Modeling of water erosion by the erosion potential method in a pilot subbasin in southern Minas Gerais

Abstract

Soil losses due to water erosion threaten the sustainability of agriculture and the food security of current and future generations. This study estimated potential soil losses and sediment production under different types of land uses in a subbasin in the Municipality of Alfenas, southern Minas Gerais, southeastern Brazil. The objective of this research was to evaluate the application of the Potential Erosion Method by the Intensity of Erosion and Drainage program and correlate the findings with the results obtained by the Revised Universal Soil Loss Equation as well as geoprocessing techniques and statistical analyses. In the Potential Erosion Method, the coefficient indicating the mean erosion intensity was 0.37, which corresponded to erosion category IV and indicated weak laminar erosion processes, and the total soil loss was 649.31 Mg year -1 and the mean was 1.46 Mg ha -1 year -1 . These results were consistent in magnitude with those obtained in the Revised Universal Soil Loss Equation, which estimated a mean soil loss of 1.52 Mg ha -1 year -1 and a total soil loss of 668.26 Mg year -1 . The Potential Erosion Method suggests that 1.5% of the area presents potential soil losses above the soil loss tolerance limit, which ranged from 5.19 to 5.90 Mg ha -1 year -1 , while the Revised Universal Soil Loss Equation indicated that 7.3% of the area has potential soil losses above the limit. The maximum sediment discharge was 60 Mg year -1 , meaning that 9.3% of the total soil loss reached the depositional areas of the river plains or watercourses. The Potential Erosion Method was efficient in the evaluation of water erosion in tropical soils, and the results were consistent with models widely employed in the estimation of soil losses. Thus, the model can support the evaluation of soil losses in Brazil and is a robust tool for evaluating the sustainability of agricultural activities.

Estimates of soil losses by the erosion potential method in tropical latosols

“…The observed mean was close to that found by Mendes Júnior et al (2018), which evaluated the potential soil losses with the RUSLE method in the same region obtained a value of 1.52 Mg ha -1 year -1 . The data also agree with the results obtained by Tavares et al (2019), who observed losses of 1.46 Mg ha -1 year -1 using EPM. The proximity of the results with the values of the literature indicates precision and reliability in the estimation performed by the method.…”

“…The parameters used in the T calculations are present in table 4. The T values corroborate with the results found by Tavares et al (2019) for a dystrophic Red Latosol in the south of Minas Gerais. However, Cândido et al (2014) studying a dystrophic Red Latosol in the Mato Grosso do Sul State found values of 9 to 10 Mg ha -1 year -1 .…”

“…tropical geographic and climatic conditions (Mendes et al, 2018;Tavares et al, 2019). Furthermore, the EPM application already fulfilled the purpose of being an accessible predictive tool to estimate soil losses by water erosion with low cost and less complex than field experiments.…”

“…Researches on the mechanisms and intensity of water erosion in the coffee crop are limited (Prochnow et al, 2005;Carvalho et al, 2007;Scharrón;Sánchez, 2017;Mendes Júnior et al, 2018;Tavares et al, 2019). Thus, it is necessary to adopt instruments that provide erosion data in tropical areas under coffee cultivation to proposing possible mitigating practices (Sánchez et al, 2015).…”

“…The Erosion Potential Method (EPM) (Gavrilovic, 1988) is a soil loss estimation model used in the former Yugoslavia, Balkan regions, Eastern Europe, Middle Orient, Italy, North Africa and, more recently, in Brazil (Stefanidis;Stathis, 2018;Tavares et al, 2019). EPM has acceptable accuracy and provides similar results to established methods such as the Revised Universal Soil Loss Equation (RUSLE) (Renard et al, 1997) and the Universal Soil Loss Equation (USLE) (Wischmeier;Smith, 1978), with the advantage of having a simple structure and requiring little input data (Efthimiou et al, 2016;Tavares et al, 2019). Another advantage of the EPM is the retention coefficient (R u ) (Gavrilovic, 1988), that provides an estimate of the fraction of the eroded sediment that reaches the water body system and the fraction that was deposited in relief depressions, which is not possible by USLE and RUSLE.…”