水土保持学报2018，Vol.32Issue(2)：27-33,7.DOI:10.13870/j.cnki.stbcxb.2018.02.004
坡面氮素流失的坡度和雨强效应模拟研究
Effects of Slope Gradient and Rainfall Intensity on Nitrogen Loss Under Artificial Simulated Rainfall
摘要
Abstract
In order to investigate the effects of different slope gradients (5°,8°,15° and 25°) and rainfall intensities (60,90,120 and 150 mm/h) on TN (total nitrogen) loss in surface runoff and subsurface flow,an artificial simulated rainfall experiment was conducted,and decomposed granite soil vas taken as the experiment object.As the test design,the rainfall duration was 90 min after the appearance of surface runoff,and the test ended up when the subsurface flow disappeared.The results showed that:(1) The loss concentrations of TN in surface runoff declined rapidly at the early stage,and increased with the reduction of rainfall intensity and the increasing of slope gradient,and then tended to be stable.(2) The loss concentrations of TN in subsurface flow were significantly higher than those in surface runoff,and the curves of TN loss concentration in subsurface flow all followed a law of "rising-falling-slightly rising-steady".Generally,the loss concentrations increased with the reduction of rainfall intensity and the increasing of slope gradient.(3) The total losses of TN in surface runoff and subsurface flow were both increased with the increasing of rain intensity and slope gradient.Subsurface flow was the main approach of TN loss on slope,and its proportion could reach 91.26％ to 99.61％.The proportion of TN loss in surface runoff increased with the enhancement of rainfall intensity.(4) Rainfall intensity and runoff volume were both extremely significantly positively related to the TN loss in surface runoff and subsurface flow,while slope gradient only significantly positively correlated with the TN loss in subsurface flow.(5) There was a critical rainfall intensity between 90 mm/h and 120 mm/h,over which,the TN loss in surface runoff and its proportion in total loss would sharply rise.关键词
模拟降雨/坡面径流/壤中流/坡度/雨强/风化花岗岩母质发育土壤Key words
artificial stimulated rainfall/surface runoff/subsurface flow/slope gradient/rainfall intensity/decomposed granite soil分类
农业科技引用本文复制引用
邬燕虹,张丽萍,邓龙洲,范晓娟..坡面氮素流失的坡度和雨强效应模拟研究[J].水土保持学报,2018,32(2):27-33,7.基金项目
国家自然科学基金项目(41471221) （41471221）
