Determining the capacity of the surface runoff treatment facilities in the Volga federal district

Summary

Summarized data on the maximum rainfall precipitation depth removed as surface runoff to the treatment facilities of the Volga federal district are presented. The analysis of the revealed trends is given. In order to determine the maximum precipitation depth the data obtained by the weather stations in the process of long-term rainfall observations in a specific region (for more than 10–15 years) as well as the records of the nearest representative weather stations can be used as baseline information. In the absence of long-term data the value of the maximum precipitation depth in the range of 5–10 mm can be taken. The conducted research provided for determining the daily precipitation depth of low-intensive frequent rains with the period of single exceedance of the predicted rate Р = 0.05–0.1 year. The daily precipitation depth in most big cities of the Volga federal district varies from 2.2 to 8.9 mm; the precipitation depth providing for more than 70% of the annual runoff varies in a more narrow range of 4.6–6.1 mm.

Key words

rainfall volume , precipitation depth , distribution function , predicted rate exceedance , local treatment facilities capacity

Rainfall parameters for the calculation of the capacity of surface runoff treatment facilities

Summary

The summarized data on the maximum depth of the rainfall that is completely removed to the treatment facilities (like the runoff from the group 1 residential and industrial areas in big cities of the Russian Federation) is presented. The analysis of the revealed regularities was carried out. The calculated values of the rainfall depth obtained in the course of observations at 87 meteorological stations on the territory of the Russian Federation are needed for calculating the capacity of the surface runoff treatment facilities and can be used in the process of making designs for settlements where the data of the meteorological stations is representative. The rainfall depth that provides for removing at least 70 % of the annual rainfall to the treatment facilities in most cases corresponds to the upper limit of the recommended range of 5–10 mm.

Key words

surface runoff , rainfall volume , precipitation depth , distribution function , meteorological station