analysis of the ecological environment change by geoinformatics technology at special erosion area in taiwan | 量子荧光|微型光纤光谱仪-ag贵宾会

in southwestern taiwan, mudstone area covers broadly. the area scatters in chayi, tainan and kaohsiung, counties and cities, which takes up 3% of the total surface on taiwan island. mudstone area has soils with high salinity and high clay content. the soil becomes very hard when dry and very susceptible to erosion when wet. therefore revegetation is urgently needed in mudstone area, which is mainly located in southwestern taiwan. in the recent forty years, there were plenty of disturbances happened in the mudstone area in the southwestern taiwan, resulting in desertification, improper reclamation and management, and over fertilization on orchards, pollutions from farms, and improper land-use and so on. aerial photography showed that the bare area was only 2,532.58 ha in 1967; however, it increased up to 3,836.28 ha in 1987. in 1997, the satellite imagery from landsat tm showed the mudstone bare area was expanded to 11,179.5 ha (lin and chang, 1999), 3 times the area of the initial. the expand rate had been larger and larger these years, from 65 ha per year (1967-1987) to 730 ha (1987-1997), so that neither vegetation engineering nor natural vegetation could be built on it, and it would easily result into desertification, micro-climate change. these results may make reciprocal effect to endanger the mudstone area of southwestern taiwan (chang et al., 2001, 2002, 2003; chang et al., 2002 a, b; lin et al., 2003).