Evaluating the trend of urban green space changes using landscape metrics (Case study: Qazvin city)

Rising temperatures and the formation of Urban Heat Islands (UHI) are the main consequences of population growth and uncontrolled expansion of cities. Green infrastructures are one of the nature based solutions. These infrastructures can be considered as an important strategy to reduce the damages caused by urban development and increase the quality of citizens’s life. Landscape ecology and its metrics are among the methods of evaluating green infrastructure in urban environments. Hence, the main objective of this research is to evaluate changes in urban green infrastructure during the period of 2013-2019 in Qazvin city. To do so, green infrastructures changes were investigated using remote sensing data and landscape metrics including presence (Class Area), stability (Mean Patch Size) and distribution (Patch Density, Mean Euclidean Distance Neighbor) in three regions of Qazvin. The results showed a decrease of 73.71 hectares in the Class Area (presence) and an increase of 0.1061 hectares in their Mean Patch Size (stability). Furthermore, the density of green infrastructures has experienced 0.8075 decrease per 100 hectares while the Mean Euclidean distance neighbor has increased about 5.5846 meters. These results indicate the conversion of small classes of green infrastructures to bigger classes and increase their stability despite the decrease in their presence. Therefore, planning and management by creating and expansion of green lands seems necessary in order to reduce the effects of urban development, improve the quality of citizen’s life and preserving green infrastructures of Qazvin.