ASSESSMENT OF THE USSURI RIVER FLOOD REGIME CHANGES REGARDING TO CLIMATE PROJECTIONS TO THE END OF THE XXI CENTURY

Abstract

Detecting reaction of river systems to climate changes is one of the key problems in modern hydrology. Moreover, this is the case of the Far East of Russia, where moisture regime variability is well known. The presented article deals with the assessment results of changes in the flood characteristics of the Ussuri rivers basins under the expected climate changes, linked with global warming. The estimates are based on dynamic–stochastic modeling scheme, in which numerous synthetic precipitation series are input to the hydrological model for searching of all kinds of humidification conditions at the investigated catchments. There was used a regional hydrological Flood Cycle Model of small river basin that focuses on the description of runoff formation processes in the summer–autumn flood period. Climate changes input is based on the integration of the regional stochastic rainfall model and General Circulation Models (GCM) data to the end of XXI century (2071–2100). It is shown that an increase in precipitation sum leads to an unproportional response of the evaluated flood flow characteristics. The relative increase in the mean values of the maximum flow reaches 4–5 times and 2–3 times for the seasonal runoff depth depending on applied GCM and climate scenarios. The obtained results are consistent with the analysis of observational data using the “elasticity coefficient” and previous investigations. Therefore, flood risks could be expected at the investigated territory due to climate changes.