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Applying Object-Oriented method automatically generate Slope-Unit 報告者:簡瑋延 指導教授:李錫堤 2011.03.31.

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Presentation on theme: "Applying Object-Oriented method automatically generate Slope-Unit 報告者:簡瑋延 指導教授:李錫堤 2011.03.31."— Presentation transcript:

1 Applying Object-Oriented method automatically generate Slope-Unit 報告者:簡瑋延 指導教授:李錫堤

2 OUTLINE Introduction Material and methods Case studies Results Future Works

3 Introduction Because of the climate changing and extreme rainfall, more and more geologic hazard appearing in recent years. For the purpose of landslides study and sensitive zone planning, we need to use the appropriate mapping unit to create various types of landslide potential evaluation system.

4 Introduction The classic ways to incorporate relief units into a landscape assessment is to delineate them during field survey or using stereo aerial photographs.

5 Introduction Mapping unit (Carrara et al., 1995 ) (Guzzeti et al.,1999) (a) Grid cells (b) Slope units (c) Geomorphological, Terrain units

6 Introduction (b) Slope units

7 Introduction (b) Slope units

8 Introduction (b) Slope units

9 Introduction (b) Slope units

10 Introduction Main enhancements of automatic methods The reduction of human errors by eliminating manual classification steps The facilitation of comparisons of results derived from different datasets The reduction in processing time This study applied automatic method to generate a suitable slope unit.

11 Introduction Automatic image interpretation Pixel-based methods are ill-suited to represent a geomorphic process salt & pepper Object-oriented method is a knowledge driven method Pixels Based Objects Based

12 資料蒐集 分類準則 程序建立 數 值 地形模型 資料處理 光譜、空間均調 性參數選定 選定圖層權重 影像切割結果檢核 輔助結果檢核 調整各門檻 值 等高線圖 彩繪明暗圖 完成斜坡單元 自動 產 製程序 合理 不合理 應用於驗證區域 進一步修正準則 坡度 坡向 曲率 水系 一級河集水區

13 Material and methods DTMs and digital geomorphologic analysis During the last two decades the availability of DTM data has been continuously growing, data accuracy has improved, and additional algorithms have been developed to derive new attributes from gridded DTMs Derivatives from the DTMs Slope, Aspect, Curvature, Catchment, River…

14 Material and methods Terrain Analysis ( Wilson and Gallant, 2000 )

15 h1h1 h2h2 計算中心網格Z5之坡度及坡向 2h 1 2h 2 Slope Aspect (0,South 90,West)

16 h1h1 h2h2 計算中心網格Z5之曲率 2h 1 2h 2 Profile Curvature Plan Curvature

17 INPUT DTM 坡向圖層暫存 函式定義 輸出影像 ERDAS IMAGINE

18 ArcGIS ArcHydro

19 Material and methods Using the “Definiens “ object based image analysis software multi-scale segmentation and object relationship modeling The largest homogeneity within the slope-unit The largest heterogeneity between slope-units ‘build’ topomorphologic objects in the multi-scale segmentation step, delineating areas of relative homogeneity within the spatial layers of topographic variables such as slope, curvature, aspect,catchment, catchment, river..

20 Scale parameter Decides the segmentation size Color / Shape factor Smoothness / Compactness

21 Aspect

22 Material and methods

23

24 Case studies Height 大漢溪流域 宇內溪集水區

25 Results

26

27 Future works Adjust the weight of each layer and produce a more reasonable slope-unit Adjust and discuss the river threshold value, generate the appropriate size catchment Appling this criteria in other regions for validation, and review the effectiveness Statistics the distribution of gradient, aspect and unit-size, and discussion

28 Thanks for your attention


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