The Ishim Plain is sometimes called the Ishim Steppe in Russia. And in Kazakhstan - the North Kazakh Plain. It is composed of lacustrine-alluvial deposits, as it is located between two large water arteries: the Tobol and the Irtysh.
The Ishim Plain on the map of Russia is a unique area of the great West Siberian Plain. From the south, it is limited by small mountains of the Kazakh uplands. In the west, it is bordered by the vast valley of the Tobol, and in the east by the Irtysh. In the southeast, the Ishim plain gradually turns into Pavlodar. And in the north, going down, it passes into the Middle Irtysh lowland.
Relief: height above sea level of the Ishim Plain
The relief of this steppe is a flat lowland with weak dissection and small maximum heights up to 140 meters. The Ishim plain has a slight slope to the east. The relief is also characterized by shallow hollows left by ancient rivers and rivulets.
There is also a runoff valley on its territory, which is called"Kamyshlov log". A fairly full-flowing river Ishim flows smoothly across the plain. In some places, the surface of the steppe has depressions called depressions. They often contain shallow lakes or extensive swamps.
Climate
In the forest-steppe part of the plain, there is a great difference between daily and annual temperatures. Winters are cold and severe, the average January temperature is from -18 to -20 degrees. Minimum temperatures reach -52 degrees. It is warm in summer, the average July temperatures range from +18 to +19 degrees, but there are also forty-degree heat.
In summer, cyclones bring moisture to the plain. From 300 to 400 millimeters of precipitation falls annually, most of it during the summer: from 250 to 300. In winter, up to 45 centimeters of snow falls, this is relatively little, in addition, it lies unevenly on the plain. Therefore, the soil here freezes up to 1.5 meters.
In the steppe zone, high temperatures in summer, combined with dry winds, make these areas very dry. Grain crops in the fields suffer from a severe drought every three years and grow poorly, despite a longer growing season than in the forest-steppe zone. The annual rainfall is less than 300 millimeters. In Kustanai - 252 millimeters, and in Pavlodar - 260. The largest amount of precipitation falls in the summer, 35-40 millimeters per month. Despite this, due to the winds, very strong evaporation occurs (85-90 percent of annual precipitation) and the soil loses a large amount of moisture. Sometimes there are phenomena such as dry winds incombined with a dust storm. The temperature sometimes rises to 40 degrees, and the soil warms up to 65.
Winter in the steppe is long and cold. The average temperature in January is from 16 to 22 degrees below zero, but on some days the temperature drops to -40 and -50 degrees. Snow falls late, and in the first half of the winter period its thickness reaches only 16-30 centimeters. The snow cover lies steadily from 130 to 160 days a year. Spring comes late, does not last long, there is little rainfall during this period. Autumn is also short and dry in the first months.
Rivers and lakes
The Ishim and Irtysh flow in the developed valleys, in their floodplain there are water meadows. The tributaries of these two rivers are small, have little water and often dry up in summer.
But there are a lot of rivers, small lakes and swamps on the Ishim Plain. The rivers here are calm, flowing slowly through the steppe, as the slopes are very small. Therefore, their channel meanders strongly. In the wide floodplains of the rivers, oxbow lakes are often found. The formation of water arteries on the Ishim Plain is prevented by drainless and numerous basins. They absorb all surface and ground water. Numerous lakes appear due to these landforms - hollows and depressions. But these fresh water bodies are gradually overgrown with mud and swamp along the banks. All flat sections of watersheds become swamps: all kinds of depressions, hollows, depressions and rear sections of river terraces. The swampiness of the Ishim Plain gradually decreases in the direction from north tosouth. Bogs occupy a smaller area and move from sphagnum to sedge-hypnum.
Lake Seletteniz on the Ishim Plain (Kazakhstan)
The largest drainless s alt lake Seletteniz is located on the North Kazakh plain. This reservoir is located at the bottom of a large depression, located at an altitude of 64 meters above sea level. Its area is 750 square kilometers. The average depth is from 2 to 2.2 meters, and the maximum is 3.2 meters. This steppe reservoir is powered by melting snow.
The coastline is uneven, heavily indented, forming many bays and peninsulas. The eastern and northern shores rise above the lake, while the low-lying ones (western and southern) gradually turn into s alt marshes and swamps. In spring, during high water, the Sileti River flows into the lake. Two rivers constantly replenish the reservoir: Zholaksay and Kashirbai.
Vegetation
Most of the territory is occupied by peg forest-steppes. This zone of the Ishim Plain on the map of Russia stretches along the Trans-Siberian Railway between Chelyabinsk and Omsk. To the south, feather grass steppes are already beginning, which are called the Kustanai and Ishim steppes. And then, closer to the Irtysh, there is a lowland.
Dark chestnut soils and chernozems with solonchaks predominate. 90 percent of the territory adjacent to the Irtysh and Ishim has been plowed up. Growing in the wild:
- feather grass;
- steppe tulips;
- bow;
- tipchak;
- thyme;
- zopnik;
- wormwood;
- irises.
Wormwood grows on the s alt marshes of the Ishim steppe,soleros, licorice, chia, species of sweet clover and other plants resistant to soil salinity. In more humid places of the steppe, there are such shrubs as honeysuckle, acacia, dog rose, and spirea. There are also birch pegs. There are light pine forests in the river valleys.
