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By study and searching in this region, we
should differentiate between the elements,
and regional factors. temperature – pressure
and radiation, each of them concern to a regional
element. The combination of these elements
that is a physical condition of atmosphere
like temperature, raining or the amount of
clouds in the sky, are regional elements.
But elevation – langitude – latitude. mountainside
and plant covering, which are important in
searching are, concerned as regional factors.
Here we study the norms of province regions
that are a total conclusion of available statistics
of atmosphere elements. |
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The
air temperature:
Searching the different parameters of temperature
is very important in planting programs and
improvements, also industrial projects, and
city building. The province of chaharmahal
and Bakhtiary is one of the coldest of all.
The annual average of temperature in different
parts is under the cause of different regional
factors. In the center of province, Shahrekord,
the average temperature is 11.5 degrees centigrade
- Borujen 10.5, in colder places like Koohrang
9.2 and at warm places like Lordegan is 15.2
. In Chaharmahal va Bakhtiyary province, usually
the warmest month is July and the coldest
is January. The Min absolute temperature in
some of the places like Dezzak has been reached
to -34.5 degrees centigrade. In the center
of province the Min absolute temperature recorded
during the last 30 years in Shahrekord -32
and the Max has been 42 degrees centigrade.
The most absolute temperature that has been
observed in lordegan in 47.5, that is explanatory
of a warm condition in this place of the province.
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Amount
of freezing days:
If during a day and night (24 hours) the Min
of temp is 0 (zero) or under that, we call
it a freezing day. Freezing days are different
in the different parts of the province. The
least of them is in lordegan with 83 days
(period of 1972-2000) and the most of them
in Dezzak with 140 days (period of 1972-2000).
Naturally in mountains having no signal –
man, it may be more than what we recorded.
Freezing days in the center of the province,shahrekord,are
124 days and Koohrang 132 days, Borujen 132
days and Lordegan 113 days respectivly, (1958-2000).
On June - July - Aug, the cities are without
freezing days. Most of the freezing days are
in January. Freezing taking place in spring
leads to frost – bite of blossoms. This damages
a lot of trees and gardens and fields. So
this parameter is very important. |
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Relative
humidity:
Because of heights and huge sources of water
also rivers and entering the humid flows (rain
– snow), relative humidity is in a good condition.
The average of relative humidity is representing
in percent. This is %46 for Shahrekord - %38
for Borujen -%45/7 for Lordegan -%46 for Koohrang
%50 for Avargan-%46 for Dezzak -%48 for Emam
gheis – and %50 for Zamankhan. Considering
the distance between the station and moisture
sources like rivers, this quantity clarifies
the Condition around the stations.
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Precipitation:
The province of Chaharmahal va Bakhtiary is
situated at the foot of middle Zagros and
is one of the submergible places in our country.
The kind of precipitation in the province
is different from one place to another. For
example in high regions, half of the rain
is freezing. the rate of snowfall coefficient
in the height of Koohrang in different years,
has been different from %34 to %59. So the
effects of the combination of rain – and snow
over the climate is observable. Time of precipitation
in this province is like the west of Iran.
Most of the rains are between December and
the end of April. The dry season of the province
is Conforming with summer. The maximum month
precipitation in cities and different places
of province is most in January – February
and sometimes in march or December and rarely
it rains in April. These are usually taking
place at the higher places of the province.
As a matter of rain, winter is at the top
and after that autumn and spring comes. Summer
has a little rain and often is a dry season.
The maximum daily precipitation in Koohrang
is 145 mm. The annual total average of in
Koohrang station is 1414 mm. This is at the
top. In other stations the amount of rain
has been reported as follows: Shahrekord 319
- Borujen 245.2- Lordegan 509.6 - Dezzak 424
- Avargan 545.5 Emam Gheis 570.2 and in Zamankhan
336.9 mm. |
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Wind
direction and speed:
Wind direction in the Chaharmahal and Bakhtiary
province is usually from the west and the
southwest. In the center of the province Shahrekord
the wind direction are frequently the southwest
in the winter and spring. Also in July and
August the flow is from the East and in September
and autumn is from the southwest. The annual
average of the wind speed in Shahrekord is
4.1 m/s. In Lordegan – kiar and Gandoman,
the flow of the wind is southwest and western.
In winter the blowing of the winds is very
cold. All the west part of Dopolan, Absabz
and the Valley of Dopollan, the high mountains,
block the strong winds. The most intense wind
has been reported in this province is 20 m/s
in Shahrekord, 28 m/s in koohrang 15 m/s in
Lordegan and 20 m/s in Borujen.
The
yearly windrose of shahrekord synoptic station
Shahrekord
synoptic windrose station in spring
Shahrekord
synoptic windrose station in summer
Shahrekord
synoptic windrose station in autumn
Shahrekord
synoptic windrose station in winter
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The
cloud covering:
In winter the amount of cloud in the sky is
more than other seasons, like most of the
parts of our country. Cloud covering in spring
decrease and in summer reaches to the least.
At the beginning of autumn, the cloud covering
will increase againe. Among of cloud in the
sky is explaining with numbers. For example
8 of 8 clarifies the complete cloud covering.
If we divide the sky into 8 parts and if 6
parts of it is cloudy, we use 6/8. According
to this division, a complete and perfect covering
of cloud (8/8) has been reported in Shahrekord
37 days, Borujen 21 days, Lordegan 33 days
and Koohrang 48 days. |
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The
sunshine hours:
An instrument measures it. Usually the sunshine
hours related to latitude, season and the
amount of cloud in the sky. In Chaharmahal
and Bakhtiary the average of annual sunny
hours (totally) in Shahrekord is 3144 hours,and
in Borujen 3377.2, in Lordegan 3171 hours
and in Koohrang 3.2879 hours have been observed.
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Thunderstorm:
In Shahrekord, the center of ChaharMahal va
Bakhtiary, for 6 or 7 days a year, storm and
Thundering is taking place. Most of them are
in April and may. Koohrang, regarding to thunder
and storm is at the top with 26 days a year.
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Snow and rain or snowy days:
In the center of Chaharmahal va Bakhtiary
in shahrekord snow with or without the rain
appear in 17 days a year. Koohrang is at the
top with 53 days a year. Perhaps in cold and
high places, snowing is more than this, but
because there is no measuring station and
observer, the days of snowing haven’t been
measured. Considering topographic condition
of the province, which is related to Alpine
mountain ridge, also a lot of high places
and huge amount of snow cause flood and avalanche,
which is going to be considered in regional
projects and plans. |
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Dusty days:
Just a few dusty days of year are dusty. Shahrekord
5 days and Borujen 17 days, have been the
least and the most in the province respectively.
Dusty days in warm month are more than cold
months, because of dry flows of the regions
or local. |
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| Charcteristics
of synoptic stations |
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Koohrang |
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Lordegan |
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Borujen |
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Shahrekord |
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Station
name |
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North
32-26 |
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North
31-31 |
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North
32-00 |
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North
32-20 |
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Latitude |
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East
50-07 |
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East
50-48 |
|
East
51-18 |
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East
50-51 |
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Longitude |
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2285 |
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1564 |
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2197 |
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2061 |
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Elevation |
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Next
to the tunnel 1 |
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Inside
the city |
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Inside
the city |
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Shahrekord
airport |
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Position
of station |
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Mountainous |
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Plain |
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Plain |
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Plain |
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Geographical
location
of region |
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more |
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more |
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more |
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more |
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Climate
type |
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Goat’s
- Thorn |
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Acorn
jungle |
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Steppe |
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Steppe |
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vegetation |
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Synoptic
1366
Climatologic 1338 |
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Synoptic
1372
Climatology 1336 |
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1367 |
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1335 |
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The
year of establishment |
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| Regional
normal of the synoptic stations |
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Koohrang |
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Lordegan |
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Borujen |
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Shahrekord |
|
Station
name |
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1987-2000 |
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1995-2000 |
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1988-2000 |
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1955-2000 |
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Statistical
period |
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-30.6 |
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-21 |
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-26.8 |
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-32 |
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Absolute
Min. temp. |
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35.8 |
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47.5 |
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36.6 |
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42 |
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Absolute
Max. temp. |
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9.2 |
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15.3 |
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10.5 |
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11.8 |
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Average
of daily temp. |
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1414 |
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475.8 |
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245.2 |
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319 |
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Average
of annual
precipitation |
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|
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46 |
|
45 |
|
38 |
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46 |
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Average
of relative
humidity |
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145 |
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72 |
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76 |
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Daily
High Tide of raining
(mm) |
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58 |
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30 |
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39 |
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41 |
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Max.
wind speed
observed |
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132 |
|
113 |
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132.2 |
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124 |
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Freezing
days |
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|
|
|
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2879.3 |
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3296.4 |
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3377.2 |
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3144 |
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Average
of yearly
sunshine |
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47.6 |
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33 |
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21 |
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37.2 |
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Full
cloudy days |
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