Soil losses in the State of Rondônia, Brazil

Guilherme Henrique Expedito Lense,Taya Cristo Parreiras,Junior Cesar Avanzi,Ronaldo Luiz Mincato,Velibor Spalevic

doi:10.1590/0103-8478cr20200460

Guilherme Henrique Expedito Lense, Taya Cristo Parreiras + Show 3 more

Open Access

https://doi.org/10.1590/0103-8478cr20200460

Copy DOI

Abstract

ABSTRACT: In the state of Rondônia, deforestation, and inadequate soil use and management have intensified the water erosion process, causing degradation of agricultural land. Modeling is a tool that can assist in the adoption of targeted and effective measures for soil and water conservation in the region. In this context, the objective of the research was to model soil losses due to water erosion in the state of Rondônia using the Revised Universal Soil Loss Equation (RUSLE). The parameters related to rain erosivity, relief, erodibility, and soil cover, as well as the conservation practices of the state of Rondônia, were considered. The modeling steps were performed with the aid of the Geographic Information System. Results were validated with data of total sediments transported with water discharge. The estimated total soil loss was about 605 million tons per year, corresponding to an average loss of 22.50 Mg ha-1 year-1. In 19% of the state, the erosion rate was higher than the soil loss tolerance(T), and these areas should be prioritized for adopting measures to mitigate the erosion process. The RUSLE underestimated the generation of sediments at 0.56 Mg ha-1 year-1, which corresponds to an error of 18.60%. Results obtained can assist in the development of different soil use and management scenarios and provide options for policymakers to encourage soil conservation in the state of Rondônia.

Highlights

The state of Rondônia was the scene of several changes in land use and occupation, marked by developmental public policies and territorial occupation based on the removal of native vegetation (PIONTEKOWSKI et al, 2014)
The rainfall erosivity (R factor) of the state of Rondônia ranged between 8,962 to 12,409 MJ mm ha-1 h-1 year-1 (Figure 4A), which is in agreement with was observed by MELLO et al (2013)
These authors classified the erosivity on the State as compelling, due to the high rainfall rate in the Amazon region

Summary

Introduction

The state of Rondônia was the scene of several changes in land use and occupation, marked by developmental public policies and territorial occupation based on the removal of native vegetation (PIONTEKOWSKI et al, 2014). According to SCHLINDEWEIN et al (2012), deforestation, combined with inadequate soil management and the high rate of precipitation in the northern region of Brazil, intensified the water erosion process, generating a loss of nutrients and organic matter, and the degradation of Rondônia agricultural lands. Erosion models increase our understanding of environmental processes and facilitate land use and occupation planning, as well as decisionmaking in watershed management (PANAGOS & KATSOYIANNIS, 2019). This type of approach positively influences the proposition and adoption of agricultural and environmental policies to control water erosion (ALEWELL et al, 2019, MEDEIROS et al, 2016)

Objectives

Methods

Results

Conclusion