TASCC方法在研究山区流域氨氮输移转化中的应用

Application of TASCC Approach in the Study of NH+4-N Uptake in a Mountainous Catchment

为探究基于TASCC的养分添加示踪方法在山区流域内不同特征河道的氨氮吸收能力研究中的适用性及其优缺点,以浙江西南部山区小港流域为研究对象,在自上游至下游的8处试验点开展了氨氮的营养盐添加示踪试验,同时采集流域水生态环境特征数据。结果表明,基于TASCC方法和Michaelis-Menten吸收动力学模型量化小港流域的氨氮吸收能力,除在下游低流量的宽河道外都有较好的应用效果外,流域内氨氮吸收能力的空间分布差异可能与河道断面几何形态、流量、流速、背景浓度和水生态环境等因子有关。

To investigate the feasibility,advantages and disadvantages of nutrient tracer addition method based on TASCC for NH+4-N uptake capacity of rivers with different characteristics in a mountainous catchment,this research takes the Xiaogang Catchment,a headwater stream in the southwestern mountainous area of Zhejiang Province,as the study area,and eight nutrient addition experiments are conducted at different experiment sites from upstream to downstream and from tributaries to main streams.At the same time,the water ecological environment characteristics of the catchment is also collected.The results indicate that quantifying the NH+4-N uptake capacity based on TASCC approach and the Michaelis-Menten kinetics model has satisfactory application in Xiaogang Catchment,except in wide downstream rivers with low flow.In addition,the spatial distribution differences of NH+4-N uptake capacity within the catchment may be related to river hydraulic geometry,flow volume,flow velocity,ambient concentration and water eco-environment.