Zoning Marine Disposal for Dredged Material Management: A Case Study in Vietnam

Abstract

The fast growth of Hai Phong ports in the two last decades requires not only their upgrading facilities but also expanding port area and dredging their shipping channels (existing and new ones) that generate a huge amount of unused dredged materials. While all existing dumping sites in sea waters and on land get over capacity, looking for new dumping sites in sea waters is an urgent need. This study is to zone coastal waters of Hai Phong for suitable dumping sites meeting sustainable coastal management. Multi-criteria overlay analysis on GIS platform was employed with the criteria of natural conditions, environment and socio-economics for zoning coastal waters of Hai Phong. These criteria were detailed into eight subcriteria and then developed to eight GIS weighted thematic sub-layers of bottom depth, litho-hydrodynamics, ecosystems, distribution of benthos, distance to residential areas and tourist sites, distance to aquaculture area, distance to ecosystems and distance to conservation areas. Analysis results show the highly suitable zone for dredged material dumping in South, South West Hai Phong at depth below 15m to the deeper areas. Disposals of dredged materials in the zone would minimize impacts on the environment, ecology and socio-economics in surrounding waters and coastal areas