Geography Reference
In-Depth Information
identifying the extent of variability for soil properties based on their CV
values, where CV values of 0-15, 16-35 and >36 indicate little, moderate and
high variability, respectively.
Typical ranges of CV values of salient soil properties are reported in the
literature (Jury, 1986; Jury et al., 1987; Beven et al., 1993; Wollenhaupt et al.,
1997).
6.
GIS
F
RAMEWORK FOR
G
ROUNDWATER
V
ULNERABILITY
M
APPING
6.1. Groundwater Vulnerability Concept
The groundwater vulnerability concept, evolved during end of the 1960s
in France, aimed at creating awareness of groundwater contamination (Margat,
1968; Albinet and Margat, 1970). The vulnerability concept in hydrogeology
began to be widely used in the 1980s (Haertle, 1983; Aller et al., 1987). It was
defined as the possibility of percolation and diffusion of contaminants from
the ground surface into the groundwater system.
Groundwater vulnerability deals only with the hydrogeological setting and
does not include pollutant attenuation. Initially, the term ‗vulnerability' was
meant as relative susceptibility of aquifers to anthropogenic pollution without
any formal definition. Later on, the concept began to mean different things to
different people. Margat (1968) used the term ‗vulnerability' to mean the
degree of protection that the natural environment provides against the ingress
of pollutants to groundwater. Thereafter, several definitions of vulnerability
have been proposed. Foster (1987) defined aquifer pollution vulnerability as
the intrinsic character of the strata separating the saturated aquifer from the
immediately overlying land surface which determines its sensitivity to being
adversely affected by a surface applied (anthropogenic) contaminated load.
National Research Council (1993) defined groundwater ‗vulnerability' to
contamination as the tendency or likelihood for contaminants to reach a
specified position in the groundwater system after introduction at some
location above the uppermost aquifer. Vrba and Zaporocec (1994) defined
‗vulnerability' as an intrinsic property of groundwater, depending on its
susceptibility to natural and/or human impact. The groundwater vulnerability
is a specific characteristic of the underlying groundwater system and cannot be
practically measured in the field.
