摘要
研究坡面次降雨土壤入渗及产流产沙特征,对于坡地水土流失防治及水土资源管理利用具有重要意义。基于广东省五华县水土保持试验推广站野外径流场2014年的观测数据,研究不同下垫面条件下坡面入渗及产流产沙特征。次降雨入渗量与地表植被盖度间存在显著相关关系（P〈0.05,R=0.95）。入渗量随降雨强度增加,呈先增后减的变化趋势,存在入渗量达最大值的临界降雨强度;人工林及灌草地临界降雨强度为19.9~27.8 mm/h,均高于自然撂荒地。次降雨径流深和土壤流失量与地表植被盖度间,存在显著负相关关系（P〈0.05）,相关系数超过0.9。土壤侵蚀率随径流系数呈幂函数增加趋势,径流中泥沙浓度随径流系数、降雨侵蚀力呈对数函数增加趋势,土壤流失量随降雨侵蚀力及次降雨径流深均呈线性递增趋势。次降雨径流深20 mm为土壤流失量变化拐点,径流深超过20 mm后,土壤流失量随径流深递增速率较快。
[ Background] It is significant for slope soil loss control, soil and water resources utilization and management to study slope soil infiltration, runoff and sediment yield characteristics at slope scales. [ Methods] Based on the field artificial runoff plots in the Promotion Test Station of Wuhua County in Guangdong Province, the characteristics of soil infiltration and runoff and sediment yield were investigated and analyzed with the natural rainfall events of 2014. The experimental treatment includes： the natural abandoned land （NAL）, artificial forest （AF）, as well as shrubs and grass land （SGL）. [ Results] There was a significant correlation （P 〈 0.05, R = 0.95） between infiltration amount （Inf） and the surface vegetation cover （Lvc）. If increased firstly and then decreased with the rainfall intensity （Rsi） increasing. There was a critical Rai which induced the largest infiltration amount. The critical Rai for the AF and SGL ranged from 19.9 to 27.8 mm/h, both were larger than that under the NAL. There are significant negative correlations （P 〈 0.05 ） between runoff depth, soil loss and L,w with all the correlation coefficients over 0.9. Erosion rate was positively related to runoff coefficient by a power function, the sediment concentration increased with runoff coefficient and rainfall erosivity increasing by logarithmic functions, soil loss increased with both rainfall erosivity and runoff depth increasing by linear functions. [ Conclusions] The runoff depth of 20 mm was an inflection point for soil loss, the soil loss rate was high when the runoff depth was over 20 mm. Compared with the NAL, the AF and SGL obviously improved soil infiltration and reduced runoff and sediment yield.
出处
《中国水土保持科学》
CSCD
北大核心
2016年第2期23-30,共8页
Science of Soil and Water Conservation
基金
水利部黄土高原水土流失过程与控制重点实验室开放课题基金资助项目"红壤区小流域水沙输移规律研究"(2016006)
国家自然科学基金青年项目"天然林演替为人工林对林地水量平衡及土壤水影响作用机制"(41501019)
关键词
临界降雨强度
土壤入渗
植被覆盖
径流场
critical rainfall intensity
soil infiltration
land surface vegetation cover
runoff plot
