蒲河流域降雨侵蚀力时空分布规律研究

Study on spatial and temporal distribution of rainfall erosivity in Puhe river basin

降雨侵蚀力时空分布规律是研究土壤侵蚀预报的基础,是反映流域降雨对土壤侵蚀程度的重要指标。根据蒲河流域9个水文气象站的日降雨量资料,分析蒲河流域的降雨侵蚀力时空分布规律。研究可知:蒲河流域在37年的长系列中,年降雨量与年降雨侵蚀力的变化趋势都呈逐步上升趋势,其变化趋势并不明显。全年降雨侵蚀力主要集中在6—9月,年内降雨侵蚀力的高峰值则主要出现在8月,年内降雨侵蚀力的分布呈明显的单峰型。蒲河流域多年平均降雨侵蚀力变化趋势大致由流域的东北部向西南部逐步降低。

The spatial and temporal distribution law of rainfall erosivity is considered the basis fot the study of soil erosion prediction and an important index to reflect the degree of soil erosion caused by precipitation in the watershed.Based on the daily rainfall data of nine hydrometeorologial stations in Puhe river basin is ana-lyzed.The results show that,in thirty-seven years long series of Puhe river basin,the change trend of annual rainfall and annual rainfall erosivity shows a unobvious but gradual upward trend.The rainfall erosivity of the whole year is mainly concentrated from June to September,and the peak value of rainfall erosivity mainly appears in August.The distribution of rainfall erosivity of the year shows an obvious single peak.The variation trend of annual rainfall erosivity in Puhe river basin decreases gradually from the north-east to the south-west of the basin.