A GIS Assessment of the Green Space Percentage in a Big Industrial City (Dnipro, Ukraine)

Green spaces in an industrially polluted city are extremely important for the physical activity and mental health of its inhabitants. The study aim was to analyze the urban green space dynamics and the greening degree of different functional zones typical for a big Ukrainian industrial city (Dnipro, Ukraine). This article used the remote sensing methods and geographic information systems (GIS) to assess the percentage of green spaces in the city of Dnipro, its eight districts, parks, ravines, and sanitary protection zones. The Normalized Difference Vegetation Index (NDVI) was used for mapping the urban green spaces within the ravines, parks, and sanitary protection zones. According to our results, 67% of Dnipro city is greened (NDVI >0.3). On average, there are 219 m² of green spaces per person, which is 24 and 4 times more than the minimum and optimal values recommended by the World Health Organization (WHO), respectively. It was found that the NDVI values were significantly lower in the territories of sanitary protection zones, compared to the other functional zones. The results of NDVI analysis indicate a significant variation of the studied parameter during the vegetative season, with two typical peaks of the green space vegetative activity. The peak of plant vegetative activity occurs in the first decade of June, followed by slight decline for 2–3 weeks, then there is another increase in the activity, reaching the maximum in mid-July. Even in autumn, the photosynthetic activity remains relatively high for most of the urban areas, declining only from mid-October. In addition, a method and algorithm for estimating and standardizing the level of the urban area greening based on the remote sensing methods and zonal statistics tools are proposed.