Land use impact on soil erosion at different scales in the Brazilian semi-arid

Julio Cesar Neves dos Santos, Eunice Maia de Andrade, Pedro Henrique Augusto Medeiros, Maria João Simas Guerreiro, Helba Araújo de Queiroz Palácio

Resumo


Erosion and sediment transport processes are strongly dependent on the spatial scale and land use. The objective of this study is to analyse the effects of slash and burn of vegetation followed by grass cultivation for grazing, on the hydrological and sedimentological behaviour at different spatial scales in a semiarid region in Brazil. Rainfall, runoff and soil loss were measured during three years (total of 116 rainfall-runoff events) at three spatial scales: 1 m² and 20 m² plots and 2.8 ha watershed. During the first year (2009) the native dry tropical forest/Caatinga vegetation was maintained, whereas on the following years (2010 and 2011) the original vegetation was cleared using slash and burn techniques to grow pasture (Andropogon gayanus Kunt). Annual runoff coefficient is highest at the 20 m² plot among the investigated scales. Runoff presented the same trend in all years. Sediment yield was strongly influenced by the land cover. Slash, burn and pasture cultivation strongly impacted sediment yield: the first two events after the land cover change yielded roughly ten times more sediment than similar events in the years with native cover and after grass development. The change was most noticeable at the catchment scale due to erosion along the stream, redefining the drainage network.


Palavras-chave


Hydrological and sedimentological behaviour; Soil loss; Scale effect

Texto completo:

PDF

Referências


BAGARELLO, V.; FERRO, V. Plot-scale measurement of soil erosion at the experimental area of Sparacia (southern Italy). Hydrological Processes, v. 18, p. 141-157, 2004.

BAKKER, M. M. et al. Soil erosion as a driver of land-use change. Agriculture, Ecosystems & Environment, v. 105, p. 467-481, 2005.

BOIX-FAYOS, C. et al. Causes and underlying processes of measurement variability in field erosion plots in Mediterranean conditions. Earth Surf Processes Landforms, v. 32, p. 85–101, 2007.

BOIX-FAYOS, C. et al. Concise review of interrill erosion studies in SE Spain (Alicante and Murcia): erosion rates and progress of the knowledge from the 1980s. Land Degradation and Development, v. 16, p. 517-528, 2005.

CERDAN, O. et al. Rates and spatial variations of soil erosion in Europe: a study based on erosion plot data. Geomorphology, v. 122, p. 167-177, 2010.

CHAPLOT, V. et al. Dynamic modelling for linear erosion initiation and development under climate and land-use changes in northern Laos. Catena, v. 63, p. 318–328, 2005.

CHAPLOT, V.; LE BISSONAIS, Y. Field measurements of interrill erosion under different slopes and plot sizes. Earth Surf Processes Landforms, v. 25, p. 145–153, 2000.

DE VENTE, J.; POESEN, J. Predicting soil erosion and sediment yield at the basin scale: scale issues and semiquantitative models. Earth-Science Reviews, v. 71, p. 95-125, 2005.

DLAMINI, P. et al. Controlling factors of sheet erosion under degraded grasslands in the Sloping lands of KwaZulu-Natal, South Africa. Agricultural Water Management, v. 98, p. 1711-1718, 2011.

FOSTER, G. R. et al. Conversion of the Universal Soil Loss Equation the SI metric units. Journal of Soil and Water Conservation, v. 36, p. 355-359, 1981.

GAFUR, A. et al. Runoff and losses of soil and nutrients from small watersheds under shifting cultivation (Jhum) in the Chittagong Hill Tracts of Bangladesh. Journal of Hydrology, v. 274, p. 30-46, 2003.

GALLART, F. et al. Hydrological processes and their seasonal controls in a small Mediterranean mountain catchment in the Pyrenees. Hydrology and Earth System Sciences, v. 6, n. 3, p. 527-537, 2002.

LE BISSONAIS, Y. et al. Crusting, runoff and sheet erosion on silty loamy soils at various scales and upscaling from m2 to small catchments. Soil and Tillage Research, v. 46, p. 69–80, 1998.

MAYOR, A. G. et al. Scale-dependent variation in runoff and sediment yield in a semiarid Mediterranean catchment. Journal of Hydrology, v. 397, p. 128-135, 2011.

MEDEIROS, P. H. A. et al. Modelling spatio-temporal patterns of sediment yield and connectivity in a semi-arid catchment with the WASA-SED model. Hydrological Sciences Journal, v. 55, p. 636-648, 2010.

MEDEIROS, P. H. A.; ARAÚJO, J. C. de. Temporal variability of rainfall in a semiarid environment in Brazil and its effect on sediment transport processes. Journal of Soils and Sediments, v. 14, p. 1216-1223, 2014.

MERRITT, W. S. et al. A review of erosion and sediment transport models. Environmental Modelling & Software, v. 18, p. 761-799, 2003.

OAKES, E. G. M. et al. Controls on a scale explicit analysis of sheet erosion. Earth Surf Processes Landforms, v. 37, p. 847-854, 2012.

ORCHARD, C. M. et al. Spatial and temporal variations of overland flow during rainfall events and in relation to catchment conditions. Hydrological Processes, v. 27, p. 2325-2338, 2013.

PODWOJEWSKI, P. et al. Influence of grass soil cover on water runoff and soil detachment under rainfall simulation in a sub-humid South African degraded rangeland. Earth Surf Processes Landforms, v. 36, p. 911-922, 2011.

PUIGDEFÁBREGAS, J. The role of vegetation patterns in structuring runoff and sediment fluxes in drylands. Earth Surf Processes Landforms, v. 30, p. 133-147, 2005.

SADEGHI, S. H. R. et al. Plot sizes dependency of runoff and sediment yield estimates from a small watershed. Catena, v. 102, p. 55-61, 2013.

SANTOS, J. C. N. et al. Runoff and soil and nutrient losses in semiarid uncultivated fields. Revista Ciência Agronômica, v. 42, n. 3, p. 813-820, 2011.

SCHULER, J.; SATTLER, C. The estimation of agricultural policy effects on soil erosion - an application for the bio-economic model MODAM. Land Use Policy, v. 27, p. 61-69, 2010.

THOMAZ, E. L. The influence of traditional steep land agricultural practices on runoff and soil loss. Agriculture, Ecosystems and Environment, v. 130, p. 23-30, 2009.

VERHEIJEN, F. G .A. et al. Tolerable versus actual soil erosion rates in Europe. Earth-Science Reviews, v. 94, p. 23-38, 2009.

YAN, L. J. et al. Effects of transport capacity and erodibility on rill erosion processes: a model study using the Finite Element method. Geoderma, v. 146, p. 114-120, 2008.




Revista Ciência Agronômica ISSN 1806-6690 (online) 0045-6888 (impresso), Site: www.ccarevista.ufc.br, e-mail: ccarev@ufc.br - Fone: (85) 3366.9702 - Expediente: 2ª a 6ª feira - de 7 às 17h.