秦岭-黄淮平原交界带自然地理若干特征分析

Some Features of Physical Geography in Transitional Region Between Qinling Mountains and Huanghuai Plain

文章探讨了秦岭-黄淮平原交界带划分的依据和方法,然后就其自然地理过渡性、暴雨频繁发生和坡地暖带及其自然地理效应进行讨论。研究表明:交界带自然地理要素不仅具有西部山地和东部平原之间的过渡性,而且北亚热带和暖温带地理成分在这里彼此交汇。交界带暴雨频繁,且以大暴雨为主,集中分布在海拔100～200m之间。交界带冬季气温高于平原0.5～0.8℃,1月最高气温出现在海拔350～400m之间,形成特有的坡地暖带,暖带厚度100～250m。交界带暴雨频繁和暖坡效应是大气环流和交界带地貌格局共同作用的结果,且对本区土壤发育和植物分布等具有重大影响。

The boundary of the transitional region between Qinling Mountains and Huanghuai Plain was divided first in this paper, then some features of physical geography in the transitional region were discussed. (1) The east boundary of the transitional region is at the contour about 100 m, and the west boundary is at the contour about 500 m. The area of the transitional region is about 26 000 km^2,which makes up 15.9% of total area in Henan Province.(2) The natural features in the transitional region possess transitional characters evidently in two directions, one is from the western mountain to the eastern plain and the other is from southern subtropical zone to northern temperate zone. (3) Torrential rain especially for strong torrential rain is frequent in the transition region, and there are many torrential rain centers, such as Lushan torrential rain center, Biyang torrential rain center, and so on. A majority of torrential rain is distributed among 100-200 m above sea level. (4) The winter temperature at 100-400 m above sea level in the transitional region is not only higher than in Huanghuai Plain where its altitude is lower than the transition region's, but also higher than in Qinling Mountains where its altitude is higher than the transitional region's. The highest temperature in January appears at 350-400 m above sea level in the transitional region. The warmer belt in the transitional region is called warm slope belt, of which thickness varies from 100 m to 250 m above sea level. (5) Torrential rain and warm slope belt in the transitional region were formed by atmospheric circulation and local terrain. Frequent torrential rain and warm slope belt had tremendous influence on soil properties, plant distribution and local climate in the transitional region.