Mitigation of cumulative environmental impacts in coastal ecosystems : case studies in Thailand and India | |
| Author | Nanda, Satya Swarup |
| Call Number | AIT Thesis no.EV-06-47 |
| Subject(s) | Water--Pullution--Thailand Water--Pollution--India Coastal ecology--Thailand Coastal ecology--India |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management, School ofEnviromnent, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-06-47 |
| Abstract | The coastal water quality management is always a task of multiple variables with several phenomenons happening and affecting to the ultimate environment. There are quick and small events which have quite visible effects whereas several other parameters affect the coastal ecosystem in a broader magnitude. Water quality in an inter-tidal environment depends upon many indicators such as hydrological regime, microbiological community, climatic conditions, and the exchanges at basin level. In this context this present study has tried to find out the indictors responsible to draw substantial effects to the referred ecosystem in a cumulative manner and the reasons were examined critically. The comparison of the two ecosystems has been done on the basis of water quality analysis. The study further substantiated by a pollutional mapping from upstream to down stream by using both GIS mapping and a water quality modeling; i.e. MIKE 11. On the other hand, the hypothesis for the study was to use mangroves for mitigating the cumulative effects, incurred in the system. The hydrodynamics of both the systems was studied by using the model and it was concluded that in both the cases the formation of sand bars and mud flats has changed the hydrology to a greater extent and thus has influenced the pollutional transportation. The obstruction created by the sand bars have forced the pollution traces not to move or being dispersed and thus has decreased the natural assimilation capacity of the streams. The accumulation of pollution has affected detrimentally on the benthic community and on aquatic biodiversity and decrease of aquatic production observed both temporally and in spatially. This observation was also supported by the change in population dynamics in case of Chilika lagoon in particular. Mangroves have effected tremendously to the assimilation of pollutants. It was observed that despite of a large industrial pollution the periphery of Bang Pu Nature Reserve in Chaophrya estuary the water quality seemed to be up to the standard. It was notable that a patch of the mudflat region and surrounding water body was not preferred by the fishes, strengthening our claim of a sedimentary pollution. However, a sediment level examination of the pollution traces was avoided due to the limitation of the study. The steady increase in nutrient level from upstream to down stream proved transportation and accumulation of pollutants. In case of Chilika lagoon the presence of mangrove wetland and the mud flat has a positive effect on fish population. The data showed a steady increase of fish population and especially the rare Irrawaddy dolphins. Their presence near the wetland indicated a positive effect of Mangroves. The industrial pollution was more evident in Chao Phraya where in case of Chilika phosphates transported from near by farmlands have effected in big way. However, the change in hydrology because of the dredging of mouth in Chilika has been able to mitigate the cumulative effect hampering the ecosystem. The increase in salinity level and greater biodiversity signifies this. The study recommends similar action in Chaao phraya estuarine system which is also facing same problem of agricultural runoff. Lastly the study further brings the need of broad level examination of dynamics of water quality indicators and a parallel verification of mangrove sediments which can bring micro level composition of the available community and the effect of the pollutants on them. |
| Year | 2006 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-06-47 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Shipin, Oleg V. |
| Examination Committee(s) | Tripathi, Nitin Kumar; Preeda Parkpian |
| Scholarship Donor(s) | Government of France & Asian Institute of Technology |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2006 |