Estimating Spatiotemporal Distribution of Wastewater Generated by Ships in Coastal Areas

With the increase in shipping density, the risk of wastewater generated by ships in coastal areas has raised much attention. The present study proposes a model to estimate the spatiotemporal distribution of wastewater including greywater and sewage generated by ships in coastal areas. The model is applied to estimate the wastewater generated by the ships operated near the great bay area. The shipping traffic characterization in this region is presented and the spatiotemporal distribution of the wastewater generated by ships is demonstrated. It was found that the total amount of wastewater generated by the ships operated in the whole research area during six-month period is 11.8×10 7 m 3 , in which 1.86×10 7 m 3 is for the sewage and 9.97×10 7 m 3 is for the greywater. Passenger ships contributed 83 % of the total wastewater, while cargo ships accounted for 12% of the total wastewater. The amount of monthly wastewater is not only just varied over the total amount, the spatial distribution was also varied as the shipping activities are different across the research area. The model presented in this study increase the spatiotemporal resolution of wastewater generated in the research area and can distinguish the contribution of different ship types to the total amount of wastewater generated at the whole research area monthly. The results can be used to optimize the wastewater collection strategies and to better design the collection facilitates in the research area