• 关键词：人工林地  降雨径流  非点源污染  流失特征

• 基金项目：“十一五”国家科技支撑计划课题(No.2007BAC22B02)

• 胡舒
• 清华大学环境科学与工程系, 北京 100084

• 张旭
• 清华大学环境科学与工程系, 北京 100084

• 张晓凤
• 清华大学环境科学与工程系, 北京 100084

• 李广贺
• 清华大学环境科学与工程系, 北京 100084

• 刘通
• 清华大学环境科学与工程系, 北京 100084

• 摘要：选取北京奥林匹克森林公园的典型人工林地为研究对象,通过对天然降雨径流过程及泥沙、氮、磷等污染物浓度随径流变化过程的监测,研究公园典型密草林地覆盖下,不同坡形及人工沟渠汇流条件下的径流及污染物浓度、形态和负荷的输出特征.结果表明,相同降雨条件下,林地1的坡长/坡宽比小,径流深度大,林地1坡度较大的草皮型汇流沟渠对径流的削减作用弱于林地2坡度较小的植草型汇流沟渠.两林地的泥沙浓度随径流量变化明显,总氮、总磷浓度在径流过程中的变化幅度较小.氮、磷的流失以可溶性为主,可溶性氮、磷在总氮、总磷中的比例分别为60%～80%和60%～64%.降雨量为6.8mm时,林地1的径流深度为0.16mm,总氮、总磷单位面积的流失负荷分别为0.74mg·m^-2和0.09mg·m^-2,林地2无径流;当降雨量为45mm时,林地1的径流深度为7.77mm,泥沙、总氮和总磷单位面积的流失负荷分别为1662.82mg·m^-2、35.58mg·m^-2和3.24mg·m^-2,林地2的径流深度为0.41mm,泥沙、总氮和总磷单位面积的流失负荷分别为86.48mg·m^-2、2.49mg·m^-2和0.31mg·m^-2.径流深度对泥沙、总氮、总磷单位面积的流失负荷影响较大.因此,要减少公园林地非点源污染负荷,应重点控制地表径流总量.

• Abstract：In order to discover the characteristics of non-point source pollution in Beijing Olympic Forest Park,two typical artificial forest lands with different topography and vegetation covers were selected to study the rainfall-runoff process and pollutant concentrations combined with natural rainfall events. The results showed that the runoff depth of site 1 with smaller length/width ratio was deeper than site 2 with larger length/width ratio. The planted grass swales in site 2 had a better performance in runoff reduction than the artificial turf swales in site 1. Ahigh variability of sediment concentration range and a lower variability of total nitrogen(TN) and total phosphorus(TP) concentration range were obtained during the runoff process. The majority of TNand TPlost were in dissolved form,in which,the TDN/TNand TDP/TPratios were from 60%～80% and 60%～64%,respectively in the two sites. In a 6.8 mm rainfall event,the observed runoff depth was 0.16 mm,and the losses of TNand TPwere 0.74 mg·m^-2 and 0.09 mg·m^-2 respectively in site 1; while there was no runoff yield in site 2. In a 45 mm rainfall event,the runoff depth was 7.77 mm,and the losses of sediment,TN and TP were 1662.82 mg·m^-2,35.58 mg·m^-2 and 3.24 mg·m^-2 respectively in site 1; while in site 2,the runoff depth was 0.41 mm,and the losses of sediment,TNand TPwere 86.48 mg·m^-2,2.49 mg·m^-2 and 0.31 mg·m^-2 respectively. It was shown that the runoff depth could reflect the significant impact on pollutant loss. Thus reducing the runoff yield is critical to non-point source pollution control in the park.

• Key words：artificial forest land  rainfall-runoff  non-point source pollution  loss characteristics

• 
  摘要点击次数： 2790 全文下载次数： 3019