Study Of Ground Subsidence Based On GIS And SPSS

In a broad sense, ground subsidence is the earth' s surface dropping vertically formed by natural factor and human factor. Ground subsidence in the narrow sense of the word is formed by human factor, namely usually ground subsidence calamity. This article taking the urban area of Jining in Shandong province as an example, tries to use GIS and SPSS to research ground subsidence. This article includes nine parts:First part is an introduction about the concept, danger, the research history of the ground subsidence both at home and abroad, and current situation.Second part is a brief introduction about the background of the researched problem selected and the research approaches adopted.The third part is a brief introduction of the overview of the researched area.In the fourth part the history of ground subsidence happened in the researched area and its danger were introduced.In the fifth part comprehensive analyses of the conditions, mechanism, and influence factors of the ground subsidence happened in the researched area were made. The natural factors of the ground subsidence include crustal movement, geological structure, geology, physiognomy, and hydrology, etc. The human factor includes excessive exploitations of fluid resources, such as groundwater, etc.In the sixth part, the collection and management of data, the establishment and management of the database, and the protraction and usage of related maps in the research of ground subsidence were introduced and discussed.In the seventh part, the conversion between the data of SPSS and GIS and the data editing function of SPSS were introduced. And simulations of the space distributions of the ground subsidence and its influencefactors were performed by SPSS. The lowest precision of the simulation is 86. 7%, and the highest precision of the simulation is 97. 6%. The trend surfaces tally well with the actual space distributions of all the elements. The relation between the surface subsidence and its influence factors also were analyzed in this part. Linear fits between the surface subsidence and every related influence factors were performed. The result indicates the ground subsidence keep close relations with ground water level of deep layer in 1998, the varieties of ground water level, and distributions of viscidity soil thickness. Among all the influence factors, the contribution of thickness of the viscidity soil distributing between 0~110m is the most great, secondly is groundwater level of deep layer in1998.In the eighth part forecast models of ground subsidence were discussed. And the grey model was applied to forecast some tendency of the ground subsidence in urban area of Jining city.The ninth part is discussion and conclusion.