Establishment And Application Of Seismic Landslide Database In Loess Area

The loess region of China is located in the northern part of the north-south seismic belt,where earthquakes occur frequently.The seismicity is characterized by large magnitude,short period and heavy earthquake damage.In history,there were many strong seismic activities in the loess area,which induced a large number of geological disasters such as landslide,collapse,and ground fissures,among which the most serious is the earthquake landslide disaster,which caused a devastating blow to the people in the earthquake area.Therefore,the study of seismic landslide disaster in the loess area has important theory and significance for reducing the seismic disaster loss and exploring the mechanism of seismic landslide disaster in the loess area.In this paper,the loess landslide induced by Haiyuan earthquake is taken as the research object,and on the basis of sorting out and checking the data of loess seismic landslide collected in the field,a database management system which can store,input,update,query and download a large number of loess seismic landslide data is preliminarily established.At the same time,the distribution law of loess seismic landslide in the study area is preliminarily analyzed by using the data of the system.The work in this paper can provide basic data for the formation conditions of loess seismic landslides,the formation mechanism of earthquake-induced loess landslides,the topographic restoration of seismic paleolandslides in the loess region and the study of seismic sites.The main work and research achievements are as follows:1.The basic situation of Haiyuan earthquake and related research results are summarized and introduced.On the basis of collecting and collating the existing research results of Haiyuan earthquake,this paper systematically introduces the basic information of Haiyuan earthquake,such as seismogenic time,epicenter location,magnitude and focal depth,casualties and economic losses,structural damage and seismic and geological disasters.This paper summarizes the geological background of haiyuan earthquake from five aspects of landform,stratigraphic lithology,geological structure,historical seismicity and hydrometeorological conditions,and briefly analyzes the relationship between the development of loess earthquake landslide and geological environment in haiyuan earthquake,which provides background materials for the establishment of seismic landslide database in loess area.2.The functions of different databases are analyzed and compared,and the Access software is introduced in detail.On the basis of the existing data,the database system of the composition,characteristics,and main types of database system(hierarchical database system,network database system,a relational database system,objectoriented database system and No SQL database system),as well as the advantages and disadvantages of their corresponding typical software system has carried on the simple analysis and discussion.According to the overview,advantages and disadvantages of the database building software-Access software system adopted in this paper,as well as the changes of the characteristics of the 13 versions in common at the present stage,the corresponding explanation is made.The six working objects of the Access 2019 software system selected in this research are mainly introduced,such as table,query,form,report form,macro and module.These works have laid a solid foundation for the establishment of seismic landslide database in the loess area.3.Completed the sorting,checking,unified coding and standardized design of a large number of loess seismic landslide data in the field.Briefly describes the loess seismic landslide data collection,the latitude and longitude coordinates from the landslide point,name,length,width and shape of the original data was introduced in detail from the aspects such as landslide corrective actions,the data structure of the database and the unified coding standardized design,the database structure and function of the preliminary design,to complete the preparations for the loess area,the earthquake landslide database established.4.The Access 2019 database software was used to complete the establishment of the seismic landslide database system in the loess area.Based on the seismic landslide data of Haiyuan earthquake induced by the author's research group,the basic framework of seismic landslide database in the loess area is constructed,and the functions of storage,input,update,query and download of seismic landslide data in the loess area are initially realized.This paper briefly introduces the maintenance method of the database.5.Using database call database property parameters,and statistical analysis of the seismic landslides and landslides length,width,earthquake intensity and main sliding direction,maximum horizontal distance,vertical distance,the original slope slope direction,the original slope,slope Angle,relative distance,relative epicenter azimuth,epicenter distribution characteristics of relative parameters such as the distance of the fault.