Study on the characteristics of runoff pollution control in different configurations of rural vegetation buffer strips
A vegetation buffer strip is an important spatial barrier in rivers and lakes.It is used to alleviate the direct interference of human activities on rivers and lakes and block agricultural nonpoint source pollution.Eight buffer strips were designed in a small watershed Dingyuan in Zhangshan to systematically study the effect of interception provided by different types of buffer strips on pollutants such as N and P in farmland.Combined with natural rainfall methods,the reduction effects of different buffer strips on surface runoff and its main pollutants such as total N(TN),total P(TP),and chemical oxygen demand(COD)were observed for two years.The results showed that forest land and 3°and 8°cross-ridge tillage buffer had the highest runoff interception efficiency,with interception rates of 62.4%,52.0%,and 60.6%for TN,TP,and COD,respectively.The runoff increased first and then decreased with the increase of rainfall intensity.Compared with the 8° slope treatment,the sediment reduction rates of the cultivated land buffer zone in the downhill(3°)treatment for vertical ridge and cross-ridge were 53.3%and 50.9%.The nutrient loss of rainfall runoff on the slope was mainly composed of N and organic matter,the average interception rate of NH+4-N in the runoff was as high as 95.2%.All buffer strips had good retention effect on TP in the runoff,and the loss of CODMn on the slope of 3° and 8° cross-ridge cultivation was the lowest,and the interception rate reached 53.0%and 58.6%.Our results indicated that the presence of high coverage vegetation and developed roots in the forest buffer strip can effectively slow down the erosion caused by rainfall on the surface and reduce runoff and nutrient loss.The implementation of cross-ridge cultivation in rural hilly and mountainous areas in the south is also an effective measure to retain runoff and reduce the risk of nonpoint source pollution.
vegetation buffer stripagricultural nonpoint source pollutionrunoffsedimentnitrogen and phosphorus loss
万方数据
维普
