CEN/TR 16588:2014

SLOVENSKI STANDARD
01-junij-2014
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Manual measurement of snow water equivalent
Manuelle Messung des Schneewasseräquivalents
Mesure manuel de l’équivalent en eau de la neige
Ta slovenski standard je istoveten z: CEN/TR 16588:2014
ICS:
07.060 Geologija. Meteorologija. Geology. Meteorology.
Hidrologija Hydrology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 16588
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
March 2014
ICS 07.060
English Version
Manual measurement of snow water equivalent
Mesure manuelle de l'équivalent en eau de la neige Manuelle Messung des Schneewasseräquivalents

This Technical Report was approved by CEN on 3 September 2013. It has been drawn up by the Technical Committee CEN/TC 318.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16588:2014 E
worldwide for CEN national Members.

Contents Page
Foreword .4
Introduction .5
1 Scope .6
2 Terms and definitions .6
3 Symbols . 10
4 Objective . 10
4.1 Spatial estimation of SWE . 10
4.2 Snow load assessment . 11
4.3 Snow profile . 11
4.4 Water content in newly fallen snow . 11
4.5 Reference to automatic SWE measurements . 12
5 Principle of manual SWE measurements . 12
6 Measurement sites. 12
6.1 General . 12
6.2 Manual measurements . 13
7 Measurements . 14
7.1 General . 14
7.2 Snow density . 14
7.3 Snow depth . 15
7.3.1 Manual probing . 15
7.3.2 Manual readings on fixed snow stakes . 15
7.3.3 Automatic recording . 15
7.3.4 Remote sensing . 16
8 Manual SWE sampling methods . 16
8.1 General . 16
8.2 Snow tubes . 16
8.3 Core drills . 17
8.4 Density cutters . 17
9 Spatial estimation . 18
9.1 General . 18
9.2 Interpolation methods . 18
9.3 Snow courses . 19
9.4 Regression modelling . 19
9.5 Hydrologic and land surface modelling . 20
9.6 Remote sensing systems for snow monitoring . 20
10 Maintenance . 21
11 Uncertainties . 21
11.1 Environmental factors . 21
11.2 Technical factors . 21
11.3 Human factors . 22
12 Assessment of quality . 22
13 Measurement uncertainty . 22
14 Recommendations . 22
Annex A (informative) List of methods for determination of SWE in total snowpack . 24
Annex B (informative) Manual SWE measuring bodies in Europe . 25
Annex C (informative) Determination of mass of snow sample . 26
Annex D (informative) Determination of water volume in snow sample . 27
Annex E (informative) Snow stakes . 28
Annex F (informative) List of samplers for detection of SWE . 29
Annex G (informative) Snow tubes . 30
Annex H (informative) Core drills . 31
Annex I (informative) Density cutters . 32
Annex J (informative) On-line glossaries . 33
Bibliography . 34

Foreword
This document (CEN/TR 16588:2014) has been prepared by Technical Committee CEN/TC 318
“Hydrometry”, the secretariat of which is held by BSI.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
Introduction
Snow water equivalent (SWE) measurements
Snow water equivalent (SWE), also called “water equivalent of snow”, is the depth of water that would be
obtained by melting the snowpack in a given area, and is normally expressed in millimetres. In other words,
SWE corresponds to the mass of snow over a given area.
Measurements of SWE in snowpack, and new snow, improve the estimation of winter precipitation, especially
in areas with a sparse network of meteorological stations. The measurements are mainly made for the
purpose of estimating the spatial distribution of the total water content in catchment areas, as knowledge of
the SWE in river basins is fundamental for estimating the expected snowmelt runoff.
Information about snow accumulation and daily melt rate is essential in flood forecasting during the snowmelt
season. SWE is also used in avalanche theory and forecasting, as well as for risk assessment of heavy snow
loads. Furthermore, the data is important in glaciological mass balance studies and climate monitoring. The
melt from polar ice sheets is a major factor in sea level rise.
Methods and instruments, which have been developed for determination of SWE, are listed in Annex A.
Manual SWE measurements
The first station networks with manual SWE measurements were established in the early 20th century at
meteorological institutes in North America and Europe. Today the measurements are made routinely at
federal and national meteorological and hydrological institutes, within the hydropower industry, and by
universities, in cold climate countries all over the world. Annex B shows a list of manual SWE measuring
bodies in Europe.
Automized methods have been developed to be used in remote areas, as well as to enable continuous
recording, but manual measurements are still more common, as they can provide high quality data for a
relatively low capital cost. The importance of manual measurements is also reflected in their use as reference
to other SWE measuring methods.
1 Scope
This Technical Report defines the requirements for manual measurements of SWE over land, see ice and
glaciers, under natural environmental conditions, and shows methods for calculating the spatial distribution of
the data. It includes measurements with snow tubes, core drills and density cutters.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
Note 1 to entry Primarily ‘The International Classification for Seasonal Snow on the Ground’ (UNESCO), ‘Cryospheric
Glossary’ (NSIDC) and ‘Glossary of Meteorology’ (AMS) has been used as reference.
2.1
ablation
removal of material from the surface of an object by vaporization, chipping, or other erosive processes. In this
case the opposite of snow accumulation
2.2
blowing snow
an ensemble of snow particles raised by the wind to moderate or great heights above the ground; the
horizontal visibility at eye level is generally very poor
Note 1 to entry  See also drifting snow.
2.3
condensation
the change of the physical state of matter from gaseous phase into liquid phase (opposite of evaporation)
2.4
deposition
(1) a process by which water vapour is deposited as ice without first forming liquid water (opposite of
sublimation)
(2) the process by which snow is deposited on the ground either with or without wind action
Note 1 to entry As a result, stationary snow deposits such as snow dunes, snowdrifts, or the snow cover itself may
form.
2.5
drifting snow
snow raised from the snow surface by the wind to a height of less than 2 metres; it does not restrict horizontal
visibility at 2 metres or more above the surface
Note 1 to entry  See also blowing snow.
2.6
evaporation
vaporization of a liquid that only occurs on the surface of a liquid, at temperatures below the boiling point
(opposite of condensation)
2.7
firn
well-bonded and compacted snow that has survived the summer season, but has not been transformed to
glacier ice
SIST-TP CEN/TR 16
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