UV-B Changing Characteristics of Alpine Meadow Area at Haibei Station in Qiliang Mountain

UV-B changing characteristics and the percentage of UV-B account for Eg were analyzed based on Eg and UV-B data during 2002 at alpine meadow area of Haibei Station among Qiliang Mountain.It is suggested that there are stronger UV-B at Haibei Station area,daily instantaneouspeak is near 10W·m~(-2),daily gross is 0.204MJ·m~(-2);and significant positive correlation exists between daily and annual change of UVB and Eg.The daily and annual changes of rations between UV-B and Eg(η)are obvious,morning and evening higher than that at noontime,and at June it reach the peak and December to rock bottom.Annual mean(is 0.54% and during growing season(May to September) is 0.65%,approximately.Annual gross Eg and UV-B are 6387.436 MJ·m~(-2)and 35.981 MJ·m~(-2)of alpine meadow area at Harbei Station,respectively.