Reasons for the lowest solar radiation in Sichuan basin

The reasons for the lowest solar radiation in Sichuan Basin are rainy weather, low altitude and dense atmosphere.

Sichuan Basin is one of the four great basin cities in China, most of which are located in Sichuan Province, with a total area of more than 260,000 square kilometers. Located in the south-central part of the Asian continent, between 2810' and 32 25' north latitude, the southwest of China, including the central and eastern Sichuan Province, is surrounded by the Qinghai-Tibet Plateau, Daba Mountain, Huaying Mountain and Yungui Plateau.

The surrounding mountains are mostly between 1000m and 3000m above sea level, covering an area of about 654.38+10,000 square kilometers. The middle basin bottom is low, with an altitude of 250m-750m and an area of about 160000 square kilometers, which can be clearly divided into two parts: marginal mountain and basin bottom. Generally, there are 2 ~ 5 vertical natural zones from bottom to top in marginal mountainous areas. On the northwest is a long Longmen Mountain.

The bottom of Sichuan Basin is divided into Chengdu Plain, hills in the middle of Sichuan and parallel ridges and valleys in the east of Sichuan from west to east.

Sichuan Basin is a famous red bed basin in China. The surface rocks are mainly purple sandstone and shale, which are easily weathered and developed into purple soil, rich in nutrients such as calcium, phosphorus and potassium, and are the most fertile natural soil in China.

The climate of the basin belongs to subtropical monsoon humid climate, with high temperature in the east and low temperature in the west, high temperature in the south and low temperature in the north, high basin bottom, low edge and concentric isotherm distribution.

The average temperature in summer is between 24℃ and 28℃, and the extreme high temperature is between 36℃ and 42℃. The average temperature in winter is 4~8℃, and the extreme low temperature is -8 ~-2℃. The annual precipitation in Sichuan Basin is 1000 ~ 1300mm, but winter drought, spring drought, summer waterlogging and autumn rain are unevenly distributed during the year, and 70-75% of the rainfall is concentrated in summer (June ~ 10).

Sichuan Basin is also rich in fossil energy such as coal, oil and natural gas, as well as minerals such as salt, apatite and sulfur, among which natural gas and mirabilite rank first in China, and there are also important strontium minerals in China. The marginal mountainous area is the base of various economic trees and timber forests in Sichuan, and the bottom of the basin is contiguous with cultivated land, which is the largest rice and rape producing area in China.

Hundreds of millions of years ago, Sichuan was a rough Wang Yang.

Its seabed is a set of extremely thick strata, mainly marine carbonate rocks formed in the early days of the earth. By the Triassic period about 250 million years ago, this area still belonged to the periphery of the Tethys Sea.

The communication with the open sea water was blocked, and a set of rocks with a maximum thickness of 500 meters and rich in salt was gradually deposited, which became the source of brine resources in Sichuan. Volcanic eruptions have taken place in some places, leaving a magical "mung bean rock".

During the subduction collision of Jurassic tectonic plates about 200 million years ago, the Tethys Sea gradually disappeared. Western Sichuan uplifted into land, and crustal materials squeezed eastward, forming the ancient Longmen Mountain. The mountain bends the lithosphere, thus forming the Lu Qian Basin on its east side, which is the earliest prototype of the Sichuan Basin, and its scope is much larger than that of the Sichuan Basin in geography and geomorphology.

At the same time, debris and other substances on the mountain gradually filled and deposited in the basin, and the seawater covered in the early stage became shallower and shallower, gradually becoming a swamp with alternating land and sea.