| Author | Shakthi Kalpani Gunawardana |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | The study assesses the impact of climate change on hydrology and pollutant load generated from mining areas in the Chindwin river basin in Myanmar. The toxic heavy metal pollutant loads of Mercury and Arsenic along with Iron was accessed. First the hydrological condition of the selected area of Chindwin basin was modelled using physically based partially distributed model SHETRAN. The model was able to capture the outlet discharge with a relatively good performance. Therefore, the calibrated model was used to simulate the discharges at the water quality monitoring stations.
Geochemical model PHREEQC was utilized to conduct speciation and saturation indexes modelling along the river in order to quantify the precipitated minerals along the river. Results show possible precipitation of Iron species with increased precipitation in the regains where water is Alkaline. Thereafter a regression relationship along with LOADEST model was utilized to quantify the heavy metal loads along the river. Results indicate high loads of toxic heavy metal pollutants with a decreasing pattern in the annual average load in the baseline period. The wet seasonal heavy metal loads are higher than that in the dry season, the wet seasonal loads follow the pattern in the total annual load.
The future climate was projected using four RCM’s namely ACCESS1, CCSM4, CNRM and MPI ESM. They were bias corrected using linear scale method. Both minimum and maximum temperature show increasing pattern with time in future but there was no clear pattern in the future rainfall projections. Ensemble of the above climate parameters were conducted using EnsembleBMA package in R software. The uncertainties indicated in the probability density plots are reduced with the BMA ensembled averages.
Future discharges at water quality monitoring stations were projected using the averaged ensembles. The results show decreasing trend in the future discharges due to the increased evaporation. The future loads were generated using the above discharges and the calibrated LOADEST models. The projected load also shows a decreasing pattern which is similar to the projected discharge pattern. In both baseline and future climate conditions, the area between stations Naung Po Aung and Uru Downstream show the highest load effluent in both Arsenic and Mercury while the area between stations Uru Downstream and Mokekale show the highest load effluent of Iron.
Finally, the load under three different scenarios was analyzed with and without the climate change effect. Increment and reduction in pollutant concertation under changing mining areas and the reduction in the upstream discharge due to increase in abstractions for irrigation requirements were the three defined scenarios. Results indicate increase in pollutant load under increase in concentration and vice versa. Also, under reduction in the discharge the pollutant load shows decreasing pattern.
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| Year | 2018 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Shrestha, Sangam; |
| Examination Committee(s) | Babel, Mukand S.;Duc Hoang Nguyen;Thanapon Piman ; |
| Scholarship Donor(s) | AIT Fellowship ; |