Meteorological conditions for frequent debris flows from Guxiang Glacier, Mount Nyenchen Tanglha, China

Abstract

Destructive debris flows occur frequently on glacierized Mount Nyenchen Tanglha, Bomi, Tibet. Since 1953, hundreds of such flows have occurred in the Guxiang valley during periods of atypically hot or rainy weather in summer or early autumn. From 1964 to 1965, 95 debris flows were documented at a temporary debris flow observation station; 25 of these debris flows with a peak discharge Qmax above 50 m3/s were considered in the present study. Supported by meteorological data from the nearby Bomi station, statistical analysis showed that outburst debris flows from the Guxiang glacier are highly correlated with atypical weather. Finally, the conditional probability of a debris flow from the Guxiang glacier as a function of daily rainfall R and maximum temperature Tmax for rainy days (R ≥ 5 mm) and dry days (R < 5 mm) is suggested as a plausible link between weather and outbursts of debris flow. © 2013 International Mountain Society.