A Square Parking Lot Of 250m On A Side The Surface Of The Lot Is Plan A square parking lot with a side length of 250 meters has a plan surface that is sloped toward one of its edges where a gutter is located. This gutter drains the entire parking lot and is inclined from both ends toward a sewer inlet at its center. The time of concentration for runoff from this lot is estimated to be 20 minutes, with 18 minutes attributable to overland flow across the surface and 2 minutes for water to travel down each half of the gutter. Assuming the rational runoff formula applies, with a runoff coefficient of 0.75, determine which of the following storm events will produce the highest peak runoff rate, and calculate that peak runoff rate for each case: a) A 100 mm/h rainfall intensity lasting 10 minutes b) A 25 mm/h rainfall intensity lasting 40 minutes c) A 15 mm/h rainfall intensity lasting 66.7 minutes
Paper For Above instruction Introduction Rainfall-runoff modeling is a critical component in hydrological engineering, particularly in urban areas such as parking lots where surface runoff management is essential for stormwater control. The rational method is widely used due to its simplicity and applicability for small catchments with relatively uniform rainfall and runoff characteristics. In this paper, we analyze a square parking lot with a specific configuration and hydrological parameters to determine which storm intensity results in the highest peak runoff rate. This involves calculating the runoff for different storm durations and intensities, comprehending the influence of the catchment’s physical and hydrological properties, and applying the rational formula appropriately. Site and Hydrological Parameters The study area consists of a square parking lot measuring 250 meters on each side, giving a total area of: Area, A = 250 m × 250 m = 62,500 m² The catchment is characterized by an average runoff coefficient (C) of 0.75, indicating significant imperviousness, typical for parking surfaces. The time of concentration (Tc), which includes overland flow and gutter flow, is approximately 20 minutes, with overland flow taking about 18 minutes and gutter flow