Development of selected aspects of the decision-making tool of the cumulative effects assessment : a case study of the Nam Ngum River Basin Wetlands, Lao PDR | |
| Author | Phonepasong Sithideth |
| Call Number | AIT Thesis no.EV-10-13 |
| Subject(s) | Cumulative effects assessment--Environmental aspects--Laos--Nam Ngum River Basin Wetlands Wetlands--Environmental aspects--Laos Nam Ngam River Basin Wetlands (Laos) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | The Cumulative Effect Assessment (CEA) as a tool to quantitatively assess the cumulative effects (impacts) in multifunctional wetlands coupled with Rapid Environmental Impact Assessment (EIA) and Participatory Rural Appraisal (PRA) was used to analyze local anthropogenic and natural impacts in the Nam Ngum River Basin (Lao PDR). The lack of environmental data sets in the study area is a serious implication in this regard, which was further scrutinized by the Rapid EIA, PRA and Expert opinion despite its strong validity under the circumstances when the required environmental data sets are not available to achieve the objectives of the study, i.e., (i) identifying different drivers of Nam Ngum River Basin (ii) analyzing cumulative effects of the other relevant drivers using matrix analysis and PRA methodology (iii) cumulative effect assessment approach within the Strategic Environmental Assessment process. At least twenty drivers (stressors) were identified which are exerting impacts on Nam Ngum River Basin (NNRB). Assessment of interrelationships between relevant drivers (stressors) by matrix analysis, clustering and principle components analysis (PCA) showed that only six drivers were found to be strongly interconnected. Surface water with vulnerability index of 0.85 (85%) was found to be most vulnerable by the multitude of drivers on Valued Ecosystem Components (VECs) and their services for Nam Ngum area. Rapid EIA and Participatory Rural Appraisal (PRA) conducted in the Nam Ngum River Basin (NNRB) Wetlands (at target village zone/ downstream and upstream) through group discussions, structured interviews among the different groups: farmers, fishermen, aquaculture pond owners and relevant government/non-government officials yielded that Strategic Environmental Assessment (SEA) and Cumulative Impact Assessment processes in the study area need to be upgraded due to its great hydropower development potential in future with implications on impacts on water levels, sediment loads and water quality as experienced after the development of Nam Ngum 1 reservoir, while the cumulative impacts of multiple hydropower developments could be much more significant. PRA results showed that the cumulative effect of all the primary drivers to the multifunction of wetland ecosystem was found to have high effect to ecosystems’ multifunction. Other primary direct drivers were considered to have high effects on biological ecosystem: i.e., land use change and agriculture while hydropower, mining, overfishing, flooding and pollution were rated to have moderate effects and the drivers such as aquaculture, drought and other industries were rated to have low effects by the participants in the surveys. The regulation function of the river ecosystem was highly affected by primary direct drivers followed by production and carrier functions whereas information function was not very affected which implies if mitigation measures are both put in place that may cause continued degradation of downstream wetlands’ multifunction leading to food security and health problems. After the surveys in the nearby districts in Nam Ngum Reservoir 1, it was found that excessive fishing and inappropriate fishing practices were considered as one of the primary direct drivers which cause wetland degradation; it was also found that some fish were becoming rare as catches per family of that fish were considered to be diminishing. |
| Year | 2010 |
| 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) | Preeda Pakpian;Ebbers, Theo;Phonekeo, Vivarad; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2010 |