Gaoyuan qixiang (Apr 2022)
The Variation Characteristics of Snowfall and Its Infulence on Runoff in Three-Rivers-Source Region
Abstract
Based on daily temperature and precipitation data of 19 Meteorological stations in the Three-Rivers-Source region from 1961 to 2019， the temporal and spatial variations of snowfall， snowfall days and snowfall/rainfall ratio were analyzed.The results indicated that as follows： The mean snowfall was 146.5 mm from 1961 to 2019， and snowfall was decreasing every 14.8 mm per 10 years， the period of 1985 to 1999 witnessed more snowfalls， Since the 2000s， the snowfall has decreased distinctly.There was an obviously decreasing trend every 4.0% per 10 years for snowfall/rainfall ratio in Three-Rivers-Source region， especially in the west of yangtze river source region and yellow river source region， the mean snowfall days was 91-day in the recent 59 years in Three-Rivers-Source region， Qu Malai， Wu Daoliang， Tuo Tuohe in yangtze river source region and the west and central of yellow river source region were more snowfall days than other regions， snowfall days was decreasing every 14 days per 10 years， this trend was obviously in the west of the yellow river source region； The snowfall and snowfall days showed double peaks distribution in the research period， the snowfall days and snowfall are more happened in May， the light snow is more happened in March and April， medium snow and heavy snow are more happened in the late autumn and spring； The trend of snowfall days and snowfall showed increasing as the altitude rises， and it decreases as the longitude rises.In addition， global warming is the mainly reason for decreasing snowfall and snowfall days， there was a high relationship between snowfall in clod phase and runoff in spring， and it also had a big difference in Three-Rivers-Source region， the runoff is lagged response to snowfall.
Keywords
