Contribution of Tropical Cyclones to Precipitation around Reclaimed Islands in the South China Sea

Abstract

Tropical cyclones (TCs) play an important role in the precipitation of tropical oceans and islands. The temporal and spatial characteristics of precipitation have become more complex in recent years with climate change. Global warming tips the original water and energy balance in oceans and atmosphere, giving rise to extreme precipitation events. In this study, the monthly precipitation ratio method, spatial analysis, and correlation analysis were employed to detect variations in precipitation in the South China Sea (SCS). The results showed that the contribution of TCs was 5.9% to 10.1% in the rainy season and 7.9% to 16.8% in the dry season. The seven islands have the same annual variations in the precipitation contributed by TCs. An 800 km radius of interest was better for representing the contribution of TC-derived precipitation than a 500 km conventional radius around reclaimed islands in the SCS. Four track patterns of TCs were defined. The order according to the primary pattern of contribution was I (26–85.3%) > IV (12.8–29.8%) > III (4.3–29%) > II (11.5–24%). The average distance between islands and TCs was 1163 and 712 km in the rainy and dry seasons, respectively. The average contribution was larger in La Niña than in El Niño periods. These results could be beneficial for managing rainwater resources, especially the TC-induced precipitation in the reclaimed islands.