提出基于DEM的山区气温地形修正模型,以具有多种地貌类型的陕西省耀县为实验样区,以DEM模拟的坡面与平面太阳总辐射量为地形调节因子,实现对传统山区温度空间推算模型的改进,并与TM6热波段反映的地表温度进行了对比验证。实验结果显示,该方法能够较为精细地刻画山区局地温度随地形的空间分异规律,一定程度上提高了山区地面温度推算的精度。
The geographical features, i.e. latitude, altitude, distance to large water area and mountain structure, etc. , are commonly accepted as the global factors impacting the spatial distribution of groud surface temperature. However in the mountainous area, local topographical features, such as slope gradient, aspect and terrain the shading play a significant role to the redistribution of thermal energy. The traditional method for calculating spatial distribution of surface temperature in rugged areas usually employs a model of statistic regression, namely a regression of temperature against latitude, longitude and altitude, etc. , which is suitable for revealing the regional surface temperature, but not for refined climatic source exploration and application. Taking Yaoxian County in Shaanxi Province as a test area, DEM dataset of 1:50 000 map as basic information sources, the authors conducted a terrain-revised model for calculating by cell revising of traditional model by calculating temperature at local slope level. The key process is a cell the astronomical radiation based on DEM. A comparison between simulated temperature and radiation one from TM6 thermal infrared image shows that the new method gets more reasonable result which could reveal not only accurate local temperature, but also their finer distribution. It will be great helpful to improve the temperature simulation both qualitatively and effectively.