空載光達技術進行地層下陷監測之可行性分析

The Feasibility of airborne LIDAR Technology for Land Subsidence Monitoring

地層下陷是台灣西南部地區嚴重的問題，受地層持續下陷影響，每當颱風侵襲期間，持續性的大雨或豪雨之後常導致排水不良，造成相當嚴重的災情。因此，為求有效了解地層下陷量並進行地層下陷監控，地表空間資訊獲取方式中已有傳統的精密水準測量，以及GPS高程測量方法實際應用於地層下陷量的監測。然這兩種監測方式均需藉到現地觀測，且觀測資訊均屬點或線的分佈型態，除較無法獲取全面性的監測資料之外，所需要的時間成本也較多。因此，本研究擬以最新的空載光達測量技術，利用其能在短時間自動獲取大區域範圍且具高精度高密度的特性進行地層下陷可行性的探討與評估。以目前空載光達測量技術，可達到的高程精度約為15cm，且可提供甚多之細節。若評估可行，將來將更有助於未來地層下陷監測工作之進行和後續地層下陷成因之分析。 Land subsidence along the southwestern area in Taiwan is a serious problem. Thecontinuous land subsidence leads to the poor drainage, causing serious flood during the heavyrainfall. Therefore, traditional precise leveling surveying and GPS height surveyingtechniques have been implemented for effective land subsidence monitoring. However, thesetwo surveying techniques are time-consuming and not cost-effective because they need to collectthe height data by setting up theinstruments on site. In addition, those collected point-scattering orprofile-scattering data cannot provide the global data for whole area to conductcomprehensive analysis and evaluation for land subsidence. Therefore, this study willevaluate and investigate the feasibility of airborne LIDAR (LIght Detection And Ranging)data for land subsidence. Airborne LIDAR data is acquired by airborne LIDAR surveyingtechnique. This whole new surveying technique can collect 3-D point clouds with high heightaccuracy and high point density in short time. Thus it is highly potential to provide global datafor land subsidence without time-consuming and cost-effective. If the land subsidence monitoring by using airborne LIDAR data is feasible, the research results will be useful forfuture land subsidence monitoring and analysis.

Land subsidence along the southwestern area in Taiwan is a serious problem. Thecontinuous land subsidence leads to the poor drainage, causing serious flood during the heavyrainfall. Therefore, traditional precise leveling surveying and GPS height surveyingtechniques have been implemented for effective land subsidence monitoring. However, thesetwo surveying techniques are time-consuming and not cost-effective because they need to collectthe height data by setting up theinstruments on site. In addition, those collected point-scattering orprofile-scattering data cannot provide the global data for whole area to conductcomprehensive analysis and evaluation for land subsidence. Therefore, this study willevaluate and investigate the feasibility of airborne LIDAR (LIght Detection And Ranging)data for land subsidence. Airborne LIDAR data is acquired by airborne LIDAR surveyingtechnique. This whole new surveying technique can collect 3-D point clouds with high heightaccuracy and high point density in short time. Thus it is highly potential to provide global datafor land subsidence without time-consuming and cost-effective. If the land subsidence monitoring by using airborne LIDAR data is feasible, the research results will be useful forfuture land subsidence monitoring and analysis.