IMPACT OF CLIMATE CHANGE ON THE HYDRAULIC MODES OF OPERATION OF SURFACE RUNOFF DRAINAGE SYSTEMS

Abstract

Introduction. Based on Resolution of the Government of the Russian Federation No. 782 “On water supply and wastewater disposal plans”, the volume of generated wastewater should be forecast for a period of at least 10 years. Along with this, it is also necessary to assess the hydraulic modes of operation of networks and collectors, specified earlier. However, the existing regulatory literature lacks data on the dynamics of calculated rain intensities and their prospective values. The analysis of the subject area showed that it is possible to determine the climatic parameters of an area, and thus establish the values for the characteristics of calculated rain, based on the data of long-term observations (from 20 years) with one self-recording rain gauge, or with a network of similar rain gauges, with a duration of observations of 5 years or more. A similar network of rain gauges is available in St. Petersburg. It makes it possible to assess the actual values of climatic parameters, but due to the lack of statistical data does not allow for assessing the dynamics of their changes. Therefore, the purpose of this article is to roughly estimate the dynamics of changes in climatic parameters in St. Petersburg and the degree of their impact on the hydraulic modes of operation of surface runoff drainage networks and collectors. Methods. In the course of the study, we analyzed the dynamics of changes in the total annual precipitation H and rain force in St. Petersburg and examined the influence of the dynamics of rain force changes on the operation of surface runoff drainage networks and collectors. Results. At the first stage of the study, we obtained the results of linear approximation of the H data, the calculated values of rain force changes Δ, and the results of linear approximation of the Δ data. The second stage of the study resulted in changes in the hydraulic modes of runoff input during the design period and in 50 years. Conclusion. We experimentally substantiated the possibility to determine the dynamics of rain force changes (at P = 0.33 and with acceptable accuracy) depending on the dynamics of changes in the total annual precipitation. For networks designed and laid 50 years ago, the actual rain force changes will be 9 %. As a result of climate change, water consumption in the calculation periods increased by about 26% with an increase in the total volume of discharged water by 9–10 %.