Analysis Of Spatial And Temporal Characteristics Of Wave Energy Resources Along The Coast Of China Based On ERA5

With the rapid development of the global economy,the energy problem has gradually become an important concern for the whole world.In the past two or three hundred years,due to the uncontrolled use of traditional energy,it is facing the crisis of depletion.Wave energy has huge reserves,which is a green and renewable marine energy worth developing and utilizing.The rational utilization of marine energy resources is based on the scientific evaluation of wave energy resources.Since the traditional wave energy evaluation formula P?0.49H_s ~2 T_e is derived from the linear wave theory of deep water waves,using this formula to evaluate the wave energy in shallow water and transitional water areas will lead to higher errors,and the accuracy of wave data used by predecessors is poor,and the wave data density in time and space is relatively low,which further leads to the inaccuracy of wave energy evaluation results.Based on the research results of Beji and Simarro,a new wave energy evaluation formula is derived in this paper.It is verified that the new formula overcomes the shortcomings of the traditional formula in overestimation of wave energy in shallow water area and has applicability under various water depth conditions.On this basis,this paper uses the latest ERA5 from ECMWF(European Center for Medium-Range Weather Forecast)and the more accurate global wave data so far,to evaluate the wave energy resources in Chinese waters from 1979 to 2018.The main evaluation indicators include wave energy availability frequency,enrichment degree,coefficient of variation and ratio of available wave height.The results of this study show that the availability frequency and enrichment frequency of waves in the South China Sea and the East China Sea are both high.The availability frequency is between 60%and 90%,and the enrichment frequency is between 10%and 20%.with availability frequencies ranging from 60%to 90%,and enrichment frequencies ranging from 10%to 20%.The wave enrichment frequency in the East China Sea is slightly higher than that in the South China Sea.In addition,the energy level frequency of wave energy in China seas has obvious seasonality.Autumn and winter are higher,spring and summer are lower.Winter is the best season for the development of wave energy resources.In general,the coefficient of variation of wave energy in China tends to increase from south to north.The low-value areas of 40 years variation coefficient of wave energy in coastal areas appear in Zhuhaikou and the southeastern Taiwan Island,and the high-value areas are located in the coastal areas of the southern Bohai Sea,the northern Yellow Sea and the coastal area of Beibu Gulf.Taking the Spratly Islands sea area as a typical sea area,a comprehensive assessment of its wave energy resources will provide a more scientific basis for the development and utilization of marine resources in the South China Sea.