Coastal land use changes in Yunlin County, Taiwan between 1996 and 2011

Abstract
Located in west coast of Taiwan, Yunlin County is more vulnerable for industrialization and rapid urban growth. The objective of the study is to investigate human induced coastal land use changes in Yunlin County between 1996 and 2011.  SPOT image of 1996 and FORMOSAT-2 image of 2011 were used for this study, and 5km width coastal belt from coastline to inland was selected as study area to analyze the coastal land use changes. The entire study area in both years were classified into seven different land use types; agriculture, aquaculture, industry, settlements, sandy coast, vegetation and abandoned lands. Land use maps were developed using ArcGIS 10.1, and land use changes between 1996 and 2011 were analyzed in detail. As results revealed, industrial areas and residential areas have increased by 70.3% and 71.96% respectively during fifteen years while agricultural areas decreased by 11.46%, aquaculture by 32.92% and sandy coast by 92.51%. However, vegetation in Yunlin coastal area has increased by 45.82% and 0.31% of total land area in 1996 has become abandoned up to 2011. The results of the present study reflect, between 1996 and 2011, coastal zone in Yunlin County has undergone significant land use changes due to human intervention, and the most prominent change was dramatic increase of industrial and residential areas. 

Effects of land use/ land cover changes induced by Typhoon Morakot in Linbian Watershed, Taiwan

Abstract
This study analyses the significant impacts of typhoons on the land cover change.  The occurrence of landslides following typhoons is a major indicator of natural disturbance. On 8 August 2009, the extreme rainfall of Typhoon Morakot triggered enormous landslides in mountainous regions of southern Taiwan, causing catastrophic infrastructure and property damages and human casualties. In the above study land use change was assessed from 2006 to 2012 time period. The land use changes revealed by four remote images corresponded to typhoon Morakot in southern Taiwan. This study was carried out through remote sensing and GIS approach using Formostat-2 satellite images from May 2006, May 2009, August 2009 and October 2012 in Linbian watershed, Taiwan.  The study watershed is dominated by the vegetation cover. Most often this vegetation is cultivations. The land cover change results indicate that immediately after typhoon Morakot the vegetation cover reduced by 30%. Similar to that fallow land has been converted to barren land in 30 %.  The Linbian River has become widen due to the deposition of sediment, after the Morakot.  There is no considerable change observed in settlements due to typhoon attack.  The land use cover of 2012 show recovery is gradually happening by after three years. However, it is necessary to closely monitor the land use/land cover changes for maintaining a sustainable environment.
Keywords：Land cover change、Remote sensing data、Typhoon、Vegetation、Sediment

Impacts of Invasive Tradescantia fluminenesis (Vell.) distribution on native biological diversity－a comparison between Yangmingshan National Park and Alishan National Recreation Area, Taiwan

Abstract
Geographic Information System is a first-rate tool for mapping spatial distribution of vegetation in forest ecosystems. This paper based on distribution and mapping of notorious invasive herb species Tradescantia fluminenesis (Vell) in Yangmingshan National park and  Alishan Recreation area. Study mainly focused on Yangmingshan National Park due to the past studies reveal T. fluminenesis fastest growing patterns among alien species in Yangmingshan National Park, and presented in 108 of roadside locations, and highest occurrence and optimization recorded on elevation 650-850m. But the present observations of the park indicate the distribution moving more toward higher elevational gradients as well. Most propagules occupied in roadside vegetation along the mixed broad leaf forests. Most higher elevation of the park dominated by grass (Miscanthus floridulus) and bamboo (Pseudosasa usawai). The distribution of T. fluminenesis with in grasslands and bamboo forests still in initial stage. In Alishan National Recreation Area all the recorded locations were elevated more than 2000m. Comparing distribution patterns within mid elevation of Yangmingshan, the Alishan distribution is more preliminary stage. Due to lack of undergrowth layer underneath the cypress forest there is a high ability to spread the T. fluminenesis deeper forests areas. The both forests areas are responsible for high plant and animal diversity. The high invasive capability of T. fluminenesis will be troublesome for the forest regeneration and native biodiversity in future.

Key words：Alishan、Biological invasion、Geographic Information System、Tradescantia fluminenesis、Yangmingshan