Banca de DEFESA: WENDSON DE OLIVEIRA SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : WENDSON DE OLIVEIRA SOUZA
DATE: 13/07/2022
TIME: 08:00
LOCAL: Pos Graduação Engenharia Civil
TITLE:

Use of Satellite Radar Interferometry in The Monitoring of Land Subsidence Caused by the Exploitation of Groundwater Resources in the City of Recife-PE

KEY WORDS:

SAR interferometry; Recife; land subsidence; groundwater.

PAGES: 295
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The scarcity of drinking water is a recurring problem in several cities around the world, such as Recife, located in the Northeast of Brazil. In the capital of Pernambuco, underground springs are used as an alternative source to meet the growing demand. However, for decades most of the collections operate in an excessive way. This has provided an intense reduction in the levels of confined aquifers with risk of land subsidence. The geological phenomenon causes surface lowering and causes greater concern in urban areas. The deformation of the land can generate significant impacts on infrastructure and the environment, cause economic and social losses, and compromise the quality of life of the inhabitants. The objective of the research is to evaluate the land subsidence of the coastal plain of Recife caused by the exploitation of groundwater resources by means of Interferometric Synthetic Aperture Radar (InSAR). The technology allows accurate detection in surface-structural displacement with a high density of observation points and high temporal resolution. The procedure employs Persistent Scatterer Interferometric (PSI) in the analysis of SAR data, consisting of: 100 COSMO-SkyMed images (ascending orbit, HH polarization, X band) for the period from 2011 to 2019, 135 Sentinel-1 images (descending orbit, VV polarization, C band) for the period 2016 to 2021 and 41 PAZ images (19 ascending and 22 descending, HH polarization, X band) for the period 2019 to 2021. The results reveal several places of drawdown in Recife. There is a correlation between land subsidence and groundwater reduction in the South zone due to soil desaturation in the neighborhood of Boa Viagem, with a velocity of a few millimeters (mm) per year at 3.8 mm/year. Secondly, there is a correlation between land subsidence and urbanization in the West and North regions, resulting from soil compaction from recent constructions. In the West zone, there are large areas of lowering along the Prado, Afogados, Torrões, Cordeiro, Bongi, San Martin, Curado, Várzea and Caxangá neighborhoods, with a value of around 15 mm/year. Similar cases, but with a smaller area, occur between the neighborhoods of Ibura and Ipsep with a rate of up to 25 mm/year – responsible for the largest sinking in the city. In the North region, there are also smaller areas of lowering between the neighborhoods of Arruda and Campo Grande with a velocity of around 20 mm/year. In addition to the vertical movement, there is a horizontal displacement of the Recife plain for the period from 2019 to 2021. The movement occurs in the West region with a velocity of -10 mm/year towards the West and in the North-South zone with a rate of 7 mm/year towards the East, and may be related to the land subsidence. The study highlights that Recife is a very vulnerable city to land subsidence. The analysis of the effects shows impacts on geodetics structures and interference in urban drainage. However, the phenomenon has the potential to make its action more worrying in the coming years. The use of InSAR is an assertive strategy to face the challenges of Recife with benefits to groundwater sustainability and the well-being of the population.

BANKING MEMBERS:
Externo à Instituição - JOAQUIM JOÃO MOREIRA DE SOUSA
Externo ao Programa - 311662 - ADMILSON DA PENHA PACHECO
Externo à Instituição - ALEXANDRE DUARTE GUSMAO - UPE
Interno - 1688881 - ALFREDO RIBEIRO NETO
Presidente - 1528736 - SYLVANA MELO DOS SANTOS