Study on measurement and evaluation of land transformation using photogramtry and GIS

就日本近年来的地震灾害而言，郊区的住宅区受到了影响。这些庄园是通过在山谷中填平和在山脊上切割的土地改造在山上开发的。本研究的目的是利用摄影测量和GIS技术，测量土地的变化，评价土地的抗地震条件。从改造前后土地dem的编制，到GIS中土地状况指数的形成，再到多变量分析，探讨了房屋破坏与土地状况的关系。在土地改造前无法获得大比例尺地形图的情况下，可以使用航空照片获取DEM。然而，通过试点研究，证明了利用数字摄影技术直接生成DEM难以精确获得DEM。通过航拍→立体标绘等高线→数字化等高线→在GIS中生成DEM等一系列技术获得DEM。采用一系列技术对钏路、神户、福冈等地改造后的房屋破坏情况进行了分析。采用交叉表法和logistic回归分析方法，分析了各案例震害（建筑震害）的空间分布与各土地条件指标的关系。因此，“填土厚度”和“离填土边界线的距离”被认为是影响建筑物破坏的重要土地条件。此外，对案例研究的结果进行了检验，以预测改造后土地的未来损害。并对2003年发生在研究期间的北宫城地震所造成的破坏进行了调查和思考。

As for the earthquake disaster in recent years in Japan, housing estates in the suburban area have been affected. These estates were developed in the hills by land transformation with fills in the valleys and cuts on the ridges. The purpose of this study is to measure the land transformation and to evaluate the land conditions of the land against earthquake, using photographic surveying and GIS. A series of analyses is developed from the preparation of the DEMs of the land before and after transformation, through formation of the land condition indices in GIS, to multivariate analysis to discuss the relationship between the housing damage and land conditions.In the case that large scale topographical maps are not available to obtain the DEM before land transformation, air photographs may be available. However, it was proved that direct DEM formation by digital photogrametry technology was difficult to obtain the DEM precisely by the pilot study. Instead, the DEM was obtained by a series of techniques : air photographs → stereoplotting contours → digitize the contours → DEM formation in GIS.Housing damages in the transformed land in Kushiro, Kobe and Fukuoka were analyzed by the series of the techniques. The relationship between the spatial distribution of earthquake damage (building damage) of each case and the various land condition indices were analyzed by the cross tabulation and logistic regression analysis.As a result, "thickness of fills" and "distance from cut-fill boundary line" were recognized influencing building damage as significant land conditions. Furthermore, the results of the cases studies are examined in order to predict future damage in the transformed land. The damage of Northern Miyagi earthquake which occurred in 2003 in the study period were investigated and considered, as well.