Research On Spectrum And Statistical Characteristics Of Wind-wave Of East Dongting-lake

This paper is completed under the subsidy of Natural science fund project in Hunan Province and Subject of research association of sustainable development of Dongting-lake.Dongting-lake is the second limonitic lake in our country and Dongting-lake is the emphasis area of preventing and controlling flood in Hunan province. Because the wind waves carry much energy, Firstly wind waves which gales arose will greatly impact on dykes and badly threatened the safety of banks of Dongting-lake, secondly being an important water dynamical factor of lake, wind wave has a different effect upon matter diffusion comparing with other water dynamical factors, Thirdly it will occur ships overwhelmed and sunk when wind wave is strong. The wind wave of Dongting lake mainly takes place in the intersection of river and lake, especially in the areas of East Dongting-lake and the export of Yueyang to Chenglingji, the maximum wave height may be more than two meters. the characteristics that east Dongting lake is greater than south Dongting lake, south Dongting lake is greater than west Dongting lake on space distribution .the study of wind wave is the foundation of studies on interaction between wind wave and bank, and base on the research on statistical characteristics and Forecast Method of wind-wave of south Dongting-lake, it is imminently for studying on statistical characteristic and spectrum estimation of wind wave of East Dongting-lake and will offer scientific bases on realizing persistent development.With the help of hydro station of Cheng Lingji, the author carried out the prototype observation on the East Dongting-lake between July and September in 2005.In this paper, based on the field data of wind wave in Dongting-lake, power spectrum estimated by the Maximum Entropy Method (MEM) is compared with that estimated by using conventional methods of FTA. The results show that, the MEM is superior to the conventional method of spectral estimation. The spectrum estimation by MEM avoids the shortcomings of using the window function, a new spectrum analytical technique for the time series data of wind wave is proposed, finally the author derive spectrum formula by using FTA and MEM. At last, this paper discusses one-dimensional and two-dimensional combined distributions of wind wave heights and periods in East Dongting-lake. Based on the analytical results of continuous wave records and various statistic characteristics, the empirical distribution model of wave heights and periods are deriver by using methods of mathematical statistics and...