What is used for irrigation in some walnut plains along the Yellow River?

Hetao refers to the zigzag bend of the Yellow River and its surrounding basins. Hetao Plain is generally divided into Yinchuan Plain between Qingtongxia and Shizuishan in Ningxia, also known as "Tao Xi" and "Tao Dong" in Inner Mongolia. Sometimes "Hetao Plain" only refers to Tao Dong, which is juxtaposed with Yinchuan Plain. Tao Dong is divided into Bayannaoer Plain between Bayangaole and Xishanzui, also known as "back cover", and Tumochuan Plain (namely Chilechuan) between Baotou, Hohhot and Lamawan. Sometimes the Hetao Plain is called the Hetao-Tumochuan Plain.

Irrigation cause

Due to the long-term development of irrigation, the zonal constraints of desert grassland and desert in Hetao Plain have been broken, showing a landscape with connected buildings, vertical and horizontal ditches and lush vegetation. Chestnut soil and brown calcium soil only remain in some areas, and most areas have been replaced by irrigated silt soil, but irrigation is unreasonable, and saline soil is widely distributed in irrigation areas.

The Hetao Plain is rich in groundwater, and the piedmont of the north bank of the Yellow River is deeply buried, and the plain is shallow, which is reduced from10 ~ 30m to 2 ~ 3m. The aquifer becomes thinner from thick, and the water inflow decreases from 100 tons/hour to 60 tons/hour; Salinity increases gradually, generally from 0.5g/L to 3g/L. The groundwater depth in the south bank of the Yellow River is about 1 ~ 3m, the water inflow is/10 ~ 40t/h/h, and the salt content is1~ 3g/L. ..

Sanshenggong Yellow River Water Conservancy Project The Yellow River enters the plain from Bayangaole, Dengkou County, and flows out in Lama Bay, Qingshuihe County, with a total length of 550 kilometers. The river course is winding, meandering, the river bed gradient is small, the water flow is stable, the annual runoff is 25-30 billion cubic meters, and the salt content is 0.3-0.6 g/L. As early as Qin and Han Dynasties, troops were stationed and immigrated, and farmland was irrigated with Yellow River water. Tang Zeng dug a big passage in the back cover. Since the middle of Qing Dynasty, irrigation has developed rapidly, including Yongji Canal, Changji Canal, Huang Ji Canal, Yangjiayun River and Tabu Canal. By the end of Qing Dynasty, there were eight main canals on both sides of the Yellow River, with an irrigation area of 200,000 hectares. During the Republic of China, Sanhuhe Irrigation District was built in the east of Houtao Irrigation District, and Minsheng Irrigation District was built in the front. But there is no comprehensive planning, the canal system is disordered, there is no dam to flow by itself, it does not enter the canal in dry season, and it overflows in flood season. Since 1950s, irrigation in Hetao Plain has developed rapidly. The three sheng Public Water Conservancy Project has been built on the main stream of the Yellow River, with more than 500 kilometers of main canals on the north and south banks, and the irrigation area has been expanded from 654.38+066.7 thousand hectares before the 1950s to 666.7 thousand hectares. At present, there are 5 main irrigation canals and 3 main drainage canals 13, with branches, buckets and canals criss-crossing. There are more than 9.6 million mu of cultivated land in Hetao Plain, and nearly 5 million mu has been reclaimed. Wheat, corn, sorghum, millet, flax, beet, hops, sunflower seeds and other crops are abundant here. It is an important grain and sugar base in China and the autonomous region, and is known as the "granary" and "Jiangnan". Due to years of poor drainage, rising groundwater level and serious secondary salinization of soil, comprehensive treatment has been carried out.