Changes in Doha Bay flushing time driven by the coastal reclamation and development projects.

Details

Supervisors

Hanert, Emmanuel

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en chimie et bioindustries, à finalité spécialisée

Abstract

The rapid industrialisation of Qatar, particularly in Doha, has led to an intensification of land reclamation projects, causing a narrowing of Doha’s bay entrance. In this study, we look at variations in water residence time over three distinct periods (1985, 2000 and 2020) in order to determine the influence of successive land reclamation projects. To investigate this, we combine the multi-scale ocean model SLIM with a Lagrangian Particule Tracker dispersion model to compute Doha Bay water residence time. We then compare the different topographies to analyse changes in residence time. We also analyse the mean residence time around sea outfalls, where wastewater is discharged. This allows us to assess whether these areas have a high residence time, indicating stagnation of wastewater and a higher concentration of pollutants. Our results show a small increase (about 18% in average) in residence time between 1985 and 2000, followed by a significant increase between 2000 and 2020 (about 60% in average). Some areas of the bay experienced a fourfold increase in water residence time. At the same time, the standard deviation of residence time has increased progressively over the years. Overall, given the continuing population growth along the coast, it is expected that artificial structures and coastal reclamation will keep on expanding, hence further increasing the stagnation of pollutants in the bay. This study can be used as a reference to assess the potential impact of new artificial structures on residence time and provides a better understanding of the consequences of these developments on water quality.