ST13-Estrategia para el manejo de suelos.pdf - Unesco

SUMMARY
In order to improve catchment management, it is necessary: 1) to understand both the physical
characteristics (such as morphological and relief features, climatic characteristics, soils and
land use or land cover), and the socio-economic characteristics of the catchment; 2) to be able
to predict objectively the catchment’s response to a major (especially extreme) rainfall or
sudden snowmelt event; 3) to understand the current physical and socioeconomic state of the
catchment, considering: a) its potential production and development possibilities, and b) its
characteristic stresses and current degradation processes; 4) to set up clearly the aims to be
achieved through the adopted improvement measures; and 5) to understand the appropriate
improvement techniques and their performance. All these aspects have been developed as
strategies in this Guidelines for improved catchment management.
The document begins (Section 1) by defining the main effects that major rainfall events can
produce in a catchment, and their possible impacts on human populations. The origins are
described of traditional Water & Forest Management measures for protecting against such
events and for maintaining a sustainable land use in the catchment. A state-of-the-art review
is presented of the most appropriate measures and techniques for catchment Water & Forest
Management and Restoration in different natural scenarios, based on elevation, relief and
potential vegetation.
In Section 2, the role of forests in the water and sediment cycles, and their potential for
controlling the impacts of erosion, sediment transport and flood flows resulting from major
rainfall events are analyzed. Also the effect of forests on water resources availability and
supply during the periods between extreme events is assessed.
In the third section, the framework of Water & Agricultural Management and Water & Forest
Restoration within the EPIC FORCE Project is presented. Specific aspects of both concepts
are explained and the main objectives are identified as: 1) catchment protection, to reduce the
flood and sediment effects that could be produced by major rainfall events, both moderate and
extreme, or sudden snowmelt; and 2) optimal management of water and land resources use in
the catchment, i.e., its sustainable use.
In the fourth section, the economic analysis of a catchment’s Water & Agricultural
Management is considered in the context of the foregoing objectives, i.e.: 1) catchment
protection; and 2) the sustainable use of resources.
Section 5 is focused on a preliminary application of the Water & Agricultural Management
framework within the EPIC FORCE Project, for different Latin American catchments located
in different geographic environments. The Río Pejibaye (Costa Rica) and Río Chanchán and
its tributary Río Guabalcón (Ecuador) catchments represent the intermediate and high
mountain tropical area of Latin America; and the Buena Esperanza stream catchment, located
in Tierra de Fuego (Argentina), represents the Andean-Patagonian region. In addition, best
practices for the management of fast-growth forest plantation in the Valdivia region of Chile
are reviewed, in support of environmental certification for forestry operations.
The document closes with a set of conclusions and recommendations, amongst which, must
be highlighted one that rejects the traditional wisdom: that forest protects against every
torrential event or, more clearly, the lack of forest is the cause of every disaster and loss.
Forests protect efficiently against the predictable effects of moderate events (i.e., those with
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