## 2 Materials and Methods
### Environmental Capacity Assessment System (ECAS)
#### 2.2.2.1 Environmental Capacity Estimation
 \tag{8}\]  
where:  
_Z_: objective function;  
_Q_: coefficient vector; when the total amount of pollutants reaches the maximum value, \(Q\) = [1, 1,..., 1]T;  
_A_: response coefficient matrix, generated by the concentration response field of pollution sources and the water quality monitoring points;  
_a_ij: pollution contribution coefficient of unit load of the _j_th sewage outlet to the _i_th water quality monitoring point;  
_m_: number of water quality monitoring points;\(n\): number of pollution sources;  
\(B\): pollutant background concentration vector, \(B=[b_{1},b_{2},\ldots,b_{m}]^{T}\);  
\(S\): standard vector of water quality, \(S=[s_{1},s_{2},\ldots,s_{m}]^{T}\);  
\(X\): pollutants discharge load, \(X=[x_{1},x_{2},\ldots,x_{n}]^{T}\); \(X_{i}\): the lower limit vector of pollutant discharge load, \(X_{i}=[x_{i1},x_{i2},\ldots,x_{in}]^{T}\); \(X_{j}\): the upper limit vector of pollutant discharge load, \(X_{j}=[x_{j1},x_{j2},\ldots,x_{jn}]^{T}\);  
Equation (6): objective function equation;  
Equation (7): constraint equations of water quality and pollution source load. The verification results of the hydrodynamic model and water quality model in this paper are shown in the Supplementary Materials. Determination of Water Quality Objectives  
According to the classification system and classification standards of \"Technical Guidelines for Marine Function Zoning\", \"National Marine Function Zoning\", \"Jiangsu Province Marine Function Zoning (2011-2020)\" and \"Lianyungang City Marine Function Zoning (2013-2020)\", the marine function zoning of Lianyungang adopted a five-category and four-level system which was divided into five categories: development and utilization areas, regulation and utilization areas, marine protection areas, special function areas, and reserved area. In this study, 13 routine water quality monitoring points of the Environmental Monitoring Center were selected, and their water quality targets were determined according to their zoning locations (Table 2). In Haizhou Bay, 12 main discharge outlets of pollution sources and estuaries of rivers entering the sea were selected to calculate the response coefficient matrix of pollution sources to water quality monitoring points (Figure 5). Response Coefficient Field  
Due to the transport and diffusion characteristics of ocean water, the distribution of response coefficient values in the sea will vary with different locations, thus, forming a response coefficient field. It reflects the response relationship of water quality to a pollution source. In view of 12 important pollution sources in Haizhou Bay, the response coefficient fields of each pollution source to water quality monitoring points after the implementation of each reclamation project were calculated, and the influence of each reclamation project on the distribution of pollutant response concentration fields was analyzed. Figure 6 shows the response concentration fields of COD formed by 12 pollution sources under different reclamation schemes in scenario 3. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Water Quality Monitoring Point** & **Function Description** & **Water Quality Standard** \\ \hline
1 & Storm surge area & Class II \\
2 & Reserved tourist area & Class III \\
3 & Marine fishing area & Class II \\
4 & No fishing area & Class II \\
5 & Sewage discharge area & Class IV \\
6 & Mariculture area & Class II \\
7 & Mariculture area & Class II \\
8 & Haizhou Bay Tourist Resort & Class III \\
9 & Lianyungang Port area & Class IV \\
10 & Coastal salt farming area & Class II \\
11 & Lianyungang Port area & Class IV \\
12 & Fishery breeding area & Class II \\
13 & Storm surge area & Class IV \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Water quality target at monitoring points.