Long-term prediction of runoff characteristics using the mathematical modeling of hydrological processes

Abstract

In recent decades, climatic anomalies have been recorded that give rise to long-term changes in the hydrometeorological regime and the system of interaction of the water mass with the underlying surface, in particular, on channel and floodplain sections of rivers that are the site of underwater crossings of main pipelines. Currently, these changes are not taken into account during the course of design & engineering, construction and operation of underwater crossings, although the period of safe operation of the pipeline depends on the conditions that the engineering structure is exposed to. In this article, the influence of long-term changes in the hydro-meteorological situation on the runoff characteristics of the river Ob located near the alignment of the underwater crossing of the Aleksandrovskoe – Anzhero-Sudzhensk main pipeline has been considered. It has been determined that the method developed by the Russian State Hydrometeorological University is optimal for runoff characteristics prediction. Using this mathematical model, changes in the hydrometeorological regime have been assessed in the river Ob – Aleksandrovskoe section, a violation of its stationarity in 1979–1980 was established. The main flow-forming factors – the amount of precipitation and the temperature regime – have been determined. Approbation of the runoff formation model showed that the maximum convergence of the predicted and actual values is observed when using predictions with an additional parameter. To predict the runoff characteristics for 2011–2040, climatic scenarios were used as initial data – representative concentration trajectories according to which the temperature and precipitation amount is expected to increase during the specified period of time. The results obtained indicate a tendency for an increase in water content and a redistribution of runoff vs. time, which, in turn, will catalyze the intensity of the processes of channel and floodplain deformation. It is concluded that it is necessary to consolidate the use of the prediction of runoff characteristics in regulatory documents in order to increase the efficiency of measures to ensure the safe operation of underwater crossings of trunk pipelines, as well as the accuracy of calculations in the design and construction of these facilities.