The Study On The Effect Of Different Surface Coverage On Soil Erosion

Soil erosion generally occurs in nature,often leading to soil degradation,soil thinning and land productivity decline.Surface mulch is one of the crucial measures to inhibit soil erosion,and there are various types of mulch.To explore the influence of different mulching conditions on soil erosion,this paper takes red loam soil as the research object,mainly analyzes the variation characteristics of runoff and sediment yield on the slope under three mulching conditions and the influence mechanism of coverage and thickness on runoff and sediment yield on the elope,and optimizes the C factor estimation model based on related research,and establishes a C factor estimation model including coverage and thickness.The main conclusions are as follows:(1)When the small rainfall intensity,the time of runoff production on the slope decreases gradually with the increase of coverage and thickness,but this law is not apparent with the growth of rain intensity.(2)With the increase in the number of knitting needles,the velocity of the downhill slope covered by the dust-proof net generally increases at first and then decreases;Under the condition of Pinus massoniana litter coverage,the slope velocity decreases with the increase of coverage and thickness.The rate of the slope covered with straw decreased with the addition of coverage,but growth with the increase of viscosity.(3)The relationship between steady runoff yield rate and coverage,rainfall intensity and knitting needle number is positive correlation,but negative correlation with thickness.Slope runoff gradually decreased with the increase of the thickness of mulch,and the difference gradually became significant when the heavy rain was intense(P < 0.05).With the proliferation of coverage and the number of needles,the runoff on the slope shows a gradual increase trend,in which the number of hands has no significant effect on runoff.In contrast,the coverage has a significant impact on runoff(P < 0.05).(4)The stable sediment yield rate is negatively correlated with coverage,thickness and number of knitting needles.With the increase in coverage,thickness or number of arrows,the sediment yield on slope shows a decreasing trend.Among them,the number of hands has no significant effect on sediment yield;Coverage has a substantial impact on sediment yield;Thickness significantly reduces the sediment yield on the slope under moderate and light rain intensity,while the influence of thickness change on sediment yield under heavy rain intensity is covered by rain intensity.(5)The relationship between vegetation coverage and management measures C factor and coverage and thickness shows a negative correlation.Based on estimating C value through range,the thickness factor is added to optimize the C factor estimation model,and a C factor estimation model including coverage and thickness is established.The determination coefficients of this model are 0.826(Pinus massoniana litter),0.922(straw mulching)and 0.974(dust net)respectively.