Chaharmahal va Bakhtiary province with 16532
sq. km. is situated between to 31° 09' North
latitude and also to 32° 48' East longitude.
This Province located at the center of Zagros
Mountains, between the internal mountains
and Isfahan mountains. This province is limited
to Isfahan from the north and the East, from
the west to Khoozestan province, from the
south to kohkilooyeh and Boyer Ahmad and from
the Northwest to Lorestan province.
According to the lost division of our country
(political) this province is divided into
6 towns, 24 cities, 15 parts and 34 village
. This region owns one percent of the whole
country, which is in the bed of zagros. About
%10 of water sources are in this province.
Because of high mountains, the humid Mediterranean
winds evacuate all over these places. This
province has a very proper rain. Frequently
at the mountains and height, we have snowing.
Snow covered heights is one of the regional
aspects. Because mountain creation is young
in this place, natural calamities like Earth
quake – flood and the land movement are observed
in most of the places.
Also freezing , chilling , drought and the
thunderstorm are of its natural disaster.
Rain and snow over the heights make two branches
called karoon and Zayandeh Rood Rivers. Karoon
is 13800 and Zayandehrood is 2720 sq. km.
Zayandeh rood, Karoon, Karkheh and Dez Rivers
are branched from Zagros heights. These four
rivers are the main water sources in the region.
About %45 to %50 of our country water sources
is provide in this province. The charming
beautiful nature in this province, especially
in spring, summer and winter attracts many
travelers from inside and outside of the country.
Chaharmahal va Bakhtiary has various climate.
The rains are mostly affected by Mediterranean
flows. These flows come from the west and
the southwest and have an effect of a bout
8 months on the region. The rain starts from
October. In January it will go to the top
and in may it will decrease, %19 of rain is
fallen in January more than %90 percent of
rain is between November to April. Less than
%10 percent of rain is from June to October.
The west height of the province with yearly
1600 mm rain is the most rainy regen. The
heights of sabzKooh has an average of 1400
mm, the southwest with 900 mm rain are the
second and the third respectively. As a matter
of rain, the lowest is the East and the north
East area with yearly rainfall about 250 to
300 mm. The average of the rain in the whole
province is about 560 mm. Because of the mountainous
region of the province, and knowing the fact
of the height affect on the temperature, there
will be different regions as matter of temperature.
The Max absolute temp has been recorded in
Lordegan synoptic station with 47.5° and the
Min absolute Temp in Dezzak climatolgical
station with -34.5° . The most frequency freezing
days, has been taken place in 1962 with 171
days in Chelgerd (Koohrang) the least absolute
freezing days also has been taken place in
Lordegan station with 58 day (the year 1998).
main flows affecting the weather of the province
The winter flows:
In winter season, our country is a affected
by Siberia high pressure flows. The Siberian
high pressure is spreading all over the Asia.
Siberian High Pressure transfers the polar
continental mass from the north west to the
west. The results are obsolute minimum temperature
of about 32 in Shahrekord and -34 in Koohrang,
also 120 freezing days in Shahrekord and more
than -125 freezing days in the north west
of the province.
Another High Pressure mass is in the north
Atlantic. This H.P.mass affects on the regional
flows in two ways:
1 - A flow that brings the Mediterranean humid
and also Atlantic weather to the country (Tropical
Maritime). This flow is usually Mediterranean
low pressure, and causes more than %60 of
precipitation in Iran. The western - Eastern
flows will be continued till the middle of
spring. In summer they will be stopped. These
humid flows hits to the cold flows of central
Asia and Siberian flows and this will lead
to a lot of rain and snow in the north west
2 - The North Atlantic flows a part of which
is Azures mass ,will be pushed to the north
Europe and Scandinavian at the beginning,
then over the black sea and Ghafghaz enters
to the north west of Iran. This mass of weather
is actually polar Maritime. But its identity
will be chaned during this distance.
In Summer the core of LP (is called the thermal
low pressure) affects the region from the
south. This core is the droughty center of
two H.P. of the north Atlantic, that will
pass over the Eastern Europe warm lands and
then from the northwest enters in Iran.
Sudanese low pressure system:
In addition to Mediterranean flows, Sudanic
L.P. in winter and spring affect on the south,
the south west and some times the west weather
of the country. Strong raining in the southwest
is as a cause of the Sudanic l.p. The combination
of flows at the land and high levels of atmosphere,
it will be activated and make rain a flood.
Some times a combination between Sudanic and
Mediterranean flows will lead to very strong
rain and floody precipitation. At the time
of sudanic flow activation, 145 mm in Koohrang
(in Mars 1998) 70 mm in Lordagan and Malkhlifeh,
has been reported during a 24 hours .
According to koopen division, the east of
the province is a temperate and cold region
with dry and warm summer, (Dcas). For example
we can consider Shahrekord station and Emam
Gheis on this condition. Heights of 2500 to
3000 meters have cold temperate and dry summer
(DCAS) like chelgerd(kohrang) . The western
regions are covered of Acorn Jungles. Like
semi hot regions of Lordegan and Monj,with
warm and dry summer. The heights of above
3000 meters has mountainous climate (H) and
is always snow covered.
the region of the central part of Iran by
suggested method (Dr. Karimi):
Using this method Chaharmahal va Bakhtiary
is divided into 6 regions:
1 - Elevated regions more than 3500 meters
from the sea,with poor plant covering, short
period of plant growth and most of the time
2 - Temperate humid region and very cold,
next to the heights, slightly surface of the
province, poor plant covering Just soap wort
plant and also Juniper grow in these areas.
3 - Semi humid cold temperate region has got
most of the province climate. The central
parts of province and many plains are situated
in this region. It consists of central parts
like shalamzar, Laran, Ben and a part of Saman
and central part o f Borujen – Farsan town
– Naghan in Ardal town.
4 - Cold humid temperate region: It is under
the region number 3 (semi humid cold temperate),but
amount of rain is a little more in this region.
It is consist of Emamgheis in Boroojen,and
Dinaran part of Ardal ,sodejan and marghmalek
in shahrekord town.