Spatial Distribution of Annual and Monthly Rainfall Erosivity in the Jaguarí River Basin

Abstract

ABSTRACT:The Jaguarí River Basin forms the main water supply sources for the São Paulo Metropolitan Region and other cities in the state. Since the kinetic energy of rainfall is the driving force of water erosion, the main cause of land and water degradation, we tested the hypothesis of correlation between the erosive potential of rainfall (erosivity) and geographical coordinates and altitude for the purpose of predicting the spatial and temporal distribution of the rainfall erosivity index (EI 30 ) in the basin. An equation was used to estimate the (EI 30 ) in accordance with the average monthly and total annual rainfall at rainfall stations with data available for the study area. In the regression kriging technique, the deterministic part was modeled using multiple linear regression between the dependent variable (EI 30 ) and environmental predictor variables: latitude, longitude, and altitude. From the result of equations and the maps generated, a direct correlation between erosivity and altitude could be observed. Erosivity has a markedly seasonal behavior in accordance with the rainy season from October to March. ), a region that should be prioritized in soil and water conservation efforts. From this validation, good precision and accuracy of the model was observed for the long period of the annual average, which is the main factor used in soil loss prediction models.

Monitoring land use impacts on sediment production: a case study of the pilot catchment from the Brazilian program of payment for environmental services

“…The large number of deep furrows and gullies with a direct connection to the fluvial channels together with the large areas under degraded pasture (78 % of the catchment), associated with high erosivity values and with very hilly relief in the region of study (Pontes et al, 2017), may explain the significant contributions of these sources to the sediments produced in the catchment (Figure 4). Silva et al (2013) stated that pasture is the most adequate use for the region to prevent water erosion.…”