Environmental impact assessment of development interventions in mangrove areas: in case of thu bon estuary, Quang nam province, central of Vietnam | |
| Author | Somkid Tangkan |
| Call Number | AIT Thesis no.EV-16-19 |
| Subject(s) | Mangrove ecology Mangrove conservation Environmental aspects |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-16-19 |
| Abstract | Through its projects over the last decade the Wetland Alliance Programme (WAP) aimed to improve the environmental quality and living standards of people in the UNESCO Heritage site, Hoi An city, Quang Nam province, Central Vietnam. The development aid covered three communes: Cam Thanh and Duy Vinh near Hoi An town centered around nipa palm mangroves, and the third commune, Tam Hai, centered around non-nipa mangrove in An Hoa lagoon, a distant stretch of the delta. The community aid strived to balance out extensive industrial and tourism-related developments promoted by the government of Quang Nam province with a view to making the area one of the major hubs of Vietnam in the near future. Specific objectives were to identify the most significant change in the environment and socio-economics from WAP aid activities, as well as measure rate of pollution from recent industrial development interventions and human settlements and small scale fishing, to identify the interrelationships of WAP interventions and economic development interventions on the mangrove areas, and propose community-based mitigation measures to achieve sustainability in the studied areas. 12 most significant change stories were collected in the field through assessment of the most significant impacts from WAP activities. The most significant change was described as the story focused on the unexpected socio-economic change expressed as the rising tourism awareness of local people with regard to growing ecological and economic concerns, and an attitude shift with respect to the environment, when main career of some local individuals in Cam Thanh commune changed drastically from fishing to eco-tourism industry. Another unexpected change observed was that many local organizations realized importance of the diversity of co-benefits from delta wetlands. Organizations started to donate money to develop the same livelihood issues as those of the WAP projects. This indicates a leading role of WAP in the studied areas with regard to sustainable wetland development in Hoi An. Anthropogenic activities around An Hoa lagoon had been generating toxic pollutants to mangrove environment. Eight sampling sites near possible sources in An Hoa lagoon were investigated: near point source of domestic wastewater in Tam Hai commune, the remnant natural mangrove in Tam Hai commune, point source of shrimp farming wastewater discharging site in Tam Hai commune, sea grass beds, Chu Lai sea port, point source of soda industrial wastewater discharging site, local fishers’ ship port and point source of Chu Lai economic zone wastewater discharging site. Heavy metals and Polycyclic Aromatic Hydrocarbons (PAH) examined by inductively coupled plasma-optical emission spectroscopy and High-Performance Liquid Chromatography showed considerable presence of toxicants in mangrove sediments as compared to the Canadian sediment quality guidelines for the protection of aquatic life (CCGQ). Heavy metals were found to be lower than the CCGQ standard, except for Pb (<30.2 mg/kg) and Zn (<124 mg/kg). Total PAH concentration ranged between 1.160-9.655 mg/kg (ave. 4.270 mg/kg) which exceeded the CCGQ standard (<1.664 mg/kg) at domestic wastewater discharging site, aquaculture discharging site and industrial site. The highest concentrations of individual PAHs in sediments were those with low molecular weight (naphthalene and acenaphthylene). Zn concentrations in several sites were higher than Effect Range Median sediment screening level affecting 50% of sediment organisms. With regard of the pollution trend in An Hoa lagoon, decreasing trend of toxicant concentration in sediments was for Fe, As and Cd. Increasing trend of toxic concentration in sediments was for total PAHs, Zn and Pb generated by human activities. Ecological risk assessment established PAHs as moderately harmful for mangroves in Tam Hai commune. It is clear that WAP mangrove interventions played significant role in abatement of the pollution. However, effluent quality from Chu Lai industrial estate should be further improved to control heavy metal and PAHs contaminations in sediments. |
| Year | 2016 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Shipin, Oleg V.; |
| Examination Committee(s) | Nguyen, Thi Kim Oanh;Ebbers, Theo; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2016 |