| Summary: | 碩士 === 國立屏東科技大學 === 水土保持系所 === 106 === On August 8, 2009, Typhoon Morakot brought a large amount of rainfall, causing disasters in southern and eastern Taiwan, and related problems arising from the continuous downward movement of sediments in the wake of the Morakot wind disaster. The Taitung Forest District Office is located at the 800 meters upstream of Le Lin Bridge in and out of the Zhiben Forest Recreation area to set up a adjustable steel pipe check dam, and to remove the existing sediments control dam downstream. In this study, the river channel from the upstream adjustable check dam to the downstream No. 1 dam in the forest recreation area was used as the study area, the control points were measured by VBS-RTK, and the subsequent data were analyzed through the image data of the previous and the following six periods. The results show that section A of the four sections of the channel is an area of sediments silting, and the silting height of the channel is about 5 meters in front of the adjustable check dam, and the area of deposition in this area accounts for about 87%.B section of the total area, which is the erosion section of the sediments. The depth of the channel is about 5 ~ 10 meters, and the erosion area of this area is about 71%.C of the total area. The section of section C is a section of sediments erosion, and the depth of the river is about 2 or 4 meters, and the area of erosion is about 78%.D section of the total area, which is a silt section of sediments. Part of the upstream channel is deposited about 2 meters, and the downstream part of the channel is brushed at a depth of about 2 or 4 meters, and the area accounts for about 68% of the total area. By using the construction of the regulating sediments control dam and the demolition no. 6 dam, the sediments in section B is moved down, and the river channel changes conform to the original planning concept of the adjustable check dam, thus easing the safety concerns of Lelin Bridge and Zhiben Forest Recreation area.
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