碩士 / 國立中興大學 / 水土保持學系所 / 96 / Due to the characteristics of flat terrain, huge bare soil in drought season, and the monsoon effect, the estuaries of rivers in central Taiwan are susceptible to serious wind erosion. Large amounts of dust emission to inland decrease the living quality and affect the human health nearby in the monsoon season. Therefore, it is important to delineate the potential areas where are mostly susceptible to wind erosion on the riverbed and to make some vegetation strategies for the areas of dust emission.
The section of Jhuoshei River was selected as the study area. The satellite imagery and water level are used to calculate vegetation indices, texture factors and the frequency of water level. The supervised back propagation neural network technology was employed to compare the accuracy of image processing by using the vegetation indices and/or the texture factors which derived from SPOT satellite imagery for the bare land, farm, vegetation, water classification.
In addition to use the reflection of spectrum and three kind of moving window sizes to calculate texture factors for classifying landcover, and discussed what kind bands of combination is the best. Gumbell’s extreme value type I and type III distribution calculated the frequency of water level, and then coupled with DEM to delineate the dust emission potential areas.
The results showed that (1) Original bands plus vegetation index showing different performance in interpretation, it should be carefully selected for the certain study area. (2)The image processing with original bands plus NDVI and texture factors has the best interpretation. The best moving window size is 7×7 for the texture factors calculation. (3) The potential areas of dust emission can be categorized the bare sites along the main channel and the uncultivated/cultivated areas at the flood plain. (4) According to image classification, frequency analysis of water level, and DEM, most potential areas are located at the uncultivated riverbed. To make some vegetation strategies for these areas can effectively decrease the damage of dust and maintained the vegetation facilities for sustainable estuary management.
| Identifer | oai:union.ndltd.org:TW/096NCHU5080033 |
| Date | January 2008 |
| Creators | Cheng-Jyun Li, 李承寯 |
| Contributors | 林昭遠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 85 |
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