with a 15.2% loss. This UGI destruction has led to a collapse in the city's ecosystem services capacity. The land-use change between 1990 and 2018 caused a net deterioration of approximately 39,672 tons of CO₂ annually in the city's carbon budget. In the 2018 micro-scale analysis, the metropolitan area was identified as a "carbon source" with an annual deficit of approximately 4,141.5 tons of CO₂, and structural emissions were found to be 35 times greater than the sequestration capacity of existing urban green spaces. In the resilience analysis, a statistically significant increase of approximately 1.83 °C in UHI intensity was observed between 2013 and 2024, independent of regional climate trends. This local warming is directly correlated with the declining trend in NDVI values. Consequently, the rapid urbanization model of the Van Metropolis, which disregards UGI, has exceeded the city's ecological carrying capacity. The city possesses critically low resilience against severe climatic warming—which could reach +5.42°C under the RCP8.5 scenario—and unstable precipitation projections. It was determined that many of the green space targets envisaged in the 1/5000 scale master plan are neither realistic nor feasible, as they overlap with existing built-up areas. There is an urgent need for a new planning paradigm that includes immediate, feasible, and nature-based solutions to enhance the city's resilience.