The Development of Irrigation in the Yellow River

摘要

The Yellow River basin is the cradle of the Chinese nation. During a very long historic period, it has been the political, economic and cultural center of our country. It is located between the arid area in the northwest and the wet area in the southeast. The climate of these places belongs to the mainland monsoonal climate in the arid and semiarid area. The mean annual precipitation is 478mm in the area. Apparently, the precipitation distribution is not the uniformity in the space-time. And, it existed the great difference between the years and in the whole year. Annual precipitation is concentrated on June to September. It is 65% ~ 80% of the volume of the whole year. The mean annual evaporation is 1100mm. They present the large diversity with the difference of the landform, hypsography and the condition of the climate. The total land area in the Yellow River basin and the regions which diver water from Yellow River in the downstream is roughly 850 thousand km~2 , of which most is mountain and hill area; The plain only accounts 20% , being concentrated in Hetao plain of Ningxia and Inner Mongolia in the upper Yellow River, Fenwei basin in the middle Yellow Kiver and plains of the Yellow sea and Huai sea in the lower Yellow River. These regions are the most proper places for developing irrigation. Since the new China being established, the irrigation career in Yellow River has come into a new developing stage,during which the irrigation area enlarged quickly , yields of cereals and economy crops increased greatly. The Yellow River irrigation districts has became the important manufacture base of grain, cotton and oil of each province and greatly accelerated the development of local economy and the raising of living standard of people.