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Aquifer heterogeneity controls on adverse human health effects and the concept of the hazard attenuation factor
Author(s) -
de Barros F. P. J.,
Bellin A.,
Cvetkovic V.,
Dagan G.,
Fiori A.
Publication year - 2016
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1002/2016wr018933
Subject(s) - attenuation , aquifer , hydraulic conductivity , hazard , cumulative distribution function , statistics , soil science , environmental science , random variable , permeability (electromagnetism) , probability density function , mathematics , geology , geotechnical engineering , groundwater , physics , chemistry , organic chemistry , membrane , optics , soil water , biochemistry
We analyze the probability distribution of the hazard attenuation factor for a noncarcinogenic reactive compound captured by a well in heterogeneous porous formations. The hazard attenuation factor is defined as the ratio between the hazard index HI at a detection well and at the source. Heterogeneity of the aquifer is represented through the multi‐indicator model (a collection of blocks of independent permeability) while flow and transport are solved by the means of the self‐consistent approach that is able to deal with any degree of heterogeneity. Due to formation heterogeneity, HI is a random variable and similar for hazard attenuation index. The latter can be fully characterized by its cumulative distribution function (CDF), which in turn can be related to the statistics of the travel time of solute particles, from the source to the detection well. The approach is applied to the case of a solute which undergoes decay and a well with a screen much smaller than the correlation scale of hydraulic conductivity. The results show that the probability of exceeding a given acceptable threshold of the hazard index is significantly affected by the level of heterogeneity comparable to the one observed for the MADE site, and the distance between the source and the well.