Abstract: The Piliqing River is located in the transport routeway of water vapour from the west in the west Tianshan Mountains, where the mountain body is high, the river valley is deep, mountain slope is steep, and flood occurs frequently. According to the hydrological data measured at Piliqing Hydrological Station in recent more than 50 years, the model comparison coefficient, variation coefficient and skew coefficient were all in an increase trend with the time, which reveals that the flood frequency and discharge were in an increase trend. After analyzing the data of air temperature, precipitation and silt content at Piliqing Hydrological Station, it was found that flood occurrence in the drainage basin during the period from April to July was closely related to the violent melt of thick snow cover and heavy rainfall. The frequent occurrence of flood was mainly caused by heavy snowfall in winter, continuous increase of temperature in spring and vegetation destruction caused by excessive pasturing in the mountainous region in the upper reaches.

Key words: flood, precipitation, air temperature, disaster prevention and reduction, the Piliqing River, west Tianshan Mountains, China