Spatiotemporal Dynamics of Maximum Wind Speed Using the Wind Multiplier Downscaling Method in the Yangtze River Inland Waterway from 1980 to 2017

Abstract

Wind speed affects the navigational safety of the Yangtze River, and assessing its spatiotemporal dynamics provides support for navigation management and disaster prevention. We developed a wind multiplier downscaling method integrating the effects of land use and topography, and used meteorological station observations and European Center for Medium-Range Weather Forecasts (ECMWF) Reanalysis Interim (ERA-Interim) reanalysis data for statistical downscaling in the Yangtze River inland waterway region from 1980 to 2017. Compared with reanalysis data, the downscaling products showed improved accuracy (especially at 5–10 m/s), and are consistent with site-based interannual variability observations. Increasing maximum wind speeds in the middle–downstream area was observed from 1980 to 1990, while a decreasing trend was observed from 2010 to 2017; the opposite was observed for the upstream. Land use has significant influence on wind speed, with a decreasing trend observed year by year for wind speed above grade 9. Although the proportion of grade 4–8 wind speed over water is small and the trend is not obvious, grade 9–10 wind speeds displayed an increasing trend from 2010 to 2017, indicating that changes in surface roughness have a significant influence on wind speed in the Yangtze River inland waterway.