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

Abstract

The integration of ecosystem service mapping in decision-making is crucial to place effective urban design and sustainable planning solutions. Nonetheless, often ecosystem service maps are the product of different data inputs that influences the final modeling output thus affecting final decisions, especially when a finer and site-specific assessment is required to design practical and effective solutions. In this work, the city of Turin (Northwest Italy) was selected as a test site for an empirical experiment of ecosystem service mapping using the software Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST): two habitat quality models of the city were compared in a Geographic Information System environment, the first using the “traditional” sensitivity employed during the LIFE SAM4CP European research while the second using the natural difference vegetation index to re-assign the sensitivity scores. Results demonstrate that the integration of site-specific information in the habitat quality input model generates a different result, which is capable of differentiating all those dense built-up areas of the dense settlement system that provide ecosystem supporting functions at the city-level. These differences were analyzed to define new green hotspots in the compact city while furnishing a new perspective for sustainable city planning.

Spatiotemporal Evolution Characteristics of Ecosystem Service Values Based on NDVI Changes in Island Cities

“…The normalized difference vegetation index (NDVI) is a common index that measures regional vegetation cover. The value of NDVI is in the range of [−1, 1], and NDVI is positively correlated with vegetation biomass [35], [36]. In this study, the NDVI values of island counties in China are calculated using the band operation tool of the ENVI5.3 software.…”

“…Among them, Chongming District covers the largest area, 1,413 square kilometers, while Changdao County has the smallest area at 56. 35 Then, the ArcGIS 10.2 spatial analysis tool is used to determine pixel superposition statistics of NDVI images, in each period of the year, to obtain the annual composite values of NDVI. A total of 216 remote sensing images of 12 island counties were used.…”

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

“…The Integrated Evaluation of Ecosystem Service and Tradeoff (InVEST) provided by the Natural Capital Program is an open-source suite of tools designed to meet the needs of public administrators, urban planners, soil scientists, and researchers of mapping ecosystem services while directly visualizing the biophysical od economic value of natural capital in a GIS environment. Among the many ES mapping software, InVEST has been widely diffused and shared among researchers for its simplicity, accessibility, and usability, having an online user's guide that provides information and practical rules for model's functioning [27][28][29].…”

“…The inputs of the model are four, which include a raster image with the LULC classification, a raster image of habitat threats, the table of threats that assign a weight to each identified threat (see Table 3), and a sensitivity table for each LULC to the selected threats (see Table 4). While the raster inputs are the product of the above-described LULC product by supervised classification sampling method, the values of input tables (Tables 3 and 4) were assigned using the already acquired experience of modeling in this AOI during the LIFE Soil Administration Model 4 Community Profit research conducted during 2015-2018 [29,34].…”

“…This product has been originally used to monitor forest productivity and health of natural or semi-natural areas or consider plant growth while maximizing soil productivity in an open field for agricultural efficiency [36,37]. Nowadays, the NDVI is massively used to monitor the health of urban areas due to this indicator's capacity to detect the consistency of vegetation canopy even in small permeable areas, although not on small private spaces (building courts) or green roofs [29].…”