Banca de DEFESA: VERÔNICA BERNARDES DE SOUZA LÉO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : VERÔNICA BERNARDES DE SOUZA LÉO
DATE: 15/12/2020
TIME: 09:00
LOCAL: Defesa remota - https://conferenciaweb.rnp.br/webconf/hersilia-de-andrade-e-santos
TITLE:

Methodology for determining Ecological Flow Regimes in Tropical Rivers

KEY WORDS:

Environmental flow, multicriteria method, suitability curves. PHABSIM. IHA

PAGES: 100
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Engenharia Hidráulica
SPECIALTY: Hidráulica
SUMMARY:

The poor management of water resources combined with growth in water demand and climate change are impacting factors in the flow regime of rivers, directly interfering with the biodiversity of aquatic ecosystems and hindering the development of local economic activities. In this context, studies on ecological flow (flow magnitude) have been developed around the world since the 1970s and in recent years this approach has evolved to the determination of an ecological regime (environmental hydrogram) with all its components. There are more than 200 methodologies related to the subject in the world, and in Brazil the legislation determines the application of the simplest methods (hydrologic approach) for granting water. Recent studies in Brazil apply more complex methods of determining ecological flow and even ecological regime, but do not propose an adaptive approach that takes into account the particularities of low availability of ecological data in comparison to the ample biodiversity of tropical areas and scarcity of financial resources of countries normally located in these areas. Thus, this work sought to answer the following research questions: (1) What are the main methods and studies of regime of ecological flow applied in tropical regions with low availability of ecological data compared to local biodiversity and scarce financial resources? (2) When did these studies start and what are the main considerations of these studies in relation to the application of the methodology by water resource management bodies? (3) What are the main altered rates of the flow regime of a stretch of river without the presence of dams? (4) Is there a correlation of the hydrologic alteration indices of the river flow regime chosen for the study with parameters indicative of climate change and anthropic alteration? (5) Which species of fish would have the availability of physical habitat most impacted by anthropic or climatic actions on the flow regime? (6) What are the implications on the availability of habitats in the scenarios related to anthropic and/or climatic actions on the flow regime of a river? (7) What is the most appropriate multi-criteria method for determining an environmental hydrogram in tropical regions that considers ecological, economic and social criteria and has practicality of application by water use regulatory agencies? For the development of the work, a systematic bibliographic research on the subject was carried out and a stretch of the Preto River, a tributary of the Paraíba do Sul River, was chosen, where the following stages were accomplished: (1) characterization of the study area, (2) collection of information in the field, (3) application of methods to approach the range of variability (RVA) and linear correlation between climatic and anthropic variables with the flow regime, (4) hydrodynamic modeling of the stretch with application of habitat simulation of the main Neotropical fish species (PHABSIM) and (5) development and application of new methodology for ecological flow regime. For the development of the work, a systematic bibliographical research on the subject was carried out and a stretch of the Preto River, a tributary of the Paraíba do Sul River, was chosen, where the following stages were accomplished: (1) characterization of the study area, (2) collection of information in the field, (3) application of methods to approach the range of variability (in English RVA) and linear correlation between climatic and anthropic variables with the flow regime, (4) hydrodynamic modeling of the stretch with application of habitat simulation of the main Neotropical fish species (in English PHABSIM) and (5) development and application of new methodology for ecological flow regime. As results, the flow regime in the studied area presented IHA with high change in four river components (magnitude, frequency, duration and rate of variation) over time. By relating the changes found in the flow regime with anthropic and climatic metrics, it was shown a strong correlation, in the most current period, of local flows with changes in the behavior of the Atlantic Ocean (climatic change) and with changes in the number of cattle in the region (anthropic change). These results implied a decrease of approximately 40% in surface discharge due to the effects of livestock and 10% due to global climate change. When simulated, using the PHABSIM method, these changes in the flow for the developed aptitude curves of the 6 local species found with greater abundance, indicated that the species of Brycon opalinus and Astyanax intermedius require greater attention in scenarios of greater impairment of the amount of water due to anthropic activities and climate change. The minimum flows established by Brazilian legislation generate an area of available physical habitat quite different among themselves, especially when considering different scenarios of anthropic and climatic impact. With all these variables found that are related to the environmental flow regime, the ARVE methodology was then developed and in applying it, consistent results were achieved that indicate that the proposed multi-criteria model correctly responds to the proposed environmental, economic and social criteria and that it can be used by water managers in order to simulate existing or even future scenarios. In general, it is concluded that the flow regime in tropical headwaters rivers is highly altered by human activity and is still intensified by climate change, and that these changes can be simulated to verify and better manage the flow regime of watercourses. It is suggested for future research to consider other anthropic (economic and social) and climatic variables that impact the dynamics of rivers. In general, the proposal of a new method for determining the ecological regime, which considers environmental, economic and social variables, helps policies for managing the water resources of tropical areas located in places with low availability of ecological data and low financial incentive.

BANKING MEMBERS:
Presidente - HERSILIA DE ANDRADE E SANTOS
Interno - ROGERIO CABRAL DE AZEVEDO
Interno - LINEKER MAX GOULART COELHO
Externo à Instituição - TAILAN MORETTI MATTOS - UFF
Externo à Instituição - FRANCISCO MARTÍNEZ CAPEL
Externo à Instituição - MARILIA CARVALHO DE MELO