International Activities Related to Dryland Degradation Assessment and Drought - Monitoring and Predicting Agricultural Drought: A Global Study - page 422

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tion is also severe and widespread in Asia, Latin America, as well as other
regions of the globe. Continuous land degradation is accelerating the loss
of agricultural productivity and food production in the world. Over the
next 50 years, food production needs to triple in order to provide a nu-
tritionally adequate diet for the world's growing population. This will be
difficult to achieve even under favorable circumstances. If land degradation
is not checked and reversed, food yields in many affected areas will decline,
and, as a result, malnutrition, starvation, and ultimately famine may occur.
This chapter provides state-of-the-art information on international activi-
ties related to dryland degradation assessment and drought early warning.

Fa ctors Affecting Land Degradation
Many processes, simple or complex, that arise from human activities and
habitation patterns are responsible for land degradation. These processes
include soil erosion caused by wind and/or water; deterioration of the phys-
ical, chemical, biological, or economic properties of soil; and long-term
loss of natural vegetation. In addition, overgrazing, excessive irrigation,
and intensive tillage and cropping have been among some of the other fac-
tors responsible for land degradation. Some of these causes are related to
poverty and food insecurity among the people who inhabit the land.

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M onitoring Land Degradation
Previous and existing approaches to assessing and monitoring land degra-
dation have not been effective because the system for collecting and dis-
seminating information and adoption of sustainable land use and manage-
ment practices have been weak in the dryland regions that represent many
poor countries. Some countries have databases on the biophysical aspects
of land and land resource use and degradation and on various aspects of
society and the economy. However, these data are usually not comparable
in terms of scale, are often not compatible, and certainly are not integrated
and interlinked enough to facilitate decision-making and policy-making.
Information about land degradation is rarely standardized or integrated
into local planning and management processes. At the international level,
this information is not comparable and has insufficient resolution for defin-
ing and implementing regional and national action plans (RAPs, NAPs) for
international conventions such as the United Nations Conference on En-
vironment and Development (UNCED) held in Rio de Janeiro, Brazil, in
1992.
The earliest assessment of land degradation was biophysical in nature
and was derived at the farm level using the universal soil loss equation
(Wischmeier, 1976). Early attempts to assess land degradation on larger
scales, such as at river basin and bioregional scales, using a combination
of remote sensing and ground-based techniques, encountered difficulties
mainly due to lack of financial resources and technical limitations. In 1979,

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