空間監測系統對大漢溪河谷進行地形變遷時序變化之研究

A Study on Time-Changes of terrain changes in Dahan River Valley by Spatial Monitoring System

本研究使用三維光達雷射掃描技術（3D LiDAR），配合內政部國土測繪中心之電子化全球衛星即時動態定位系統（e-GNSS），結合多元量測技術之數值資料，藉以長期監測大漢溪河谷之地形變遷。
本研究之研究目的有二：1.多衛星資料套合e-GNSS觀測系統進行控制點位之量測；2. 3D LiDAR觀測資料對大漢溪河谷進行階段性地形監測；3.建立大漢溪河谷動態之時序變化。
自106年至111年多次監測，再經本實驗數據分析，顯示布設之控制點平面位置較差在0.013~0.05公尺之間，實驗區域點雲拚度精度約在0.0030~0.0070公尺。從各時期觀測資料相較，皆可得出河床逐漸遷移的證明。本研究對大漢溪河谷長期監測，成果顯示大漢溪河谷地形逐漸變遷之事實存在，也提出結合利用多元化空間量測技術之另類監測模式的可行性。

For long-term monitoring terrain-changes in the Dahan River Valley, this research integrated numerical data of 3D LiDAR( three-dimensional Light Detection and Ranging ), e-GNSS (Electronic Global Navigation Satellite System) and multiple measurement technologies to compare with Google Earth image record,
The aims of those studies are summarized as follow: 1. Useing multi-satellite data integrated e-GNSS technology to implement measurement of control points. 2. Using 3D LiDAR observation data for periodic monitoring the terrain-changes in the Dahan River Valley. 3. Establishing dynamic timing-changes of the terrain changes in Dahan River Valley.
From 2017 to 2022 of multiple monitoring, and after analyzing of the experiment, differences of the plane accuracy of control points is between 0.013 ~ 0.551m, and fitting accuracy of the point clouds is about 0.0030~0.0070m. From comparion of two-period observational data, it can be proved that the evidence of the gradual left deviation of the riverbed. The results of this study shows the existence of the terrain-changes in the Dahan River Valley, and proposes the feasibility of the monitoring mode of 3D LiDAR.