利用水准数据的天津市地面沉降时空特征分析

Spatial-temporal characteristics of land subsidence in Tianjin city based on leveling data

地面不均匀沉降可能对城市的发展与人民的安全造成危害,天津市的地面沉降情况尤为严重。针对该问题,本文收集天津市2005—2012年、2016—2017年水准观测数据,以固定水准点位的沉降量、沉降速率、沉降加速率为状态向量,构建卡尔曼滤波模型,对天津市历年的水准观测数据进行滤波;根据滤波后的结果,本文利用多项式加权内插的方法,以距离、沉降速率、沉降加速率信息确定权值大小,对地面沉降情况进行内插;并以中误差作为精度评定参数,比较多种内插方法的精度。通过对内插结果的试验分析发现,2005—2017年天津市地面累计平均沉降量为394.4775 mm,最大沉降量为1143.5 mm;主要沉降区域为北辰、大港、塘沽等地区,且随着时间的增长,这些区域呈现漏斗式下沉。试验证明本文结合卡尔曼滤波与多项式加权内插的方式能够较好地反映地面沉降的时空特征分布情况并对未来一段时间的沉降情况进行预测,对天津市的城市发展及建设有一定的参考意义。

Uneven land subsidence may endanger urban development and people’s safety.The land subsidence in Tianjin city is particularly serious.Aiming at this problem,this paper collects the leveling observation data of Tianjin city from 2005 to 2012 and from2016 to 2017.The Kalman filter model is constructed based on the state vector of the settlement amount,settlement rate,and settlement acceleration rate at a fixed level to filter the level observation data in Tianjin city over the years.According to the results of filtering,this paper uses the method of polynomial weighted interpolation to determine the weights by the information of distance,settlement rate and settlement acceleration rate,and to interpolate the land subsidence.The accuracy of various interpolation methods is compared by using the root mean square error as the precision evaluation parameter.Based on the experimental analysis of the interpolation results,the cumulative average ground settlement in Tianjin city from 2005 to 2017 is 394.4775 mm,and the maximum settlement is 1143.5 mm.The main settlement areas are Beichen,Dagang,Tanggu and other areas.And with the increase of time,these areas present funnel-like subsidence.Experiments prove that this method combined with Kalman filter and polynomial weighted interpolation can better reflect the spatial and temporal distribution of land subsidence,and predict the settlement in the future,which has a certain reference significance for the urban development and construction of Tianjin.