Panthi Jeeban, Li Fengting, Wang Hongtao, Aryal Suman, Dahal Piyush, Ghimire Sheila, Kabenge Martin
The Small Earth Nepal, PO Box#20533, Kathmandu, Nepal.
College of Environmental Science and Engineering, UNEP TONGJI Institute of Environment for Sustainable Development, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.
Environ Monit Assess. 2017 Jun;189(6):292. doi: 10.1007/s10661-017-6000-9. Epub 2017 May 24.
Both climatic and non-climatic factors affect surface water quality. Similar to its effect across various sectors and areas, climate change has potential to affect surface water quality directly and indirectly. On the one hand, the rise in temperature enhances the microbial activity and decomposition of organic matter in the river system and changes in rainfall alter discharge and water flow in the river ultimately affecting pollution dilution level. On the other hand, the disposal of organic waste and channelizing municipal sewage into the rivers seriously worsen water quality. This study attempts to relate hydro-climatology, water quality, and impact of climatic and non-climatic stresses in affecting river water quality in the upper Bagmati basin in Central Nepal. The results showed that the key water quality indicators such as dissolved oxygen and chemical oxygen demand are getting worse in recent years. No significant relationships were found between the key water quality indicators and changes in key climatic variables. However, the water quality indicators correlated with the increase in urban population and per capita waste production in the city. The findings of this study indicate that dealing with non-climatic stressors such as reducing direct disposal of sewerage and other wastes in the river rather than emphasizing on working with the effects from climate change would largely help to improve water quality in the river flowing from highly populated urban areas.
气候因素和非气候因素都会影响地表水水质。与气候变化对各个部门和地区的影响类似，气候变化有可能直接或间接地影响地表水水质。一方面，气温上升会增强河流系统中微生物的活性和有机物的分解，降雨变化会改变河流的流量和水流，最终影响污染稀释水平。另一方面，有机废物的排放以及将城市污水排入河道会严重恶化水质。本研究试图探讨水文气候学、水质以及气候和非气候压力对尼泊尔中部巴格马蒂河上游河水水质的影响。结果表明，近年来溶解氧和化学需氧量等关键水质指标正变得越来越差。关键水质指标与关键气候变量的变化之间未发现显著关系。然而，水质指标与城市人口增长和城市人均垃圾产量增加相关。本研究结果表明，应对非气候压力源，比如减少污水和其他废物直接排入河流，而非仅仅关注气候变化的影响，将在很大程度上有助于改善流经人口密集城市地区的河流的水质。
