闽北地区降雨侵蚀力R值的分布特征

R Value Distributing Character of Rainfall Erosivity in the Area of North Fujian

降雨侵蚀力反映了降雨对土壤侵蚀影响的潜在能力,它是建立水土流失预报模型的基础。为了研究闽北地区的降雨侵蚀力,对建瓯研究地区的二年的降雨资料进行统计分析,得出了闽北地区降雨侵蚀力R的最佳模式为:R=ΣE·I10/100。年降雨侵蚀力主要集中在4-8月份,其R值占年R值的82.4％,4-8月是水土流失的危险期和高峰期。大雨以上降雨产生的R值占年R值的80％以上,是产生水土流失的主要降雨类型。

Rainfall erosivity indicated the latency capability of the rainfall influenced to the soil erosion. It was the basic of establishing forecast-model of soil loss.In order to indicated the soil erosion condition, protection measure and rainfall erosivity of the cultivated island the survey was done by interpreting precipitation and amount of soil loss statistical two years data in Jianou North Fujiang The results showed that the best model of rainfall erosivity could be calculated by :R=ΣE·I10/100. The R values were much different in the year and mainly distributed from Aprial to August,in which the R value made up 82.4% of the total year,which indicated that rainy season was peak period when soil and water happened frequently. Also R value induced by heavy rain(or storm)occupied >80% of annual R value. It was obvious that heavy rain was the primary rain type that may cause soil and water losses.