天水市罗玉沟流域降雨量和降雨侵蚀力变化特征研究

Variation Characteristics of Rainfall and Rainfall Erosivity of Luoyugou Watershed in Tianshui City

为给流域水土流失风险评估和防治等提供可靠有效的参考依据,根据2016—2020年罗玉沟流域内的17个雨量站的日连续实测降雨数据,运用日降雨量数据进行了降雨侵蚀力风险评估,分析了该区域降雨量及降雨侵蚀力的变化规律。结果表明:罗玉沟流域降雨侵蚀力与降雨量关系呈现出较为显著的正向相关性,决定系数R 2=0.8521;罗玉沟流域及各雨量站的年内降雨侵蚀力和降水量分布不均,呈现单峰型趋势,8月是峰值拐点,过8月后逐渐下降;流域侵蚀性降雨量占总降雨量的比例总体呈上升趋势,且降雨量、侵蚀性雨量和降雨侵蚀力年际总体呈波动上升趋势,三者之间保持一定的相关性。

According to the daily continuous measured rainfall data of 17 rainfall stations in the coverage area of Luoyugou watershed from 2016 to2020,the paper made risk assessment of rainfall erosivity by using daily rainfall data and analyzed the variation law of rainfall and rainfall erosivity in this region,which has provided reliable and effective reference for the risk assessment and prevention of soil erosion in watershed.The outcomes show that a) there is a significant positive correlation between rainfall erosivity and rainfall in the watershed and the coefficient of determination R2= 0.852 1;b) the annual rainfall erosivity and precipitation are unevenly distributed in each rainfall station of the watershed,presenting a unimodal trend distribution. August is the peak inflection point on the whole process of rainfall and after August,rainfall and rainfall erosivity gradually decrease and;c) the proportion of erosive rainfall in total rainfall shows an upward trend. The rainfall,erosive rainfall and erosivity of rainfall show an increasing trend and there is a certain correlation among the three.