霍林河下游洪泛区湿地土壤中铵态氮水平运移模拟研究  

Horizontal Diffusion of Ammonium Nitrogen in Marsh Soils from a Floodplain Wetland on the Lower Reach of Huolin River,China

作　　者：白军红[1] 王庆改[2] 肖蓉[1] 高海峰[1] 黄来斌[1] 

机构地区：[1]北京师范大学环境学院,水环境模拟国家重点实验室,北京100875 [2]环境保护部环境工程评估中心,北京100012

出　　处：《农业环境科学学报》2010年第11期2203-2207,共5页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(Nos.40701003,50879005);国家重点基础研究计划(973)项目(Nos.2006CB403301,2010CB951102);长江学者和创新团队发展计划(No.IRT0809);北京师范大学自主科研基金(2009SD-24)

摘　　要：选择二百方子洪泛区湿地作为典型研究区,以NH4Cl为示踪剂,模拟研究了铵态氮在洪泛区湿地不同土层中的水平运移过程。结果表明,沼泽湿地土壤中铵态氮的运移通量随运移距离的增加呈一阶衰减指数变化;0-10cm土层中铵态氮的运移通量最小,20~60cm土层次之,10~20cm土层具有最高的铵态氮通量。各层土壤运移通量在0~6cm内最大,而后迅速下降,到18cm时3层土壤中铵态氮的运移通量相近并趋近于零。各层土壤中铵态氮的运移通量与土壤水扩散率及土壤含水量都呈一阶指数增长变化;在土壤水扩散率或土壤含水量达到一定数值前,铵态氮运移通量增长缓慢,之后则开始骤然增加。Few studies have been carried out regarding horizontal movements of ammonium nitrogen in marsh soils of the floodplain wetlands,despite they play the very important role in protecting water quality of rivers or lakes.Horizontal movement of ammonium nitrogen was simulated using NH4Cl tracer in horizontal soil columns from Erbaifangzi floodplain wetland located on the lower reach of Huolin River,in order to study the horizontal diffusion of ammonium nitrogen in wetland soils from the floodplains and to reveal the effects of water diffusion rates and volumetric water contents on ammonium nitrogen movement.Results showed that movement fluxes of ammonium nitrogen decreased exponentially with increasing distances far away from water head.The highest movement fluxes of ammonium nitrogen were observed at 10~20 cm soil horizons,followed by 20~60 cm,and the lowest for 0~10 cm soil horizons.The higher movement fluxes of ammonium nitrogen occurred at the distances from 0 to 6 cm,and then showed a rapid decrease at the distances from 6 to 18 cm.After that they kept constant and nearly approached to zero at the distances exceeding 18 cm.The movement fluxes of ammonium nitrogen at all soil horizons were closely linked to water diffusion rates and volumetric water contents,and they increased exponentially with increasing water diffusion rates and volumetric water contents.The movement fluxes of ammonium nitrogen at each soil horizon showed a slow increase,but increased rapidly after water diffusion rates or volumetric water contents reached a certain level.Therefore,it is very necessary for water quality security of Huolin River to monitor and control ammonium movement in subsurface soils.

关 键 词：洪泛区湿地 水平土柱 铵态氮 水平运移 霍林河下游 

分 类 号：X53[环境科学与工程—环境工程]