甘肃民勤小型与E-601型蒸发皿蒸发量折算系数分析

利用民勤国家基准气候站1992~2001年5~9月各月小型与E-601型2种蒸发皿蒸发量的同步对比观测资料,通过对比分析、相关分析、离差分析方法以及气候估算值分析得出:(1)各月小型与E-601型2种蒸发的折算系数在0.504~0.601之间,平均折算系数为0.574;各年2种蒸发的折算系数在0.529~0.608之间,平均折算系数为0.574;(2)2种蒸发量5~9月的月、年平均折算系数相同,2种月蒸发量的平均相关系数为0.952,相关性很好,但2种蒸发的年平均相关系数为0.330,相关性很不理想,因此利用按月计算的折算系数来换算2种蒸发量更为合理;(3)小型蒸发量的离差系数大于E-601型蒸发量,小型蒸发量的离散程度比E-601型蒸发量大。由于E-601型蒸发量只有5~9月有观测资料,在考虑民勤站小型蒸发与E-601型蒸发资料互相换算时,首先考虑将E-601型蒸发量换算为小型蒸发量来利用,为有效利用民勤长序列小型蒸发量资料做了很好的衔接。

Analysis on Small Type and E-601 Type Evaporation Conversion Coefficient in Minqin of Gansu Province

Based on the synchronization contrastive observational data of small evaporation pan and E-601 type from May to September during 1992-2001 in Minqin national reference climate station,two kinds of evaporation were compared and analyzed by using correlation,deviation and climate estimation methods. The results are as follows：（ 1） The monthly conversion coefficients of two kinds of evaporation varied from 0. 504 to 0. 601,and the average value was 0. 574,while the annual conversion coefficients of them varied from0. 529 to 0. 608,and their average value was 0. 574.（ 2） Although the monthly and the annual conversion coefficients of small pan evaporation and E-601 type evaporation were same,and the monthly average correlation coefficient of two kinds of evaporation was 0.952 which showed a good correlation,the annual average correlation coefficients of two kinds of evaporation was only 0. 330,so it was more reasonable that two kinds of evaporation shoud be converted through the calculated monthly conversion coefficients.（ 3） The dispersion coefficient and dispersion degree of small pan evaporation was larger than those of E-601 type. Since E-601 evaporation was only observed from May to September,when small pan evaporation and E-601 type evaporation were inter-converted,it should be firstly considered that E-601 type evaporation was changed into small pan evaporation,which was a good connection for effective utilization of the long sequence small pan evaporation data.