河北山地落叶松林河岸缓冲带去污效果试验研究

The water purification effect of larch forest riparian buffer zone in mountainous area of Hebei

选用3种浓度铵态氮和总磷溶液,分别以0.67L/s、1.82L/s两种流量对河北省围场县落叶松林河岸缓冲带进行灌水试验,分析河岸缓冲带对不同浓度、不同流量地表径流中铵态氮、总磷的削减效果。结果表明,随缓冲距离增加,河岸缓冲带对地表径流铵态氮和总磷削减效果呈增强趋势。在相同缓冲距离处,较小地表径流量下对铵态氮和总磷削减率普遍大于较大流量下的削减率。随着缓冲距离增大,较小径流量下铵态氮削减率和较大流量下铵态氮削减率的差值表现出先增大后减小的趋势。经20m的落叶松林河岸缓冲带后,地表径流量对各污染条件下铵态氮和总磷削减率的影响逐渐变小。在两种径流量下,落叶松河岸缓冲带对铵态氮和总磷的削减率都呈现出重度污染削减率>中度污染削减率>轻度污染削减率的规律。

To fully understand the reduction effects of larch forest riparian buffer zones on surface runoff pollutants,we used ammonium nitrogen and total phosphorus solutions of three concentrations to irrigate the larch forest riparian buffer zone in Weichang County of Hebei Province at flow rates of 0.67L/s and 1.82L/s.The results showed that the reduction effect of riparian buffer zone on the ammonium nitrogen and total phosphorus in surface runoff would be enhanced with the increase of buffer length.At the same buffer distance in the riparian buffer zone,the reduction rates of ammonium nitrogen and total phosphorus in the smaller surface runoff were both better than those in the larger runoff.With the increase of buffer distance,the difference of the reduction rate of ammonium nitrogen between smaller runoff and larger runoff showed a trend of increasing first and then decreasing.When the polluted water flowed through 20 mlarch forest riparian buffer zone,the influence of surface runoff on the reduction rates of ammonium nitrogen and total phosphorus became smaller in all the pollution conditions.At both runoff volumes,the reduction rates of ammonium nitrogen and total phosphorus in the larch riparian buffer zone showed the laws of heavy pollution reduction rate>moderate pollution reduction rate>light pollution reduction rate.