GPS在三峡水库区云阳县滑坡监测中的应用

文章概述了在库区云阳段建立GPS滑坡监测网的观测实践,以黄泥巴蹬坎滑体为例,介绍了GPS相对定位技术在云阳县滑坡的应用现状和进展。在采用GPS监测、深部位移监测、宏观地质巡视的同时,还监测降雨量、地下水位、库水位及不合理的人类工程活动。通过多种监测方法分析,发现在雨季滑坡容易产生变形,非雨季变形缓慢。目前,雨季日变率均小于5mm,而在非雨季平均日变率小于1mm。认为该边坡处于缓慢变形阶段(警惕线)。此外,在巡视过程中,也发现了多条宽1~5mm、长度不等的裂缝和高度不等的局部错台。根据近2年所获得的观测成果分析,深部位移监测、GPS监测和宏观巡视的结果十分吻合,效果令人满意。文章还总结了在滑坡监测中消除GPS测量主要误差的对策。满足方便快捷的同时,在不同时段采集GPS监测数据,适当延长监测时段,每个监测点至少观测2h的要求。多方收集信息,尽量避开潮汐、太阳黑子等活动的时段进行GPS监测。

Application of GPS technique for landslide monitoring in Yunyang County of the Three Gorges Reservoir area

The paper generalizes about the application of GPS landslide monitoring network in Yunyang of the Three Gorges Reservoir area and takes Huangnibadengkan Landslide as an example to illustrate the application of GPS relative measurement technique in the landslide monitoring in Yunyang County.While adopting GPS monitoring,deep displacement monitoring and macro-geological inspection tour,we monitor rainfall,the change in groundwater level and reservoir water level as well as improper human engineering activities.Through analysis of multi-method monitoring,we find that landslides tend to become deformed in rainy season,while in non-rainy season deformation slows down.At present,daily deformation of the landslide is smaller than 5mm in rainy season and smaller than 1mm in non-rainy season. We consider that it is at the stage of slow deformation(or warning stage).Besides,in our inspection tour,we found several cracks ranging in width from 1mm to 5mm and malposition of platforms with various heights.Based on the analysis of the monitoring data in the past two years,we find the results of deep deformation monitoring,GPS monitoring and macro-geological inspection tours satisfactorily coincide.The paper also summarizes the measures of avoiding main errors in landslide monitoring. We take advantage of the convenience and high-speed of GPS monitoring,at the same time,we should collect GPS monitoring data at different periods of time and lengthen the time of monitoring to at least two hours at each monitoring spot.GPS monitoring should not be done at the time of the activities of tide or sunspots.