基于GIS的冰川动力学模型部分参数自动提取研究

GIS-Based Study of Automatic Extraction of Glacier Dynamics Model Parameters

对冰川进行动力学模拟,对于理解和预测冰川对气候变化的响应具有非常重要的意义.每条冰川主流线上各节点间的面积-高程分布、坡度等是冰川动力学模拟中必需的参数,采用人工方法提取冰川的这些参数需要耗费大量时间和人力.因此,在GIS技术支持下提高获取参数的自动化程度对于获取参数的效率十分重要.以叶尔羌河流域为例,以冰川分布矢量、冰川主流线、流域的数字高程模型为基础,开展了冰川动力学模型参数自动提取流程的试验研究.研究参考了人工提取的流程,先自动提取冰川主流线上各节点处的高程,进而获取主流线上各节点之间的分带面积,最后计算出其他参数,如冰川作用差、长度、坡度等.整个过程基本实现了提取流程的自动化,为流域冰川动力学模拟提供了有效工具.

Glacier dynamic model is very important to understand the process of glacier change and forecast its future response to climate change.Some parameters of glacier dynamic model have been manually generated,which is time-consuming.In this paper,a new process,which couples ESRI Arc Micro Language（AML） and Visual Basic for Applications（VBA）,is process to semi-auto extract the parameters,such as elevation,slope,and band area of each node along the mainstream of a glacier.As examples,the glaciers in Yarkand River basin are introduced,by using the vector map of glaciers,glacier mainstream lines,Digital Elevation Model（DEM）.The nodes in the mainstream are auto-extracted at first,then the elevation of each node is auto-extracted,and the band area between two nodes is automatically calculated on the basis of ＂zonalstats＂.At last,the results are integrated in one file for the model input.This process greatly enhances the efficiency of preparing the parameters of dynamic glacier model,and will be widely applied.