The Southern Cross-Island Highway is one of the major channels that bridged the eastern and western part of Taiwan. With the purposes of national defense, development of local community, mining of the mountain resources, traveling and tourism, it is essential to investigate the natural disasters along the roadside slope. To afford the references of future protection on the slope failures along the highway, the information system, used to creat a disaster database has been developed and introduced to this research.
To understand the slope failure along the roadside and the distribution of the natural environment, the Global Position Systems(GPS)and Geographic Information Systems(GIS)with positional investigation and overlay statistics has been adopted to examine the landslide and slope failures along the Southern Cross-Island Highway between Ya-Ko and Hai-Duan. According to the examination and analysis, most of slope failures usually happened on the northeastern and northern facing slope, the elevations within 500 to 1000 meters, and the steep from 60 to 70 degrees. The major slope failures, including slope slump and rock fall, occurred on the upper slope. Because of the soil layer serious scouring on slopes triggered by the weathering of rock strata, runoff erosion and seepage flow, the slope slide has been found on the down slope along highway.
Besides, the Geo-environmental investigation, the multivariate analysis and unstable index, and geographic environment factor have been conducted to evaluate the risk of slope failures along the highway. According to this analysis, the highway between Wu-Lu and Chu-Lai is the highest risk section that should be considered as the first priority to deal with. This section is also recognized as the most serious slope failures along the highway during the investigations.
Finally, the Geo-Information database integrated with the database systems from Chia-Shuan to Ya-Ko has been created according to the positioning investigation of landslide, natural environmental information, government administration file and disaster surrounding data. Take advantage of this database, the Geo-Information Database Query Systems of Southern Cross-Island Highway is completed set up by integrating datalink program and Graphic User Interface with Visual Basic and Avenue scripts.
