基于DEM的天山山区气温时空模拟研究

Spatiotemporal Distribution of Temperature in the Tianshan Mountains Based on DEM

山区气温主要由太阳辐射决定,在地球表面的分布与区域地形特征密不可分（特别是山区）。采用GIS分析技术,借助DEM和气温观测数据等,在传统气温统计模型的基础上,利用地形的坡度、坡向、地形遮蔽度等因子进行山区气温空间小尺度模拟修正,构建了分布式山区地形修正模型。结果表明,该修正模型模拟效果优于常规气温统计模型;天山山区气温分布规律和趋势与其他方法研究结果一致,温度空间分布差异以冬季最小,夏季最大;气温垂直递减率季节变化为：夏季〉春季〉秋季〉冬季,冬季在1 000-2 000 m之间存在明显逆温现象;气温随坡度的变化率表现为在0°-15°地形上较为剧烈。该修正模型为山区任一地域单元气温空间分布的较高精度计算提供了一种可行的方法,对山区气温模拟和生态水文过程等相关研究具有一定的参考价值。

Temperature in mountainous areas is mainly determined and decided by the solar radiation,and the distribution on the surface of the earth is closely and inescapably related to the regional topographic conditions,especially in mountainous areas. The GIS analysis technology and DEM as well as the data of temperature observation,slope of the terrain,slope aspect,terrain shading areas and other factors were used and utilized in this study on the basis of the traditional temperature statistical model. The purposes of this study were to carry out small-scale simulation and correction of air temperature in mountainous area,and to build a distributed mountainous terrain correction model. The results indicated that the values simulated by the modified model were better than those by the conventional temperature statistical model. The temperature distribution patterns and trends in the Tianshan mountainous areas were consistent with those obtained by other methods. The difference of temperature and space distribution was the lowest in winter but the highest in summer. The lapse rate of seasonal temperature variation was in an order of summer spring autumn winter,and there was an obvious temperature inversion in a vertical zone of 1 000-2 000 m a. s. l. in winter. The change rate of the temperature with slop was the highest in a slope range of 0°-15°. The modified model is feasible and viable method for high-precision calculation of spatial distribution of air temperature in any regional unit in mountainous area,and could be referred a certain reference value for researching the air temperature simulation and ecological hydrological processes in mountainous areas.