雪氷チーム

Snow and Ice Research Team

極端気象がもたらす雪氷災害の被害軽減のための技術開発
Development of Technologies for Mitigating Damage from Snow- and Ice-related Disasters Caused by Extreme Climatic Events
近年、気候変動の影響による異常な吹雪、降雪、雪崩に伴い、多数の車両の立ち往生や長時間に亘る通行止め、集落の孤立などの障害が発生しています。極端気象がもたらす、雪氷災害の発生地域や発生形態、災害規模は変化しており、多発化・複雑化がみられることから、その対策は喫緊の課題であります。
そのため、近年の気候変動などにより激甚化する多量降雪や吹雪、気温の変動により多発化する湿雪雪崩などの災害に対応し、国民生活や社会経済活動への影響を緩和するため、以下の研究に取り組んでいます。

激甚化する雪氷災害（2010.1 えりも町）
Snow- and ice-related disasters have intensified.
(Jan. 2010, Erimo)

In recent years, extreme snowstorms, snowfalls and snow avalanches have resulted in many cases of vehicles being stranded inblowing snow, long hours of road closures, and the isolation of communities. The areas of disaster caused by snow and ice andthe conditions and scales of such disasters have been changing with increases in the number of extreme weather events. The development of measures against such disasters is an urgent task for us, because disasters caused by extreme weather events have been increasing and their conditions have become complicated.
We have been pursuing the following studies in order to mitigate the influence of snow- and ice-related disasters on the socioeconomic activities of our nation. The technologies being developed are for responding to extremely heavy snowfalls and snowstorms, which have become increasingly severe because of climatic changes in recent
years, and to increases in wet-snow avalanches, which occur because of temperature changes.

極端な暴風雪等の評価技術に関する研究

短時間の多量降雪による雪崩危険度評価に関する研究

気象変動に伴い増大する極端気象による暴風雪等の実態を解明し、一回の暴風雪・大雪の厳しさを適切に評価する指標の提案や、暴風雪および大雪に関するハザードマップの開発を行います。

短時間の多量降雪により発生する雪崩に関して、雪崩発生の条件を明らかにし、雪崩発生の危険度評価手法を提案します。

By clarifying the actual conditions of snowstorms and other extreme-weather-related snow andice disasters, which have been increasing with climatic changes, an index will be proposed thatcan be used to appropriately evaluate the severity of any given snowstorm or heavy snowfall.
A hazard map exclusively for snowstorms and heavy snowfalls will be developed.

With regard to snow avalanches caused by intense heavy
snowfalls, a method for evaluating the risk of snow
avalanche occurrence will be proposed based on a study forclarifying the conditions under which such avalanches occur.

Risk
Case 1 < Case 2

大High

Understanding the areas at riskof avalanche occurrence

短時間多量降雪による雪崩発生

大 High高 High小Low

Snow transport

吹雪量

事例1 < 事例2

事例２
Case 2

雪崩危険エリアを把握

暴風雪危険度Snowstorm risk

山梨での雪崩発生状況
An avalanche site in
Yamanashi Prefecture

事例１
Case 1

低 Low

継続時間

小 Low

Duration (hours)▲吹雪量、継続時間、災害発生との関係（イメージ）
Relationship among snow transport, snowstorm duration,and disaster occurrence (schematic)▲短時間多量降雪による雪崩発生頻度分布（イメージ）
Distribution of avalanches caused byintense snowfall (conceptual diagram)▲暴風雪の分布図（イメージ）
Distribution map of snowstorms(schematic example)

Avalanche caused
by intense snowfall

降雪強度

リスクの度合い

災害発生
Disaster occurrence

Hazard assessment for avalanches caused by intense heavy snowfall

Snowfall intensity

Studies on technologies for assessing the intensity of extremely severe snowstorms

低Low

気温Air temperature

高High▲降雪強度と気温を指標にした
雪崩発生条件（イメージ）
Avalanche occurrence conditions when thesnowfall intensity and temperature are used
as indexes (conceptual diagram)

広域的な吹雪視程障害予測技術の開発に関する研究

防雪林の安定的な防雪性能確保に関する研究

多様な気象環境下における吹雪視程障害の予測技術を開発し、吹雪時にドライバーや道路管理者にリアルタイムに情報提供をすることで、吹雪時の安全性を高めます。

吹雪対策として高い効果が期待できる防雪林の安定的な防雪性能確保に向け、下枝の枯れ上がりの見られる防雪林の補助対策や管理手法を提案します。

We will develop a forecasting technology for snowstorm-induced
poor visibility under various weather conditions and will contributeto traffic safety improvements during blowing snow by providing
real-time information to drivers and road administrators.

Towards securing stable snowbreak performance for snowbreak woods from which highly
effective blowing-snow control can be expected, we will propose an improvement measureand management techniques for snowbreak woods with withered lower branches.

Research on Technologies for assessing snowstorm-induced poor visibility in a wide area

風速 (m/s) Wind speed20

地吹雪非発生降雪あり

Blowing snow does not occur.

With snowfall

15

既往研究の吹雪発生条件
Blowing snow occurrence
conditions identified inprevious studies

1050

気温（℃）

50-5-10 Temperature

地吹雪なし Without blowing snow▲「吹雪の視界情報」(現状)
Snowstorm Visibility
Information System (current)

A study on securing stable snowbreak performance for snowbreak woods▲本州での吹雪災害の発生
Disasters from blowing snow
in Honshu

地吹雪あり With blowing snow

既往の地吹雪発生臨界風速（竹内ら 1986）Critical wind speed for occurrence of blowing snow

identified in a previous study (Takeuchi et al., 1986)▲地吹雪発生有無と気象条件
With and without blowing snow and related weather conditions

防雪柵の端部・開口部対策に関する研究▲吹雪対策として高い効果が期待される防雪林
Snowbreak woods from whichhighly effective blowing-snow
control can be expected▲間引き遅れにより下枝が枯れ上がった林帯
Wood zone where the lowerbranches are withered becauseof a lack of insolation▲縮小模型による防雪林の風洞実験
A wind tunnel experimentusing a miniature model ofsnowbreak woods

A study on measures for the end and apertures of snow fences

防雪柵の整備において課題として残っている端部や開口部のように視程が急変する箇所について、視程急変メカニズムを解明や緩和対策効果を定量的に示すことで、条件に応じた対策の選定方法を提案します。
The mechanism of drastic visibility changes at the ends and openings in snow fences
has not been clarified. In developing snow fences, we will clarify the mechanism ofdrastic visibility change at the ends and openings of snow fences, quantitatively show
the visibility reduction mitigation effects of some countermeasures, and propose how
to select a countermeasure that suits a location with certain conditions.

安全・快適

北の道

Safe, pleasant driving on Northern Roads▲気象観測車と防雪柵開口部の状況
A weather observation vehicle and the visibility
conditions near the open parts of a snow fence

国立研究開発法人土木研究所 寒地土木研究所▲防雪柵の端部対策例
Examples of treatments for snow fence end parts

National Research and Development Agency Public Works Research Institute Civil Engineering Research Institute for Cold Region