以太湖流域东战备河自然河道为对象,比较分析了4种植被类型及3m和6m宽度河岸带分别对TN、NH4-N、TP和COD等4种面源污染物去除效果的影响。结果表明,不同植被类型对污染物的去除率受季节和污染物种类变化的影响。灌草植被河岸带对面源污染物的去除率在全年内均较高,草本植被对污染物去除率在夏秋季最高而冬季最低,乔灌草植被的去除率高于乔草。不同河岸带宽度对污染物去除率的影响随季节、污染物类型和植被类型而变化,表现为冬季大于夏季,TN大于TP,乔草大于灌草。总体来看,现行条件下4种植被除了对TN的去除率较低,全年仅为20%-40%外,对NH4+-N、TP和COD的去除率分别达到了20%-70%、50%~90%和40%-80%,去除效果显著。
Riparian buffer play an important role in improving and protecting water quality from non-point source pollu- tion. Understanding the riparian structure and width is critical for its function and management. In this study, the select- ed natural buffers were in the Dongzhanbei River basin in Danyang city. The effects of four vegetation types and two kinds of vegetation width (3 m and 6 m) on TN, NH4+ -N, TP and COD removal were assessed respectively. The re- sults indicated that vegetation types had significant effect on pollutant's removal and the removal ratio varied with differ- ent seasons, vegetations and pollutants. The removal values of shrub-herb buffer for these four pollutants were higher than the other three vegetation types all through the year. In summer and autumn, the removal rate of riparian buffer with reed was the highest, while it was the lowest in winter. It was also demonstrated that the pollutant removal rates of ripari- an buffer with arbor- shrub-herb were higher than that of arbor-herb. The removal efficiency of pollutants for different buffer widths varied with seasons, vegetation and pollutant types. And it was higher in winter than in summer, for TN than for TP, and for arbor-herb than shrub-herb. Overall, the removal rates of the four vegetation types were changing with 20% - 40% for TN, 20% - 70% for NH4+ - N, 50% - 90% for TP and 40% - 80% for COD.