冰川变化可视化计算方法研究

A Visualized Computation Method for Glacier Variation

以天山乌鲁木齐河源1号冰川为例，给出一种基于地理信息系统（GIS）的新型冰川变化，尤其是冰川体积变化的可视化计算方法其原理是利用冰川表面数字高程模型（DEM）。通过格网化对冰面进行连续模拟，计算各格网点高度变化，进而逐点推求整个冰川的变化与传统的冰川物质平衡测量（花杆法）和计算方法（等值线法）相比，该方法是在遥感（RS）和全球定位系统（GPS）技术条件下可实现的快捷、直观的方法，在理论和实践上都具有很大优越性．

A new method, visualized method GIS-based, for computing glacier variation is put forward. The Glacier No.1 at the headwaiers of theUrumqi River, Tianshan Mountains, is taken as an example. By tradition. pole method was widely used,whose substance is estimating mass balance for a whole glacier from a few typical and discrete records.Therefore calculated result depends on sampling number, accuracy and representative. The visualized method continuously simulates the change of glacier surface through grid data of DEM and computes glacier variation in a certain duration. The method needs digitized glacier map in different duration or remote sensing data or direct measurement using Global Position System (GPS). As compared with traditional polemethod and calculation method (isoline method), the visualized method has quick, visual and economic advantages and may be realized through remote sensing (RS) and GPS technique. In this paper the principle,process and computing program of the visualized method are discussed. A satisfied result is obtained as applying this method to the Glacier No.1 at the headwaiers of the Urumqi River. The computation result is compared with measured mass balance. In the compared duration from 1980 to 1986, the height of glacier surface and ice volume computed by the visualized method decreased about 1 653 mm and 2.87×106 m3 and those by traditional method decreased 1961 mm and 3.61×106 m3. If measured specific mass balance is corrected based on glacier area change, then the height of glacier surface and ice volume computed by traditional method should decrease 1849 mm and -3.30×106 m3. It is also found that there is a close relation between the visualized method and pole method. The causes of error have been analyzed. Most of error come from measurement and calculation of mass balance. Partial error is caused by digitized DEM and visualized computation. In general, this study is concerned with the application of 3S technique to glaciology. The purpose is now focused on methodology. The method provides a route for study of glacier variation using 3S technique.