Analysis of a major storm over the Dongjiang reservoir basin associated with Typhoon Bilis (2006)

Abstract

An unexpected major storm on July 14, 2006, resulted in great loss to the Dongjiang reservoir basin in Zixing City, Hunan Province, China, during the dominance of Typhoon Bilis (2006). The rainfall characteristics and temporal evolution of this major storm were studied with rain gauge data and high-resolution radar reflectivity data to investigate the connections between typhoon, reservoir and convective storm. Our investigations found that the intense convective storm, which was characterized by a banded structure, brought heavy rainfall concentrated in the Dongjiang reservoir basin while the center of Typhoon Bilis was nearly 450 km away from the basin. By applying geographical information system techniques, analyses of radar reflectivity demonstrated that the topography of the Dongjiang reservoir has big influence on the development of convective storm. Furthermore, intense convective cells with strong radar reflectivity ([50 dBZ) arose more frequently over the edges of the reservoir, especially over the southern mountain valley in the basin. More importantly, our investigations indicate that the occurrence of this convective storm is closely related to a strong atmospheric inversion by examining the Atmospheric Infrared Sounder data.

Methodology for geohazard assessment for hydropower projects

“…This is especially valid in arid and Mediterranean climates (Degu et al 2011;Zhao et al 2012;Hossain 2010;Hossain et al 2010), as for such conditions, the triggering potential might be considered medium or strong. The weak interrelation to climate also encompasses the special case reported on a large reservoir, where Zou et al (2013) found an increasing risk of convective storms. Another example of weak interrelation is the remote possibility of a hazard chain initiated by an RTE that might further trigger events leading to glacial outburst floods.…”