Description Of Soil Erosion Energy In The Loess Slope

The slope is the most important landscape unit which constitutes the mountain hills andbroken Loess Plateau. When the rainfall intensity is greater than the soil infiltration capacity,the extra rainfall will be transformed into surface runoff, and then runoff erosion surface isone of the main ways of leading to Soil Erosion. Carrying out of water and sedimenttwo-phase flow energy research has important practical significance for exploring the areasloping land soil erosion regular pattern and preventing soil erosion that caused by soildegradation, soil and water conservation and guiding practice work. This paper used thevariable slope soil bin simulated loess slope to study different soil characteristics have theimpact on raindrop energy transfer, different slope and surface roughness conditions of runoffenergy transfer pattern with the methods of artificial drainage and artificial rainfall. Combinedwith the experimental observations, and reached the following conclusions:1,Soil structure had a significant impact on splash erosion. When the raindrop diameteris3.65mm and rain drops is300the splash erosion amount of loose dry soil (density is1.07g/cm~3) reached1.93g. and when the soil density is1.31g/cm~3, the splash erosion amountwas only1.19g.Therefore, it can be considered that the splash erosion mainly occurs in thecase that the soil surface density is more smaller, at this point, the soil particles loose and onlyconsume very little energy to eliminate the interaction in the soil particles when the raindropshit the soil surface.2. The surface water layers played the weaken role on raindrop splash erosion,whenraindrop energy was constant. The soil splash erosion amount gradually reduced with theincreasing of the water layer thickness,Through comparative analysis, the soil splasherosion amount was only22.45%of the saturated soil under the2mm water layer; the soilsplash erosion amount was only19.42%of the saturated soil under4mm water layer; the soilsplash erosion amount was only16.97%of the saturated soil under6mm water layer; the soilsplash erosion amount was only12.31%of the saturated soil under8mm water layer,.Raindrop splash erosion gradually decreased with the increase of the water layer thicknessafter the surface water layer appeared. When the water layer thickness h was larger than theraindrop diameter d, the kinetic energy of raindrops was completely consumed in thedisturbance of the water layer, and the raindrop splash erosion amount decreased to zero. 3. When the surface roughness n, the water flow rate Q and the surface slope p changed,the slope flow velocity v and the water depth h would also change accordingly, and thesewould cause changes of the water flow pattern, the flow state and the drag coefficient..4. The runoff energy Ej and the runoff kinetic energy Ed of the different slopes had thesimilar variation. The runoff energy Ej presented the trend of gradual decline in differentsections which were far away from the top of slope. But the runoff kinetic energy showed amore complex variation, it reduced with the lower slope position at first, and then graduallyincreased.5. Rainfall disturbance would increase the runoff energy consumption in erosion andsediment yield. Analyzed and compared the sediment content when there were rainfalldisturbance of runoff and had no rainfall disturbance of runoff, the tendencies of theincreasing amount of runoff sediment concentration were different in the different period afterthe rainfall disturbance. Compared the runoff sediment content without rainfall, in the former10min, the effect of the rainfall disturbance was so obvious that the runoff sediment contentof rainfall perturbation average increased384.06%;in the10min~15min stage, the rainfalldisturbance weakened, the runoff sediment content of rainfall perturbation average increased24.04%.