Stage and step dynamic control agricultural field drainage design method

Abstract

The invention relates to the field of agricultural irrigation and drainage, and specifically provides a staged and graded dynamic control design method for farmland drainage. According to the actual demand for drainage, the present invention divides the three stages of the early stage, the middle stage and the late stage in time, respectively proposes the dynamic control index of groundwater level as the design standard of different levels of drainage projects, and determines the fields, water collection and water delivery ( or backbone) and other different levels of drainage ditches (pipes), not only reduces the depth of drainage works at all levels, reduces the difficulty of controlling open ditch collapse, makes it easy to obtain artesian drainage, facilitates management, and improves the field drainage effect, making drainage The overall combination of the system is more reasonable. Compared with the original method, the present invention is more suitable for canal irrigation areas irrigated all the year round in the north, has strong adaptability, is easy to implement, and can save engineering investment and management and maintenance costs.

Description

technical field [0001] The invention relates to the field of agricultural irrigation and drainage, and specifically provides a staged and graded dynamic control farmland drainage design method for determining reasonable specifications of the drainage system according to new design standards. Background technique [0002] Under the existing technology, in northern canal irrigation areas that have the requirement of preventing and controlling salinization, the critical depth is generally used as the control drawdown index that should be achieved, which is used to design the final drainage works in the field, and based on this, the depth of drainage works at all levels and the corresponding Spacing specification. However, because the current standards are not completely realistic, the result is often that the effect of field engineering cannot achieve the desired effect, and the maintenance and operation of the drainage system are also difficult. Especially in light soil areas...

AI Technical Summary

Problems solved by technology

If the three levels (bucket, branch, and trunk) are calculated downward, and the height difference between each level is calculated as 0.2m, the depth of the main drainage ditch will reach about 3.0m, and the required outflow water level at the main drainage outlet will be lower. In general, artesian drainage is easily blocked

[0021] 2. When the depth of the final fixed ditch (pipe) is large, the calculated spacing is relatively large. Due to various factors, the actual depth is difficult to meet the design requirements, which makes the drainage project control the groundwater level and prevent salinization The effect of the ditch is relatively weakened, often the effect is still obvious near the ditch, and the effect is worse at a little distance, and the middle part of the ditch (pipe) is even worse. The result is that the control effect is extremely unevenly distributed within the control range

[0022] 3. Due to the large depth of drainage ditches at all levels, in most light soil areas that are prone to stains and alkalis, the problems of drainage ditch side slope collapse and channel siltation are very prominent, which have become a major bottleneck restricting the development of farmland drainage projects in these areas ; and to deal with the collapse and siltation problems step by step, not only the project cost is high, but also the management is difficult. In the case of generally deep ditches, it is often difficult to cure them

[0023] 4. It happens from time to time that the water level of the drainage area is jacked up at the main outlet of the drainage, and the artesian drainage is restricted. Under the condition of difficult artesian drainage, a pumping station must be established, which will increase a considerable investment in station construction projects. , and the burden of electricity charges during the year-round operation is relatively heavy, which is often impossible to implement and difficult to maintain

Images