Importance of snowmelt contribution to seasonal runoff and summer low flows in Czechia

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F20%3A10414257" target="_blank" >RIV/00216208:11310/20:10414257 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=F.SyI8vv8o" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=F.SyI8vv8o</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5194/hess-24-3475-2020" target="_blank" >10.5194/hess-24-3475-2020</a>

Result language

angličtina

Original language name

Importance of snowmelt contribution to seasonal runoff and summer low flows in Czechia

Original language description

The streamflow seasonality in mountain catchments is often influenced by snow. However, a shift from snowfall to rain is expected in the future. Consequently, a decrease in snow storage and earlier snowmelt is predicted, which will cause changes not only in seasonal runoff distribution in snow-dominated catchments, but it may also affect the total annual runoff. The objectives of this study were to quantify (1) how inter-annual variations in snow storages affect spring and summer runoff, including summer low flows, and (2) the importance of snowmelt in generating runoff compared to rainfall. The snow storage, groundwater recharge and streamflow were simulated for 59 mountain catchments in Czechia in the period from 1980 to 2014 using a bucket-type catchment model. The model output was evaluated against observed daily runoff and snow water equivalent. Hypothetical scenarios were performed, which allowed for analysing the effect of inter-annual variations in snow storage on seasonal runoff separately from other components of the water balance. The results showed that 17 %-42 % (26 % on average) of the total runoff in the study catchments originates as snowmelt, despite the fact that only 12 %-37 % (20 % on average) of the precipitation falls as snow. This means that snow is more effective in generating catchment runoff compared to liquid precipitation. This was demonstrated by modelling experiments which showed that total annual runoff and groundwater recharge decrease in the case of a precipitation shift from snow to rain. In general, snow-poor years were clearly characterized by a lower snowmelt runoff contribution compared to snow-rich years in the analysed period. Additionally, snowmelt started earlier in these snow-poor years and caused lower groundwater recharge. This also affected summer baseflow. For most of the catchments, the lowest summer baseflow was reached in years with both relatively low summer precipitation and snow storage. This showed that summer low flows (directly related to baseflow) in our study catchments are not only a function of low precipitation and high evapotranspiration, but they are significantly affected by the previous winter snowpack. This effect might intensify drought periods in the future when generally less snow is expected.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10508 - Physical geography

Project

<a href="/en/project/GJ18-06217Y" target="_blank" >GJ18-06217Y: Influence of seasonal snowpack on summer low flows: climate change implications on hydrological drought</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Hydrology and Earth System Sciences

ISSN

1027-5606

e-ISSN

—

Volume of the periodical

24

Issue of the periodical within the volume

7

Country of publishing house

DE - GERMANY

Number of pages

17

Pages from-to

3475-3491

UT code for WoS article

000550695200001

EID of the result in the Scopus database

2-s2.0-85088232691