The Qinling-Huaihe line is what we often call the geographical dividing line between the north and south of China. There are obvious differences between the north and the south of this line in natural conditions, agricultural production methods, geographical characteristics and people's living customs.
According to the climate characteristics, rivers and lakes freeze in winter in most areas north of Qinhuai. When winter comes and the north wind whistles, most trees will lose their leaves, and the leaves that do not lose their leaves are mostly needle-shaped, which is called conifers. Because the annual precipitation in the northern region is less, and the precipitation is mostly concentrated in summer, the river water volume is small and the water level changes greatly. The flood season is only formed in summer, the time is relatively short, and the river sediment concentration is relatively large. In the south of Qinhuai, on the other hand, there is no ice in winter, no deciduous trees and evergreen seasons. The river water volume is large, the water level changes little, the flood season lasts long, and the river sediment concentration is small.
Agriculture and customs, from the perspective of agricultural production and people's living customs, the difference between the north and the south of Qinhuai is more obvious. The cultivated land in the north is dry land, and the main crops are wheat and miscellaneous grains, which are harvested twice a year or thrice every two years; Paddy fields are the main crops in the south, and subtropical cash crops such as rice, sugarcane and tea are the main crops. Two or three seasons a year. People usually say that "northern wheat and southern rice, southern boats and northern horses" is a true portrayal of this difference.
The Qinling-Huaihe line runs through Gansu, Shaanxi, Henan, Anhui and Jiangsu provinces, which is an important geographical dividing line in central and eastern China. There are significant differences in climate, rivers, vegetation, soil and agricultural production between the north and the south. South China pays attention to the construction of river networks for water storage, soil and water conservation, and the protection of agriculture 100 days without rain, so the unit output of agriculture is high, industrial and agricultural production can be guaranteed, and the economy can develop sustainably. There is no water supply in the north, which is prone to natural disasters, heavy rain and drought, which has caused instability to industrial and agricultural production and urban water supply.