基于DEM的克亚吉尔冰川湖容积插值计算研究

Study on Volume Interpolation Calculation of Kyagar Glacier Lake Based on DEM

克亚吉尔冰川湖的突发洪水灾害是叶尔羌河流域的主要灾害之一。为了解该湖不同高程对应的湖面积和湖容积,通过GIS中的湖痕线和最新的DEM进行了等高线分析,利用拉格朗日四点插值公式查算两条相邻等高线之间高程中点对应的湖面积值,用抛物线法估算得到不同高程对应的湖面积和湖容积。结果表明:湖水位4760、4785、4810 m时对应的湖面积分别为0.089、0.378、1.082 km2,湖容积分别为10万、538万、2200万m3;2011年、2012年冰川湖容积最小为450万m3,最大为950万m3,冰川湖突发洪水的潜在危险等级较低。

Glacial Lake outburst is one of the main hazards on the Yarkant River. For the area and volume of glacial lake corresponding with different elevations,a graphical method or a four-point Lagrange interpolation formula could be calculated area values of lake area by the midpoint between two adjacent elevation contour lines,based on database of GIS and DEM of satellite data in Kyagar Glacier Lake area. Then it used the parabolic interpolation method to calculate the volume of glacial lake corresponding with different elevations. The results show that the area and volume of Kyagar Glacial Lake with different water levels are 0. 089 km^2 and 10 × 10^6 m^3 with 4 760 m,0. 378 km^2 and 538 ×10^6 m^3 with 4 785 m,1. 082 km^2 and 2 200 × 10^6 m^3 with 4 810 m. The minimum volume of Kyagar Glacial Lake is 4. 5 × 10^6 m3 ,and the maximum volume is 9. 5 × 10^6 m^3 from 2011 to 2012. The identification of the glacial lake outburst floods hazard potential is low.