Device for observing rainfall erosion process

Abstract

The invention discloses a rainfall erosion process observation device, and relates to the technical field of water and soil conservation research, the rainfall erosion process observation device comprises a test shed, a rainfall simulator, a test tank, a splash erosion collector and a runoff sediment collector, the test tank is used for containing an experimental soil body, the rainfall simulator is installed on the test shed and is located right above the test tank, and the splash erosion collector is located right above the test tank. The test tank is located at the upper end of the test tank and used for simulating rainfall erosion of a soil body in the test tank, the splash erosion collector is located on the periphery of the upper end of the test tank and used for collecting splash erosion soil particles, the runoff sediment collector is located on one side of the test tank, and the upper end of the runoff sediment collector is communicated with the upper end of the test tank and used for collecting a runoff sediment sample. According to the observation device for the rainfall erosion process, the raindrop splash erosion amount and the runoff migration amount of soil particles in the rainfall erosion process can be observed, and the authenticity of a research result is improved.

Description

technical field [0001] The invention relates to the technical field of soil and water conservation research, in particular to an observation device for a rainfall erosion process. Background technique [0002] Hydraulic erosion refers to the process of stripping, transporting and depositing soil particles under the action of hydraulic force, which not only leads to thinning of soil layers and deterioration of soil quality, but also reduces land productivity. Rainfall is the main driving force for the occurrence of hydraulic erosion. The impact of raindrops can damage the surface soil structure and block soil pores, thereby reducing soil permeability and providing favorable conditions for the formation of surface runoff. [0003] At present, most researches on soil particle breakage and migration focus on raindrop splash erosion. However, in the splash corrosion test, the water storage phenomenon on the soil surface in the experimental device will have a great influence on t...

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Problems solved by technology

However, in the splash erosion test, the water storage phenomenon on the soil surface in the experimental device will have a greater impact on the splash erosion results.

There are two reasons: first, the range of rainfall intensity selected in the study is 30-100 mm h -1 (Ma RM, Li ZX, Cai CF, et al. The dynamic response of splasherosion to aggregate mechanical breakdown throughrainfall simulation events in Ultisols (subtropical China) Catena, 2014, 121(7): 279-287.), and the rainfall lasted longer ( 45~120min), the soil should be in the state of full runoff in the late rainfall period (LiuT, Luo J, Zhang ZC, et al. Effects of rainfall intensity on splash erosion and its spatial distribution undermaize canopy. Natural Hazards, 2016, 84: 233-247 .), the accumulated water layer will reduce the impact of raindrops, which will cause errors in the results; second, the test devices for splash erosion are mostly placed horizontally, and the excess water cannot be discharged except for infiltration, so as the rainfall lasts In this case, the excess water carries part of the soil particles and overflows from the outer edge of the splash erosion area and enters the collection device, which will cause errors in the splash results. At this time, the collected The amount of splash erosion cannot accurately characterize the migration of eroded soil particles

In the process of natural rainfall, rainfall and runoff are complementary and affect each other, and it is not sufficient to discuss the change of a certain process alone

However, the traditional rainfall erosion collection method cannot distinguish and quantify the splashed soil particles and the washed out soil particles under the same erosion conditions. Therefore, the revealing of the soil particle fragmentation mechanism can only be discussed separately from the perspective of splash erosion or erosion, resulting in rainfall-driven There is a lack of research on the dispersion and transport of eroded soil particles, and it is difficult to identify how much broken soil particles can be contributed by rainfall to slope runoff during a rainfall event.

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