1960-2014年间淮河流域降雨侵蚀力的时空变化特征

Spatial and Temporal Variation of Rainfall Erosivity in Huaihe River basin from 1960 to 2014

降雨侵蚀力是降水对土壤侵蚀的潜在能力,其时空分布规律的研究对于水土流失治理具有重要意义.基于淮河流域1960-2014年逐日雨量资料,分析了流域降雨侵蚀力的时空变化特征.结果表明:具有侵蚀力的年降雨与汛期降水总体变化幅度较大,年降雨侵蚀力与汛期降雨侵蚀力的波动类似,总体无明显变化趋势;年降雨侵蚀力与汛期降雨侵蚀力除在2000年左右存在约2a的周期外,其余年份无明显周期性;年降雨侵蚀力与汛期降雨侵蚀力均由南向北逐渐减少,但以流域西南部上游地区为最高.年降雨侵蚀力与汛期降雨侵蚀力的多年变化趋势总体以减少为主,仅在流域南部及西南部地区存在上升趋势.

Rainfall erosivity has the potential capacity for the soil erosion,its spatial and temporal variation is of great significance for soil erosion control.Based on the daily rainfall data of Huaihe River Basin from 1960 to 2014,the temporal and spatial variation characteristics of rainfall erosivity were analyzed.The annual rainfall and the rainfall in flood season that have the erosivity capacity vary greatly.The fluctuation of annual rainfall erosivity and the rainfall erosivity in flood season are similar,but there are no obvious change trend.The annual rainfall erosivity and the rainfall erosivity in flood season both have a period of about 2 years in around 2000,but there is no obvious periodicity in the others years.The annual rainfall erosivity and the rainfall erosivity in flood season decrease from south to north gradually,but the highest value lies in the upstream area and the southwest of the basin.The annual rainfall erosivity and the rainfall erosivity in flood season both have decreasing trend in recent 55 years generally,and upward trend occurred only in the South and southwest of the basin.