Studies On The Characteristics Of Farmland Road Erosion And Prevention And Control Technology In Black Soil Region

Field roads are the way to meet the transportation of agricultural materials,agricultural cultivation and other agricultural production activities.At present,more than 70%of the cultivated land in the hilly area is sloping farmland,and the design standard of the field road is low,mainly based on properties of soil road;To reduce the land occupation,the road width<3m is the lower limit of the field road standard.Most of the roads have no drainage on both sides,the compaction of soil surface leads to super seepage flow production,and the runoff from both sides of the farmland is drained into the road,which aggravates the erosion of the soil road,forms ravines,silkworm erosion farmland,and seriously affects agricultural production.At the present stage,the work focuses more on the erosion of highway construction.There are few reports on low-grade roads,especially the research on the erosion of farmland roads in black soil areas.This paper combines the artificial simulation with the field experiment,analyzes the influence of the topography,slope,rainfall,and other factors on the runoff and the sediment yield processes of different types of roads in farmlands in the black soil region of Northeast China,and also reveals the law of farmland erosion;In order to provide the theoretical reference for the prevention and control of the farmland road erosion in the black soil area,several research conclusions are drawn based on the prevention and control of the farmland road erosion.?1?The road surface flow time is basically earlier than 2 minutes when it is raining.The effect of rainfall intensity and slope on surface runoff was not significant,and the main change was 56.3⁶1.8 mm but the efect on surface erosion was significant.With the increase of rainfall intensity and slope,soil erosion rate increased respectively by 1.8¹1.0 times and 1.2¹0.0 times.The influence degree of runoff on the rainfall intensity is stronger than the influence degree of the slope,and the sand content of the surface increases with the increase of rainfall intensity and slope.The flow velocity of surface runoff increases with the increase of rainfall intensity and slope,and varies between 2.07³.80 cm/s,but the influence of slope decreases gradually with the increase of rainfall intensity.The Reynolds number increases with the increase of rainfall intensity and slope.The Fred number affected by rainfall intensity and slope is not significantly,and is changed between 0.17⁰.30.The resistance coefficient decreased significantly with the increase of rainfall intensity and slope.?2?The runoff time of the four black soil areas common farmland road surface soil road,rut road,sand-stone road,and plough marks road is less than 2min,and the runoff coefficient of each road is not very different,and it is in 71.6%⁸8.8%.The runoff process is similar,the early production runoff increases rapidly and when the rainfall is about 10min enters the stable stage.The road surface erosion rates were3.38 g·m^-2·min?15.43 g·m^-2·min?2.48 g·m^-2·min?8.86 g·m^-2·min,with significantly difference.The sediment production process has significantly difference.The sediment yield of soil road,sand-stone road and plough marks road before rainfall 5min increases rapidly.Then the sediment yield of soil road and sand-stone road surface tends to be stable gradually,and the yield of plough marks road surface has a continuous increasing trend.However,the sediment yield of the plough mark was rapidly decreased from a higher value in the early period of rainfall,and then fluctuated up and down at a higher level.There are obvious differences in the development of the four kinds of road rills.The rills in soil ploughed roadare developing faster;There are more rills than the soil ploughed road on the soil flat road,and the development of rills ends earlier,the flat sand-stone road produces rill less and develops slowly.?3?The rill erosion of farmland roads in black soil area mostly occurs at the downslope of the road surface.The runoff time of the road surface is earlier than 2min,and gradually advances with the increase of rainfall.The runoff coefficient is between 85%and 90%,which tends to increase with the increase of rainfall.Through the change of sediment concentration,rill erosion can be roughly divided into four stages:the stage of surface erosion,the forming stage of step-down floor,the retrogressive erosion stage of gully headand the erosion stage of gully wall.The rill erosion rate can well express the erosion of road surface,and its correlation coefficient with road erosion rate is as high as 0.967.The split degree of the rill is the best index to describe the morphological characteristics of the rill.?4?The effect of the prevention and control measures for road erosion in the field was obvious,and the amount of road surface erosion was 30%lower than in previous years.The width,depth,and Amount of roadside erosion were 90%and 92%lower than in previous years.The effect of the stone wall from the uphill to the downhill enhanced gradually,and the benefit index for prevention and control has increased from 4.6%to 18.8%.