Spatial variability of the rainfall erosivity in southern region of Minas Gerais state, Brazil

Ciência e Agrotecnologia

Regimeire Freitas Aquino²  Marx Leandro Naves Silva¹  Diego Antonio França De Freitas¹  Nilton Curi¹  Carlos Rogério De Mello¹  Junior Cesar Avanzi¹ 

[1] ,Instituto Federal de Educação, Ciência e Tecnologia do Sudeste de Minas GeraisSão João Del Rei MG ,Brasil

关键词: Erosive potential;    soil sustainability;    kriging;    Potencial erosivo;    sustentabilidade do solo;    krigagem;   

DOI  :  10.1590/S1413-70542012000500006

来源: SciELO

【 摘 要 】

Rainfall erosivity and its spatial variability were studied for 54 pluviometric stations in Southern Minas Gerais State (48º00' - 44º00'W; 23º50' - 20º00'S), aiming to plan the land-use strategies. Therefore, erosivity factor was determined for the pluviometric stations, using long-term rainfall data sets obtained along with the Brazilian National Water Agency- ANA, which varied from 15 to 40 years. The monthly and annual erosivity indexes were generated using Fournier equation for Lavras, MG and the spatial distribution of rainfall erosivity was studied on the basis of geostatistical approaches considering only the distance which separates them, developing the isotropic experimental semivariogram. The semivariogram adjustment was done based on the Weighted Least Squares method and the spatial dependence degree. Once the structure and the semivariogram adjustment were defined, the ordinary kriging maps were created, providing erosivity spatial behavior in Southern Minas Gerais. It was observed that the Southern Minas Gerais presents high erosivity patterns, ranging from 5,145 to 7,776 MJ mm ha-1 h-1 year-1, in Ijaci (north of region) and Itajubá (southern region), respectively. Besides, it was verified that the erosivity indexes are intensely influenced by the topography, associated with climatic conditions. Higher erosivity is connected to areas with a higher altitude, such as along the Mantiqueira Range Mountain, and on high plateaus and mountain ranges in the North-Central part of the region. The geostatistical approach using long-term rainfall data in Southern region of Minas Gerais state, which is a relatively heterogeneous region in terms of altitude, soil depth and slope, showed to be adequate to the proposal of this study.

【 授权许可】

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