Post mining hydrodynamics in Kizel coal basin (the West Urals, Russia)
Rybnikov, Petr (1); Rybnikova, Liudmila (1); Maksimovich, Nikolay (2)
1: The Institute of mining, Ural branch Russian Academy of Sciences, Russian Federation; 2: Natural Science Institute of Perm State University, Institute of Natural Science
Perm region is an old mining region. Mining has been underway for more than 300 years. Deposits of the Kizel coal basin are the subject of study. These deposits were developed from the end of the 19th to the beginning of the 2000s. High water inflows were common - total drainage reached 10-12 thousand m3/hour. The mines have been flooded since the beginning of the 90s of the last century, by now all the mines have been flooded, 16 springs of mine waters have been formed. The total average annual flow rate of springs of mine waters is more than 3000 m3/hour. The waters of the mine water springs are sulphate high-metal with low ph. These springs for tens of kilometers pollute the rivers of the Kama basin, the Volga tributary.
Geofiltration models have been developed for all watersheds of mine fields. The geofiltration pattern and stratification of model layers is the main problem. The model took into account aquifer complexes confined to rocks from the Permian to the Devonian age. The angles of incidence of rocks reach 700, the total depth varies from full pinching to 1200 m. The width of catchments is from 5 to 14 km with a length of 2-3 times more.
The balance structure of the groundwater formation at different stages of the territory development was first evaluated. The following stages are considered: natural conditions, the situation at the end of mining, the current situation with mine springs, the forecast for the implementation of various water protection measures. Resources of the coal-bearing strata provided no more than 50% of the mine drainage flow. In the simulation, it was necessary to add to the model the interaction of the coal aquifer with the overlying (Visean-Artinsky) and underlying (Franco-Tournaisian) aquifers.
Clear seasonality of mine springs flow rates has been established. Due to the consumption of surface runoff, up to 50% of the flow rate of springs is formed. Drainage of surface runoff by ditches is proposed here as a basic water protection measure. Embedding of the spout points is effective where the springs are small in terms of discharge rate. The implementation of this event will lead to the cessation of outflow and increased discharge in the bottom of the rivers. To ensure the centralized discharge and concentrated purification of groundwater, options for organizing pumping from coal-bearing strata or Visean aquifer are also considered.