摘要
崩岗崩积体是崩岗的主要沙源地。基于人工模拟降雨试验及三维激光扫描技术,研究崩岗崩积体坡面侵蚀过程。研究表明:利用三维激光扫描的点云数据能定量分析降雨前后坡面水蚀特征。全坡面及各坡位均为片蚀总量大于细沟侵蚀总量,但各坡位的侵蚀强度有所差异,其细沟侵蚀强度由大到小表现为下坡、中坡、上坡,片蚀强度由大到小表现为上坡、中坡、下坡。坡面空间糙度由大到小大致呈现下坡位、中坡位、上坡位,坡面侵蚀方式可影响坡面糙度值及变化趋势,而坡面糙度亦能影响各侵蚀方式的侵蚀强度。整个降雨时段内全坡面侵蚀量最大、产沙量次之,沉积量最小,受坡面糙度变化影响,全坡面侵蚀、产沙量均呈现递减趋势。而上坡位的侵蚀、产沙量无明显变化,中、下坡位的侵蚀、产沙量呈对数减小趋势。此外,除上、下坡位沉积量间存在显著差异外,各坡位间侵蚀量、产沙量均无显著差异。
Benggang erosion is an important erosion type,which frequently occurs in Southeastern China.Colluvial deposits of Benggang is an important source of the Benggang sediment. Based on simulated rainfall experiments and three-dimensional（ 3 D） laser scanning,the characteristics of spatial-temporal differentiation of soil erosion processes on the colluvial deposits of Benggang were investigated. An indoor rainfall experiment was conducted with a 30° slope of the Benggang deposit and a rainfall erosion intensity of 3. 33 mm/min,which represented a typically higher rain intensity in the study region. Rainfall simulation experiments were conducted in 2016 in the rainfall simulation hall of Laboratory of Red Soil Erosion and Flow Hydraulic in South China in Guangzhou City,Guangdong Province. The results showed that point cloud data from the 3 D laser scanning can reflect the characteristics of soil erosion,deposition and sediment yield before and after rainfall events. Total amount of rill erosion,sheet erosion were0. 036 6 m3 and 0. 113 5 m3,respectively. Slope position had little influence on sheet erosion,while it had a significant impact on rill erosion. Roughness of soil surface was increased first and then decreased with time during the experiment. The values of roughness of soil surface were in a descending sequence of lower slopes,middle slopes and upper slopes,and it varied with time at different slope positions.Roughness of soil surface on lower and middle slope was increased firstly and then decreased with timeduring the experiment,while it was increased constantly with time on the upper slope. No significant variation of soil erosion on upper slopes occurred with rainfall events. The soil erosion amount and sediment yield were decreased logarithmically with time. The difference of erosion amount between upper and lower slopes was significant,whereas slope positions showed insignificant influence on soil erosion and sediment yield.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2017年第11期300-306,270,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
水利部公益性行业科研专项(201501047)
广东省自然科学基金研究团队项目(S2012030006144)
广东省科学院引进高层次领军人才专项资金项目(2060599)
省院创新平台建设专项(2016GDASPT-0105
2016GDASPT-0304)
农田重金属污染治理创新人才队伍建设项目(2016B070701015)
关键词
崩岗崩积体
侵蚀方式
糙度
时空分异
三维激光扫描
colluvial deposits of Benggang
erosion pattern
soil surface roughness
spatial-temporal differentiation
3D laser scanning
