Recent decades have seen a change in the runoff characteristics of the Suntar River in Eastern Siberia. This study attempts to attribute these changed hydrological conditions through parameterizing a hydrological model based on historical short-term observations conducted in 1957-1959 at the Suntar-Khayata research station. The Hydrograph model is applied as it has the advantage of using observed physical properties of landscapes as its parameters. The developed parametrization of the goltsy landscape (rocky-talus) is verified by comparison of the results of simulations of variable states of snow and frozen ground with observations carried out in 1957-1959. Continuous simulations of streamflow on a daily time step are conducted for the period 1957-2012 in the Suntar River (area 7680 km2, altitude 828-2794 m) with mean and median values of Nash-Sutcliff criteria reaching 0.58 and 0.67 respectively. The results of simulations have shown that the largest component of runoff (about 70%) is produced in the high-altitude area which comprises only 44% of the Suntar River basin area. The simulated streamflow reproduces the patterns of recently observed changes, including the increase in low flows, suggesting that the increase in the proportion of liquid precipitation in autumn due to air temperature rise is an important factor in driving streamflow changes in the region. The data presented are unique for the vast mountainous parts of North-Eastern Eurasia which play an important role in global climate system. The results indicate that parameterizing a hydrological model based on observations rather than blind calibration allows the model to be used in studying the response of river basins to climate change with greater confidence.

The study investigates the possibility to parameterize a hydrological model for remote high-altitude permafrost basin based on the data of historical short-term observations conducted in 1957-1959 at the Suntar-Khayata research station (Eastern Siberia) and simulate the changes of runoff observed in recent decades in the region. The Hydrograph model is applied as it has the advantage of using observed physical properties of landscapes as its parameters. The developed parametrization of the goltsy landscape is verified by the results of simulations of variable states of snow and frozen ground. Continuous simulations of streamflow with daily time step are conducted for the period of 1957-2012 at the Suntar River basin (area 7680 km2, altitude 828-2794 m) with average and median values of Nash-Sutcliff criteria reaching 0.58 and 0.67 respectively. The results of simulations have shown that the largest part of runoff (about 70%) is formed in the high-altitude area which takes only 44% of the Suntar River basin area. Simulated series of streamflow reproduce the patterns of recently observed changes, including the increase of low flow, by magnitude of trends and their change period, suggesting that the increase of the increase of liquid precipitation share in autumn months due to air temperature rise can be important factor of streamflow changes in the region. The data presented in the paper are unique for the vast mountainous parts of North-Eastern Eurasia which play important role in general climate circulation. The results indicate that if the assessment of hydrological model parameters is based on observation data instead of calibration, the models can be used in the tasks of studying the response of river basins to climate change with more confidence.

The study investigates the possibility to parameterize a hydrological model for remote high-altitude permafrost basin based on the data of historical short-term observations conducted in 1957-1959 at the Suntar-Khayata research station (Eastern Siberia) and simulate the changes of runoff observed in recent decades in the region. The Hydrograph model is applied as it has the advantage of using observed physical properties of landscapes as its parameters. The developed parametrization of the goltsy landscape is verified by the results of simulations of variable states of snow and frozen ground. Continuous simulations of streamflow with daily time step are conducted for the period of 1957-2012 at the Suntar River basin (area 7680 km2, altitude 828-2794 m) with average and median values of Nash-Sutcliff criteria reaching 0.58 and 0.67 respectively. The results of simulations have shown that the largest part of runoff (about 70%) is formed in the high-altitude area which takes only 44% of the Suntar River basin area. Simulated series of streamflow reproduce the patterns of recently observed changes, including the increase of low flow, by magnitude of trends and their change period, suggesting that the increase of the increase of liquid precipitation share in autumn months due to air temperature rise can be important factor of streamflow changes in the region. The data presented in the paper are unique for the vast mountainous parts of North-Eastern Eurasia which play important role in general climate circulation. The results indicate that if the assessment of hydrological model parameters is based on observation data instead of calibration, the models can be used in the tasks of studying the response of river basins to climate change with more confidence.