基于GIS的库岸滑坡滑速计算方法

结合GIS(geographic information systems,地理信息系统)的空间数据处理能力,将潘家铮法从二维扩展到三维,提出一个基于栅格柱体单元的库岸滑坡滑速计算方法。建立了基于栅格柱体单元的三维滑坡滑速计算分析模型,给出了模型参数在GIS中的空间计算表达式。其次,通过对计算模型进行受力分析,结合牛顿运动定律,选取了沿滑体滑动方向和垂直方向来建立动力平衡方程,从而求解三维滑坡滑速。在GIS中开发出一个三维滑坡滑速计算扩展模块,并通过实例与潘家铮法所得结果进行对比。结果表明,该方法比潘家铮法计算的最大速度结果大15.2%,比启动加速度结果大32.8%,比达到最大速度的滑动时间短1 s。

A method for calculating the three-dimensional landslide speed of reservoir bank based on GIS

Combined with the spatial data processing capabilities of GIS, a calculation method for reservoir bank landslide speed based on grid column elements was proposed. The Pan Jiazheng method was extended from two-dimensional to three-dimensional. A three-dimensional (3D) landslide speed calculation model based on grid column elements was first established, and the spatial computational expression of each parameter in GIS was clearly specified. Secondly, based on the Newton's law of motion, the dynamic equilibrium equations were established along and perpendicular to the sliding direction to derive the three-dimensional landslide speed. Finally, an expanded module of 3D landslide speed calculation was embedded in GIS platform, and the result of a case study was compared with that obtained from the Pan Jiazheng method. The results showed that compared to results from the Pan Jiazheng method, the maximum speed calculated by the method in this paper is 15.2 % higher and the acceleration is 32.8 % higher, and 1 s shorter for reaching the maximum speed.