Huang Kai, Liu Rui-Lu, Qin Li, Song Tao, Liu Zhong-Xian, Li Rui
School of Karst Science, Guizhou Normal University, Guiyang 550001, China.
State Engineering Technology Institute for Karst Desertification Control, Guiyang 550001, China.
Ying Yong Sheng Tai Xue Bao. 2021 Jan;32(1):271-280. doi: 10.13287/j.1001-9332.202101.020.
Based on the runoff and sediment yield data from 59 erosive rainfall plots with different slope lengths (5, 10, 15, 20, 25 m) in Shiqiao small watershed of Guizhou Province from 2012 to 2014, we analyzed the relationship between runoff and sediment yield and slope length under diffe-rent rainfall conditions. The results showed that, with the increases of slope length, the runoff yield of slope showed a 'V-shape' pattern, the sediment yield of slope increased first and then decreased. According to rainfall amount, rainfall duration, and average rainfall intensity, the 59 erosive rainfall in the study area could be divided into three types, including type A with short duration, heavy rain intensity and small rainfall, type B with medium duration, light rain intensity and medium rainfall, and type C with long duration, medium rain intensity and large rainfall. The relationships between runoff and sediment yield and slope length were different under different rainfall patterns. There was about 20 m critical slope length of sediment yield under type A and B. The sediment yield gradually increased with the increases of slope length under type C. There was a good cubic function relationship between slope length and runoff and sediment yield under different rainfall patterns. The variable amplitude of runoff and sediment yield was different among different slope lengths. Except the slope length of 15-20 m, the variable amplitude of runoff and sediment yield under type C was relatively large. The variation amplitude of sediment yield was significantly higher than that under other rainfall patterns. The total runoff yield under different rainfall patterns was type A>B>C. The sediment yield under type B was the smallest, that of type A at the slope length of 20 m was the largest and that of type C at other slope lengths was the largest. The correlation between compound rainfall factors and runoff and sediment yield was better than that of single rainfall factor under type A (common rainfall type in the study area). Rainfall amount (), the pro-duct of rainfall duration and maximum 30 min rainfall intensity (), product of rainfall duration and average rainfall intensity (), product of rainfall amount and rainfall duration () were significantly correlated with the runoff and sediment yield. Among those factors, and had the strongest correlation with runoff. Further, the relationship between them and runoff under different slope lengths could be expressed by linear equation and S-curve. There was a good cubic function relationship between the sediment yield and its corresponding rainfall factors under different slope lengths.
基于贵州省石桥小流域2012 - 2014年59个不同坡长（5、10、15、20、25米）侵蚀性降雨小区的径流和产沙数据，分析了不同降雨条件下径流、产沙与坡长之间的关系。结果表明，随着坡长增加，坡面径流呈现“V”形变化，坡面产沙量先增加后减少。根据降雨量、降雨历时和平均降雨强度，将研究区内59场侵蚀性降雨分为3类，即历时短、雨强大、降雨量小的A型，历时中等、雨强小、降雨量中等的B型，历时长、雨强中等、降雨量大的C型。不同降雨类型下径流、产沙与坡长之间关系不同。A型和B型产沙存在约20米的临界坡长，C型产沙量随坡长增加逐渐增大。不同降雨类型下，坡长与径流、产沙量存在良好的三次函数关系。不同坡长径流和产沙量的变幅不同。除15 - 20米坡长外，C型径流和产沙量变幅相对较大，产沙量变幅显著高于其他降雨类型。不同降雨类型下总径流量为A型 > B型 > C型；B型产沙量最小，A型在坡长20米时产沙量最大；C型在其他坡长时产沙量最大。在研究区常见降雨类型A型下复合降雨因子与径流和产沙量的相关性优于单一降雨因子；降雨量（）、降雨历时与最大30分钟雨强的乘积（）、降雨历时与平均降雨强度的乘积（）、降雨量与降雨历时的乘积（）与径流和产沙量显著相关。其中，和与径流相关性最强。进一步，不同坡长下它们与径流的关系可用线性方程和S曲线表示。不同坡长下产沙量与其相应降雨因子之间存在良好的三次函数关系。
