Banca de DEFESA: EDSON DE OLIVEIRA SOUZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EDSON DE OLIVEIRA SOUZA
DATE: 02/04/2021
TIME: 09:00
LOCAL: VIDEOCONFERÊNCIA
TITLE:

ESTIMATION AND SPACIALIZATION OF EROSIVITY IN THE STATE OF ALAGOAS

KEY WORDS:

rainfall erosivity; spatial interpolation; soil loss

PAGES: 109
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SUMMARY:

The lack of rainfall data in the state of Alagoas, similar in many regions of the country, makes use of the regression equations obtained in other regions of Brazil to calculate the R factor of the Universal Soil Loss Equation (USLE). To date, Alagoas does not have a study on rain erosivity. Therefore, the study aims to: i) define an equation to estimate rainfall erosivity based on the index EI30 and the rain coefficient ( R c ) and ii) characterize erosivity in the state of Alagoas in historical rainfall data. Rainfall data from 54 stations in the 56-year period (1960 - 2016) were used in the estimate, filling in the gaps via the imputation method (mtdsi package) in the R environment. The equation used showed consistency and significant correlation between the observed data and the estimated ones, based on the coefficients R2 (86%) and r (93%) and the lowest RMSE (775.2 MJ.mm.ha-1 .h-1 ), which in turn indicated Ordinary Kriging (KO) as better spatial interpolator. Based on the cluster analysis (AA), three homogeneous groups (G1, G2 and G3) of erosivity were identified in the State, the Complete method being defined as the best from the Cophenetic Correlation Coefficient (CCC)> 0.7. The G1 group is the smallest group, located in eastern Alagoas. Groups G2 and G3 are the largest in extension and are located in the climatic mesoregions of Agreste and Sertão. The monthly isoerosivity showed that the highest rates occurred between April and July, with variations between 325.4 and 2.215.9 MJ.mm.ha-1 .h-1 . In annual erosivity, the most erosive locations were in Eastern Alagoas, close to the coast. Highlight for the stations Satuba (11,469.8 MJ.mm.ha-1 .h-1 .year-1 ), Maceió (9,945.4 MJ.mm.ha-1 .h-1 .year-1 ), São Luiz Quitunde (9,806.2 MJ.mm.ha-1 .h-1 .year-1 ) and Flexeiras (9,723.6 MJ.mm.ha-1.h-1.year1), being categorized between moderate and strong. Therefore, the erosivity equation can be used to estimate the USLE R factor in the state of Alagoas. Regarding the use of precipitation products CHIRPS and CHELSA to estimate erosivity, both proved to be an alternative based on the statistical data found. Regarding the trends of rain and erosivity, the first showed a growth trend in the central region of the State, mainly in the Sertão Alagoano mesoregion, while the erosivity trend showed a greater growth close to the coast in the eastern Alagoan mesoregion. The results obtained in this study support the planning of conservationist practices, especially in vulnerable areas in Alagoas

BANKING MEMBERS:
Externa à Instituição - JOSICLEIA PEREIRA ROGERIO - UFRJ
Presidente - 1850795 - JOSE FRANCISCO DE OLIVEIRA JUNIOR
Externo ao Programa - 1145750 - MARCOS ANTONIO LIMA MOURA
Externa à Instituição - MICEJANE DA SILVA COSTA - UFRN
Interno - 1121315 - ROBERTO FERNANDO DA FONSECA LYRA