2014 SONG JIE i Acknowledgements First and foremost, I would like to thank my supervisor, Assoc Prof. Law Wing-Keung, Adrian, for his invaluable guidance and help throughout the study. He has taught me a lot, not only in the theoretical studies of hydrodynamics, but also in the field work and data analysis. He fosters my capabilities in mathematics and writing skills in English, and inspires my interests and creations in research. He has been teaching me, working and discussing with me all the time over the period of the study.