Distribution characteristics of wave energy in the Zhe-Min coastal area

A 10-year(2003–2012)hindcast was conducted to study the wave field in the Zhe-Min coastal area(Key Area OE-W2)located off Zhejiang and Fujian provinces of China.Forced by the wind field from a weather research and forecasting model(WRF),high-resolution wave modelling using the SWAN was carried out in the study area.The simulated wave fields show a good agreement with observations.Using the simulation results,we conducted statistical analysis of wave power density in terms of spatial distribution and temporal variation.The effective duration of wave energy in the sea area was discussed,and the stability of wave energy was evaluated using the coefficient of variation of wave power density.Results indicate that the wave energy resource in the study area was about 4.11×10^(6) kW.The distribution of wave energy tends to increase from the north(off Zhejiang coast)to the south(off Fujian coast),and from near-shore area to the open sea.The sea areas with wave power density greater than 2 kW/m are mostly distributed seaward of the 10-m isobath,and the contours of the wave power density are almost parallel to the shoreline.The sea areas around the islands that are far from the mainland are rich in wave energy,usually more than 6 kW/m,and therefore are of obvious advantages in planning wave energy development and utilization.The effective duration of wave energy in the offshore area shows an increasing trend from north(off Zhejiang coast)to south(off Fujian coast),with values of∼3500 h in the north and∼4450 h in the south.The coefficient of variation of wave energy in this region is mostly in the range of 1.5–3.0,and gradually decreases from the north to the south,suggesting that the wave energy in the south is more stable than that in the north.