张掖地区春小麦生长期的辐射平衡观测

THE RADIATION BALANCE OBSERVATION DURING THE GROWING STAGES OF SPRING WHEATIN ZHANGYE AREA

张掖地区春小麦的反射率在整个生育期内比较稳定，变化范围在１５％－１９％；有效辐射在总辐射中所占比例随小麦的生长而迅速降低，从小麦的三叶期到抽穗期，该比例从３３％下降至２０％，抽穗以后，变化缓慢，最后降为１７％；与有效辐射的情况相反，净辐射在总辐射中的比例随小麦的生长而增加，比值从５０％增至６８％

In this paper, the radiation balance properties during the different growing stages of spring wheat are analysed by using the observational data of radiation balance in Zhangye area from April to July 1991 in HEIFE The preliminaly results show: the albedos in spring wheat field are relatively stable in the whole growing stages,and the value range is between 15% and 19% The ratio of effective radiation to global radiation decreases rapidly along with the growing of wheat,and the range is between 33% and 17% On the contrary, the ratio of net radiation to global radiation increases along with the growing of wheat,and the ratio increases from 50% to 68%