Geoscience Reference
In-Depth Information
⎛
⎜
⎞
⎟
⋅
dec
llp
⋅
frac
llp
dec
slp
⋅
frac
slp
)
∗
frac
sb
(14)
(
)
+ 1−
frac
sb
(
θ
i
=
1
−
−
1
−
frac
sb
dec
llp
+
r
dec
slp
+
r
frac
slp
=
1
−
frac
llp
(15)
epc
i
=
pc
i
⋅
leak
i
(16)
Net Present Value of Agriculture
The net present value of agriculture (A
i
) is calculated with a two-factor Cobb-Douglas
production function (equation 17). It depends on the agriculture suitability and the
population density. A high agriculture suitability and a high population density causes
high agricultural values. The value ranges between a given minimum and a maximum
land price. The parameters α
i
and γ
i
determine the relative importance of the agricul-
ture suitability and the population density and ν
i
determines the price level for land.
The agriculture suitability and the population density are normalized between 1 and
10.
SAgS
i
α
i
SPd
i
γ
i
A
i
=
v
i
⋅
⋅
(17)
10
AgS
i
≥
0.5
⎩
(18)
SAgS
i
=
1
+
9
⋅
AgS
/ 0.5
AgS
i
<
0.5
(
)
− ln
PL
min
(
)
ln
PL
max
(19)
α
i
=
()
2
⋅
ln 10
γ
i
= α
i
(20)
Decision of Deforestation
The deforestation decision is expressed by equation (21). It compares the agricultural
and forestry net present values corrected by values for deforestation and carbon se-
questration. For the deforestation decision the amount of removed biomass from the
forest is an important variable. The agricultural value needed for deforestation increas-
es with the amount of timber sales and its concomitant flow to the wood products pool
(HWP) pool. On the other hand the agriculture value will be decreased by the amount
of released carbon to the atmosphere. This mechanism is expressed by a deforestation
value (DV
i
, equation 22). The model also allows for compensation of ancillary benefits
from forests. This additional income is modeled either as a periodical income or a one
time payment and will increase the forestry value by (IP
i
). If it is a periodic payment it
has to be discounted, which has been done in equation (23).
Yes
A
i
+
DV
i
>
F
i
⋅
H
i
+
IP
i
⎧
⎪
∧
not
Pr
otected
(21)
Defor
=
⎨
No
A
i
+
DV
i
≤
F
i
⋅
H
i
+
IP
i
⎪
⎪
∨
Pr
otected
⎩
