In this graduation thesis, we evaluated the influence of blue-green infrastructure (BGI) on surface runoff in a small urban area in Ljubljana. Based on 15 rainfall events, with precipitation amount equal to or greater than 10 mm, measured between April and October 2024, we compared measured discharges with theoretical ones. We evaluated the influence of BGI using the Rational Method for peak runoff estimation and the Soil Conservation Service (SCS) rainfall loss method for runoff volume estimation. We proposed six BGIscenarios of different extents, based on realistic constraints of the area. We applied green roofs, infitration and trees with structural cells as measures. We assumed that each BGI scenario must reduce the peak runoff by at least 10 % to be considered suitable for further analysis. Of the 6 scenarios only one did not meet the hypothesis, specifically scenario 2 (trees with structural cells), which reduced the peak runoff by only 5 %. The remaining BGI scenarios proved both relevant and realistically achievable. The greatest impact was achieved by scenario 6 (green roofs, trees with structural cells, infiltration) which reduced the peak by 34 %. This was followed by scenario 3 (infiltration), reducing the peak by 22 %, scenario 5 (green roofs, trees with structural cells, infiltration), reducing the peak by 19 %, scenario 4 (trees with structural cells, infiltration), reducing the peak by 18 % and scenario 1 (green roofs), reducing the peak by 16 %.
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