川北紫色土深丘区径流及土壤侵蚀研究

Study on Runoff and Soil Erosion in Purple Soil Deep Hilly Region in Northern Sichuan

研究川北紫色土深丘区径流及土壤侵蚀规律可为土壤侵蚀模型提供参数和依据,对试验区长期定位观测获取的11a的降雨、径流及泥沙数据,年内及年际的分布特征进行分析,并对径流和泥沙进行曲线回归分析。结果表明:试验区径流及土壤流失主要集中在6—8月;相关性分析显示径流与降雨达到了显著水平,土壤流失与径流达到显著或极显著水平,与降雨量未达到显著水平。径流对降雨变化的响应程度更为剧烈,并表现出一定的滞后性。土壤流失量对径流的变化响应则较为复杂,但其总体变化趋势一致。回归分析表明径流月/年回归模型分别以指数/幂函数模型为最佳,且月回归模型优于年回归模型;泥沙月/年回归模型均以幂函数模型最佳,年回归模型估算较月回归模型准确。

In order to study runoff and soil erosion rule and provid parameters for the model and the basis for rule of soil erosion in purple soil deep hilly region in northern of Sichuan Province, based on the long-term positioning observation, the rainfall, runoff and sediment data of 11 years in experimental area were analyzed, mainly included the annual and inter-annual distribution characteristics, and did the curve regression analysis on the runoff and sediment. The results showed that runoff and soil erosion mainly oecurred in June, July and August. The correlation analysis showed that rainfall and runoff had significant relation. Soil erosion and runoff had significant or very significant correlation, and these two parameters have no significant correlation with rainfall. The responses of runoff to change in rainfall was more extreme, and showed some of the lag. The response of soil loss to change of runoff was more complex, but the general trend was consistent. Regression analysis showed that monthly or yearly regression models for runoff in the form of index model and power model were the best, and monthly regression model was better than the yearly one. Sediment monthly or yearly regression models in the form of power model were the best, it was more accurate that yearly regression model estimated regression model.