机械夷平地侵蚀形式与特征研究

Study on Erosion Forms and Features of Mechanical Planation Ground

以深圳市境内观澜河流域为例,在野外调查和试验研究资料的基础上,利用回归相关等分析方法,对工业机械夷平地侵蚀形式与特征进行了研究。结果表明,机械夷平地的主要侵蚀形式:开挖陡坡为重力侵蚀、开挖平地为雨滴溅蚀和片侵、堆积平地为切沟侵蚀、堆积陡坡为切沟侵蚀和片蚀;切沟的径流泥沙含量峰值先于雨强峰值出现,堆积陡坡坡面则滞后于雨强峰值;决定侵蚀量大小的主要因子是降雨强度,引起侵蚀最大 30min雨强的临界值为10.00mm/h;机械夷平地堆积陡坡坡面侵蚀模数达58 428 t/(km^2·a);机械夷平地规模的大小直接影响到河流泥沙含量的高低,受到机械夷平地明显干扰的河流断面泥沙含量是受到干扰较小河流断面的 2.5～5.5倍。

On the basis of field survey and test and by means of regression and correlation analysis, with the example of Guanian river watershed in Shenzhen city, the preliminary study on the erosion forms and features on industrial mechanical planation ground is presented. Results shows that, the main erosion forms on mechanical planation ground are gravity erosion for excavated steep slope, rain- drop-splash erosion and sneet erosion for excavated fiat ground, guily erosion for accumulated flat ground,and gully erosion and sheet erosion for accumuiated steep slope. The peak value of sediment concentration in gully runoff appears earlier than that of rainfall intensity, but in the runoff on accu- mulated steep slope it appears later. The main factor determining erosion amount is rainfall intensity. The critical value of maximum rainfall intensity in 30 minutes to cause erosion is 10.00mm /h. For the surface of the accumulated steep slope, the erosion modulus is 58 428t/km^2·a. The size of the me- chanical planation area directly influences the sediment content in river. The sediment content in river section disturbed evidently by mechanical planation ground is 2.5～5.5 times as much as that dis- turbed less by the kind of ground.