Name: LUCIANO MELO COUTINHO
Publication date: 27/03/2026
Examining board:
Name |
Role |
|---|---|
| ADELSOM SOARES FILHO | Examinador Externo |
| ANDRE LUIZ NASCENTES COELHO | Examinador Interno |
| EBERVAL MARCHIORO | Presidente |
| MARISTELA DENISE MORESCO MEZZOMO | Examinador Externo |
| ROBERTO AVELINO CECILIO | Examinador Interno |
Summary: Water erosion is a hydrogeomorphological process caused by the action of rainwater and
surface water on slopes, which involves the process of detachment, dragging, and deposition
of soil particles, contributing to the morphodynamics of the landscape. This process is
exacerbated by anthropogenic interventions in the natural environment, resulting in
accelerated water erosion, contributing to increased soil loss in different
hydrogeomorphological landscapes. Due to that, this, this study was conducted in the Murilo
Stream Watershed (MSW), located in the municipality of Cachoeiro de Itapemirim (ES), with
the objective of evaluating the spatial-temporal evolution of soil loss between 1970 and 2020,
identifying the factors that contribute to soil loss, and locating hotspots erosion (>200
tons/ha/year). Thus, due to the impacts and prejudice caused by water erosion, mathematical
models were developed to measure, predict and identify trends in erosive behavior on slopes,
agricultural plots, and watersheds. Among the empirical models of water erosion, the Revised
Universal Soil Loss Equation (RUSLE) stands out, widely applied to assess the evolution of
soil loss (SL) at different spatial-temporal scales. Soil losses values are obtained in this model
by multiplying the geographical factors resulting from water erosion (SL = R*K*L*S*C*P)
and are provided in units of t.ha-1
year-1
. Mapping data was processed in a computer
environment using a Geographic Information System (GIS), which allowed the RUSLE
factors to be represented and multiplied by map algebra for the study of soil loss in the area,
beyng: (i) rainfall erosivity R obtained from 100 year historical precipitation series; (ii) soil
erodibility K derived from experiments by consulting the literature; (iii) the ramp length L and
the slope gradient S obtained from the treatment of altimetry and hydrography data to
generation a Hydrologically Consistent Digital Terrain Model (HCDTM); and (iv) use and
land cover attributes C and conservation practices P from the literature. Adverse factors
influencing water erosion are observed in this basin, which led to the development of
adaptations to the RUSLE model to verify the impacts of temporal changes in use and land
cover and areas affected by recurring forest fires. The results identified soil losses by
simulating the Natural Erosion Potential (NEP) in the best-case scenario of total native forest
cover (16,616.28 tons/year) and for the years 1970 (109,591.93 tons/year) and 2020
(113,982.77 tons/year). This study found that anthropogenic interventions influenced the
behavior of water erosion in this watershed, resulting in an increase of 4,390.84 tons/year of
soil loss in the period analyzed. At the headwaters, soil loss is mitigated by remnants of native
forest, while the lower, flat areas favor human occupation (agriculture, buildings, and
transportation infrastructure) and recurring forest fires that increase water erosion. The MSW
showed an increase in critical soil losses (>200 tons/ha/year) between the modeled years,
exacerbated by human interventions and the effects of forest fires, with sections considered
hotspots erosion.
