中文摘要：

为充分发挥森林防火GIS和视频监控系统各自优势,实现优势互补。根据数字高程模型（DEM）的特点,以视频视线的可视域分析为基础,基于视频监控系统中摄像机和镜头等参数,提出了基于DEM的视频可视域提取算法,实现了视频可视域的提取及在DEM上的同步跟踪,以及防火GIS和视频监控系统间的联动。利用浙江省临安市森林防火GIS和锦城街道的DEM,分别对摄像机和镜头等在不同参数下进行实验与验证。结果表明：基于DEM的视频可视域提取算法与视频监控设备的参数有密切的联系,跟踪效果基本能满足实际工作需要。

英文摘要：

In order to take full advantage of a video monitoring system and forest fire prevention GIS,we propose an extraction algorithm for video visualization based on a digital elevation model（DEM）.By analyzing the visualization domain,given camera and lens parameters in the video monitoring system,we realized real-time extraction of video and the interaction between forest fire prevention GIS and the video monitoring system.We validated the algorithm by using Lin＇an City in Zhejiang Province,as our study site.The test results show that the video extraction algorithm based on the DEM,is closely linked with the parameters of the video monitoring equipments and fits the demands for practical applications.