Study On The Integration Technique Of Precision Ground Irrigation

The content studied in this paper is the national high-tech research and development project — the integration technique of precision ground irrigation (project serial number: 2002AA2Z4311). At the present time, the technique of ground irrigation is still widespread used in whole world, especially developing country. The above ninety-eight percent of irrigated area in our country use ground irrigation. Because of census confinement, ground irrigation is still the primary irrigation methods in our country. Comparing with the traditional ground irrigation methods, the precision ground irrigation technique hold the merit of the high irrigation evenness degree, the high-usage of field moisture and the small irrigation requirement, and so on. The study of the regularity of soil moisture movement in ground irrigation, the analysis of impact factors of ground irrigation technical parameters, and the discovery of optimizing those irrigation parameters are important to enrich irrigation theory and improve the study on soil-moisture movement. Furthermore, they supply the scientific basis on promoting the utility of precision ground irrigation technique and designing the operating parameters of precision ground irrigation system. Meanwhile they are of great value for concluding the synthetic technic system, which is suit for arid region to develop the precision ground irrigation engineering.In this paper, based on the tracing field infiltration tests and ground irrigation tests into soils of laser flat surface with multiform species of soil texture and structure in project region, the basic infiltration characteristics and major factors influencing soil infiltration characteristics are studies systematically and comprehensive. A model used in predicting the infiltration capacity and infiltrationmodel parameters of field soils through some soil physics parameters is build up and methods for predicting the infiltration procedure of field soils are put forward. The flow movement characteristics and irrigation effectiveness characteristics of ground irrigation are analyzed and studied, a integration model optimizing irrigation technique parameters of ground irrigation is set up, which combines the kinematic wave model of surface irrigation flow with the irrigation effectiveness optimize model. Technical measure for heightening irrigation effectiveness of ground irrigation are set forward, mentioned above contents are organically integrated into the integration technique of precision ground irrigation.The thesis pointed out the technique composition and integration relationship of the integration technique of precision ground-irrigation quantitatively and qualitatively. The main conclusion and innovation included:(l)According to the infiltration tests of field soils, the variation characteristic of the field soils moisture infiltration capacity was analyzed, the main factors affecting the field soils moisture infiltration characteristic was performed, which was soil texture, structure, moisture and sediment concentration of irrigation water.(2)It is feasible to predict infiltration capacities and infiltration model parameters of field soils by routine physical parameters with the help of linear regression model with multiple units. If the content of physical clay (O.Olmm), bulk specific gravity and moisture of soils are used to predict infiltration capacities and the parameters of the infiltration model of field soils, the predicted results are satisfactory.(3) The flow movement characteristics and irrigation effectiveness characteristics of ground irrigation are analyzed and studied, a integration model optimizing irrigation technique parameters of ground irrigation is set up, which combines the kinematic wave model of surface irrigation flow with the irrigation effectiveness optimize model, solving optimizing unit discharge under the terms of definite field length and ground line gradient and solving optimizing unit field length under the terms of definite field unit discharge and ground line gradient wasimplemented, which supplied powerful tool for determining optimizing irrigation technique parameters under the terms of variable irrigation water. Meanwhile the combine model of field engineering of clear water and flooding irrigation was obtain. Through adopting the method of integrating experimental investigation and simulation analysis, optimize irrigation technology parameters of ground supplement water irrigation and groundwater recharge irrigation and some technique measures which increased the irrigation effectiveness and groundwater recharge efficiency were put forward.(4) The technique of laser flat surface, the prediction technique of the infiltration capacity and infiltration model parameters of field soils, the simulation technique of ground irrigation process and the integration "model technique of clear water and flooding irrigation net are organically integrated into the integration technique of precision ground irrigation.The paper makes progress and achievement in some way such as the analysis of moisture infiltration mechanics of field soils and the discussion on optimization techniques of irrigation technology parameters. But there will be much work to do because the result of experiment is greatly influenced by time, experimental condition and human factors. The work include: (l)The improvement of the model of the predict infiltration capacities and infiltration model parameters of field soils , especially the foundation of the non-linear model; (2) Increasing of the accuracy of model to predicting the infiltration capacity and infiltration model parameters of field soils; (3) Increasing of the accuracy of the numerical simulation of flow movement of flooding irrigation.