Mixing study of the Ras-Laffandesalination plant outfall in Qatar coastal waters, methodology

Abstract

An extensive field survey was conducted to study the near-field and far-field mixing patterns of the Ras Laffan Industrial City surface outfall in Qatar. A coupled field remote-sensing method was proposed to study the mixing process of thermal plumes. The thermal infrared satellite photos were calibrated versus the measured temperature data with CTD. The effect of tidal currents and waves on the plume dynamics was investigated. The entrainment coefficient as a result of jet mixing and buoyant spreading was also estimated separately. The calibrated satellite photos show that the proposed method can be used in investigating the dynamics of thermal plumes. 1. INTRODUCTION Surface outfalls are the most common outfall system due to their simplicity, low construction cost and high discharge capacity. They have been historically used as the outfall system for industrial compounds, especially for cooling effluents. The rivers discharging into the seas and oceans are also analogous to the surface jets, with different densities to those of the receiving waters. Due to the popularity of the surface outfalls as well as the high rates of population growth and industrialization, much research has been conducted in the last few decades on the mixing patterns of surface outfalls. These studies can be generally categorized as experimental, field and numerical studies. Some of them were focused on investigating different parameters such as outfall geometry, discharge condition, ambient water