The seasonal variation of the Caspian sea level, which season has the highest sea water level

The water level in the Caspian Sea is the highest in July and the lowest in February, with a difference of 2 3 meters in the north and only 20 50 centimeters in the central and southern regions, and the maximum does not exceed a meter. The water temperature in the Caspian Sea is about 26 in the northern and southern waters in summer. In winter, the water temperature in the north is below 0.

The average temperature in the south is 8 10 and the shallow waters in the north are 2 to 3 months of ice age per year. In the waters of the Volga Delta, the wind decreases by up to 4 5 meters, and the wind increases by up to 2 meters.

The Caspian Sea is located in a desert and semi-desert environment, the climate is arid, and water evaporation is very strong. According to statistics, the total amount of water entering the Caspian Sea each year is, and the annual water consumption is less in and more out, and there is a shortage of income"Deficits", the water level of the lake will inevitably gradually decline. In 1930, the area of the lake was 10,000 square kilometers, and by 1970 it had shrunk to 10,000 square kilometers.

The significant change in the long period and the ultra-long period of the water level is the most striking phenomenon in the Caspian Sea. One of the more fascinating aspects of the Caspian Sea study is the reproduction of long-term water level fluctuations over many centuries based on archaeological, geographical, and historical evidence. Studies confirm that the Caspian Sea level appears to have fluctuated by at least 7 meters since the first century BC.

The main reason for these long-term variations is the climatic conditions that determine the balance between water recharge (river infusion and precipitation) and loss (evaporation and flow to the Gulf of Karabogazgore). 7 During the 11th century, there was a low water level. The water level in the Caspian Sea at the beginning of the 19th century was 22 meters lower than it was 4,000,600 years ago.

From 1930 to 1957, the water level fell again due to the construction of a reservoir on the Volga River, excessive water use by industry and agriculture, and a dry climate. Since the beginning of the 70s of the 20th century, the Caspian Sea level has remained around meters. In the early 90s, the Caspian Sea was 27 meters below sea level.

The water level varies greatly from season to season, with a high level in spring and summer and a low level in winter, with an annual variation of up to 33 cm.

The drop in water levels is due to increased evaporation due to climate change reducing river inflows – a situation exacerbated by the construction of reservoirs on the Wowa River – and also due to the consumption of river water by irrigation and industry. The rise in water levels is related to climatic factors that have led to an increase in the inflow of the Wowa River, which has been well above average for several years. Increased precipitation and reduced evaporation at sea surface also contribute to this phenomenon.

The seasonal variation of the Caspian Sea level and its causes.

1. The water level of the Caspian Sea is the highest in July and the lowest in February;

2. The difference between the height of the water level in the north is 2 to 3 meters, and the difference between the central and southern levels is only 20 to 50 centimeters, and the maximum is not more than meters;

3. The water temperature of the Caspian Sea is basically the same in the northern and southern waters in summer, which is about 26 degrees Celsius. In winter, the water temperature in the north is below 0 degrees Celsius. The average temperature in the south is 8 to 10 degrees Celsius, and the shallow waters in the north have ice ages of 2 to 3 months per year;

4. The wind increase and decrease in the Caspian Sea is very significant, and in the waters of the Volga Delta, sometimes the wind and water decrease can reach 4 to 5 meters, and the wind increase can also reach 2 meters;

5. The Caspian Sea is in a desert and semi-desert environment, the climate is arid, and the evaporation of water is very strong.

It mainly depends on what season it is!

1.The water level in the equatorial region is basically unchanged.

2.The Pacific Northwest is affected by the monsoon, and the Northern Hemisphere receives more precipitation in summer (July and August) and less precipitation in winter, and high water levels in summer.

3.In the northern part of the Indian Ocean, the region has a tropical monsoon climate, with more precipitation and higher sea levels in the northern hemisphere during spring and summer.

4.Near the Tropic of Cancer, the area has a Mediterranean climate with rainy winters, and when it is winter, the sea level is high, such as the Mediterranean.

5.In the mid-latitude seas, the climate change is not much, and the water level has not changed much.

In addition, there is another kind of good slippery that is affected by the gravitational pull of the moon and produces tides.

Influencing factors: recharge type - precipitation (seasonal variation); The amount of groundwater, the amount of tributaries, and the area of the basin.

Natural loss mode: evaporation, infiltration.

Topographic vegetation. Human activity.

Water level refers to the elevation of the free water surface relative to a certain base surface, and the distance between the water surface and the bottom of the river is called the water depth. The base surface used to calculate the water level can be the zero level base surface with a certain characteristic sea level elevation, which is called the absolute base surface, and the base surface of the Yellow Sea is commonly used. It is also possible to use the elevation of a specific point as the zero point of the reference to calculate the water level, which is called the base surface of the station.

Water level is the most intuitive factor reflecting the water condition of the water body, and its change is mainly caused by the increase or decrease of the water volume of the water body. The water level process line is the curve of the water level at a certain place as a function of time, with the horizontal coordinates being the time and the vertical coordinates being the water level.

(1) Distribution law: from south to north, from near shore to open sea. Reason:

From south to north, the latitude is getting lower and lower, and more and more solar radiation is obtained; The nearshore is affected by the cold current (Peru) and has lower surface water temperatures than other seas at the same latitude. (2) If the surface sea temperature increases, the coastal temperature increases and the precipitation increases; If the surface sea temperature decreases, the coastal temperature decreases and precipitation decreases.