1980-2009年闽东南地区降雨侵蚀力的时空分布特征

目的]揭示闽东南地区降雨侵蚀力的时空变异特征,为区域水土流失防治及水土保持规划提供依据。方法]基于闽东南地区1980—2009年26个雨量站的逐日降雨数据,运用福建省降雨侵蚀力简易算法。结果]闽东南地区降雨侵蚀力年内分布集中于5—8月,呈现双峰式分布;降雨侵蚀力年际间变化幅度较大。1982年年降雨侵蚀力(R值)低至253.82(MJ·mm)/(hm2·h),2006年R值高达725.39(MJ·mm)/(hm2·h),极值比为2.86;30a内的闽东南地区的降雨侵蚀力并未出现明显的突变现象。结论]研究区内降雨侵蚀力R值空间分布不均匀,总体上呈现沿海向内陆增加,西南高东北低的趋势。

Temporal and Spatial Characteristics of Rainfall Erosivity in Southeast Fujian Province During 1980-2009

Objective] Studying the distribution pattern of rainfall erosivity in the southeastern area of Fujian Province to privide basis for soil erosion control and soil and water conservation plan.Methods] Based on the data from 26 rainfall station in the Southeastern Fujian Province during 1980-2009, simple algorithm for rainfall erosivity was used.Results] Rainfall erosivity in Southeastern Fujian Province showed a bimodal distribution as it occoured mainly from May to August. Rainfall erosivity varied greatly over years. The highest value was 725.39 (MJ·mm)/(hm²·h) occurred in 2006, while the lowest value was 253.82 (MJ·mm)/(hm²·h) occurred in 1982, with the extreme ratio of 2.86. Rainfall erosivity in Southeast Fujian Province during the past 30 years did not showed abrupt changes.Conclusion] Rainfall erosivity showed an uneven distribution pattern with increasing trend from coast to inland, and the value was comparatively higher in southwest than that in northeast.