This study considered data of six monitoring stations and two sewage treatment
plants. The EPB of Heilongjiang Province is responsible for water quality
monitoring and management. Data for Harbin City Reach of the Songhua River
system were collected from six regular monitoring stations (see Fig. 1) for eight
years (2005e2012); monitored parameters included water velocity, water flow,
and eight important water quality variables. The data of two sewage treatment
plants were also collected for the same eight-year period (2005e2012). All samples
were collected on a monthly basis. The first six years data (2005e2010) was
used to set up the WQM and the last two years data (2011e2012) was used to test
the model. Ammonia represented an important characteristic of municipal
wastewater and also was one of the main pollution parameters of the Songhua
River system in recent years (Zhou, 2011). Thus, in this study, an ammonia WQM
was established and the resulting multi-loads were estimated via a Bayesian
approach.