摘要
本文用研究区１４７０～１９８５年的旱涝等级资料，讨论了该地区５００年来旱涝区域分异变化的阶段性，恢复了各阶段的旱涝分布和旱涝区域分异格局。结果表明，研究区旱涝区域分异的变化可分成４个区域分界格局相对多变和３个相对稳定交替出现的阶段。５００年来的旱涝变化与温度变化对比发现，较寒冷期，研究区的旱涝区域分异格局较稳定、旱涝分布的东西差异显著；较温暖期，旱涝区域分异格局的变动较频繁、旱涝分布各有特点且均无明显的东西差异；在小冰期最寒冷阶段，旱涝区域分异格局的变动最频繁且区域差异性最大、旱涝分布的南北差异明显。
ased on the dry-wet index (D-W) data of North China from 1470 A. D. to1985 A. D., the studied area's dry-wet regional differentiation changes and itsrelationship with the changes of temperature during the past 500 years were discussedin this paper The main work and the main conclusions are as follows.(1) The moving-correlation coefficients (r) of the D-W between every twostations of the studied region from 1470A. D. to 1985A. D. were computed first.Then, the abrupt-changing behaviors within each moving-correlation coefficient serieswere analyzed, through the M-K method. The analysis of the temporal distributingfeatures of the abrupt-changing points obtained here shows that the dry-wet regionaldifferentiation changes of North China during the past 500 years can be divided intoseven stages-1470~1560A. D. (I ), 1560 ~ 1650A. D. (II ), 1650 ~ 1680A. D. (III),1680~ 1725A. D. (IV), 1725~ 1810A. D. (V ), 1810~ 1890A. D. (VI) and 1890~1985A. D. (VII), among which the stages with the relatively steady dry-wet regionaldifferentiation changes just alternate with those with the unsteady ones.(2) The original D-W matrix of the studied region from 1470A. D. to 1985A. D.was analyzed by EOF method. The comparison between the temporal distributionfeatures of the abrupt-changing points gained above and the temporal coefficient ofEOF1 obtained here shows that the steady extent of area's dry-wet regionaldifferentiation always changes sharply just in the time when the area's whole dry-wetcondition converts each other evidently.(3) The analysis of the D-W averages (D-W) of every stages as well as thewhole past 500 years shows that the W-E direction difference of the dry-wetdistributions in the stages with relatively steady dry-wet regional differentiationchanges are all very clear-the isoline of D-W= 3.0 all extend, approximately, alongthe latitude direction, and the west parts of the isoline are dry, meanwhile, the eastparts are wet. But the dry-wet distributions of the stages with the relatively unsteadydry-wet regional differenti
出处
《第四纪研究》
CAS
CSCD
北大核心
1999年第5期430-440,共11页
Quaternary Sciences
基金
国家自然科学基金
