Study On The Development And Change Of Gullies In The Black Soil Area Of Manchuan Mangang In Baiquan Count

The black soil area belongs to one of the serious areas of soil erosion in China,and the erosion ditch as its main manifestation not only affects agricultural development,but also threatens China’s food and regional ecological security.At present,the research on the development and change law and influencing factors of erosion ditches in black soil area is still relatively weak.Therefore,through surveying-grade UAV field survey and accurate comparison with historical images,this paper selects 61 typical developmental erosion ditches in Baiquan County,Qiqihar City,Heilongjiang Province as the research objects,and analyzes the development and change law of erosion ditches in Manchuan Mangang black soil area based on topography,catchment area,runoff and other influencing factors,and the results are as follows:(1)The morphological characteristics of erosion trenches and related parameter relationships were quantified.The main distribution intervals of erosion trench length,trench depth,top width,bottom width,perimeter,area,volume and section width-to-depth ratio in the study area were 100～500 m,1～5 m,5～25 m,2～6 m,300～1500m,<10000 m~2,<25000 m~3 and 2～6,respectively.The correlation between top width and bottom width was significantly related,the correlation between groove length and circumference was greater than that of groove width,and the correlation between groove length,groove width and area was basically the same.(2)The development change rate and shape complexity of erosion trenches in different years in the past 20 years were explored.The average development rates of groove length,circumference and area in 2003～2021 were 9.64 m/y,44.18 m/y and246.39 m~2/y,respectively,and the erosion rate between 2003～2013 was greater than that in 2013～2021.The morphological complexity of erosion trench is manifested as complex first and then simple,and the expansion rate of erosion trench bank is less than that of the ditch head.(3)The influencing factors of erosion furrow development were analyzed.The slope,aspect,altitude and catchment area were all related to the development and change of erosion trench,and the erosion trench developed the most violently when the slope was 2～3°,the aspect was the southeast slope,the elevation was 230～240 m and the catchment area was >20 hm~2.(4)A developmental model of erosion furrow was constructed.The fit of the forecast model of trench length,area and soil erosion with the annual mean runoff was0.7268,0.489 and 0.3562,respectively.In summary,this study analyzes the development and change laws and influencing factors of erosion trenches in depth,and puts forward relevant prediction models,which provides a certain theoretical basis and data support for the prevention and treatment of erosion ditches in the black soil area of Manchuan and Mangang in the future.