*2.3. Model Validation*

cember 2009).

chart (Figure 1a).

30 December 2009.

Hourly water elevation from 3 December to 12 December in 2009 is taken from Jiantiao station and Gangdi station are compared with model elevations in Figure 2. The result of verification basically agreed with the measured data. The relative error of the whole process could be controlled within 10%. According to spring tides and neap tides verification, the result can basically reflect the tide wave transformation of Sanmen Bay. ured data, what's more, the current velocity summit and direction changing moment are both close to each other, and relative error could be controlled under 20%. In a conclusion, the numerical simulation in Sanmen Bay can basically reflect the regional hydrodynamic situation, which offers a basis for further research on water exchange and water environ-

The current velocity and direction of each verification point coincides with the measured data, what's more, the current velocity summit and direction changing moment are both close to each other, and relative error could be controlled under 20%. In a conclusion, the numerical simulation in Sanmen Bay can basically reflect the regional hydrodynamic situation, which offers a basis for further research on water exchange and water environmental capacity (Figures 3 and 4). mental capacity (Figures 3 and 4). Compared with the measured values, the calculated values of the total tidal mean concentration in the whole sea area are also close, with an error of only 1.96%, indicating that the water quality model has successfully simulated the distribution of inorganic nitrogen concentration in Sanmen Bay.

**Figure 3.** Current velocity and direction during spring tides (**a,c**) stand for direction, (**b**,**d**) stand for velocity. **Figure 3.** Current velocity and direction during spring tides (**a,c**) stand for direction, (**b**,**d**) stand for velocity.

**Figure 4.** Current velocities and direction during neap tides, (**a**,**c**,**e**) stand for direction, (**b**,**d**,**f**) stand for velocity. **Figure 4.** Current velocities and direction during neap tides, (**a**,**c**,**e**) stand for direction, (**b**,**d**,**f**) stand for velocity.

The validation of COD is shown in Table 1. The model can simulate the contaminants well. Compared with the measured values, the calculated values of the total tidal mean concentration in the whole sea area are also close, with an error of only 1.96%, indicating that the water quality model has successfully simulated the distribution of inorganic nitrogen concentration in Sanmen Bay.

**Table 1.** Validation of COD. The validation of COD is shown in Table 1. The model can simulate the contaminants well.

Average 0.6432 0.6658 0.6545 0.642 1.96

The marine environment capacity (MEC) is decided by the following factors:

tions, tidal conditions, self-purification abilities, and other natural conditions as

(2) Rules on the utilization function of the specific maritime area usually differ. Different maritime functional areas carry out different water quality standards so that


**Station Flood (Model) Ebb (Model) Average (Model) Observation Error/(%)** S1 0.6777 0.7055 0.6916 0.717 −3.60 **Table 1.** Validation of COD.

well as group features of the ocean ecosystem.

*2.4. Method to Estimate the MEC*

their water capacity varies.
