R
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\(R=\sum_{i=1}^{12}{1.735\times 10^{\left[1.5lg\left(\frac{P_{i}^{2}}{P}\right)-0.08188\right]}}\)
(2)
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Pi: mean monthly rainfall (mm)
P: mean annual rainfall (mm)
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Prasannakumar et al. (2011)
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K
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\(K=0.1317\times K_{1}\times K_{2}\times K_{3}\times K_{4}\) (3)
And,
\[K_{1}=0.2+0.3exp\left\{-0.0256SD\left[1.0-\left(SI/100\right)\right]\right\}\]
\[K_{2}=\left[SI/\left(CL+SI\right)\right]^{0.3}\]
\[K_{3}=1.0-\left\{0.25C/\left[C+exp\left(3.72-2.95C\right)\right]\right\}\]
\[K_{4}=1.0-\left\{0.7SN/\left[SN+exp\left(-5.51+22.9SN\right)\right]\right\}\]
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SD: sand fraction (%)
SI: silt fraction (%)
CL: clay fraction (%)
C: organic carbon fraction (%)
SN: 1-SD/100
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Yang et al. (2003)
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L&S
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\(L=\left(\lambda/22.13\right)^{m}\) (4)
\(S=\left\{\begin{matrix}10.8sin\theta+0.03\ \ \theta<9\%\\
16.8sin\theta-0.50\ \ \theta\geq 9\%\\
\end{matrix}\right.\ \) (5)
And,
\[m=\beta/\left(1+\beta\right)\]
\[\beta=sin\theta/\left[3\left(\text{sinθ}\right)^{0.8}+0.56\right]\]
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λ: horizontal projection slope length
m: variable slope length exponent
β: a factor that varies with slope gradient
θ: slope angle (%).
|
McCool et al. (1989)
Zhang et al. (2013)
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C
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\(C=\left\{\begin{matrix}1\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0\leq FVC\leq 4.9\%\\
0.221-0.595lgFVC\ \ \ \ \ FVC\geq 4.9\%\\
\end{matrix}\right.\ \) (6)
And,
\[FVC=\left(EVI-\text{EVI}_{\min}\right)/\left(\text{EVI}_{\max}-\text{EVI}_{\min}\right)\]
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FVC: the fractional vegetation cover
EVImin and EVImax: the minimum
and maximum EVI values of the whole study area during the study
period
|
Liu et al. (1999)
|