Earthquake - Science in Himalayas: Ground Water Quality Change and its Implications

Abstract

In this paper, we discuss the pre-earthquake and post-earthquake groundwater scenario in context of Nepal. Nepal being one of the most earthquake vulnerable countries, the implications of earthquake in Nepal is considerable. Study requires not so only above the earth surface, but also in sub-surface conditions. Of various geo-physical and geo-chemical, subsurface conditions, this particular study concerns with groundwater chemical parameters. Before the occurrence of earthquake, groundwater chemistry has been found to change in numerous instances as promising precursor of earthquake. On the other hand, the chemical changes in groundwater have been found to continue beyond the occurrence of earthquake. Some of these changes, due to their toxic nature, are likely to cause health hazards to people who directly consume groundwater. In this premise, we deduce that constant observation of groundwater chemistry before and after earthquake is crucial for both earthquake prediction science and for monitoring health risks that may arise from consuming chemically altered groundwater due to tectonic activity.Journal of the Institute of Engineering, 2017, 13(1): 201-205

Post-Earthquake Water Quality in Bhaktapur District, Nepal

“…However, in case of Kathmandu valley previous studies and this study demonstrated the microbial contamination of water is quite common before and after the earthquake (Pant, 2010;Pant et al 2016;Uprety et al, 2017). In a country like ours where the use of ground water is prevalent for domestic and drinking purpose microbial contamination of water may have severe effect on human health (Banjara, Paudel, 2017). Physical and chemical alteration of ground water may occur after earthquake however this study exhibits that physical and chemical parameters generally are within the NDWQS (1996) guidelines while the microbial contamination of water could pose risk to the public health.…”

“…Changes in post-earthquake water quality parameters have widely been studied and changes in chemical and microbial parameters have been reported (Banjara, Paudel, 2017;Uprety et al, 2017). However, in case of Kathmandu valley previous studies and this study demonstrated the microbial contamination of water is quite common before and after the earthquake (Pant, 2010;Pant et al 2016;Uprety et al, 2017).…”

“…Massive earthquakes may cause crack in the rocksand facilitate in leaching of metallic ions to groundwater aquifer. This can change physical characteristics and chemical composition of water (Esposito et al, 2001;Hsu, Tung, 2004;Yang et al, 2007;Sato et al, 2014;Banjara, Paudel, 2017). Similarly, groundwater level also alters with equal possibility of formation and disappearance of new springs depending on the strength of quake and geological formation of earthquake affected area (Chia et al, 2001;Matsumoto et al, 2003).…”

Challenges and Opportunities on Urban Water Quality in Mexico City

“…The water quality of the wells located in the Western area of the city also corresponds to the zone where the aquitard presents the largest drawdown percentages (>60%), as reported in areas with clay thickness smaller than 25 m (Auvinet et al, 2017), a condition that may also influence water quality. Local, intermediate and regional flux type wells were used in order to assess if there was a difference in water quality according to flow regime.…”

“…Seismic zones are related to the origin of the lacustrine plain in which Mexico City was built. According to Auvinet et al (2017) the lacustrine plain was formed by progressive silting of the basin reservoir, due to the rising of Sierra del Chichinautzin. Silting with volcanic products and river drift propitiated conditions for the formation of a lake system within the Basin of Mexico.…”