Impact assessment of global environmental changes on safety and stability of water systems in Asian coastal mega cities

2004年，对胡志明市污染河段进行了病原微生物调查。结果，HCMC受污染的河流中的大肠菌群和病毒浓度与日本的污水处理水平相同。2005年1月和2月，对赤里翁河沿岸社区洪灾对健康的影响进行了调查，得出以下结论：1)受灾地区饮用水的主要来源是浅层地下水，被洪水污染；2)洪水进入房屋的时间较长，大肠菌群水平高于赤里翁河。3)洪泛区腹泻、皮肤病和流感的病例远高于非洪泛区。调查结果表明，除了溺水等直接损害外，洪水迫使当地居民延长了疏散寿命，并带来了健康影响。2005年，HCMC进行了一次与雅加达类似的洪水调查。2006年，在西贡河沿岸和流入西贡河的运河进行了水质监测。西贡河没有防潮闸，因潮汐起伏，水位波动较大。胡志明市没有中央污水处理厂，生活和工业废水都要经过沉淀等简单处理后才能进入西贡河。因此，人们发现，来自HCMC的受污染的水上升到了城市的取水点。如果全球环境变化导致水位上升，雅加达和HCMC等亚洲沿海特大城市将遭受更严重的洪灾，影响健康的病例将会上升。

In 2004, a survey on pathogenic microorganisms in contaminated river in HCMC was conducted. As a result, the concentration of coliform group and viruses in contaminated rivers in HCMC was found to be the same level as sewerage in Japan. In 2005, a survey was conducted in January and February, on the health impact of flooding in the communities along the Chiliwung River, and the following conclusions were obtained:1)The major source of drinking water in the flooded are is shallow groundwater, which was contaminated with flood water.2)The flood water that went into houses stay long hours, and the levels of coliform group were higher than Chiliwung River.3)In the flooded area, the cases of diarrhea, skin diseases and influenza, were much higher than in the non-flooded area.As a results of this survey, it was concluded that, in addition to the direct damage such as drowning, flood events force the local residents a long evacuation lives, and bring about health impacts.In 2005, a similar flood survey as Jakarta was conducted in HCMC. In 2006, water quality monitoring was conducted along Sai Gon River and canals that flow into Sai Gon River. There is no tidal gate in Sai Gon River; hence the water level fluctuates a lot due to tidal fluctuation. There is no central wastewater treatment plant in HCMC, and both domestic and industrial wastewaters go Sai Gon River only after simple treatment like sedimentation. Hence it was found that the contaminated water from HCMC goes up the point of the city's water intake. If the water level goes up due to Global Environmental Changes, Asian coastal mega-cities such as Jakarta and HCMC will suffer more severely from flood events, and the cases of health effect will go up.