Multistage ecological permeable dike for purifying small watershed water in mountain land

Abstract

The invention relates to a non-point-source pollution treatment method, in particular relates to a construction method of a multistage ecological permeable dike for purifying small watershed water in a mountain land. The specific method is as follows: farmlands with strong corrosion potentials at the both sides of the small watershed water in the mountain land are selected, and the permeable dikeis constructed at the non obvious knee or below the knee of a non main traffic flood river course, wherein the height of the permeable dike is 0.6-1.2 meters, an apron is constructed at the erodible positions at the two ends of the permeable dike, and the length L of the apron at the two sides is 1.5(H+h). According to the permeable dike, through a mode of performing water infiltration at the dike body and water filtration at the dike top, the flow speed of the flowing water is reduced, and the water depth is improved so as to beneficial to precipitation of suspending matters in river water; the stage number of the multistage permeable dike is defined according to a formula n=(C0-Cn) / n.Cx; and the multistage dike forms a multistage ecological permeable dike system. According to the invention, the proper multistage ecological permeable dike for purifying the small watershed water in a mountain land is constructed, so that the water depth of the water flowing through a small watershed river is effectively increased by 0.5-0.8 meters, the flow speed of the shallow small watershed river is retarded, and suspending solid and hydraulic drop increasing effects and the like are exerted, nitrogen, phosphorous, sand and the like in the flowing water are cut down, the self-purification capability of the river is enhanced, and the quality of the flowing water is improved.

Description

technical field [0001] The invention relates to a method for controlling non-point source pollution, in particular to a multi-stage ecological permeable dam for constructing and purifying water bodies in small mountain watersheds. Background technique [0002] With the increasing demand for food and changes in farming methods, more and more pesticides and fertilizers are used in agricultural production, but the utilization rate of pesticides and fertilizers invested in reality is low, and the unused part of pesticides and fertilizers is falling in the rain. When it occurs, it is mostly lost with surface runoff. Lost pesticides and fertilizers, rural domestic sewage, livestock and poultry manure and breeding wastewater have become the main sources of non-point source pollution of water bodies in rural areas of our country. At the same time, since non-point source pollutants are mostly rich in nutrients such as nitrogen and phosphorus, if they are not treated, they often beco...

AI Technical Summary

Problems solved by technology

However, when dealing with agricultural non-point source pollution in small mountainous watersheds, rivers in small mountainous watersheds often erode the riverbed seriously due to the large slope of rivers in small mountainous watersheds, fast water flow, and gravel riverbeds in the upper reaches. Nutrients in the sand are not easy to precipitate, and it is impossible to form a microbial and aquatic plant system that can absorb and degrade nutrients such as nitrogen and phosphorus entering the water body

At the same time, due to the occurrence of non-point source pollution in small mountainous watershed areas, it is often accompanied by different degrees of soil erosion, and the erosion of the vegetation belt on the river bank has seriously aggravated the occurrence of non-point source pollution.

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