The current situation and recent changes in vegetation indices (vis) in forested cities with dry climates. The case of the Mendoza metropolitan area, Argentina

Abstract

Cities in drylands have adapted to the scarcity of resources and the anthropic-cultural complexity of the habitat. Urban vegetation is a key element for resilience and the mitigation of climate changes when faced with the complex energy-environmental issues related to urban-building morphologies. The objective of this research is to study the current conditions and recent changes in urban vegetation in the 6 municipalities of the Mendoza Metropolitan Area (MMA) by analyzing the temporal and spatial variability of the Normalized Difference Vegetation Index (NDVI) and the Soil-Adjusted Vegetation Index (SAVI). Methodologically, the indices were determined using geographic information systems (GIS) from the analysis of satellite images from Landsat 5 (1986-2011) and Landsat 8 (2013-2017), and a statistical analysis was carried out to estimate trends and correlations. The results obtained indicate a generally decreasing slope in the mean NDVI and SAVI values during the 1986-2011period. The municipalities of Maipú and Guaymallén show the greatest decreasing slopes, and should be given priority for intervention in decision-making to resolve this trend, followed by Luján de Cuyo and Las Heras. Capital is the municipality with the most gradual decreasing slope. During the 2013-2017 period, very high positive correlations were found between municipalities. The municipality of Godoy Cruz is the priority for intervention with the increasing vegetation indices strategy, considering the results by municipality and by urban block for the entirety of the years studied. Lastly, the public green spaces of the MMA that are the priority for intervention are located in Las Heras for the increasing vegetation indices and increasing the surface area of public green spaces strategies.