5. Discussion
The ongoing increase of air temperature, changes in precipitation, and
permafrost degradation affect the hydrological cycle via seasonal
redistribution of water balance elements, changes in soil wetness and
ALT, intensification of ground and surface water runoff exchange
(Makarieva, 2019a; Rawlins et al., 2010; Shiklomanov & Lammers, 2013;
Tananaev et al., 2016; Walvoord & Kurylyk, 2016; IPCC, 2014).
For example, according to Krogh and Pomeroy (2019), hydrological
modelling results at Havikpak Creek Research Basin suggest that the
maximum peak snow accumulation will increase by 70%, snowcover period
will decrease by 26 days, ALT will deepen by 0.25 m, and
evapotranspiration will increase by 18% in northwestern Canada over the
21st century.
According to Fang and Pomeroy’s (2020) modelling, the Marmot Creek
Research Basin in the Front Ranges of the Canadian Rockies will warm up
by 4.7 ˚C and receive 16% more precipitation, 84 mm decrease in
snowmelt and 49 days shorter snow-cover period by 2091 -2099. The
streamflow changes will be significant: 236% higher in spring months
and 12% lower flows in summer and 13% higher flows in early fall.
In these studies as in ours, special observational data from research
catchments were used to obtain predictive comprehensive estimates of
changes in various elements of the water balance and variable states. In
a global review of the runoff formation studies in Northern catchments,
it was indicated that there are no modern works on this topic in Russia
(Tetzlaff et al., 2014). Russia has significantly lagged behind other
Northern countries (mainly Canada and the USA) in instrumental studies
of hydrological processes in cold regions over the past 20-30 years.
Although some of the first integrated scientific permafrost and
hydrological stations in the world were established in Russia (the
Bomnak water balance station (from 1934), the Kolyma water balance
station (from 1948)), there is not a single ongoing integrated research
watershed in the mountain permafrost zone in Russia at present.
There is a lack of data from Russia, particularly considering that
approximately 85% of the total terrestrial runoff of the Arctic Ocean
is supplied by rivers draining from the Russian Federation and most of
it is generated in mountainous areas (Aagaard & Carmack, 1989;
Makarieva et al., 2019b). Increasing flows to the Arctic Ocean could
lead to a significant impact on the thermohaline circulation, sea ice
formation etc. (Arnell, 2005; Weatherly and Walsh, 1996).
The information for parameterizing and improving hydrological models can
be integrated from short-term studies in certain landscapes and
watersheds where it would be expensive to maintain research facilities
longer-term (especially in hard-to-reach regions). The concept of such
studies was proposed by Vinogradov (1988); he called it “nonstationary
research watersheds and plots”. The idea was further developed by
Vinogradova and Vinogradov (2014) and Gartsman and Shamov (2015) who
called this approach a “mobile watershed”. According to this approach,
one or several indicative watersheds or plots are selected in the study
area. The research visits are short-term (approximately from 2-3 weeks
to 2 months) and last for several years.
Conducting short-term intensive observations on specially selected
representative watersheds, allows the formulation of a general idea of
the conditions of runoff formation and hydrological phenomena of the
territory in question, and most importantly, approximate quantitative
assessment of the parameters of mathematical models of hydrological
processes (Vinogradov & Vinogradova, 2014). However, if the data
collection is not carried out with the intent of model development and
parametrization, or refining existing methods for calculating flow
characteristics, such observations lose most of their value and do not
justify the investment.
The three-year extensive observations at the Suntar-Khayata Station can
be regarded as a good example of such an approach. Among other
expeditions to remote regions we may mention historical studies at the
Putorano Plateau in 1988-1990 (Reports…, 1988-1990), recent
studies at Chukotka (Tregubov et al., 2020) and the Lena River delta
(Tarbeeva et al., 2020). We emphasize the need for open access to the
detailed hydrometeorological data of such research sites which can
provide the opportunity for multi-criteria assessment of hydrological
models in different conditions found in the permafrost zone (e.g. Fang
et al., 2018; Makarieva 2017, 2018a; Rasouli et al., 2019).