Analysis On Water-saving Measures And Estimation On Water-saving Potential Of Agricultural Irrigation In Hetao Irrigation District Of Inner Mongolia

By choosing Hetao Irrigation District of Inner Mongolia as the research object,we deeply studied crop planting structure and water-using processes and analyzed the application of different water-saving measures in this irrigation area based on field investigation,combining with related research data and information.Under comprehensive consideration of the water use efficiency,economic benefit and ecological environment benefit in Hetao Irrigation District,a calculation model of water-saving potential of agricultural irrigation resources in Hetao Irrigation District was established based on water balance principle,and the agricultural water-saving potential of Hetao Irrigation District under limited water resources was quantitatively discussed.Thereby,providing a scientific basis for water-saving irrigation planning and management,efficient utilization of water resources and ecological environment improvement in the irrigation area.The main results this research are as below:(1)The crop planting structure directly affects the total agricultural water amount.From 1990 to 2014,the area of grain crops with a high water consumption has been decreased,and the growing area of economic crops with low water consumption has been increased.Among them,the crops with large change of planting area are mainly wheat grown in summer,maize and sunflower grown in fall.The planting structure has changed greatly,it seems stable since 2010 and level off in a certain period of the time,while only limited space to adjust.Thus,there is little water-saving potential through the planting structure adjustment.(2)In the future period of time,the main agriculture water-saving measures and technology should be implemented in Hetao Irrigation District are as following:increasing channel lining and remolding,adopting efficient field water-saving irrigation technology,optimizing autumn irrigation technology,adopting efficient water-saving technology of agricultural cultivation,developing well canal combined irrigation technology,drawing up efficient crop irrigation system and agricultural water-saving management measures and so on.(3)The present irrigation water utilization coefficient of in Hetao Irrigation District is still low,thus there is great space to improve.It can greatly reduce water leakage and improve the canal water utilization coefficient through the channel lining and seepage control of the main canal,which showed a great water-saving effect.At the same time,the water-saving effect of land consolidation,micro irrigation,no tillage mulch and other water-saving measures in the field is also obvious.(4)On the basis of crop water requirement,a model that estimating the resource-based agricultural water-saving potential of Hetao irrigation District was established by considering effective rainfall recharge,the irrigation water loss during conveyance and field.According to the current crop planting structure and water-saving irrigation techniques in Hetao Irrigation District,compared with 2014,the agricultural irrigation water-saving potential in 2020 and 2030 would be 497 million m3 and 716 million m3,respectively.That is to say the crop irrigation requirements were 3.982 m3 and 3.763 billion m3,respectively.