Department of Natural Resources, College of Environment and Natural Resources, Zhejiang University, 310058 Hangzhou, China.
Environ Manage. 2013 Aug;52(2):450-66. doi: 10.1007/s00267-013-0112-y.
A modeling system that couples a land-usebased export coefficient model, a stream nutrient transport equation, and Bayesian statistics was developed for stream nitrogen source apportionment. It divides a watershed into several sub-catchments, and then considers the major landuse categories as stream nitrogen sources in each subcatchment. The runoff depth and stream water depth are considered as the major factors influencing delivery of nitrogen from land to downstream stream node within each sub-catchment. The nitrogen sources and delivery processes are lumped into several constant parameters that were calibrated using Bayesian statistics from commonly available stream monitoring and land-use datasets. This modeling system was successfully applied to total nitrogen (TN) pollution control scheme development for the ChangLe River watershed containing six sub-catchments and four land-use categories. The temporal (across months and years) and spatial (across sub-catchments and land-use categories) variability of nonpoint source (NPS) TN export to stream channels and delivery to the watershed outlet were assessed. After adjustment for in-stream TNretention, the time periods and watershed areas with disproportionately high-TN contributions to the stream were identified. Aimed at a target stream TN level of 2 mg L-1, a quantitative TN pollution control scheme was further developed to determine which sub-catchments, which land-use categories in a sub-catchment, which time periods, and how large of NPS TN export reduction were required. This modeling system provides a powerful tool for stream nitrogen source apportionment and pollution control scheme development at the watershed scale and has only limited data requirements.
一个将基于土地利用的出口系数模型、河流养分输运方程和贝叶斯统计相结合的模型系统被开发用于河流氮源分配。它将流域划分为若干子流域，然后将主要土地利用类型视为每个子流域中的河流氮源。径流量和河流水深被认为是影响每个子流域内从陆地到下游河流节点输送氮的主要因素。氮源和输送过程被集中到几个常数量参数中，这些参数是使用贝叶斯统计从常用的河流监测和土地利用数据集进行校准的。该模型系统成功应用于包含六个子流域和四个土地利用类别的昌乐河流域的总氮 (TN) 污染控制方案的制定。评估了非点源 (NPS)TN 向河流渠道的输出以及向流域出口的输送的时间（跨月和年）和空间（跨子流域和土地利用类别）变异性。在调整了河流中的 TN 保留后，确定了对河流贡献过高-TN 的时间段和流域面积。针对目标河流 TN 水平为 2mg/L，进一步制定了定量 TN 污染控制方案，以确定需要减少哪些子流域、子流域中的哪些土地利用类别、哪些时间段以及多大比例的 NPS TN 输出。该模型系统为流域尺度的河流氮源分配和污染控制方案制定提供了一个强大的工具，并且只需要有限的数据要求。
