O‘zbekiston zamini /2019 Tahrir hayʼati

THE ROLE OF CLIMATE IN THE FORMATION OF MOUNTAIN AND FOOTHILL 
PASTURES
Land of Uzbekistan
Земля Узбекистана
4/2021

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O‘ZBEKISTON ZAMINI
4/2019
131
AverAge AnnuAl mAximum And minimum Air 
temperAture, °С
period is important for the correct identification 
of degradation factors and the implementation of 
work to prevent it.
Research object and methods.
Due to the 
fact that the object of study is the mountain and 
foothill pastures of Ahangaran district of Tashkent 
region, the study of natural and regional features of 
the district revealed the following:
Akhangaron district is one of the largest 
branches of the southern slope of the Ugam-Chatkal 
mountain range in the North-East.
Erosion, floods, landslides, deep branching 
of watercourses, erosion of rocks and others affect 
the formation of relief in mountainous areas.
Depending on the height of the terrain, it is 
divided into 2 zones: foothills (hills) and mountains, 
located at an altitude of 700-1800 meters above 
sea level. These regions are dominated by trees, 
shrubs, semi-shrubs, large plants, ephemeral and 
ephemeral plants.
This study reflects 30 years of changes 
in the natural climate of Ahangaran district of 
Tashkent region. As well as, the most important are 
the following climate indicators:
- Precipitation, mm/year;
- Maximum air temperature, °С;
- Minimum air temperature, °С;
- Wind speed, m/s;
- The average ground surface temperature 
at a height of 2 meters, °С.
Precipitation 
It can be seen from the line graph, the amount 
of annual precipitation changed dramatically 
between 1990 and 2010. For example, in 1992 
the annual rainfall was 290.9 mm, the following 
year the rainfall increased to 461.6 mm per year, 
however by 1995 this figure fell very rapidly and 
reaching the lowest point for a three-decade period 
at about 167.1 mm per year. From 2010 to 2020, 
the annual rainfall was almost unchanged and 
maintained the same trend for 10 years. The highest 
precipitation for the last 30 years was 461.6 mm in 
1993 and the lowest in 1995, which was 167.1 mm. 
From this graph we can observe that the average 
annual air temperature in Ahangaran district has 
changed every year for the last 30 years. But there 
were no very drastic changes. The maximum air 
temperature rate in the region was observed in 2016, 
where the average annual maximum temperature 
was 23.3°C, and the coldest year with minimum 8 
°C temperature was in 1993.
As the line graph shows, the wind speed in 
Ahangaran district has changed dramatically over 
the years. The lowest wind speed was observed in 
1993, while the highest was observed in 2016. In 
general, the average wind speed in the Ahangaran 
region is 15-16 m/s.
As we can see, the ground surface 
temperature has changed over the 30 years. The 
highest temperature in three decades was observed 
in 2001, when it was 4 °C. The temperature change 
trend over the analysis years is 0.5 °C, where 
this difference is not critical. Overall, the 30-year 
average ground temperature was 3.6 °C.