218
Table 7.1 Main indices for evaluation of pesticide leaching potential proposed in the literature
Index
Equation
Interpreted criteria
References
Hamaker’s RF
(Hamaker’s retardation factor)
RF
=
+
⋅
⋅ ⋅
−
(
)
{
}
−
1
1
1
0 67
(
.
Koc foc Pb
θ
0.64–1, high;
0.35–0.64, moderate; 0.1–0.35, low;
< 0.1, very low
Hamaker
(1975)
Brigg’s RF
(Briggs’s retardation factor)
log
l og
log
.
1
1
1 33
RF
−





 =
( )+ ( )−
Kow
O M
0.90–1.0, class 5 (very high); 0.89–0.65, class 4
(high); 0.64–0.35, class 3 (moderate); 0.34–0.10,
class 2 (low); 0–0.09, class 1 (very low)
Briggs
(1981)
Organic carbon-water partition
coefficient
K
K
oc
d
=
⋅100
Organic matter%
0–50 very high; 50–150 high; 150–500
medium; 500–2000 low; 2000–5000 slight;
>5000 immobile
McCall
et al. (1981)
LEACH
(leaching index)
LEACH
=
⋅
⋅
WS DT
V K
p
D C
50
Lower values mean lower leaching potential Laskovski
et al. (1982)
AF
(attenuation factor)
AF
RF
=
−
⋅ ⋅ ⋅
⋅






exp
.
/
0 693
1 2
d
q t
FC
θ
0 to
−1, high;
−1 to
−2, moderate;
−2 to
−3, low;
−3 to
−4, very low;
<
−4, nonleachable
Rao
et al. (1985)
GUS
(groundwater ubiquity score)
GUS = (logDT
50 ) ∙ (4 −  log K
DC )
>2.8, leachable;
1.8–2.8, intermediate;
<1.8, nonleachable
Gustafson
(1989)
LPI
(leaching potential index)
LPI
RF
=
⋅
⋅
⋅ ⋅ ⋅
1000
0 693
50
DT g
L
Q
fc
.
LPI > 90, very high; LPI = 75–89, high;
LPI = 50–74, moderate; LPI = 25–49, low;
LPI = 0–24, very low
Meeks and Dean
(1990)
HI
(Hornsby index)
HI
=





 ⋅
Koc
t
1 2
10
/
≤10, high;
≥2000, low
Hornsby
(1992)
PLP
(pesticide leaching potential
index)
PLP
value =
⋅ ⋅
R F t
Koc
1 2
/
PLP
index  = (logPLP
value ) ∙ (14.3) + 57
90–100, very high;
70–89, high;
50–69, moderate;
30–49, low;
0–29, very low
Warren and Weber
(1994)
B. Kovacevik et al.