鄱阳湖流域日降雨的侵蚀性雨量标准研究

确定日降雨的侵蚀性雨量标准是提高基于日降雨数据的降雨侵蚀力模型计算精度的重要前提。利用鄱阳湖流域降雨数据,采用最小偏差法,确定该流域日降雨的侵蚀力雨量标准。结果表明:(1)鄱阳湖流域次降雨的侵蚀性雨量标准为14.0 mm,降雨侵蚀力偏差系数为1.8%,土壤侵蚀损失率2.8%,降雨场次错选度为14.9%。(2)流域内各站点的逐月降雨量均表现为6月达到峰值的倒"V"形规律;侵蚀性次降雨中,降雨时间跨越2日或以上的类型最多,占总次数的54.2%。(3)流域日降雨的侵蚀性雨量标准为10.0 mm,该标准下年均次、日降雨侵蚀力偏差值为0.11%。

Study on Daily Erosive Rainfall Standard in the Poyang Lake Basin

Determining the erosive rainfall standard of daily rainfall is an important prerequisite for improving the calculation accuracy of the simple model based on the daily rainfall. The standards of erosive daily rainfall in the Poyang Lake Basin were studied with the method of minimum deviation. The results showed that:(1) The erosive event rainfall standard in Poyang Lake Basin was 14.0 mm, where the coefficient deviation was 1.8%, the loss rate for erosion amount was 2.8% and the mixing index was 14.9%. (2) The monthly rainfall at each station was the highest rainfall in June with an inverted "V" shape; the type of rainfall time spanning two days or more was the most, accounting for 52.4% of the total erosive event rainfall. (3) The erosive daily rainfall standard in the Poyang Lake Basin was 10.0 mm, where the deviation value of the annual average rainfall erosivity between daily and event rainfall was 0.11%.