Conclusion
This study examined hydrological processes at the Suntar River Basin
(area 7680 km2, elevation range 828-2794 m) located in the highlands of
the Indigirka River using the hydrological model Hydrograph.
- Model parameters were derived for the high-elevation rocky talus
landscape (goltsy in Russian) using unique observation data collected
under the program of the International Geophysical Year in 1957-1959
at the high altitude Suntar-Khayata Station (2068 m);
- The model was verified through a comparison of modelled and observed
time series of variable states of soil, snow cover, streamflow
hydrographs and water balance elements over the period of special
observations from 1957-1959. Modeling results were also compared to
observed streamflow over the period 1957 to 2012 and are considered.
As the model does not require calibration to observed streamflow, the
developed parameters can be used for modeling ungauged catchments in
other mountainous permafrost regions of Russia;
- The contribution of each runoff formation complex to the total basin
flow was estimated. Most runoff formation occurs in high-altitude
areas: the goltsy complex provides 20% of the runoff despite only
occupying 7% of the area, while tundra is the largest contributor to
the runoff formation (49%) in the Suntar River catchment, occupying
37% of the area.
- The model was able to reproduce observed trend values and change
points of streamflow during the latter part of the study period.
Modeling allowed us to calculate the autumn runoff and liquid
precipitation changes, which are the key drivers of the increase in
winter low flow.
Currently, in the mountain regions of the Yana, Indigirka and Kolyma
rivers basins, no hydrological research stations are operational to
perform a comprehensive study of runoff formation processes. Therefore,
development and verification of methods for hydrological process
modeling which can successfully utilize short-term, extremely scarce
data, become of greater interest. The study has demonstrated that the
Hydrograph model and its further development may become a foundation for
solving scientific and practical issues in permafrost regions.