Analysis of Different Vegetation toward the Development of Gully with Aerial LiDAR and Satellite Image

• Main Authors: Chi-HsingTseng, 曾繼興
• Other Authors: Teng-To Yu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/zq96qd

碩士 === 國立成功大學 === 資源工程學系 === 104 === Soil erosion by water is an important physical process that may lead to land degradation. Gully is one of the main ways for slopes to loss soil besides landslide, weathering or erosion. This study intend to use hydraulic connectivity and digital elevation models (DEMs) to detect the location of gullies, then calculate the development of gully by simple subtraction using LiDAR data gathered from different periods of time. On the other hand, distinguishing the types of land-use via methods of Object-Based Image Classification with two periods of satellite images. Finally discuss the relationship between several possible causing factors: different vegetation, slope degree and precipitation toward the development of gully. The result shows that, the hydraulic connectivity model using in this study has an accuracy about 83.3% for searching the gully successfully and has been verified by field survey. Not only the nature gully, remediation project such as river training works will also be shown in the result. Which proves the model can identify the confluence of runoff effectively. Observe the development of gully in pixel level, general erosion height is about 0.2-0.25 meters and the general height of deposition is about 1 meter during a year. Though the forest in the study area is quite complicated, there is still some tendency could be found. Seldom erosion occurred in mixed forest region; the situation of erosion and deposition is the same in the coniferous region. While bamboo and bush covered region have a massive area of erosion and rare deposition, showing that both of them aren’t a good land cover plantation for soil and water conservation, especially the bamboo.