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降雨-径流格局对土壤侵蚀过程具有重要影响,以团山沟七号全坡面径流场1961-1969年间65次径流事件的径流泥沙数据为基础,选取历时、径流深和径流变率为径流过程的特征指标,采用K均值聚类和判别分析相结合的方法,将坡面径流划分为5种类型。其中,A型径流具有超长历时、低变率、小径流的特点,是较为特殊的类型,B、C型径流具有中长历时、中高变率、大径流的特点,D型径流具有短历时、低变率、小径流的特点,是最为普遍的类型。E型径流具有中历时、中变率、中径流的特点。不同径流类型下的输沙模数、平均含沙量及最大含沙量由大到小依次为:C>B>E>D>A,B、E、C型径流应是坡面径流调控的重点。不同径流类型输沙模数的差异主要来源于径流量(深)的变化,相同径流量(深)条件下,不同径流类型输沙模数的差异主要来源于由径流历时和径流变率所引起的水沙传递关系的改变;与A型径流相比,其作用使D、E、B、C型径流的输沙模数相对增大7.9、6.3、4.8和4.5倍,增大倍数随径流量(深)的增加呈逐渐减小趋势。通过构建包含主要径流特征指标的动力参数ξ,对不同径流类型及径流阶段的径流-泥沙传递关系进行数学描述,其最优回归关系均符合S=alnξ+b的一般形式,能合理解释不同径流类型及不同径流阶段含沙量变化的主要驱动因素。研究结果可为坡面径流类型划分、水沙传递关系构建、全面评估坡面径流调控系统的水土保持意义、进一步丰富坡面径流调控理论的内涵提供一定的参考。
Based on the runoff and sediment data of 65 runoff events during the period from 1961 to 1969 in the whole slope runoff on the No.7 of the Tensan Gully, rainfall duration and runoff rate were selected as the runoff process The characteristics of indicators, the use of K-means clustering and discriminant analysis method, the slope runoff is divided into five types. Among them, Type A runoff has the characteristics of long duration, low rate of change and small runoff. It is a special type. Type B and C runoffs have characteristics of medium and long duration, medium and high rate of change and large runoff. D runoff has a short duration , Low variability, the characteristics of small runoff, is the most common type. E-type runoff in the calendar time, the rate of change, the characteristics of the flow. The runoff modulus, average sediment concentration and maximum sediment concentration under different runoff types are as follows: C> B> E> D> A, B, E and C runoff should be controlled by runoff Focus. The differences of sediment transport modulus of different runoff types are mainly due to the change of runoff (deep). Under the same runoff (deep) conditions, the differences of runoff modulus of different runoff types are mainly caused by runoff duration and runoff variability Compared with the type A runoff, its effect increased the sediment transport modulus of the runoffs D, E, B and C by 7.9, 6.3, 4.8 and 4.5 times, respectively. The increase of the runoff with the runoff (Deep) increase is gradually decreasing trend. By constructing the dynamic parameters ξ, including the characteristics of main runoff, mathematical expressions of runoff-sediment transport relationships of different runoff types and runoff stages are carried out. The optimal regression relationships are in accordance with the general form of S = alnξ + b, which can reasonably explain the differences The main driving factors of runoff type and sediment concentration in different runoff stages. The results can provide some references for the classification of runoff type, the relationship between water and sediment transmission, the comprehensive evaluation of the significance of soil and water conservation for slope runoff regulation and control system, and the enrichment of the theory of slope runoff regulation.