1.,,*+, - +./ +/2 +, -. ; +, - +* cm : Key words: snow-water content, surface soil, snow type, water permeability, water retention +,**. +,,**/.. +30- +302 ; +302 ; +313; +320,. + *+, *2// + -.*, **. **+., /. - *.0 ***- +,, +,,+ -3 +* *. N+.* -* *. E ++/ m K+.* m
146 1.,,*+, K, K+ K +1,, km -3 *3 ** N+.*,3-2 E ++* m +. A + ; A,, 2./ +*.* m,2* -/* mv + 1 A+ A,, R *. 2/3 K, -/ +30-; +302 ; +320,**. +,,0,**/.,- +0 + *3 : ** +/ : ** mv, R */. m */.0., + R *. 2/3 / cm ECHO Decagon Devices ECHO Check: Decagon Devices +312 +* cm - +** cm +33+,, mm /0 mm, m,, ECHO - cm +* cm *+. cm ECHO Check, -, +** cm + ECHO. Fig. + Relationship between data of ECHO dielectric aquameter and volumetric snow-water content (conversion value of determination by means of Akitaya type).
1.,,*+, 147 - -+ + +,,**/ +, - +-. 0 +,3 2.. + -, +*,,1. A, : *. 0 + +/, +1- cm *-. *, * 1. m,,2 : +.* cm ++ - / +. -,0 - K+ K, +33/ -,0. cm A+ -, A, :,.,,**. +,,**/. Fig., Variations of the snow depth and the water equivalent of snow (Dec.,**. Apr.,**/).
148 1.,,*+, +. -,0 K+ K, A+ A, A+ A,, L ++ - / K+ Fig. - - K+ K,,**/,,1, - +-, -,0 The structure of snow cover at K + (sand surface) and K, (lawn) (,1 Feb., +- Mar.,,0 Mar.,**/).
1.,,*+, 149 - K, K+ K, +. -,0 1. - cm - +, - +-. Fig.. A+ A, :,**/,,1, - +-, -,0 The structure of snow cover at A + (Akita cedar woods) and A, (Open field neighboring A + : grassland) (,1 Feb., +- Mar.,,0 Mar.,**/).
150 1.,,*+, / A+ A, +, - +- K, -,*,- cm K, A, K+ *33. K+ --, - K+ K, A+ A, K, K+ +*,,1, +, -+- K+ +. -,0 K+ / +/ cm -. K, K+ K, - /,**. +,,**/. Fig. / Variations of the mean density (Dec.,**. Apr.,**/).
1.,,*+, 151 A+ A, K, A+ A, A+ K + A+ A+,. A, - +0. 3 / A+ +, A, +320 A, A+ A, -/ K+ K, -. K+ K,. * cm,* cm 0 K+ 1,/., 0 * cm,**. +,,**/. Fig. 0 Variations of the volumetric snow-water content just above ground surface. Dotted line shows the value beyond coverage of the calibration (Dec.,**. Apr.,**/).
152 1.,,*+, ++ * 2* cm K+ K, K+ 1 K, 1 K+ *,* cm -0,* 0* cm K+ 0* cm - 1 +.. K,.* 3 0* cm, K, K+ 2 +, - +- 0* cm ++ 1 K+ K,,* cm,**/ +. Fig. 1 Variations of the volumetric water content (average of every,* cm depth) at K + (sand surface) and K, (lawn) (Jan.,**/ Apr.).
1.,,*+, 153 2 K+ K,,* cm,**/ +. Fig. 2 Variations of the di# erence of the volumetric snow-water content (average of every,* cm depth) between K + (sand surface) and K, (lawn) (Jan.,**/ Apr.). Fig. 3 3,**/, - Variations of the snow type ratio (Feb.,**/ Mar.). --. A +, K, ++ A, K, K, K+ K, - K+
154 1.,,*+,..+. +331 ;,,*+*. -. +** cm / cm / cm +* cm +* - 0 / cm / cm +* cm +* Fig. +* The soil samples collected from four observation spots. The left lines of the samples +33/ ;,**+ + of each observation spot were collected - / from the surface to / cm below (upper part) and the right lines were collected - from under ground surface from / cm to +* cm below (lower part). +* cm +.3 -.* *. 32 kpa - -,* cm +30. kpa + -* cm,3.. kpa +33/ ; + +331., + K:cmsec +* cm
1.,,*+, 155 K,-. alatlog h h +* +, *. +*-2t,, a : cm *./. cm,, A : cm +3. 0 cm L : cm /+. cm h : K, + cm +1 cm h :, cm 1 cm t : sec ++ +, +, U L. + / K+ K, K+ ++ U L Fig. ++ Comparison of saturated hydraulic conductivity of the soil samples. U and L letters represent the upper and the lower part respectively. Fig. +, +, ++ Comparison of water retention of the soil samples. right side are the same as Fig. ++. The marks of the
156 1.,,*+, + U L Table + Relative assessment of physical property of surface soils. U and L letters represent the upper and the lower part respectively., and marks represent good, medium and bad assessment respectively.,*+* ++ A, : A+ A, : K+ A+ -.. A, : K+ K, K+ K, A, 0 A, K+ K, A, A, K, A, A, K+ A,,. + K,,
1.,,*+, 157 0. +,/., +312:. -0 +*- +++.,*+*: +, +*2,**+:,-.,-3 - +313:. +-0.30,. +33/ :,1, pp +331: 30 ++*. +320:,*3pp +33/ : 0/ ++. +331:,.-pp. +33+ :,.. pp. +30-:.,+./ 1.. +302:.,0 11 20. +302:.,0 /-10.
158 1.,,*+, Influence of di# erent surface soils on snow-water content and snow type of the snow cover +, - Hiroshi G OTO, Katsuhiro KIKUCHI and Masahiro KAJIKAWA + Akita Society of Snow, + -.* Atago-machi, Yuzawa, Akita *+, *2//, Professor emeritus of Hokkaido University and Akita Prefectural University,, /. Momijidai, Atsubetsu-ku, Sapporo **. **+. - Professor emeritus of Akita University, +,, -+ Kurokawa-machi, Yoichi, Hokkaido *.0 ***- Abstract: This study deals with the variation in volumetric snow-water content and snow type on four di# erent ground surfaces : sand surface, lawn, Akita cedar woods and open field of grassland. During the melting period, the snow-water content of the granular snow layer adjoining the sand surface did not increase, and the total water equivalent of snow on the sand surface was smaller than that on the neighboring lawn, although the snow depth was same in both cases. These characteristics mainly result from the di# erences in the wet density depending on the vertical distribution of snow-water content and snow type. Water permeability and water retention of the four di# erent surface soils were examined. The saturated hydraulic conductivity of the sand surface was larger than that of the lawn, while the water retention of the former surface was smaller than that of the latter surface. These results suggest that the physical characteristics of the surface soils have significant influence on the snow-water content and snow type of the snow cover.,*++ / +0,*++ 2 +1,*+, +,.,*+, + -*,*+, 3 +/