Banca de DEFESA: LEIKA IRABELE TENÓRIO DE SANTANA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LEIKA IRABELE TENÓRIO DE SANTANA
DATE: 20/02/2024
TIME: 08:00
LOCAL: https://meet.google.com/set-ouur-uhw
TITLE:

Analysis of hydrological changes caused by human activity using the recurrence Plot

KEY WORDS:

Dam; Streamflow; Recurrence Plot; CRP; RQA; OPRP.

PAGES: 61
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUMMARY:

The sustainable use of freshwater resources is a major challenge due to climate change, human practices, the construction of dams and reservoirs. The operation of a dam can be modified to produce a natural-like flow without compromising its main services. The empirical analysis of streamflow data before and after dam construction can therefore provide valuable information to the sector responsible for flow control. The objective of this workis to investigte the nature of the hydrological processes of the São Francisco River basin, and the influence of the Sobradinho dam (BA). In order to detect possible hydrological alterations caused by the construction of this dam, daily streamflow data from the São Francisco River recorded at the fluviometric stations of Juazeiro (BA) and São Francisco (MG) were analyzed for the period from 1929 to 2009. The data are provided by the National Water Agency (ANA). The Recurrence Plot (RP) method, its bivariate extension, the Cross Recurrence Plot (CRP) and its modification, the Ordinal Pattern Recurrence Graph (OPRP), as well as the Recurrence Quantification Analysis (RQA) were used to analyze the non-linear dynamics of streamflow series. The visual analysis of the RP/OPRP patterns and the corresponding set of quantitative measures obtained by the RQA indicate that the operation of the reservoir induced changes in the downstream flow (recorded at the Juazeiro station) towards a less predictable and less stable regime, while the flow dynamics upstream (at the San Francisco station) remained unchanged. The temporal evolution of RQA quatifiers (obtained by applying OPRP in sliding windows) identified the influence of the Três Marias dam on the downstream of São Francisco station. Both dams induced the same downstream flow changes, with a greater degree of change for the Juazeiro station due to the shorter distance from the upstream dam. The OPRP sliding window technique showed sensitivity regarding the dam operation and also the damping process with increasing distance between the dam and the downstream hydrological stations. For the period before construction, the RQA values decrease over time scales, showing that the complexity of the flow dynamics depends on the change in time scale. This suggests that daily flow dynamics exhibit less complexity and therefore less variability than larger-scale flows. From the analysis of the relationship between flow and precipitation, it was observed that during the natural regime, flow dynamics were more predictable than precipitation dynamics, which may be the result of the influence of other factors such as evaporation, soil moisture and vegetation cover. The CRP analysis indicated a decrease in synchronization between hydrological processes in the basin after the construction of Sobradinho. The results are expected to contribute to the literature by providing new aspects of hydrological alterations caused by human activities which can be used to improve meteorological and hydrological modeling and forecasting to help with natural disasters and water resource management.

COMMITTEE MEMBERS:
Presidente - TATIJANA STOSIC
Interno - ANTONIO SAMUEL ALVES DA SILVA
Externo à Instituição - IKARO DANIEL DE CARVALHO BARRETO - UFPE
Externa à Instituição - LIDIANE DA SILVA ARAUJO COSTA - UFP
Externo à Instituição - SILVIO FERNANDO ALVES XAVIER JUNIOR - UEPB