The water-saving measures in Hetao irrigated district and the sustainable agricultural development of the lower reaches of the Huanghe River

The Hetao irrigated district draw water from the Huanghe River over 1.87 billion cubic meter per year which is one of important cause of the Huanghe River dring up.There are some measures of saving water and saving water potential in the irrigated district.Water proof layers of canals would save water by 2.2 billion cubic meter per year,improving irrigated type would save water 10%,building farmland-shelter forest would save water by 0.147 billion cubic meter per year,reusing the escape canal water would save water by 0.3 billion cubic meter per year.