ABSTRACT Water erosion is the process of disaggregation and transport of sediments, and rainfall erosivity is a numerical value that expresses the erosive capacity of rain. The scarcity of information on rainfall erosivity makes it difficult or impossible to use to estimate losses occasioned by the erosive process. The objective of this study was to develop Artificial Neural Networks (ANNs) for spatial interpolation of the monthly and annual values of rainfall erosivity at any location in the state of Rio […]

Rainfall erosivity represents the potential of rainfall causing soil erosion. This study aimed to develop a software to estimate rainfall erosivity in the state of Minas Gerais based on Artificial Neural Networks (ANNs). The annual value of the rainfall erosivity is given by the sum of the monthly values of the erosivity indexes EI30 or KE > 25. Two methodologies were used to estimate the kinetic energy for each index. Thus, four erosivity values were evaluated for each month, resulting […]

Accelerated soil erosion is a serious global problem that degrades agriculture lands. Since erosion research is normally expensive and time-consuming, the use of models allows to estimate soil losses at locations and under conditions not represented directly in the research. The objective of this study was to estimate the soil erosion in an area intensively cultivated with sugarcane near the city of Piracicaba, São Paulo, contributing to diagnose the current land uses aimed at controlling erosion. The study was carried […]

Knowledge on rainfall erosivity (R) of particular sites is fundamental for soil loss estimation by the Universal Soil Loss Equation (USLE) and therefore highly important in conservation planning. In order to obtain the R value estimates for places where it is unknown, an artificial neural network (ANN) was developed for the state of São Paulo, and its accuracy compared with the Inverse Distance Weighted (IDW) interpolation method. The developed ANN presented a smaller mean relative error in the R estimation […]

The use of the Universal Soil Loss Equation to predict erosion losses and for conservation planning requires an evaluation of index values of local rainfall erosivity. As a contribution to knowledge on these indexes in the coastal zone of Ceará State, the objectives of this study were: (a) to determine the R factor and the annual EI30 index values, its monthly distribution, probability of occurrence and return periods in Fortaleza, Ceará State, Brazil for the period of 1962 to 1981, […]

The correlation between the erosivity index EI30 and the rainfall coefficient (Rc) for the period of 1962 to 1981, in Fortaleza (CE), was evaluated to analyze the feasibility of the Rc use to update erosivity values from 1982 to 2000 in this county. An equation that could be used to estimate erosivity in other locations of the coastal region of Ceará State, where there are no rain gauge charts available, was a second aim. A high correlation coefficient (r = […]

Soil and water loss data under natural rainfall in Lages, Santa Catarina State (Brazil), from November 1992 to October 1998, were utilized to calculate the soil loss ratio (SLR) and C factor for the Universal Soil Loss Equation (USLE) under three soil tillage systems for corn and oat in rotation with other crops. The studied treatments were: plowing followed by disking twice (P + D), chiseling plus disking (C + D) and no-tillage (NT)/direct sowing, cultivated with corn (Zea mays) […]

Soil and water loss under natural rainfall in Lages (SC – Brazil), from November 1992 to October 1998, were used to calculate soil loss ratio (SLR) and C factor for the Universal Soil Loss Equation (USLE) under three soil tillage systems and two crops. Treatments studied were plowing followed by two disking (P+D), chiseling plus disking (C+D) and no-tillage (NT), cultivated in succession with soybean (Glycine max) and wheat (Triticum aestivum L.), compared to a check plot: plowing followed by […]

A set of 874 erosive individual rainfall occurrences was selected from a continuous serie of twenty-three years of recording rain gauge data. All the selected rainfall occurrences were analized. The rainfall erosivity factor computed was 7074 MJ mm ha-1 h-1 y-1, which is expected to occur at least once every 2.33 years, with a probability of occurrence of 42.92%. The values of the annual erosivity indexes at that site expected for the return periods of 2, 5, 10, 20, 50, and 100 years, were respectively 6,696, 8,730, 10,076, […]

Soil loss tolerance refers to the maximum rate of annual soil loss that will permit crop productivity to be obtained economically and indefinitely. Besides the usual form, it can also be used in the Universal Soil Loss Equation as a criteria to better define terrace spacing on croplands. This research work was developed during 1998, at the Agroveterinary Center/UDESC, in Lages, Santa Catarina, Brazil, to establish soil loss tolerance values by water erosion for 73 soil profiles of Santa Catarina, […]