Water-level regulation of lake Baikal: Problems and possible solutions

摘要

We examine the history and the main problems related to the water-level regulation of Lake Baikal as well as the preconditions, conflicts and characteristics of the institution of legislation in this field. An analysis is made of the lake's water-level fluctuations, the fluctuation range and useful water inflow for the observing period 1898?2014 as well as of the water discharges in the lower pool of the Irkutsk Hydroelectric Power Plant (IHEP) at the period of streamflow regulation. We discuss the situation with an extraordinarily low water level within the lake basin in 2014?2015, and its main causes and consequences. Assessments are made of the possible risks associated with the regulation of Baikal's water level for periods of extreme hydraulicity. We examine the current problems related to the regulation of water flow rates in the lower pool of the Irkutsk HEP, and the possible consequences of excessive discharges of water through the hydroelectric scheme, including the risks of inundations at high water-level periods, as well as the issues of ensuring the reliable operation of water intake facilities at low water-level periods. We analyze the ecological requirements for the regulation of the water level of Baikal, and demonstrate the contradictoriness of some requirements with reference to the retrospective considerations, an integral approach and the interests of other water users. Data derived from the analysis and risk assessment suggest that the existing legislation on the regulation of the water level in the lake is not possible to comply with when the values of water inflow into the lake differ greatly from mean long-term values (periods of extreme hydraulicity); otherwise a heavy damage will be inflicted to water consumers and water users. We examine international experience of the regulation of the water level in the lake?HEP?river system using, as an example, the regulation of the water level in Lake Ontario and the St. Lawrence River in connection with the operation of the Moses-Saunders Power Dam straddling the border between the USA and Canada. We suggest some lines of attack on the Baikal water level regulation problem, specifically the need to conduct special integral inter-agency and interdisciplinary investigations.