Soil erosion is recognized as one of the most serious ecological and environmental issues today.A rainfall-runoff erosivity factor,together with the effects of duration,magnitude and intensity of rainfall event,can be used to evaluate a rainfall event's potential ability to cause erosion.It is important to study the temporal and spatial distribution characteristics of rainfall erosivity in Ganyu District of Lianyungang,which is of great significance to the evaluation of soil loss,risk assessment and management in the northern rocky mountain area.Taking the Ganyu District as the study case,the daily rainfall data of 12 precipitation stations in Ganyu District during 1954-2014 in a rainfall erosivity model proposed by the Chinese scholar Zhang Wenbo were applied.The Inverse distance weighted space interpolation method,Mann-Kendall non-parametric test variation coefficient and rescaled range analysis were applied to analyze the temporal and spatial variation characteristics of rainfall erosivity.The results show that the range of annual rainfall erosivity in Ganyu District was 2 048.3-12 369.2 MJ · mm · hm-2 · h-1 · a-1 with an average value of 6 154.9 MJ · mm · hm-2 · h-1 · a-1,which is consistent with the temporal variation of annual rainfall and erosive rainfall.The distribution curve of rainfall erosivity has a single peak.The rainfall erosivity from April to September is 89％ of the whole year.The duration of flood season in Jiangsu Province is same as that in Ganyu District.The rainfall erosivity in a year was divided into four periods,including high-value period,mid-value period,low value period and non-erosive period.The rainfall erosivity from July to August accounted for 61.5％,so the risk of soil erosion in this period is high.In the spatial distribution of the Ganyu District,the rainfall erosivity decreased and the contours gradually concentrated from southeast to northwest as a whole.The interannual variation of the R value in coastal area is larger than that in inland area,and the trend of change is obvious in different regions.The whole area of Ganyu area showed a low degree of variation without a significant upward trend.The analysis showes that the rainfall erosivity will continue to increase after 2014 and soil erosion will be further aggravated.%研究连云港赣榆区降雨侵蚀力时空分布特征,对于北方土石山区水土流失预测评估、危险性评价及治理具有重要的意义.基于连云港赣榆区12个雨量站1954-2014年的日降雨资料得到降雨侵蚀力,并采用Mann-Kendall非参数检验法、反距离空间插值方法、变异系数和重标极差法分析降雨侵蚀力时空分布特征.结果表明,连云港赣榆区降雨侵蚀力分布范围为2 048.3～ 12 369.2 MJ·mm hm-2·h-1·a-1,平均值为6 154.9 MJ· mm·hm-2·h-1·a-1,其时间变化趋势与降雨量和侵蚀性降雨量的变化趋势大体一致.降雨侵蚀力年内集中分布于5-9月,降雨侵蚀力之和占全年的89％.在空间分布上,降雨侵蚀力整体上自东南向西北逐渐减少,沿海区域降雨侵蚀力年际波动较内陆区域大,变化趋势具有明显的区域差异性.连云港赣榆区呈低等程度变异且呈不明显上升趋势.2014年之后,降雨侵蚀力将继续呈增加趋势,有加剧水土流失风险的可能性.
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