紫色土丘陵区农业小流域暴雨事件磷素多尺度流失特征

发布时间：2018-07-05 10:09

本文选题：农业小流域 + 泥沙　；参考：《水土保持学报》2017年05期

【摘要】：为了揭示自然小流域尺度降雨、地形、土地利用结构等对泥沙和磷素输出的影响,根据丘陵区农业小流域自然地貌与土地利用特征,设计了不同尺度的小流域监测点,分别为苏荣、截流、大兴、万安,监测面积分别为3.0,34.6,480.3,1 236.4hm~2,并选择了降雨侵蚀力(R)分别为1 411.5,595.7,391.4 MJ·mm/(hm~2·h)的3场降雨事件监测小流域内磷素流失过程特征。结果表明:(1)以居民点集镇和耕地为主的苏荣和截流小流域水文响应速度较快,暴雨事件中径流峰值出现在降雨峰值后的5~10min,较大尺度大兴和万安小流域泥沙浓度峰值与径流峰值滞后于降雨峰值0.5~3h。(2)3场暴雨径流中泥沙与全磷、颗粒态磷均存在较一致的显著相关关系(R0.6,P0.01),泥沙、全磷流失负荷在源头小流域(苏荣、截流)最高,3场暴雨苏荣全磷平均流失负荷达到0.36kg/hm~2,万安小流域泥沙、全磷流失负荷最低,全磷平均流失负荷为0.009kg/hm~2。(3)小流域径流中颗粒态磷占全磷流失量50%以上。(4)多元回归分析结果表明,径流量和泥沙含量可用于进行磷素流失通量预测。坡耕地、林地与水田带状组合结构可显著降低小流域泥沙和磷素流失负荷。研究结果为计算丘陵区农业小流域暴雨过程中磷素多尺度流失负荷提供参考。
[Abstract]:In order to reveal the effects of rainfall, topography and land use structure on sediment and phosphorus output in natural small watershed, according to the characteristics of natural landform and land use in agricultural small watershed in hilly region, small watershed monitoring points of different scales were designed. The monitoring area was 3.0 ~ 34.6480.3N ~ 1 236.4hmm2, respectively, and three rainfall events (R = 1 411.5595.7391.4 MJ mm/ (hm~2 h) were selected to monitor the process of phosphorus loss in a small watershed. The results are as follows: (1) the hydrological response speed of Su Rong and closure watershed, which are mainly residential towns and cultivated land, is fast. The peak value of runoff occurred at 5 ~ 10 min after the peak value of rainfall, and the peak value of sediment concentration and runoff in large scale Daxing and Wanan small watershed lagged behind the peak value of rainfall of 0.5 ~ 3 h. (2) sediment and total phosphorus in three rainstorm runoff. There was a significant correlation between granular phosphorus and total phosphorus loss. The sediment and total phosphorus loss load reached 0.36 kg / hm ~ (2) and 0.36 kg / hm ~ (2) respectively in Su Rong (closure), and the total phosphorus loss load was the lowest in Wanan small watershed, and the maximum total phosphorus loss load was 0.36 kg / h ~ (-1) 路h ~ (2) ~ (-1) in the small watershed of Wanan, while the total phosphorus loss load was the lowest in the small watershed of Wanan. The average load of total phosphorus loss is 0.009 kg / h ~ (-1) 2. (3) Particle phosphorus in runoff of small watershed accounts for more than 50% of total phosphorus loss. (4) the results of multivariate regression analysis show that runoff and sediment content can be used to predict phosphorus loss flux. The belt structure of sloping farmland, woodland and paddy field can significantly reduce the load of sediment and phosphorus loss in small watershed. The results provide a reference for the calculation of multi-scale phosphorus loss load during rainstorm in agricultural small watershed in hilly region.
【作者单位】：绵阳师范学院;中国科学院水利部成都山地灾害与环境研究所;
【基金】：中国科学院STS项目(KFJ-SW-STS-142) 国家自然科学基金项目(41371241,41430750) 国家重点研发计划项目(2016YFD0200309-7)
【分类号】：X52;X712

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