Study on Sedimentation and Effects of Mitigating Measures at Port of Mar del Plata, Argentina

Study on Sedimentation and Effects of Mitigating Measures at Port of Mar del Plata, Argentina

Luteijn, J.M.

Stive, M.J.F. (mentor)
Van Rijn, L.C. (mentor)
Tonnon, P.K. (mentor)
Van der Schrieck, G.L.M. (mentor)
Walstra, D.J.R. (mentor)

Civil Engineering and Geosciences

Hydraulic Engineering

Hydraulic Engineering

2013-02-28

Problem definition The city Mar del Plata has one of Argentina's largest ports and biggest seaside beach resort. After the construction of the port, a steadily growing sandbank appeared in the port entrance and considerable erosion occurred on the northern beaches. To warrant the accessibility of the port, frequent maintenance dredging is needed, but no measures have been taken to prevent/reduce shoaling of the port access. After numerous unsafe situations for vessels, large shipping companies have decided to stop berthing at Mar del Plata. Improvement of the accessibility for large ships will significantly lower the (transport) costs and results in more income and new investments in port activities and infrastructure. Objectives The main objective of this M.Sc. study is to identify the most promising feasible measures that improve the accessibility of the port and reduce the costs of maintenance and to quantitatively evaluate the effects and costs of these measures to support further detailed morphodynamic and design studies. Methodology Available literature and data is studied and reviewed to gain insight in the local system. During a field trip in the province of Buenos Aires data is collected by performing field measurements and different meetings took place with local experts and stakeholders. To identify and quantify the physical processes influencing the accessibility of the port, a Delft3D-FLOW model of the present area around Mar del Plata is set up and validated using present and historical data. Due to the lack of (reliable) near shore wave data, the nearshore wave climate in the model is derived from offshore wave data, wind data, and bathymetric data using a Delft3D-WAVE model with a larger scale. Various theoretical measures are evaluated. The most feasible, durable, and efficient type of measures are selected and quantitatively evaluated. To estimate the effects of these measures, with a focus on sediment transports, each measure is simulated in the Delft3D-FLOW model. From the resulting sedimentation rates in the port entrance, the quantity of needed maintenance is estimated for each measure. To be able to compare the measures, the total costs of initial investments and future maintenance is estimated. Conclusions • Maintaining the original port access, without taking additional measures is not economic (total costs € 2.5 to € 5.4 million/year) and leads to frequent disturbance of the ship traffic. The irregular and uncertain circumstances are not attractive for companies and investors in the port and lead to higher transport costs. • Maintaining the original port access and construction and maintenance of a sand trap along the southern breakwater strongly reduces the maintenance need (and the disturbance for the ship traffic) inside the access channel with 90%. The maintenance of the sand trap can be executed on a regular base (without disturbance for other ship traffic) and the dredged material can be used to regularly nourish the eroding northern beaches. However, by applying this measure the expected reduction of total costs is 6% percent. • Maintaining the original port access and construction of an eastward groin at the tip of the southern breakwater appears to be the most economical solution with 80% reduction of the total costs. The groin deflects sediment to deeper water outside the navigation area and prevents the port access from shoaling, but this can also lead to a decrease of sediment supply to the northern beaches and thereby increased beach erosion.

sedimentation
accretion
shoaling
shoal
sand bank
port access
navigation channel
Mar del Plata
Buenos Aires
Argentina
drifter tracking
sediment sampling
sediment analysis
depth survey
field measurements
sedimentation study
NWW3
wave modelling
input reduction
reduced wave climate
evaluation of measures
sand trap
groin
hydrodynamics
initial sediment transports
Delft3D
cost estimation

http://resolver.tudelft.nl/uuid:d7c023d6-0d0c-45f3-8b48-1468039d3799

-38.037, -57.517

Student theses

master thesis

(c) 2013 Luteijn, J.M.