摘要
本文首先以西北五省区１９５１～１９９０年４２个代表气象（台）站的逐年降水量资料进行相关关系的运算、聚类，并综合考虑气候条件、下垫面条件、史料记载的均一性等因素，将西北五省区划分为７个研究区；根据１４７０－１９５０年各省区气候史料记载，采用区内平均等级，建立各历史旱灾序列，并据此探讨了西北五省区近５００年来旱灾的时空分布规律。
In this paper,annual precipitation data ,which come from 42 representative meterological station in Northwestern China from 1951 to 1990,are calculated and chassified by use of ralation each other.And the factors of the climate, the underlying surface ,the history data's evenness and so on are synthetically considered.Then,the whole of Northwestern China is divided into seven research regions.By the mean grade,the historical drought alignment of each research region is set up based on the data from 1470 to 1950.In the light of these,the laws of the time and space distribution of drought winthin near 500 years are tried to find out. \ \
出处
《干旱区资源与环境》
CSCD
1999年第1期28-33,共6页
Journal of Arid Land Resources and Environment
