巴山山地的气候特点

THE CLIMATOLOGICAL CHARACTERISTICS OF THE BASHAN MOUNTAINS

本文在1981年气候考察观测的基础上,应用1951—1980年,31—33°N范围内的台站资料,分析了巴山山地温度、湿度、降水、风速以及雾和日照等的垂直变化特点,并根据各种气象要素的变化规律,统一订正到500m高度上,绘出其水平分布图,以消除山区地形海拔高度的影响,更清楚地看出巴山南北气候的差异,为巴山农业、林业多种经营的发展提供气候的科学依据。

Based on two kinds of data observed from both of 30 meteorological stations during the last 30 years and some gradient investigation points, the climatorological characteristics of the Bashan mountain have been analysed in this paper. According to the vertical variation of climatic factors, the reduction to the height of 50 m above sea level has been adopted and the features of the horizontal distribution of the climatic elements in this area have been discussed. Compared with the plain area of the some latitude, the Bushan mountain seems to be another climatic barrier to the south of the Qinlin mountains. Some characteristics of the climatic factors in this area are as follows: 1. The lapse rate of annual meen temperature may be 5 /km on the north slope of the Bashan mountains, and 6.2 /km on the south slope. At the foot of the mountains, the accumn lated temperature with daily mean temperature > 10 can reach 5945 on the south slope, but only 5190 on the north slope. The effect of the mountain barrier seems most significant in January with the difference of 1.6 , but the difference is only 0.2 in July. The difference for the annual air temperature is about 1.0 . 2. The difference of vapor pressure in the latitudinal direction is more than that in the longitudinal direction. There could be a wet tongue along the south of the mountain ridge. The difference of the annual mean vapor pressure from the east to the west slopes seems to be 3? hPa. The relative humidity on the south is larger than on the north. And its variation, with height appears a significant 'S' pattern. It is noted that the turning height on the north slope is higher than on the south. 3. The maximum precipitation height on the north slope is much higher than on the south slope. The height in winter is higher than in Summer. The variation of annual precipitation with height approximates to a 'parabola' pattern. As for the horizontal distribution of annual precipitation, it is about 400?00 mm more on the south slope than on the north slope. The Bashan is famous for nocturnal rain, which could occupy 40.4 of all rain on north slope from April through October. 4. The yearly mean wind-speed gradually decreases with altidue on the south slope, but it increases on the south stope. 5. The foggy days on the north slope are less than on the south slope The sunshine time on the north slope is greatly longer than on the outh slope. Especially, The yearly mean sunshine time on the north slope below 600 m a. s. 1. is about 350 hours longer than on south slope.