Imperviousness in Hungary's Second Largest City Using Spatial Analytics

Urbanization in Debrecen, Hungary, has rapidly developed buildings and infrastructure, replacing ecosystems like vegetation, forest, and farmland. This has created a high percentage of sealed-up land, which cannot absorb water leading to water quality impairment in nearby water bodies. This research aims to examine the degree of land imperviousness in Debrecen, Hungary, and its effect on stormwater movement. Properly handling impervious surfaces can prevent future disruptions, such as inundation caused by uncontained rainwater. The Normalized Built-Up Index was used for classification in the first analysis of the images, while the Linear Spectral Mixture Analysis (LSMA) was used for post-processing, resulting in an improved classification of built-up and non-built-up regions. The Sentinel 2020 had the highest recorded accuracy of 0.6, 0.243, and 0.059 for the R2, Root Mean Square Error (RMSE), and Mean Square Error (MSE). Based on the predictions, 32.5 percent of the area is pervious. In comparison, 38 percent of the sampled locations display maximum imperviousness, resulting in a 50% runoff of precipitation per time, primarily in the city's center, where impervious surfaces such as roofs, driveways, parking lots, and roads are prevalent. The results will help municipal planners and water managers make educated choices about sealed land and its impact on stormwater movement, particularly during these shifting climatic conditions.