## 3 Results and Discussion
### Scenario Analysis
#### 3.4.1 Scenario 1: Reducing the Effect of Dredging Discharge  
The first scenario is to consider reducing the discharge of dredging materials at the dumping site by 20-40 percent. This reduction can be achieved through effective management practices in the dredging sector, such as optimizing dredging amounts, utilizing landfills instead of sea dumping, and increasing waste recycling capacity. In the initial stage of this scenario, the discharge at the site was reduced by 20% (refer to Figure 12a). As shown in Figure 12b, a 20% reduction in material discharge resulting from dredging at the dumping site leads to a corresponding 7.5% decrease in total dumping. Furthermore, with a 40% decrease, the reduction in dumping will reach 14.9% by 2030 (see Table 2).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Time (Year)** & **Total Amount of Dumping: Base** & **Total Amount of Dumping: 20\%** & **Total Amount of Dumping: 40\%** \\  & **Simulation (m3/Year)** & **Reduced (m3/Year)** & **Reduced (m3/Year)** \\ \hline
2010 & 986,659 & 986,659 & 986,659 \\
2011 & \(1.12\times 10^{6}\) & \(1.12\times 10^{6}\) & \(1.12\times 10^{6}\) \\
2012 & \(1.26\times 10^{6}\) & \(  
We should clarify that the pollution reduction scenarios were implemented as a sudden reduction in 2021. Specifically, a sudden reduction of 20-40% in pollution levels occurred in that year. The subsequent effects of these reductions were then traced until 2023, through our system dynamics model.  
Reducing the impact of dumping sites on water pollution in Charleston Harbor requires a comprehensive approach involving waste management practices, regulatory measures, and community engagement. Here are some strategies to mitigate the effects of dumping sites on water pollution:  
* _Enhanced Waste Management Practices_: Implementing proper waste management practices is crucial to minimizing the pollution caused by dumping sites. This includes the establishment of secure landfill facilities, recycling and composting programs, and the promotion of responsible waste disposal techniques. Encouraging individuals, businesses, and industries to reduce waste generation and adopt sustainable practices can significantly reduce the amount of waste ending up in dumping sites.  
Figure 12: Reducing the effect of dredging discharge: (**a**) amount of dredging discharge; (**b**) Total amount of dumping at sites.  
* _Strict Regulatory Framework:_ Enforce and strengthen regulations governing waste disposal and dumping activities. Implement robust monitoring and enforcement mechanisms to ensure compliance with waste management regulations. This includes conducting regular inspections, imposing penalties for non-compliance, and promoting responsible waste disposal practices.
* _Promote Recycling and Reuse:_ Emphasize the importance of recycling and reuse to reduce the amount of waste that needs to be disposed of at dumping sites. Implement recycling programs at the community level and promote initiatives that encourage the reuse of materials. This not only reduces the waste sent to dumping sites but also conserves resources and mitigates pollution.
* _Improved Monitoring and Surveillance:_ Enhance monitoring and surveillance systems to detect illegal dumping activities. Utilize technologies such as satellite imagery, drones, or remote sensing to identify and address unauthorized dumping sites promptly. Prompt reporting and investigation of illegal dumping incidents can help mitigate their impact on water pollution.  
By adopting these strategies, it is possible to reduce the effect of dumping sites on water pollution in Charleston Harbor, safeguarding the health of the marine ecosystem and preserving the water quality for present and future generations.