Application Of Short Baseline Set Interferometry (SBAS) Technology In Zhengzhou Urban Land Subsidence Observation Research

Land subsidence is mainly the slow reduction of the urban ground height caused by multiple natural factors in the urban geological environment.With the rapid development of urban construction,the hazards of land subsidence are becoming more and more prominent.It has a wide distribution range and the change process is not easy to be short.Discovery within time and other features.Zhengzhou is located in the central part of North China and is a major transportation hub city in the country.Due to the continuous enhancement of the functions of the central city,the rapid development of urban construction has produced many underground funnel areas.These land subsidence areas directly or indirectly hinder the urban expansion and development of Zhengzhou,and even affect the people's living environment.Therefore,timely and accurate monitoring of land subsidence and change trends is of great significance,and it is also an important task facing Zhengzhou's social and economic sustainable development.In this paper,short baseline set interferometry(SBAS)technology is used to study the characteristics of land subsidence in Zhengzhou city.The process and technical focus of SAR data processing are discussed,various parameters obtained in the SAR data processing process are analyzed,and multi-scene RADARSAT-2 radar images covering Zhengzhou urban area are selected as data,and short baseline set interferometric processing is performed.According to the settlement rate results,the characteristics of ground settlement deformation in Zhengzhou urban area are analyzed.The main achievements and understandings are as follows:?.In this study,the land subsidence of Zhengzhou City from 2015 to 2017 was extracted.The results show that the area of the settlement area with a settlement rate greater than 20 mm/a is about 166 km2.Three main subsidence areas have been formed,which are the northern subsidence area,the western subsidence area and the eastern subsidence area.Subsidence areas are mainly distributed in sub-regions of engineering geology with soft soil distribution.?.The main cause of land subsidence in the study area is human social activities.It is prominently manifested in the utilization of groundwater,exploitation of geothermal resources,and urban infrastructure construction.The scope of the subsidence area is basically consistent with the distribution of the groundwater funnel area and the dense geothermal application area formed by urban development.This result further proves that human social activities are an important factor in the formation of land subsidence in Zhengzhou.?.Accurate monitoring of the land subsidence process in urban areas has gradually become the focus of social development.How to more effectively solve the influence of errors in the process of land subsidence monitoring,expand the application scope and monitoring capabilities of differential interference technology is also the direction of further research.It is a social development trend to develop In SAR technology into conventional land subsidence monitoring technology.