Use of 7Be to document soil erosion associated with a short period of extreme rainfall
Use of 7Be to document soil erosion associated with a short period of extreme rainfall
Authors
Sepúlveda Varas, Alejandra
Schuller, Paulina
Walling, Desmond E.
Castillo, Alejandra
Schuller, Paulina
Walling, Desmond E.
Castillo, Alejandra
Authors
Date
2013-05-02
Datos de publicación:
10.1016/j.jenvrad.2007.06.010
Keywords
Cesio-137 - Erosión - Precipitación intensa - Cero labranza - Quema de residuos
Collections
Abstract
Intensification and expansion of agricultural production since the 1970s have increased soil erosion problems in south-central
Chile. Quantitative information on soil loss is needed for erosion risk assessment and to establish the effectiveness of improved land
management practices. Since information from traditional sources, such as erosion plots, is limited, attention has been directed to
the use of environmental radionuclides for documenting erosion rates. Cs-137 has been successfully utilised for this purpose, but
only provides information on medium-term erosion rates. There is also a need to document event-related soil erosion. This paper
outlines the basis for using 7Be measurements to document short-term erosion and reports its successful use for quantifying the
erosion that occurred within an arable field, as a result of a period of heavy rainfall (400 mm in 27 days) occurring in May
2005. The study field had been under a no-till, no-burning system for 18 years, but immediately prior to the period of heavy rainfall
the harvest residues were burnt. The erosion recorded therefore reflected both the extreme nature of the rainfall and the effects of the
burning in increasing surface runoff and erosion. The sampled area corresponded to that used previously by the authors to document
the medium-term erosion rates associated with both conventional tillage and the subsequent switch to a no-till system. Comparisons
between the erosion documented for the period of heavy rainfall in 2005 with these medium-term erosion rates permits some
tentative conclusions regarding the importance of extreme events and the impact of burning in increasing the erosion associated
with the no-till system.