模拟降雨对工程建设区裸露坡地产流产沙及氮素流失的影响

发布时间：2018-10-08 14:07

【摘要】：为揭示不同降雨强度下工程建设区裸露坡地土壤侵蚀过程和氮素流失特征,采用人工模拟降雨的方法,研究不同降雨强度(1,1.5,2mm/min)和处理(裸地、坡面覆盖纱网)对工程裸露坡地产流产沙及氮素流失的影响。结果表明:(1)径流强度、径流含沙量、土壤剥蚀率都与降雨强度呈正相关关系,土壤入渗率与降雨强度呈现负相关关系。(2)累积泥沙量与累积径流量在裸地处理中呈现线性函数关系,在纱网处理中呈现幂函数关系。(3)地表径流中氮素流失浓度随降雨历时呈现"下降—稳定"趋势,氮素流失量随降雨强度的增加而增大,其中NO_3~-—N流失量占总氮比重高于NH_4~+—N。(4)土壤坡面覆盖纱网后能有效控制水土流失量和氮素流失量,其中径流量和NO_3~-—N流失量在小雨强处降低效果显著,分别降低了60.21%和56.74%;TN流失量和NH_4~+—N流失量在小、中雨强处降低效果较好,均达到59.26%以上;侵蚀泥沙量在小、中、大雨强处均降低了79%以上。说明土壤坡面覆盖纱网这一措施对降低工程建设区裸露坡地土壤侵蚀量和氮素流失量具有效果显著,可以作为工程建设区水土流失防止措施。
[Abstract]:In order to reveal the soil erosion process and nitrogen loss characteristics of bare sloping land in engineering construction area under different rainfall intensity, different rainfall intensity (1 1. 5 mm / min) and treatment (bare land) were studied by artificial rainfall simulation method. The influence of sloping covering net) on real estate abortive sand and nitrogen loss on bare slope. The results showed that: (1) runoff intensity, runoff sediment content and soil erosion rate were positively correlated with rainfall intensity. There was a negative correlation between soil infiltration rate and rainfall intensity. (2) there was a linear functional relationship between accumulated sediment and cumulative runoff in bare land treatment. (3) the nitrogen loss concentration in surface runoff showed a "down-stable" trend with rainfall duration, and nitrogen loss increased with the increase of rainfall intensity. The ratio of NO_3~--N loss to total nitrogen is higher than that of NH_4~ N. (4) the soil and water loss and nitrogen loss can be effectively controlled after the soil slope covering yarn net, and the runoff and NO_3~--N loss can be decreased significantly in the light rain area. The loss of TN and NH_4~ -N were reduced by 60.21% and 56.74%, respectively. The results showed that the loss of TN and NH_4~ -N decreased by more than 59.26%, and the amount of erosion sediment decreased by more than 79% in the middle and heavy rain. The results show that the measure of covering yarn net on soil slope has a remarkable effect on reducing soil erosion and nitrogen loss in bare slope land of engineering construction area, and can be used as a measure to prevent soil erosion in engineering construction area.
【作者单位】：西南大学资源环境学院;
【基金】：国家水体污染控制与治理科技重大专项(2012ZX07104003)
【分类号】：S157.1

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