Study On Efficiency Of Agricultural Water Use In Irrigation Area Of Shiyang River Basin

The core of inland river basin in arid area lies in water and the core area is oasis.Restricted by the landscape pattern of mountainous oasis and desert,there is spatial differentiation between upstream water-producing area,mid-stream utilization area and downstream dispersed area.The oasis in the middle and lower reaches is the most water-consuming area,and it is also a highly concentrated area of man-land-water contradiction.Irrigation area refers to the irrigation area with reliable water source,diversion,distribution and drainage channel system.It is the most basic unit of the oasis in arid area and the area where water resources are most concentrated.Its efficiency not only affects the utilization situation and stability of oasis water resources,but also affects the whole basin Sansheng.The harmonious development of the system(production-life-ecology).Shiyang River Basin is one of the three major inland river basins in Hexi.It is also one of the basins with the highest exploitation and utilization of water resources,the greatest water pressure and the most serious ecological environment problems.The consumption rate of water resources in the basin is 109,and the degree of water resources exploitation and utilization is as high as 172,which far exceeds the reasonable carrying capacity of water resources.Irrigation water for agriculture is as high as 90.Therefore,the efficiency of agricultural water use determines the utilization efficiency of water resources.On the premise of continuing to develop irrigation area agriculture,the present agricultural water use efficiency of Shiyang River basin irrigation area is evaluated objectively,the water saving situation is clearly recognized,and the main cause of influencing water use efficiency is found.It is of great significance to improve the efficiency of agricultural water use in irrigated areas.Based on the previous important research results and data envelopment analysis method,this paper uses the classification efficiency model,Malmquist model and congestion index model,and takes 16 irrigation areas in Shiyang River Basin as the study area.This paper analyzes the dynamic characteristics of agricultural water use efficiency and its spatial differentiation before and after comprehensive managementof the whole watershed,the dynamic characteristics of the efficiency values during the period of 15 years,as well as the redundancy rate and congestion index of different types of irrigation areas.The main conclusions are as follows: 1 before and after comprehensive management,the agricultural water use efficiency of each irrigation district has significant temporal and spatial differentiation characteristics,the high value region has obvious clustering and regional characteristics,and the efficiency is obvious.The change and implementation of important policies are highly consistent with the difference of natural endowment among irrigation districts.2 The differences of natural endowment among irrigation districts have little effect on the technical efficiency EC,and the mixed irrigation areas can be used as the water of the experimental irrigation areas with new technology.3.Most irrigation areas in Shiyang River basin with different degrees of redundancy in soil and canal system construction have overcrowded input elements in 15 years.In order to avoid the waste of production factors,the allocation of production resources in irrigation district should consider the relationship between input elements and water consumption per unit area.Both the water use coefficient of fixed canal system and the land use coefficient of irrigation area are obviously positive phase.The relationship between Guan and the density of canal system in irrigation area was inversely correlated.Finally,based on the results of empirical analysis,the paper puts forward some countermeasures and suggestions to improve the efficiency of water use in irrigation area of Shiyang River Basin.