Research On Water Saving Reconstruction Technology Of Irrigation Projects With Pipe Conveyance In Plain Irrigation District Of Suqian

As an important part of water-saving irrigation engineering technology,irrigation projects with pipe conveyance is an important measure for the technological transformation,updating and modernization of irrigation systems.In recent years,in order to meet the needs of the development of agricultural water-saving irrigation,Suqian City has accelerated the development and application of water-saving irrigation engineering technologies.Among them,irrigation projects with pipe conveyance has been vigorously promoted.This paper aims at solving the problems and deficiencies in the popularization and application of irrigation projects with pipe conveyance in the plain irrigation area of Suqian City.The suitability of the irrigation projects with pipe conveyance in the plain irrigation area of Suqian City,the layout of the irrigation system,the appropriate scale,and the construction standards were studied.At the same time,the problem of water-saving reformation of irrigation system in large canal irrigation area in Suqian was discussed.The main research contents and results are as follows:(1)Based on the field investigation,according to the characteristics of the plain irrigation area of Suqian City,the main influencing factors of the application of irrigation projects with pipe conveyance were analyzed,and the 11 indexes that influence the application of irrigation projects with pipe conveyance were summarized,and the technical suitability evaluation indicators of the farmland irrigation projects with pipe conveyance in the plain irrigation area of Suqian City were established based on the four aspects of engineering conditions,application environment,input capacity and benefit level.The combination of AHP method and fuzzy comprehensive evaluation method was used to determine the weight of the evaluation index,and a comprehensive evaluation of suitability was conducted.The rationality of the suitability evaluation was verified through case analysis.(2)According to the differences in land management methods and crop rotation systems in the plain irrigation area of Suqian City,the areas where the irrigation projects with pipe conveyance is popularized and applied were divided into decentralized and large-scale operation areas under the general plain area rice and wheat rotation system,decentralized and large-scale management areas under the rice-wheat rotation system in the polder area,decentralized management areas under the rice-vegetable rotation system in polder area.Considering the factors of crops,water sources,field specifications,and irrigation and drainage,a suitable layout of irrigation projects with pipe conveyance in different zones is proposed.(3)Through the establishment of a simulation model of engineering investment,the approximate budget simulation and economic analysis of typical project investment and benefits are carried out to determine the appropriate scale and construction setting standards for irrigation projects with pipe conveyance in different zones.Under the decentralized operation mode of the rice-wheat rotation system in the plain area,the system is suitable to control the scale of 400～600 mu.Under the general scale operation mode of the rice-wheat rotation system in the plain area,the system is suitable to control the scale of 12 00～1400 mu.Under the decentralized operation mode of the rice-wheat rotation system in the polder area,the system is suitable for controlling the scale of 400～600 mu.Under the large-scale operation mode of the rice-wheat rotation system in the polder area,the system is suitable to control the scale of 500～700 mu.Under the decentralized operation mode of the rice-vegetable rotation system in the polder area,the system is suitable for controlling the scale of 600～800 mu.(4)Aiming at the problems of agricultural irrigation in the large-scale canal irrigation area in Suqian City,three programs for water-saving reconstruction of the tail of the large-scale canal irrigation area were proposed,and an internal independent small-scale irrigation system was set up,and a simulation function model of engineering costs was established.Through economic analysis,the optimal scheme for water-saving reconstruction was determined.The results show that a small pumping irrigation pump station as an independent water source is set up at the end of a large-scale canal irrigation area,and a technical program combining both canal and pipe irrigation is adopted.In addition,the most suitable area for pipeline irrigation control is 10%～30%of the area of the tail irrigation piece.