Paper Title
Joint Probability Analysis Of Significant Wave Heights And Extreme Water Levels At Point Reyes Station

Abstract
To ensure the safety, practicality and rationality of engineering design in the coastal areas, it is important to consider various environmental factors and their extreme values. Water level and wave height directly produce an effect on engineering design in several dominant environmental factors and they are correlative, so their correlation are seriously considered. The objective of this study is analyzing joint probability of extreme water levels and significant wave heights at Point Reyes Station. For this purpose, two joint probability distribution models, that are Gumbel Ⅱmodel and Gumbel Logistic model, are used to fit to joint probability distribution of significant wave heights and extreme water levels. Fitting results of two models are both effective though Gumbel Logistic model is slightly better. Two established models are applied to analyze the classic joint occurrences of water level and wave height, that are the combination of 10-year return period water level and 100-year return period wave height, the combination of 50-year return period water level and 50-year return period wave height, the combination of 100-year return period water level and 10-year return period wave height. It shows that joint return period is different from the return period of single variable. The return period contour lines of various combinations show that the growth rate of joint return period is increased with constant growth of single variable’s return period. Keywords - Point Reyes, California; Extreme Water Levels; Significant Wave Heights; Joint Probability; Return Period.