Project funded
by theEU–DGEnvironment
L
andsurfacerelevant
forapplication
Artificial surface
Agriculture land
Forest and semi-natural areas
Wetlands
F
inancialcosts
(C
apital
,
operation
&
maintenance
)
Costs associated with afforestation of headwater catchments include the cost
of tree
planting
and steps necessary to ensure seedling establishment.
Land
acquisition
costs can range from nil to extremely high depending on whether
the land is already owned by the state, and if it is not, what compensation is
needed for expropriation.
D
esign
The creation or maintenance of headwater forest catchments is dependent on
large scale
land conversion or preservation. Typically, an area of several ha to
tens of km2 must be afforested for there to be significant downstream benefits.
The most beneficial headwater catchments for afforestation are likely to be those
located
upstream of urban or peri-urban
areas where flood risk reduction
or improvements in water quality are desired.
S
cale
Because of the fractal nature of rivers,
headwater forests can have a beneficial
effect at almost all spatial scales. Typical-
ly, any catchment smaller than 1km
2
is
considered to be a headwater catchment.
Headwaters are
source areas
for rivers and streams. Forests in headwater areas can thus have a beneficial role for water quantity and quality. Indeed, forest
soils generally have better
infiltration
capacity than other land cover types, acting as a “sponge”, slowly releasing rainfall. In areas of high relief, afforestation
of headwater catchments can contribute to slope stabilisation and may reduce the risks associated with landslides.
Targeted land use conversion through afforestation
(F5) could transform artificial or agricultural surface
to headwater forest catchments.
FORESTRY
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