Analysis of ice-flood in Sikeshu River basin on the north slope of Xinjiang Tianshan mountain

Sikeshu River on the north slope of Xinjiang Tianshan mountain is a calamitous river.Besides summer flood the bursting ice-flood causing disaster in the winter is more remarkable.Starting with the analysis of its condition of physical geography,this paper elaborates the particular characteristics of the ice-flood,and analyzes the cause of formation of ice-flood combined with air temperature and terrain factors.Formation of ice-flood is related to the changes of air temperature and terrain When air temperature rise gradually or suddenly,the force of combination of ice-dam framework decline.While the water pressure caused by ice-dam exceed the support force of ice-dam framework,a certain loose ice-dam of the upper reach burst,ice-water flow swift to the lower reach,thus brought out a series of collapsed ice-dam and forming ice-flood.Moreover,the ice-flood evolvement and the reasons of the notable difference of ice-flood volume,nonuniformity of annual change of ice-flood and no ice-flood in stable period of ice-cover or melting period etc are also analyzed.