The use of LIDAR point clouds for spatial analysis of changes in building development in large housing estates. An example of the Widzew Wschód and Radogoszcz Wschód estates in Łódź

Urban densification can have various consequences. To identify and interpret these, spatial analyses of changes in the built environment over a specific period are needed. This article investigates the use of LIDAR point cloud data to detect changes in development in two large pre-fabricated housing estates in Łódź, Poland. Developed during the socialist era, these estates have undergone spatial and functional transformations over the past decades. The study uses LIDAR data from 2012, 2017, and 2021, supplemented with orthophotos, Google Street View, and fieldwork conducted in 2023 to identify and verify changes in development. The analysis included classification of point-cloud data, conversion to raster and subtraction of rasters to detect new and demolished buildings. The results show a clear trend to increase the density of buildings in both estates, with more than 11,000 m² of new built-up area added in each case. New developments include residential, commercial and service and communication facilities, often replacing open spaces or previously undeveloped areas. The study confirms that the LIDAR point cloud is a valuable tool for detailed detection of changes in various urban objects. Analyses based on this type of data can serve as a monitoring function. It also highlights the need to integrate historical data to capture earlier stages of transformation and suggests including development analysis in future research.