矿区地表形态将随着地下开采引发的地面沉陷而发生变化。矿山开采沉陷特征一般用二维曲线或下沉等值线图来描述，这种方式未将地形的原始信息和开采沉陷信息融合于一体，不便于描述和分析矿区地貌的动态变化特征。随着数字高程模型(DEM)理论的发展与完善，利用DEM技术对矿山开采沉陷区的原始地形信息和开采沉陷信息进行叠加，可实现开采沉陷区数字地形信息的预测更新。 本文通过研究数字高程模型的更新方法及高程内插算法，结合矿山开采沉陷的预测模型，提出了一种基于数字高程模型叠加的开采沉陷区地形图预测更新途径，即对开采沉陷区地表下沉量进行预计，在原始地形DEM中内插出下沉点的原始地面高程，对高程文件进行叠加后实现开采沉陷区数字高程模型及地形图的更新。主要研究内容及结果如下： (1)在分析数字高程模型原理的基础上，比较了几种数字高程模型更新的基本方法。针对目前DEM更新方法的局限性，结合开采沉陷变形的预测理论模型，提出了一种实现开采沉陷区数字高程模型预测更新的技术途径； (2)阐述了数字高程模型内插理论，分析了各内插方法的适用性。选用了移动曲面拟合内插算法进行高程内插；选择我国常用的概率积分预计模型进行开采沉陷预计。在此基础上，对开采沉陷区数字高程模型预测更新所需实现的关键技术与算法进行分析，采用VB语言设计并开发了数字高程模型内插与叠加的程序，在MATLAB中进行概率积分法地表下沉预计，从而实现了开采沉陷区数字高程模型的预测更新； (3)针对研究实例中的数字地形图提取地表原始高程信息，依据矿区地质条件选取预计参数并进行地表下沉预计，利用所开发的程序对开采沉陷区数字高程模型进行叠加更新，并生成了更新后的地形图，直观地反映出开采沉陷前、后的地形变化特征。 (4)针对DEM内插算法和概率积分法下沉预计模型，讨论了高程内插和下沉预计的精度。利用实例分析了开采沉陷区域中不同位置的下沉预计和高程内插的平均中误差及相对误差。结果表明，通过改进下沉预计参数的准确性可有效地提高下沉预测精度，以满足开采沉陷区一定比例尺数字地形图更新的技术要求。 本文的研究初步实现了矿山开采沉陷区数字高程模型的预测更新，所开发的数字高程模型内插叠加程序也可用于工程土方量计算及制作煤层开采深度等值线图等方面，研究结果为矿山GIS应用提供了技术基础。

Surface morphology changes with surface subsidence which caused by underground mining. Mining subsidence features are generally described by two-dimensional curve or sink contour, which can not integrate the original and subsidence information, so it is inconvenience to describe mining area landform scientifically and analyze the dynamic change characteristics. With the further development of the digital elevation model (DEM) theory, using DEM to overlay the original and subsidence terrain information in mining subsidence area, may realize the forecast updating of numeral terrain information in this area. This paper studies DEM updating methods and elevation interpolation algorithms as well as prediction model of mining subsidence, then proposes a forecast update method of topographic map in mining subsidence area by overlaying DEM, the method is: first to forecast the quantity of surface subsidence, then interpolate the original elevation of the sinking points by the original terrain DEM, at last realize DEM update in the mining subsidence area after overlaying two elevation files. Main research contents and results are as follows: (1) On the basis of the analysis of DEM principle, this paper compares several basic methods of updating DEM, in view of the current limitations of those methods, given prediction model of mining subsidence, a forecast update method of DEM in the mining subsidence area is proposed. (2) This paper elaborates DEM interpolation theory, and analyzes the applicability of each interpolation method, then chooses mobile surface fitting interpolation algorithm to interpolate elevation and commonly used probability integral forecast model as well to forecast subsidence. On this basis, this paper analyzes the key techniques and algorithms which are applied in this method, and uses VB to design and program the DEM interpolation and overlay procedure, and forecasts the quantity of surface subsidence by probability integration by MATLAB which can really realize forecast updating of DEM in mining subsidence area. (3) In view of the original elevation information extracted by the digital topographic map in the research example, this paper selects the forecast parameters according to mining geological conditions, and forecasts surface subsidence, at last overlays and updates digital elevation model by the procedure programmed, the updated topographic map can be produced to directly reflect the topographical variations before and after the mining subsidence. (4) Against the DEM interpolation algorithm and probability integral forecast model, the accuracy of elevation interpolation and subsidence forecast has been separately discussed in different parts of mining subsidence area, the result shows that we can improve subsidence forecast accuracy by correcting the forecast parameters, so that it can meet the needs of updating technical requirements of large-scale digital topographic map in mining subsidence area. The research in this paper has initially realized the forecast updating of DEM in mining subsidence areas, the procedure can also be used in producing contour maps of coal seam depth and earthwork calculation, which result can provide the technical foundation for mining GIS applications.