Design rainfall intensity model for the need of urban hydrology of the city of Słupsk

Project aim

The aim of the project was to prepare a local precipitation model for the city of Słupsk, which included:

  • Determining empirical values of design rainfall intensity for the city of Słupsk for the probability of over p=20%, based on valid precipitation data collected at the nearest weather station in Ustka. The weather station has data that has been collected for many year including continuous observational series in high time resolution of single minutes (precipitation data collected over last 30 years 1986-2015).
  • Preparing a physical model of design rainfall intensity (an IDF curve) for p=20% for empirical values from point 1.
  • Determining additional empirical values of precipitation for p=10% for time of 180 minutes at the weather station in Ustka.
  • Comparing the set values with historic formulas of design rainfall intensity that have been used so far.
  • Preparing a final report on the calculations and the potential possibility and validity of design rainfall intensity determination with extremely low probabilities, where p equals or is less than 1%.


Project description

An updated local precipitation model for Słupsk was to be used as the database for hydrological and hydrodynamic models of the city’s drainage systems composed of closed stormwater canals and a complementary system of open channels often being the receivers of stormwater runoffs.


Solutions applied

Any precipitation model for a city should be based on long-term data collection i.e. 20-30 years of collecting data on local precipitation series. Unfortunately, the city of Słupsk has no such data. The Institute of Meteorology and Water Management has not collected data on precipitation on the area of Słupsk in high time resolution in the last 30 years.

Due to restricted financial means of the Institute, precipitation has been recorded at the weather station in Słupsk only in certain years or only with general daily resolution, which is insufficient for the purpose of this study.

Having this in mind, data on precipitation in high time resolution, taken at the nearest weather station in Ustka was used.