Definition of tolerable soil erosion values

Definição de valores toleráveis de erosão

SEÇÃO VI - MANEJO E CONSERVAÇÃO DO SOLO E DA ÁGUA

Definition of tolerable soil erosion values(¹)

Definição de valores toleráveis de erosão

G. Sparovek^I; Q. Jong Van Lier^II

^IProfessor, Department of Soil Science, Universidade de São Paulo, Caixa Postal 9, CEP 13418 900 Piracicaba (SP), Brazil. CNPq researcher. Email: [e-mail]

^IIProfessor, Department of Soil Science, Universidade Federal do Rio Grande do Sul, Caixa Postal 776, CEP 90001 970 Porto Alegre (RS), Brazil. CNPq researcher. Email: [e-mail]

SUMMARY

Although the criteria for defining erosion tolerance are well established, the limits generally used are not consistent with natural, economical and technological conditions. Rates greater than soil formation can be accepted only until a minimum of soil depth is reached, provided that they are not associated with environmental hazard or productivity losses. A sequence of equations is presented to calculate erosion tolerance rates through time. The selection of equation parameters permits the definition of erosion tolerance rates in agreement with environmental, social and technical needs. The soil depth change that is related to irreversible soil degradation can be calculated. The definition of soil erosion tolerance according to these equations can be used as a guideline for sustainable land use planning and is compatible with expert systems.

Index terms: Erosion tolerance, soil depth change, land use planning.

RESUMO

Apesar dos critérios utilizados para a definição de valores toleráveis de erosão estarem bem definidos, os limites geralmente utilizados não são consistentes com as condições naturais, econômicas ou tecnológicas. Valores superiores à taxa de renovação do solo podem ser aceitos apenas até ser alcançada uma profundidade mínima do solo, associado ao fato de não poder ser aceita a degradação ambiental ou a perda de produtividade das culturas. É apresentada uma seqüência de equações para o cálculo da erosão tolerável ao longo do tempo. A seleção dos parâmetros das equações permite a definição da tolerância de perda de solo em concordância com os condicionantes ambientais, sociais e técnicos. A alteração da profundidade do solo que se relaciona com a sua degradação irreversível pode ser calculada. A definição da tolerância de perda de solo por estas equações pode servir de subsídio para o planejamento racional e sustentável do uso das terras e é compatível com sistemas automatizados.

Termos de indexação: tolerância de perda de solo, alteração de profundidade do solo, planejamento do uso da terra.

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

Received for publication in July 1996

Approved in April 1997

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(1

) Paper presented at the 24

^th Brazilian Soil Science Congress, Goiânia, 1993.

Publication Dates

• Publication in this collection
  08 Oct 2014
• Date of issue
  Sept 1997

History

• Accepted
  Apr 1997
• Received
  July 1996