Current Geo-Ecological Problems Within the Lake Khanka Drainage Basin

A brief geographical description is provided for Lake Khanka and its drainage basin where the Russian part accounts for more than 90% of the area. Sixteen rivers on the Russian territory and eight rivers on the Chinese territory flow into the lake. Only one river, Sungacha, flows out of the lake; it is a border river and connects Lake Khanka with the Ussuri river. A historical analysis of the water level dynamics in Lake Khanka for the last 10 thousand years showed that rises of the lake water level, shore erosion, an increase in flood frequency and duration, and an increase of the degree of waterlogging of the valleys corresponded to warm climatic phases. The cold phases showed a decrease in hydraulicity of the rivers and in the lake level, and an enhancement in aeolian processes in the coastal zone of the lake and its river valleys. Seismic processes and changes in groundwater flow can also be responsible for changes in the lake water level. Morphostructural analysis indicates a potentially high seismic activity of this territory and risks of magnitude 8 earthquakes. In the 20^th century, the natural processes of water level fluctuations in the lake began to be influenced by anthropogenic factors, such as the water withdrawal for irrigation of paddy fields and streamflow control. The territory of China within the Lake Malaya Khanka drainage basin is the home for extensive paddy systems which are supplied with water from the Muling river basin. The water is then directed to Lake Malaya Khanka, and through the drain facilities it enters Lake Khanka. In fact, an inter-basin transboundary water transfer is carried out, which can affect significantly the water level in the lake. Characteristics of the existing nature management practices in the Russian portion of the lake drainage basin, and also lake pollution assessments are given. The main geo-ecological problems in the Lake Khanka transboundary drainage basin associated with water level fluctuations, geodynamic processes and environmental pollution are identified. Geo-ecological problems are considered to mean changes in natural processes accompanied by the transformation of separate natural components and landscapes in general, and causing, as a rule, negative consequences for humans and for various forms of nature management. The primary and related components of the geo-ecological problems highlighted. The main directions of comprehensive research within the framework of cooperation between the People’s Republic of China and the Russian Federation in order to work out the plan for governance of sustainable nature management in the transboundary drainage basin of Lake Khanka are suggested.