Dynamic behaviors of water levels and arsenic concentration in shallow groundwater from the Hetao Basin, Inner Mongolia

摘要: article Temporal variations in groundwater As concentration are crucial for understanding the mechanisms of cycling and developing effective strategies sustainable usage low As-affected areas. Little is known about temporal shallow from Hetao basin. Groundwater samples were taken once each year July/August 2006 to 2010. Another sampling campaign was carried out November 2006. tables monitored as well. Results showed that water levels higher dur- ing December-April than during May-September front alluvial fans where irrigation relied mainly on groundwater. In contrast, highest observed May-June flat plain re- gion diverted Yellow River utilized irrigation. Concentrations Na + ,C l � ,a nd HCO3 relatively constant over 4 years, although most wells slight decreasing trends concentrations Ca 2+ Mg . Although lower 2007, there no significant changes between 2010 at p=0.05. Shallow groundwaters sampled region with surface generally July. This caused by more reducing conditions due less oxygen dispersing into aquifers when flooded soil perhaps un-saturated zone, evidenced redox potential November. μ-XRF contents well correlated Fe sediment aquifers. The plausible explanation decoupling tem- poral variation expected be reductive desorption As(V), analogical As(III) total As.