碩士 / 國立宜蘭大學 / 森林暨自然資源學系碩士班 / 101 / Wetland losses often contribute from the economic development. The purpose of the study is to understand the amounts of wetland losses and the land-use types that wetland transferred to in the coastal zones of the Lang-Yang plane by using the Geographic Information Systems and the historical maps and aerial photos.
Seven periods of maps and aerial photos in the year of 1904, 1921, 1959, 1975, 1992, 2003, and 2010, respectively, were collected, geo-corrected, and digitized into different land-use types using the GIS. The ratios of transfer-in and inheritance of each land-use type were calculated by overlaying the land-use map of a period with that of the prior period, as well as the ratios of transfer-out and retaining were calculated by comparing with that of that of the afterward period. The indices of landscape ecology were also analyzed for the qualities of the land-use types.
The results showed that the retaining and inheritance ratios of agriculture and forest types were the highest. The area of wetland type continued decreasing and the transfer-out ratio was high from 1904 till 1975, none the less the area did not decreased and the transfer-out ratio dropped down from 1992 likely due to the conservation of wetlands initiated when the wildlife conservation act took place in 1989. If the agriculture (mostly paddies) and aquaculture were considered as wetlands, then general wetland area was near 80% of the total land area before 1992, but reduced from 2003, to 62.4% in 2010, mostly transferred out to construction type. It indicated that the purpose of land development shifted to urban development.
The landscape metric of total edges, edge densities, and average fractal dimensions appear increasing, where that of average patch area display a trend of decreasing. It suggested the fragmentation of land sues. However, the landscape indices of average patch area and total edges gradually decreased, whereas those of edge densities and average fractal dimensions scarcely varied. It might suggest that he shapes of wetland were mostly irregularly.
The total area of wetland might be conserved well in recent decades, but the men-made wetlands such as paddies and aquafarms should be also conserved for its ecosystem function. The fragmentation of coastal landscape gradually increases since 1904. Wetland quality went down in the landscape points for the patches of different land-use types interlaced more intensively, and the average patch area of wetland decreased. The future land management should consider the arrangement of landscape.
| Identifer | oai:union.ndltd.org:TW/101NIU00148007 |
| Date | January 2013 |
| Creators | Han-I Wei, 魏涵義 |
| Contributors | Chung-hsin Juan, 阮忠信 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 115 |
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