地基SAR技术支持下的滑坡预警预报分析方法

Analysis Method of Landslide Early Warning and Prediction Supported by Ground-Based SAR Technology

  • 摘要: 滑坡预警预报是滑坡动力灾害研究工作的重点和难点问题,预警及时性和预报准确性是评估滑坡预警预报效果的两个核心关键指标。地基合成孔径雷达(synthetic aperture radar,SAR)为近距离遥感监测边坡、开展滑坡预警预报工作提供了先进的技术手段,为准确定位滑体位置、圈定滑体规模、分析判断滑坡风险及预测滑坡时间提供了丰富的数据源。基于经典边坡变形演化三阶段理论,采用具有近实时性、覆盖监测区域面变形信息的地基SAR监测数据,结合边坡监测数据周期短、密度大、面覆盖的特点,提出了基于变形速度和变形面积的双指标滑坡预警方法。此外,还针对监测数据振荡性强、趋势性弱、预报时效性差的问题,根据变形速度-时间序列曲线与边坡稳定性之间负相关的关系,提出了速度取倒数、去限值、不等周期平滑处理监测数据快速处理方法,并建立了一种边坡稳定度快速收敛的滑坡破坏时间预测模型。露天矿边坡的现场实践和应用表明所提出的预警预报方法实操性强,预测结果准确。

     

    Abstract:
      Objectives  Landslide early warning and prediction is the key and difficult problem in landslide dynamic disaster research. The timeliness and accuracy of early warning are two key indicators to evaluate the effect of landslide early warning and prediction.
      Methods  Remote sensing monitoring is an important technology for landslide disaster prevention and control. Ground-based SAR(synthetic aperture radar)provides an advanced technology for remote sensing monitoring of landslides in short distance, and provides a wealth of data sources for accurate positioning of landslides, delineating the scale of landslides, analysing and judging the risk of landslides and predicting the time of landslides. Based on the classic three-stage theory of slope deformation evolution, we adopt the monitoring data of ground-based SAR, which has the characteristics of near real-time, coverage monitoring area and surface deformation information. Combined with the characteristics of the short period, high density and surface coverage of slope monitoring data, a dual index landslide early warning method based on deformation speed and deformation area is proposed. According to the negative correlation between deformation velocity time series curve and slope stability, we put forward the processing methods of velocity inversion, de-limit and unequal period smooth processing, and establish the landslide prediction model with fast convergence of stability.
      Results  The landslide early warning method with double indexes of deformation velocity and deformation area can effectively improve the accuracy rate of landslide warning, and then the accuracy of landslide prediction can be effectively improved by taking the reciprocal of velocity, removing the limit value and unequal period smoothing treatment. Different periods of data processing methods have their own applicability, short processing cycle processing data curve, the prediction of landslide occurrence time is more accurate, the prediction of landslide occurrence time is late, long processing cycle is opposite.
      Conclusions  Through the field practice and application of the open pit slope, it shows that the early warning and prediction method has strong practicality and accurate prediction results.

     

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