Emilia Arasaki

Impacts of Climate Changes on Management Policy of the Harbors, Land Areas and Wetlands in the São Paulo State Coastline (Brazil)

Santosharbor and Sao Sebastiao Oil Maritime Terminal are the most important oil and gas facility in the Sao Paulo State Coastline. Santosharbor had, in the last decade, increased rapidly the container handling rate, being the first in Latin America. Santos Metropolitan Region is one of the most important of Brazilian Coastline, also considering the tourism. For that great economic growth scenario it is very important to have wave climate and tidal levels well known considering the sea hazards influence in ship operations. Since the hind-cast just represents the deep water wave climate, to make time-series of the wave’s parameters in coastal waters, for evaluation of sea hazards and ship operations, it is necessary to take into account the variations of those parameters in shallow waters with coastal instrumental data. Analysis of long term wave data-base (1957- 2002) generated by a comparison between wave’s data modeled by a “deep water model” (ERA40-ECMWF) and measured wave’s data in the years 1982-1984 by a coastal buoy in Santos littoral (Sao Paulo State, Brazil) was made. Validation checking procedures with instrumental measurements of storm surges made in other years than 1982-1984 shows high level of confidence. These data, obtained from the climatological analysis compared with a data set found from a scale model of the whole area of Santos Bay, Estuary and nearby beaches (Brazil), showed the impact of maritime climate changes, wave climate and tides upon harbor and coastal structures maintenance, beaches stability, tidal inlet saline intrusion and wetlands flooding. In the same time, the complex environmental system, that characterized the area included between Santos and Caraguatatuba, generates different natural hazard event affecting the maritime activity. A comparative study about the coastal flooding (Santos area) and the fluvial flooding (Juqueriquere river) was conducted. An analysis about the sea level rise, the wave climate and the flooding risk as well as the sediment transport was developed. Considering the increasing of the sea hazards, the high values of the facilities and infrastructures in Sao Paulo State Coastline, it is necessary to mitigate the risks from the point of view of the harbor and coastal structures maintenance and projects purposes increasing defenses procedures. Hence, based on the results obtained by the Authors in previous researches, are highlighted guidelines strategies suggested for Access Channels dimensions, wharves free-board, jetties and breakwaters dimensions, dredging rates, rigid and flexible littoral defenses, saline intrusion and land protection against flooding (including wetlands).

Extreme Events Assessment Methodology Coupling Rainfall and Tidal Levels in the Coastal Flood Plain of the Sao Paulo North Coast (Brazil) for Engineering Projects Purposes.

The North Coastal Region of the State of Sao Paulo, which comprises the Municipalities of Caraguatatuba, Sao Sebastiao, Ilhabela and Ubatuba, is one of the most prone to flooding Brazilian areas, owing to hydrological extreme rainfall events usually coupled with extreme tidal levels. This risk is also high due to human lives and material assets, with increasing population rates and the settling of large Companies such as the Oil industry, with reduced defense measures and works. The catastrophic scenario of the city of Caraguatatuba, in March of 1967, resulted from one of the most serious natural disasters in Brazil, fosters discussions about probabilities of rainfall events and rise in the sea level in coastal areas. Hence, this research is a consequence of this reality. The research presented is founded on an innovative methodology based on the analysis of past data of rainfall stations and tidal stations in the region of the North coastal zone of the State of Sao Paulo (Brazil). The analysis developed approached the meteorological, hydraulic and statistical knowledge areas. Practical results were used for designing macro-drainage, fluvial and maritime projects, that associate the probability of occurrence of certain types of rainfall coupled with their corresponding increase in tidal levels.

Impact of climate changes on the Santos Harbor, São Paulo State (Brazil)

Santos Harbor Area (SHA) in Sao Paulo Coastline (Brazil) is the most important marine cargo transfer terminal in the Southern Hemisphere. A long term relative tidal level variability assessment shows a consistent response to relative sea level rise. A wave data base Wave Watch III was compared with a long term wave data‐base generated by the ERA40‐ECMWF (2003), both local validated. The current bed level of SHA Outer Channel is ‐15.00 m (Chart Datum or, in abbreviation, CD), maintained by dredging. According to the cargo throughput forecast, in 2025, the Access Channel will have to be deepened to level of ‐17.00 m. The feasibility of that choice is discussed from a technical, economical and conceptual navigation point of view in that context. A data set found from a scale model of the whole area of Santos Bay, Estuary and nearby beaches, showed the impact of maritime climate changes upon the coastal area. In the previous researches developed by the authors, it was demonstrated that the wave climate, the tides and tidal currents affect harbor and coastal structures maintenance, beaches stability, tidal inlet, sediment transport, saline intrusion and wetlands. Considering the increasing of the sea hazards and the high values of the infrastructures in that coastline, it is necessary to mitigate the risks. Hence, based on the results obtained by the authors, are highlighted guidelines strategies suggested for Access Channels dimensions, wharves free‐board, jetties dimensions, dredging rates, rigid and flexible littoral defenses and land protection against flooding (including wetlands)

Extreme events assessment methodology as a tool for engineering adaptation measures - case study of North Coast of Sao Paulo State (SP)

The North Coastal Region of the State of Sao Paulo, which comprises the Municipalities of Caraguatatuba, Sao Sebastiao, Ilhabela and Ubatuba, is one of the Brazilian areas most prone to flooding and debris flow deposition, owing to hydrological extreme rainfall events, usually coupled with extreme tidal levels. The catastrophic scene of the city of Caraguatatuba March 18, 1967, resulting from one of the most serious natural disasters in Brazil, fosters discussions about probabilities of heavy rainfall-caused events and subsequent rise in the sea level in coastal areas. The research is founded on an innovative methodology based on the analysis of past rainfall and tidal station data, complemented with debris flow measurements and coupled with FLO-2D hydrodinamical model. The analysis involved meteorological, hydraulic, geotechnical and statistical knowledge areas applied to the region of the North coastal zone of the State of Sao Paulo (Brazil). The obtained results are a good predictor of the probability of occurrence of certain types of heavy rainfall-caused events such as flooding or debris flow, coupled with a corresponding increase in tidal levels. These practical results are intended to be used for urban planning, designs of macrodrainage, fluvial, maritime projects and debris flow retention structures.

Santos Sea Outfall Wastewater Dispersion Process: Physical Modeling Evaluation

ABSTRACT Alfredini, P.; Arasaki, E., and de Melo Bernardino, J.C., 2017. Santos sea outfall wastewater dispersion process: Physical modeling evaluation. To be environmentally sustainable, the ocean disposal of domestic sewage via a sea outfall must be carefully studied, such as previous modeling of waste-plume dispersion processes, for environmental impact assessments. A scale model, reproducing the Santos Bay and Estuary was calibrated at the Hydraulic Laboratory of Polytechnic School, University of São Paulo, Brazil. The complete modeling of this large estuarine system used numerical and scale models, which were all related to each other. Such an overall model, composed of individual hydraulic and numerical components, is called a hybrid model. It combines the advantages of both model components and adequate field survey measurements and is particularly important for simulating the plume dispersion process in Santos Bay. The goal hereby is to present a performance comparison of the outfall plume dispersion for improvement in the length of the Santos outfall. The study required preliminary numerical simulations in the near-field mixing processes to define the boundary conditions in the beginning of the far field. In addition, numerical simulations in the far field were required to reproduce the wind effect for calibrating the scale model of the air-tunnel hydro-aerodynamics. Scale model runs, using an advanced methodology for dye-plume monitoring, were calibrated with a numerical model of the plume dispersion and validated with independent runs of another numerical model of plume dispersion and comparison with satellite images of the plume. The conclusion was that an enlargement of 1 km of the outfall would reduce the risk of the plume returning.