Brief Introduction of Hetao Irrigation District National Center of Efficient Irrigation Engineering and Technology Research-Beijing Xiaoyan Guan

Main Contents Location of Hetao Irrigation District Climatic conditions Conditions of water resources Canal system of irrigation district Agriculture irrigation Existing problems Research works

Hetao irrigation district is one of the three largest gravity irrigati- on districts in China. Hetao irrigation district is located in the middle of Yellow River Basin in the west of China. From east to west is about 270km, north-south width is 40-75km, irrigation district is flat terrain, southwest of the district is high and northeast is low, the elevatio- n is m. Irrigated area of the total land area is about 1.12 million hm 2, the existing irrigation area is about 0.57 million hm 2,it is about 51.2 % of the total land area. 1. Location of Hetao Irrigation District

Yellow River Hetao Irrigation District

Hetao irrigation district is a typical arid region with continental monsoon climate, the weather is dry and hot in summer and severely cold with little snow in winter. Annual precipitation is 136.8~213.5mm, annual evaporation is mm, annual average temperature is 6-8 ℃,increasing from east to west. The average relative humidity is 40~50%. Frozen period last for 5~6 months, the greatest depth of the freezing is 1.0~1.3m. frozen period is from late November to April of the second year, frost-free period is 135~150d, the annual sunshine hours is 3100~3300h. 2. Climatic conditions

3. Conditions of water resources The surface water of Hetao irrigation district is mainly the yellow river water, the yellow river water with annual 30 billion m 3 r unning by the area is good in quality for irrigation purpose, i n spite of its high sediment concentration. Mineral content, mainly Ca(HCO 3 ) 2, is less than 1g/L. In the past years, this region takes in about 5 billion m 3 annually. Water is delivered with one single main canal and many levels of branches.

With the ever-increasing pressure of water shortage in the north part of China and the concern of the yellow river ru- nning dry at its low reach for increasingly extended period and length, the allowed water intake as set by the governm ent is now cut down to 4 billion m 3 annually. The depth of ground water table is 1.0~1.5 m during irrig-a tion periods and 0.5 m after Autumn irrigation (from Oc-t ober to November).

4. Canal system of irrigation district Irrigation water is taken from the Shanshenggong Head Work c onstructed at Dengkou on the yellow river, supplied by 180km l ong main irrigation canal, then diverted to the whole area t hrough 11 branch irrigation canals. Drainage water is collected by 11 branch irrigation canals, then drained by pumping through the main drainage canal to the Wulingshu Lake.

史海滨 内蒙古河套灌区概况 9 内蒙古河套灌区 main irrigation canal:180km main drainage canal:260km 一干渠 乌拉河干渠乌拉河干渠 杨家河干渠杨家河干渠 黄济干渠黄济干渠 永济干渠永济干渠 丰济干渠丰济干渠 皂火干渠皂火干渠 沙河干渠沙河干渠 义和干渠 通济干渠 长济干渠 塔布干渠 三湖河干渠 套 外套 外 First grade irrigation branch

Sanshenggong Water Control Project Irrigation canal

Wuliangshu Lake

5. Agriculture irrigation Irrigation in Hetao has a long history, the sustainable developmen t of agriculture irrigation scheme depends on irrigation methods and good management practices. With existing water delivery system and irrigation canals, consid- ering the high sediment concentration in water, surface irrigation is the main irrigation method in Hetao irrigation district. Micro-irrigation is another irrigation method for cash crops at part of the areas in the district. For the management side, water allocation in different parts of th e region is important besides good irrigation schedule.

Rehabilitation and water-saving reform of irrigation district canal lining

Irrigation district entironment

6. Existing problems Hetao irrigation district still have some problems to be solved such as ： Shortage of water resources Soil salination Level of irrigation management must be improved Equipment of water transmission and distribution remains to be i mproved Land production efficiency is relatively low Destruction of ecological balance in some area

Soil desertification Water seepage

7. Research works For the current problems, A number of researchers have done l ots of researches in Hetao irrigation district, such as: Water Resource Management Soil salinity control The repose of crop to water-salinity Reinforcing and rehabilitation of irrigation district Protection of ecological environment