康平县高大棚小流域侵蚀性降雨与产沙关系分析

Relationship between Erosive Rainfall and Sediment Yield in a Small Watershed with High Greenhouse in Kangping County

文章以康平县高大棚小流域为例,结合径流小区监测数据和降雨资料,选择2017-2019年的降雨历时、平均雨强、最大60min雨强、最大30min雨强、降雨量5个指标,研究了各侵蚀性降雨特征指标、降雨量、场次、降雨频率与产沙之间的相关性。结果表明:研究小流域降雨变化总体呈正态分布,从季节分布上,夏秋两季降雨集中,具有明显的干湿季节;0-5mm/h降雨强度范围内大豆地的降雨量与产沙量存在显著相关性,天然次生林的降雨量、最大60min雨强与产沙存在显著正相关性;对于降雨径流与泥沙拦截等不同覆盖度的土地利用方式存在明显差异,农作物和耕作方式影响土壤流失的程度也存在一定差异。

Taking the high greenhouse small watershed in Kangping County as an example,combined the monitoring and rainfall data of the runoff plot,five indicators including the average rainfall intensity,the maximum 60min rainfall intensity and the maximum 30min rainfall intensity from 2017 to 2019 are selected to research the correlation between rainfall frequency and sediment yield of each erosive rainfall characteristic index.The results show that the variation of rainfall in the small watershed presents a normal distribution,according to the seasonal distribution,rainfall concentrates in summer and autumn,with obvious dry and wet seasons;in the range of 0-5mm/h rainfall intensity,there is a significant correlation between precipitation and sediment yield in soybean field,and there is a significant positive correlation between rainfall in natural secondary forest and raininess of maximum 60min and sediment yield;there are significant differences in land use patterns with different coverage degrees,such as rainfall runoff and sediment interception,and crops and tillage methods also have different effects on soil loss.