Geoscience Reference
In-Depth Information
increasing demand for human settlement, and poor enforcement of land use policies
and monitoring of land use conversion, incidence of desertification, land degradation
and drought has become a prominent and recurring environmental problem.
2.1
Land Degradation
The nature of land degradation in the Philippines can be summed up as being in two
broad categories:
2.1.1
Accelerated Water Erosion
Deforestation and unsustainable land management in the uplands make topsoil
vulnerable to go with water runoff after a rainfall event. Once the rich top soil is
gone, this creates a cycle of poverty, resource exploitation, and under development.
2.1.2
Nutrient Mining and Soil Fertility Decline
There is declining trend in productivity despite fertilizer applications under modern
intensive farming methods.
About 45 % of the arable lands in the Philippines have been moderately to
severely eroded, triggering the movement of subsistence farmers to marginal lands
with the hope of meeting their day to day food requirement. Approximately 5.2 Mha
are seriously eroded resulting to 30-50 % reduction in soil productivity and water
retention capacity. This situation will predispose the degraded lands to drought and
other water availability problems.
3
Forms, Extent and Distribution of Land Degradation
3.1
Soil Erosion
The most common type of land degradation in the Philippines is soil erosion posing
a detrimental effect on soil physico-chemical and biological properties. This makes
the land less suitable to crop production or in some cases of severe erosion result to
total loss of soil less suitable to crop production or in some cases of severe erosion
result to total loss of soil productivity. Moreover, it can disrupt utilization of public
utilities. There are various degrees/classes of soil erosion ranging from no apparent
to severe in the Philippines (Table
15.2
).
Search WWH ::
Custom Search