北京地区地面沉降监测及风险评价研究

【作者】 陈蓓蓓；

【导师】 宫辉力； 李小娟；

【作者基本信息】 首都师范大学 ， 地图学与地理信息系统， 2009， 硕士

【摘要】 地面沉降是一种不可补偿的永久性环境和资源损失,是我国乃至世界范围内较为普遍的地质灾害。北京地区地面沉降已有半个世纪的历史,目前仍然处于持续发展状态,严重影响了首都社会经济的可持续发展。针对地面沉降监测方法方面,传统的地表监测手段(水准测量、分层标、GPS等)取得了一些成功的应用。但是这些方法还存在一定的不足,在传统D-InSAR技术基础上发展起来的永久散射体干涉测量技术(Persistent Scatterers for SAR Interferometry, PSInSAR)能够有效降低时间、空间去相干影响以及减弱大气延迟引起的误差组分,有助于提高形变的时、空分辨率及数据处理的精度,是全面获取地面沉降监测信息的有力手段。因此,本论文以北京市典型地面沉降区为研究区,采用永久散射体技术- StamPS算法(Hooper,2004),利用覆盖北京地区的16幅ASAR图像进行永久散射体干涉处理,通过在时间序列PS点上求解出干涉相位中各组份的分量,最终获得北京地区地面沉降监测信息。初步揭示了研究区地面沉降的空间分布特征。在利用InSAR技术获取地面沉降全面监测信息的基础上,综合考虑地面沉降灾害对社会、经济可持续发展带来的严重影响,选取北京市重点区县(密云-怀柔-顺义地区)建立基于层次分析法与模糊综合评价方法(AHP-Fuzzy)相结合的地面沉降风险评价模型,并结合GIS空间分析的方法,对地面沉降的风险范围、风险程度等进行综合分析,结果表明北京地区的地面沉降防治刻不容缓,研究结果对北京地区地面沉降灾害的防治与减缓有一定的理论和实际意义。更多还原

【Abstract】 Land Subsidence, a kind of main urban geological disasters which has occurred in our country and all over the world, is a loss of environment and resources which is unable to be compensated. The land subsidence in Beijing area that occurred about fifty years is developing continuously and deeply affects the sustainable development of social economy.The lack of observational data has made it difficult in the past to accurately define the extent of the deforming areas, the magnitude of the surface displacements, and the seasonal land-surface motion with higher temporal resolution and spatial resolution. Persistent scatterers (PS) interferometry, which is an extension of conventional differential synthetic aperture radar interferometry (D-InSAR), it can reduce the temporal and spatial decorrelation and weaken the error that occurred by atmospheric delay,enhance temporal and spatial resolution, therefore,the Persistent scatterer (PS) technology is a useful method for monitor the land subsidence . In this paper, I have used ASAR data to derive detailed maps of the time-varying surface displacement fields over the Beijing city from 2003 to 2006 with PS-InSAR techniques.Based on the land subsidence retrieved by PS-InSAR techniques using ASAR data, I establish a hazard assessment model of land subsidence in Beijing using the AHP—Fuzzy method. The AHP-Fuzzy model index system is composed of 3 first-grade factors and 9 second-grade factors, and the evaluation method is based on Remote Sensing and GIS technology. PS-InSAR techniques were used to retrieve the parameters of land subsidence by using ASAR data. The parameters are as the factors in the AHP—Fuzzy evaluation model. The AHP—Fuzzy assessment model was analyzed by using a GIS-based modeling approach. Finally, a case study was carried out in Miyun-Huairou-Shunyi area of Beijing. The more detailed results include: firstly, the risk index value of each study area was extracted by means of the AHP—Fuzzy method. Second, the risk degree of land subsidence was analyzed using the dimensional analytical method based on GIS technology. Third, combining with the present situation of groundwater overexploitation and the thickness of compressive layer, the hazard level of land subsidence can be divided into three grades: the less risk area, the middle risk area, the higher risk area. It indicates that the risk of land subsidence in Beijing is indispensable. This result is reasonable and useful for land subsidence disaster prevention and reduction.更多还原