A Bayesian approach for calculating variable total maximum daily loads and uncertainty assessment
A Bayesian approach for calculating variable total maximum daily loads and uncertainty assessment
复制标题
用于计算可变总最大日负荷和不确定性评估的贝叶斯方法
DOI：
10.1016/j.scitotenv.2012.04.042
复制
发表时间：
2012-07-15
影响因子：
9.8
通讯作者：
Lu, Jun
中科院分区：
文献类型：
--
作者：
Chen, Dingjiang;Dahlgren, Randy A.;Lu, Jun
为了同时考虑非点源污染的变异性和不确定性，将一维水质模型与贝叶斯统计和负荷持续曲线方法相结合，建立了总氮(TN)的可变总最大日负荷(TMDL)。采用贝叶斯统计方法对模型中的未知参数，即TN的区域特定输出率(E)和流内损失率系数(K)进行逆校正。根据已公布的测量结果开发了E和K的先验分布，以支持贝叶斯参数校准。然后将得到的E和K值用于水质模型，模拟了中国东部长乐农业流域的流域TN输出负荷、TMDL和所需减荷及其不确定性。结果表明，出口负荷较大。TMDL和TN所需减负量随河水流量的增加而同步增加。与这些估计相关的不确定性也表现出时间变异性，对于高流态具有较高的不确定性，对于低流态具有较低的不确定性。为确保90%符合L 2.0mgTN的目标，在低、中、高流态下，所需的负荷减少量分别为1.7x10(3)、4.6x10(3)和14.6x10(3)kg TNd(-1)。这项研究中开发的集成建模方法允许决策者确定不同TN合规水平所需的负荷减少，同时结合取决于流量的可变性和不确定性评估，以支持TMDL计划的实际适应性实施。(C)2012爱思唯尔B.V.保留所有权利。
To account for both variability and uncertainty in nonpoint source pollution, one dimensional water quality model was integrated with Bayesian statistics and load duration curve methods to develop a variable total maximum daily load (TMDL) for total nitrogen (TN). Bayesian statistics was adopted to inversely calibrate the unknown parameters in the model, i.e., area-specific export rate (E) and in-stream loss rate coefficient (K) for TN, from the stream monitoring data. Prior distributions for E and K based on published measurements were developed to support Bayesian parameter calibration. Then the resulting E and K values were used in water quality model for simulation of catchment TN export load, TMDL and required load reduction along with their uncertainties in the ChangLe River agricultural watershed in eastern China. Results indicated that the export load. TMDL and required load reduction for TN synchronously increased with increasing stream water discharge. The uncertainties associated with these estimates also presented temporal variability with higher uncertainties for the high flow regime and lower uncertainties for the low flow regime. To assure 90% compliance with the targeted in-stream TN concentration of 2.0 mg L-1, the required load reduction was determined to be 1.7 x 10(3), 4.6 x 10(3), and 14.6 x 10(3) kg TN d(-1) for low, median and high flow regimes, respectively. The integrated modeling approach developed in this study allows decision makers to determine the required load reduction for different TN compliance levels while incorporating both flow-dependent variability and uncertainty assessment to support practical adaptive implementation of TMDL programs. (C) 2012 Elsevier B.V. All rights reserved.