A New Irrigation And Drainage Pattern In North Plains

The year and inter-annual variations of water resources are large in Northern China.By agricultural and industrial layout and the geographical distribution of population, the region and type of configuration with water resources areextremely unreasonable.With the rapid development of the national economy and the rapid increase in population, the prospect is not optimistic with utilization of water resources in northern China. Rainfall is relatively scarce, evaporation is large, groundwater is buried deep, surface and groundwater resources are relatively scarce, irrigated agriculture is more prominent. Therefore, irrigation management should adhere to the principle that accumulate and highly efficient water-saving irrigation are the first place and fill is the second place to guarantee the realization that the key of Sanshui joint control is measure of water conservancy projects.In connection with status of water resources in northern, this study proposes a project model that can realize the joint control of Sanshui with irrigation, build, and make up for the integration.The so-called irrigation, build, and make up for the integration is to motor-pumped well as the center, to single well controlled area as the basic unit of farmland water conservancy construction.In the period of drought, groundwater is extracted for irrigation using motor-pumped wells; In the period of flood, groundwater is covered full from point, line, surface using motor-pumped wells, ditches and field circles around the border ridge by excess rainfall. Its main contents are as follows:(1) The background and research significance of the paper is set out. On this basis, the main content and technical routes are proposed;(2) Based on the soil infiltration and Sanshui joint scheduling principle, this paper presents soil reservoir regulation model, farmland sulcus and boundary ridge model, in order to make rainfall that is collected in a greater degree into the available soil water and groundwater, thus maintain relative balance between inter-annual of groundwater in well-controlled areas;(3) The article discusses and analies crop evapotranspiration calculation, determines method of calculating crop evapotranspiration according to results of previous studies, draws up crop irrigation principles according to crop real-time moisture real-time;(4) Based on the traditional formula for calculating water balance, this paper analies and compares effectiveness of new irrigation and drainage engineering model. This paper prepares the soil reservoir regulation model calculation program using the theory in previous chapters and VB, and analies build and fill effect of the soil water and groundwater in well-controlled areas in northern plain by the new irrigation and drainage engineering model; and proposes a new type of irrigation and drainage of non-engineering model that is used to change the cropping patterns and use rainfall resources.The new irrigation and drainage pattern that is presented in this paper uses in a greater degree surface runoff, reduces the amount of extracted groundwater.Instead of surface runoff will also be added to the groundwater, in order to allow groundwater to maintain a certain level.By doing so, irrigation, build, and make up for the integration is relized basically.So new irrigation and drainage engineering model has a greater significance for the northern plains.