岷江上游干暖河谷与元江干热河谷的气候特征比较研究

利用岷江上游和元江（红河上游）河谷区的多年气象观测资料，通过对两河谷区的光、热、水、风等气候因子的综合分析、比较，得出结论：两河谷区的日照时数均较多，日照充足，干热河谷的日照时数要比干暖河谷多。干热河谷的平均温度要比干暖河谷要高。两河谷均是气温的年较差较小，月较差较大；降水的地区差异大，有明显的干雨季之分，降水均集中在雨季，降水量干热河谷多于干暖河谷；两河谷均是山谷风大，定时风显著，风速均是干季大，雨季小。两河谷局地小气候均呈现复杂多样特征。在干热河谷中上段，光热资源较丰富，而水分资源不协调，导致水分构成了该地区发展的主要限制因子；而在干暖河谷中上段，光照可满足需要，热量和水分不足，构成了限制因子，特别在中段河谷的部分地区缺水更甚，干旱年份可影响到树木生长。对两河谷气候特征的对比、分析, 可为两流域在退耕还林、山地生态环境的治理和恢复提供科学依据。

COMPARISON OF CLIMATE CHARACTERISTICS BETWEEN A DRY-WARM VALLEY IN UPPER REACHES OF MIN RIVER AND A DRY-HOT VALLEY OF YUANJIANG RIVER

By using long-term climate data for dry-hot valley at the upper reaches of the Min River and dry-warm valley of the Yuanjiang River(the upper reaches of the Hong River), microclimate characteristics of these two valleys were analyzed and compared. In these two regions, sunshine duration was long; Annual air temperature differences were small, but monthly air temperature differences were high. Precipitation differences were greater among sites within dry-warm and dry-hot valleys, with obvious alternations in dry and rain seasons. Precipitation was concentrated in rain seasons. In addition, mountain-valley breeze speeds were all high, with bigger values in dry season and smaller values in rain season. However, compared to dry-warm valley, higher values were observed in the sunshine duration, average air temperature and precipitation for dry-hot valley. Microclimate characteristics of the two valleys were complexed and diversified. At the upside and middle part of dry-hot valley, ample light and heat resource were out of harmony with insufficient water resource, which made water a primary factor to limit development. While at the upside and middle part of dry-warm valley, light resource was plenty, but heat and water resource were not enough and became limiting factors. Especially at some places of middle part of dry-warm valley, there was even the lack of water to influence plant growth in arid years.