Water Engineering and Management, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathum Thani, 12120, Thailand.
Water Engineering and Management, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathum Thani, 12120, Thailand.
Environ Res. 2020 Feb;181:108942. doi: 10.1016/j.envres.2019.108942. Epub 2019 Nov 18.
The rapid expansion in mining activities is deteriorating the water quality in the Chindwin River of Myanmar. In addition, climate change may also aggravate this situation in future. Therefore, the aim of this study was to establish a connection between hydrology, mining area, heavy metal loading, and climate change in the Chindwin River. The hydrology of the upper Chindwin basin was modelled using SHETRAN hydrological model. Geochemical model PHREEQC was utilised to conduct speciation and saturation indexes modelling along the river in order to quantify the precipitated minerals along the river. Thereafter a regression relationship along with LOADEST model was used to quantify the heavy metal loads. Future climate was projected using four RCM's namely ACCESS1-CSIRO-CCAM, CCSM4-CSIRO-CCAM, CNRM-CM5-CSIRO-CCAM and MPI-ESM-LR-CSIRO-CCAM. Future discharges at water quality monitoring stations were simulated using the averaged ensembles. Finally, the heavy metal loading under future climate scenarios were analysed. Results indicate that climate change is likely to reduce future discharges by 3.4%-36.5% in all stations except in the Mokekalae station which shows 1.3%-9.4% increase in the near future discharges. Also, the projected metal loading under future climate conditions 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 for both arsenic and mercury while the area between stations Uru downstream and Mokekalae show the highest load of iron effluent. Although future heavy metal loadings are expected to decrease, mining activities should be carefully monitored, since they discharge a large amount of toxic heavy metal loadings into the Chindwin River which is also expected to suffer a decrease streamflow in future.
采矿业的迅速扩张正在恶化缅甸钦敦江的水质。此外，气候变化也可能在未来加剧这种情况。因此，本研究旨在建立钦敦江水文、矿区、重金属负荷和气候变化之间的联系。使用 SHETRAN 水文模型对钦敦江上游流域的水文学进行建模。利用 PHREEQC 地球化学模型对河流进行形态和饱和度指数建模，以量化河流中沉淀的矿物质。然后，使用回归关系和 LOADEST 模型来量化重金属负荷。使用四个 RCM（ACCESS1-CSIRO-CCAM、CCSM4-CSIRO-CCAM、CNRM-CM5-CSIRO-CCAM 和 MPI-ESM-LR-CSIRO-CCAM）来预测未来的气候。使用平均集合模拟未来水质监测站的未来排放量。最后，分析未来气候情景下的重金属负荷。结果表明，除 Mokekalae 站在近期显示出未来排放量增加 1.3%-9.4%外，气候变化可能导致所有站点的未来排放量减少 3.4%-36.5%。此外，未来气候条件下的预计金属负荷显示出下降趋势，这与预计的排放模式相似。在基线和未来气候条件下，Naung Po Aung 和 Uru 下游之间的站点区域显示出砷和汞的最高负荷流出，而 Uru 下游和 Mokekalae 之间的站点区域显示出铁的最高负荷流出。尽管未来的重金属负荷预计会减少，但应谨慎监测采矿活动，因为它们向钦敦江排放大量有毒重金属负荷，预计未来的河流流量也会减少。
