Agricultural damage by local wind and its countermeasure
297
Agricultural Damage by Local Wind and Its
Countermeasure
Yoshitaka Kurose 1* and Taichi Maki 2
1 Department of Agro-Environmental Management, National Agricultural Research Center for
Western Region, Hiroshima, 721-8514, Japan
2 Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka,
812-8581, Japan
ABSTRACT
The airflow over mountains is formed on the
Aso somma under conditions in stable
stratification and the prevailing southeastly wind
with a speed of over 10 m s at 850 hPa pressure
level. The wind converges in the valley of Aso
somma, creating a strong easterly wind with a
speed of over 20 m s . This strong easterly wind is
called as “Matsubori Kaze”. “Matsubori Kaze” is
often generated in April and May. “Matsubori
Kaze” that blows at this period decreases the yield
of wheat and barley. The yield of barley has
decreased when the “Matsubori Kaze” blows
within 30 days after the heading time because
“Matsubori Kaze” removes the awn of barley, thus
obstructing the ripening of the grain by
eliminating photosynthesis by the awn. The awn
of barley was removed at three years among
investigations of four years, and the damage area
was wide. On the other hand, the yield of wheat
has decreased only when “Matsubori Kaze” blows
immediately before the harvest because
“Matsubori Kaze” causes the shedding of wheat.
The shedding of wheat occurred only at one year,
and the damage area was very limited. It is
thought that wheat is more suitable for the
cultivation in this region than barley.
Key wards: Airflow over mountains, Local wind,
Wind damage.
-1
-1
* 通信作者, [email protected]
投稿日期： 2004 年 7 月 5 日
接受日期： 2004 年 10 月 1 日
作物、環境與生物資訊 1:297-304 (2004)
Crop, Environment & Bioinformatics 1:297-304 (2004)
189 Chung-Cheng Rd., Wufeng, Taichung Hsien 41301,
Taiwan (ROC)
地方風造成之農業損失及因應對策
Yoshitaka Kurose1* and Taichi Maki2
1
2
日本西部地區國家農業研究中心農業環境經營系
日本九州大學生物資源及生物環境科學研究院
摘要
在穩定的氣流層當東南方向的盛行風
在 850 hPa 氣壓下風速超過 10 m s 時，在
Aso somma 地區將形成飛越高山的氣流。
此一氣流將涵蓋 Aso somma 山谷地區，並
產生一股風速超過 20 m s 的強烈東向地方
風 (local wind) ， 被 稱 為 “Matsubori
Kaze”。此種 “Matsubori Kaze” 現象經常發
生於當地的每年四月及五月，且造成小麥及
大麥的減產。當 “Matsubori Kaze”現象在抽
穗後 30 天內颳起強風時，將移除大麥的芒
而減少光合產物的生成，在妨礙穀粒的正常
成熟下導致產量降低。在調查的四年期間，
有三年發生顯著的大麥去芒情境，在廣大地
區出現不等的減產結果。在小麥部分，僅有
其中一年當 “Matsubori Kaze” 現象發生於
收穫之前時，由於去穗掉粒效應而造成產量
的下降，受影響地區甚小。因此，在可能發
生 “Matsubori Kaze”現象的地區，栽植小麥
優於栽植大麥。
關鍵詞： 飛越高山的氣流、地方風、風害。
-1
-1
Crop, Environment & Bioinformatics, Vol. 1, December 2004
298
INTRODUCTION
There is local wind called “Matsubori Kaze”
in the western part of Japan (Kurose et al. 2002a,
2002b). This local wind causes wind damage, and
is often generated in April and May. Wheat and
barley are heading and mature in this period.
“Matsubori Kaze” that blows at this period
decreases the yield of wheat and barley.
It is known that the thousand grain weight
becomes small if “Matsubori Kaze” removes the
awn of barley at early stage after the heading. The
farmer and agriculture group require making the
scale for estimating yield decrease. It is necessary
to clarify the relation between the decrease in
barley’s yield and the growth stage when awn
was removed.
“Matsubori Kaze” that blows at the
harvesting time causes the shattering, and
decreases the yield of wheat. Therefore, the farmer
hopes for counter measure of wind damage. If the
generation of “Matsubori Kaze” is predictable
beforehand, the wind damage can be prevented
by harvesting early. It is necessary to clarify the
generation mechanism of “Matsubori Kaze” for
that.
It is necessary to observe the wind condition
at many points to clarify the actual condition of
the local wind “Matsubori Kaze”. However, such
observation situation is impossible in pecuniary.
The mobile observation system of wind is
developed as a tool to measure distribution of the
wind direction and wind velocity.
METHODS
Fig.1 shows the estimation method of the
wind direction and wind velocity. Open circles
and dashed line in figure indicate position of car
every one second and tracks of car, respectively.
The example of calculating the wind vector in the
A0 point is shown in figure. The wind vector at A0
point is estimated by the following equation.
＝ －
A0C A0B A0A-1
(1)
where, A-1 is a position of the car one second
ago, A0C is wind vector at A0 point, A0B is wind
vector on the car which was measured by sonic
anemometer, and A0A-1 is wind vector due to
movement of car which is measured by GPS.
Wind vector due to movement of car is evaluated
by shifting of the car in one second in simplicity.
Wind direction and wind velocity are estimated
every second by subtracting the wind vector due
to the movement of the automobile, measured by
GPS, from the wind vector on the automobile,
measured by sonic anemometer. The
measurement accuracy of the wind was evaluated
by comparing the wind which was observed from
the mobile observation and stationary observation.
The observations were carried out under the calm
and windy conditions. To clarify the relation
between the car speed and the measurement
accuracy of wind, the mobile observations were
carried out at 40, 60 and 80 km h .
-1
C
A0
B
A-1
Fig. 1. Estimation method of wind vector at A0.
A0C: estimated wind vector, A0A-1: wind
vector due to movement of car, A0B: wind
vector on the car. Open circles and dashed
line indicate position of car every one second
and tracks of car, respectively.
The topographical situation is shown in Fig. 2.
The junction in the crater basin of Mt. Aso, where
the river running from the north joins the river
running from the south, and from where the
confluence flows westward across the Aso somma,
is area where “Matsubori Kaze” blows. Points A
and B in Fig. 2 are observation sites of “Matsubori
Kaze”. Sites A and B are located at the center area
and leeward area where the “Matsubori Kaze”
blow, respectively. The observation sites C, D, E
and F are the AMeDAS (Automated
Meteorological Data Acquisition System) sites of
the Meteorological Agency in Japan. The site C is
Aso mountain meteorological observatory. This
site is located at the top of Aso Mountain, and the
altitude is 1143 m. The data of site C was used as
an index of the upper wind, and the data of sites D,
E and F were used as an index of the wind near
Agricultural damage by local wind and its countermeasure
the ground. The wind direction and wind velocity
were measured in each observation sites every 10
minutes. Onodera (1975) showed that the
“Matsubori Kaze” was generated most in April
and May. The stationary observation was carried
out for three years from 1999 to 2001 in April and
May. The strong wind with the following two
features was defined as “Matsubori Kaze”. The
duration of strong wind with a speed of over 10 m
s is over 4 hours, wind velocity is 2.5 times or
more of background. The sites of the background
are D, E and F.
-1
299
To clarify the relation between the awn of
barley and the ripening of the grain, the awn was
artificially removed, and the relation between the
removal of awn and the thousand grain weight
was investigated. The removal of awn was carried
out at intervals of one week after the heading. The
investigation was carried out in the laboratory’s
field and farmer's field from 2002 to 2003.
RESULTS AND DISCUSSION
The accuracy of the mobile observation of the
wind was evaluated by comparing the estimated
wind by the mobile observation with the
measured wind by the stationary observation. The
one example of the mobile observation is shown
as follows. Fig. 3 shows the wind direction and
wind velocity that was observed by the mobile
observation and stationary observation. The case
shown in Fig. 3 differed largest between the wind
velocity that was measured by the stationary
observation and the wind velocity that was
estimated by the mobile observation. The
ESE-wind with a speed of 3.8 to 10.9 m s blew at
the mobile observation period. There were
abnormal data in the estimated wind direction by
the mobile observation. These data were valued
when the car moved back. When these data were
excluded, the wind direction and wind velocity
measured by the mobile observation was almost
equal to the value of stationary observation in a
tail wind, head wind, or crosswind for the
automobile, moving at any speed. In addition, in
the cases when the mobile observations were
carried out under the calm condition, the
estimated wind velocities by the mobile
observation were 1.5 m s or less moving at any
speed. It is thought the wind velocity that was
estimated by the mobile observation becomeing a
measurement error when assuming that the wind
velocity of background was 0 m s . The
measurement accuracy of the wind velocity in
mobile observation method was 1.5 m s from the
result of observation under various wind velocity
conditions. It is possible to measure wind
direction and wind velocity in a tail wind, head
wind, or crosswind for the automobile, moving at
any speed.
-1
Fig. 2. Map of the observation field. Solid circles
indicate the observation sites and dashed line
indicates the route of mobile observation.
To clarify the distribution of wind in the area
where the “Matsubori Kaze” blows, the mobile
observation of the wind was carried out. The route
of the mobile observation is shown in Fig. 2 with
dashed line. The car starts from site B, turns up at
site A, and returns to site B. The car speed is 40
km h in average, and 30 minutes were needed for
the mobile observation of one round trip. The
mobile observation was carried out 8 times on
May 21, 2001.
The sampling survey of barley and wheat
were carried out in the area where the “Matsubori
Kaze” blows and the leeward area. Barley and
wheat were sampled at the harvest time at
intervals of about 500 m along the route shown in
Fig. 2 with dashed line. The locations of sampling
points were measured by GPS. The thousand
grain weight and degree of damage were
investigated for each sampled point. The sampling
survey was carried out for four years from 1999 to
2002.
-1
-1
-1
-1
300
Crop, Environment & Bioinformatics, Vol. 1, December 2004
Fig. 4. Time series of (A) wind direction and (B)
10-minute mean wind speed from April 17 to
April 19, 1999.
Fig. 3. Variations of (A) wind velocity, (B) wind
direction, (C) car speed and (D) moving
direction of a car. Open circles and solid line
in Figs.3 (A) and (B) indicate the estimated
values by mobile observation and the
measured values on the stationary observation
site, respectively.
It was clarified by questionnaire survey that
the strong easterly wind formed in the valley of
the Aso somma is called as “Matsubori Kaze”. The
“Matsubori Kaze” was generated 6 times for the
observation period. The “Matsubori Kaze” that
generated on April 18, 1999 and May 21, 2001 are
shown as follows.
Fig. 4 shows time series of wind direction at
the sites A and C, and 10-minute mean wind
speed at sites A, C and D from April 17 to April 19,
1999. The maximum wind speed recorded 14.2 m
s at 24:00 April 17 and the maximum
instantaneous wind speed recorded 23.6 m s at
0:06 April 18 at site A. This “Matsubori Kaze”
removed the awn of barley. The wind velocity at
site A was almost equal to the site C, and the wind
velocity at both sites was a similar time variance.
It was thought that the “Matsubori Kaze” is
closely related to the upper wind. The wind
direction of site A was ENE. However, it was from
SE to SSE at site C. The maximum wind speed of
site D, E, and F was 6 m s or less. The wind
velocity at site A was 4 times or more strong than
the surrounding observation sites.
Fig. 5 shows time series of wind direction at
the sites A and C, and 10-minute mean wind
speed at sites A, B and C from May 20 to May 22,
2001. The hatched areas in Fig. 5 denote the
periods of mobile observation. The mobile
observation was carried out 8 times from Run 1 to
Run 8 while the “Matsubori Kaze” blew. The
wheat was shattering by this “Matsubori Kaze”.
The maximum wind speed recorded 15.3 m s at
-1
-1
-1
-1
Fig. 5. Time series of (A) wind direction and (B)
10-minute mean wind speed from May 20 to
22, 2001. The hatched areas denote the periods
of mobile observation.
Agricultural damage by local wind and its countermeasure
14:30 May 21 and the maximum instantaneous
wind speed recorded 24.3 m s at 13:20 May 21 at
site A. The southeast wind with a speed of about 8
m s blew in the site C. The wind velocity in site A
was stronger than that of the site C. The wind
velocity at site B considerably attenuated
compared with site A. The wind velocity at site A
was 3 times or more strong than the sites D, E and
F. It is understood that the wind at site A is a local
wind.
Fig.6 shows the surface weather maps when
the above-mentioned “Matsubori Kaze” was
generated. The surface weather maps show a
similar pressure distribution with both cases. That
is, when the low-pressure passed over the Kyushu
Island south coast, the “Matsubori Kaze” was
generated.
-1
-1
301
Fig. 7 shows vertical profiles of the potential
temperature, wind direction and wind velocity at
9:00 May 21 in Fukuoka and Kagoshima. Fukuoka
and Kagoshima are located in the north end and
south end of Kyushu Island, respectively. The
potential temperature rose while increasing in
altitude. It is understood that the atmosphere was
stable condition. The southeastly wind blew at
altitude 3400 m or less in Fukuoka and at altitude
2300 m or less in Kagoshima. The wind velocities
of Fukuoka and Kagoshima at 850 hPa pressure
level were 7 m s and 16 m s , respectively.
The “Matsubori Kaze” was formed 6 times for
three years from 1999 to 2001 in April and May.
All cases are formed under stable stratification
conditions and prevailing southeastly wind with a
speed of over 10 m s at a pressure level of about
850 hPa. In addition, the 5 cases were generated
when the low-pressure passed over the Kyushu
Island south coast. It was thought that the
“Matsubori Kaze” is formed under such condition.
-1
-1
-1
Fig. 7. Vertical profiles of (A) potential temperature,
(B) wind velocity and wind direction at 9:00
May 21, 2001.
Fig. 6. Surface weather maps at (A) April 18, 1999
and (B) May 21, 2001.
The observation case when the airflow over
mountains was formed under above-mentioned
condition is shown as follows. Fig. 8 shows
horizontal variations of wind direction and wind
velocity along the route in Fig. 2 at Run 7 in Fig. 5
on May 21, 2001. The shattering damage of wheat
occurred from 130o56’ longitude on the east side
by this “Matsubori Kaze”. That is, the area where
wind damage occurs was very limited. The wind
direction and wind velocity show the complex
distribution as shown in Fig. 8. The wind direction
Crop, Environment & Bioinformatics, Vol. 1, December 2004
302
and wind velocity was greatly different according
to the area. The westly wind in the opposite
direction for the “Matsubori Kaze” blew from East
longitude 130o54.4’ to 130o52.5’. Moreover, the
wind of this area was weak, the wind velocity was
about 3 m s . On the other hand, the eastly wind
with a speed of about 14 m s and 8 m s blew at
sites A and B, respectively. The similar
distribution of the wind direction and wind
velocity was shown in the other mobile
observations.
-1
-1
-1
on the lee side at the local wind "Yamaji Kaze"
blowing. And the airflow in the opposite direction
is called "Domai". It is thought that the complex
distribution of the wind direction and wind
velocity as shown in Fig.8 was formed by the
airflow over mountains and the leeward wave.
Arakawa (1971) shows that the wind damage by
the airflow over mountains is extensive in the
saddle in mountain range especially. This is
because the air flow converges in the saddle in
mountain range, creating a strong wind. The
valley of the Aso somma corresponds to the
saddle and the air flow converges in the valley of
the Aso somma, creating a strong wind with a
speed over 20 m s and 2.5 times or more of
background. This strong wind is “Matsubori
Kaze”.
-1
Fig. 8. Horizontal variations in (A) wind direction
and (B) wind velocity along the route in Fig.2
at Run 7 in Fig.5 on May 21, 2001.
Fig. 9 shows a picture facing Aso taken at site
B. There are cap cloud and rotar cloud which
appeared while “Matsubori Kaze” was blowing.
Cap cloud and rotar cloud spread in parallel with
Aso somma. Corby (1954) and Alaka (1960) show
the relation between those clouds and the airflow
over mountains. The cap cloud hanging on the
ridge of the mountain range, when the air flow
over the mountains reaches condensation level. In
addition, the air flow over the mountains rotates
up and down in the lee side. This air flow is called
a leeward wave and the rotar cloud is formed by
the leeward wave. The formation of those cloud
suggested that the airflow over mountains and
leeward wave are generated on the Aso somma
and lee side. Corby (1954) and Alaka (1960) show
that the leeward wave forms the airflow in the
opposite direction for the airflow over mountains
near the ground. Saito and Ikawa (1991) shows
that the airflow in the opposite direction is formed
Fig. 9. Cap cloud and rotar cloud which appeared
while "Matsubori Kaze" was blowing. (A) A
picture facing Aso taken at Site B. (B) Rotar
cloud which spread in parallel with Aso
somma.
Fig. 10 shows pictures of barley in the same
field immediately before harvest time. This field is
located in the area where the “Matsubori Kaze”
blows. There is no awn in the panicle in 1999 and
2001, and the grain is small in 1999. The awn was
removed by the “Matsubori Kaze” at April 18 in
1999 and May 7 in 2001. The conditions of the
Agricultural damage by local wind and its countermeasure
panicle and the grain were different every year.
The awn was not removed in 1999 to 2001 and the
grain was large in 1999 in the area where the
“Matsubori Kaze” doesn't blow. The awn was
removed at April 24 in 2002, the grain is small as
well as in 1999.
Fig.11 shows variations in percentage of
panicle from which awn is removed, that was
obtained by the sampling survey from 1999 to
2002. The percentage of panicle from which awn is
removed was 20% or less from 130o54’ longitude
on the west side. On the other hand, it was almost
100% from 130o54’ longitude on the east side in
1999, 2001 and 2002. There is reproducibility in the
variations of damage, the damage area is almost
same in 1999, 2001 and 2002. The wind damage by
the “Matsubori Kaze” did not occur in 2000.
100
％) ( el ci nap dega madf o oit a R
80
Y/Y’=0.8+0.006 ･ X
:2000
:2001
:2002
(2)
where, Y is thousand grain weight which was
measured for panicle without awn, Y’ is thousand
grain weight which was measured for panicle
with awn, and X is number of days after the
heading time when awn is removed. This equation
is effective, when the awn is removed within 30
days after the heading time. The decrease in the
thousand grain weight in 1999 and 2002 were
calculated by using the equation (2). The
decreasing rate of the thousand grain weight was
estimated at 9.8% and 5.6%, and it was almost
equal to the value of sampling survey. When the
awn was removed immediately after the heading
time, the decreasing rate of the thousand grain
weight was estimated 20%. It became possible to
estimate the decrease in the thousand grain
weight of barley by using equation (2).
1.1
:Laboratory's field,2002
:Farm er's field,2002
:Laboratory's field,2003
:Farm er's field,2003
1.0
:1999
60
0.9
40
20
0 50'
130
゜
field. The thousand grain weight has changed
rectilinearly in conjunction with the treatment day,
when the awn is removed within 30 days after the
heading time. However, the thousand grain
weight has not decreased, when the awn is
removed after 30 days from the heading time. The
yield decrease of barley is calculated using the
following equation:
t hgi e wni ar g dnas uoht f o oit a R
Fig.10. Pictures of barley in the same field
immediately before harvest in (A) 1999, (B)
2000 and (C) 2001.
303
0.8
52'
54'
Longitude
56'
58'
Fig. 11. Variations in percentage of panicle from
which awn is removed in 1999, 2000, 2001 and
2002.
Fig.12 shows relationship between ratio of
thousand grain weight and the treatment day that
removed the awn of barley. Treatment day denote
the number of days after heading. Treatments
were carried out in farmer’s field and laboratory’s
0
10
20
30
40
Treatment day (Days after heading)
50
Fig. 12. Relationship between ratio of thousand grain
weight and the treatment day that removed
the awn of barley. Treatment day denote the
number of days after heading.
The local wind, “Matsubori Kaze”, causes
wind damage on its generating area. “Matsubori
Kaze” removes the awn of barley, thus obstructing
the ripening of the grain by eliminating
photosynthesis by the awn. “Matsubori Kaze”
304
Crop, Environment & Bioinformatics, Vol. 1, December 2004
removed the awn of barley for three years, and
thousand grain weight of barley has decreased for
two years among investigations of four years. In
1999 and 2002, “Matsubori Kaze” blew at early
stage of ripening removing the awn of barley.
Thousand grain weight of barley has decreased by
about 10% to 6% when compared with the
leeward zone where there was no wind damage.
The decrease in the thousand grain weight
occurred from 130° 54’ longitude on the east side.
On the other hand, “Matsubori Kaze” blowing at
maturity time of wheat causes the shedding for
wheat, and decreases the yield of wheat.
However, the shedding of wheat occurred only at
one year among investigations of four years, the
damage area was very limited. In addition, the
yield of barley has decreased when the
“Matsubori Kaze” blew within 30 days after the
heading time, while the yield of wheat has
decreased only when the “Matsubori Kaze” blew
immediately before the harvest. “Matsubori Kaze”
can be forecast because it is generated by specific
distribution of atmospheric pressure. When
“Matsubori Kaze” is forecast at the harvesting
time of wheat, the decrease in yield can be
prevented by bringing the harvest forward. It is
thought that wheat is more suitable for the
cultivation in this region than barley.
CONCLUSION
The mobile observation system of wind was
developed. The wind direction and wind velocity
can be measured in every second by using this
system while moving by automobile. The
measurement accuracy of the wind velocity in this
observation method was 1.5 m s . It is possible
to measure wind direction and wind velocity in a
tail wind, head wind, or crosswind for the
automobile, moving at any speed.
-1
The airflow over mountains is formed on the
Aso somma under conditions in stable
stratification and the prevailing southeastly wind
with a speed over 10 m s at 850 hPa pressure
level. The air flow over the mountains converges
in the valley of Aso somma, creating a strong
easterly wind with a speed of over 20 m s . This
strong wind is “Matsubori Kaze”.
“Matsubori Kaze” removes the awn of barley
within 30 days after the heading time, thus
obstructing the ripening of the grain by
eliminating photosynthesis by the awn. The
damage of barley occurred from 130° 54’
longitude on the east side. The scale for estimating
yield decrease for barley was made. It is possible
to estimate the decrease in the thousand grain
weight of barley by using equation (2).
-1
-1
REFERENCES
Alaka MA (1960) The airflow over mountains.
WMO Tech. Note 34:1-135.
Arakawa S (1971) On the local strong wind.
TENKI 18: 103-115.
Corby GA (1954) The airflow over mountains.
Quart. J. R. Met. Soc. 80, 491-521.
Kurose Y, K Ohba, A Maruyama, T Maki (2002a)
Characteristics of Local Wind “Aso Oroshi”. J.
Agric. Meteorol. 58: 93-101.
Kurose Y, K Ohba, A Maruyama, T Maki (2002b)
Characteristics of Local Wind “Matsubori
Kaze” and Its Wind Damage. J. Agric.
Meteorol. 58, 103-113.
Onodera S (1975) On the local strong wind
“Matsubori Kaze”. TENKI 22: 139-143.
Saito K, M Ikawa (1991) A numerical study of the
local downslope wind “Yamaji-Kaze” in Japan.
J. Meteorol. Soc. Jpn. 69: 31-56.