12 research outputs found

    Texture Analysis of Satellite Images for Slopeland Monitoring and Management

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    The spatial distribution of gray-tone of remotely sensed spectral images were calculated in this study for discussing the texture characteristics. The changed site extracted from the images were used as the samples to compute the co-occurrence matrix and the texture descriptors by applying the methods of SGLDM(Spatial Grey Level Dependence Matrix)The remotely sensed images of hillside in Nantou were chosen for discussing the texture descriptors such as angular second moment, contrast, correlation, homogeneity, entropy, sum entropy, difference entropy, cluster tendency and probability to segment images of different classes of land cover. The result showed that texture analysis can be efficiently used to distinguish and classify the landuse for the better wave band images by screening the suitable texture descriptor and other factors of the images in advance. It shows better results using CON, ENT, HOMO, PRL texture descriptor, but still need to study for further distinguishing the similar texture is legal or illegal.由於山坡地違規查報工作繁重加上人情壓力等問題,嚴重影響山坡地之監測管理工作。利用SPOT衛星影像,結合衛星定位系統,能有效的監測山坡地之開發行為,避免違規使用,為目前山坡地監測之首要工作。本研究以南投山區為例,針對山坡地土地利用型態變遷分析影像,探討影像灰階值之空間關係,選取不同的變異點,以共生矩陣紋理分析法(Spatial Grey Level Dependence Matrix,SGLDM),計算其共生矩陣及紋理特徵值,探討光譜空間影像之角二次距、對比、相關度、熵、熵總合、熵差、群集傾向度及行長機率等紋理特性,作為辨識變異點地物紋理特徵之參考,藉以了解山坡地變異點之紋理趨勢。分析結果顯示影像紋理可作為地物類別辨識之先驅工作,於多譜影像中能篩選較佳的波段使辨識分類更有效率,在分析中CON、ENT、HOMO、PRL,這些紋理描述子在一般條件下,都可以達到較佳的辨識結果,惟地物種類呈像紋理極為相似時,如何判定為違規使用或非違規使用仍須其他方法輔助比對。目 錄 摘 要 Ⅰ Abstract Ⅱ 目 錄 Ⅲ 表 目 錄 V 圖 目 錄 VI 第一章 前 言 1 第二章 文獻回顧 3 2.1衛星遙測技術之應用 3 2.1.1遙測基本原理 3 2.1.2遙測技術用於變遷監測 6 2.1.3變遷監測的流程與方法 7 2.1.4 山坡地變遷監測發展現況 12 2.2紋理分析及相關研究 15 2.2.1紋理 15 2.2.2紋理分類 15 2.2.3 紋理分析在地物辨識上相關研究 17 第三章 研究理論分析 19 3.1 影像紋理分析 19 3.2.紋理分析的方法 19 3.3 共生矩陣法 23 3.3.1 NGLDM共生矩陣 23 3.3.2 SGLDM共生矩陣 24 3.4 SGLDM紋理分析法 25 3.5紋理特徵抽取之方法 28 3.6 紋理描述子 30 3.7 SGLDM分析法的參數說明 35 3.7.1 輸入影像的灰階值範圍 36 3.7.2移動視窗的大小 36 3.7.3 位移向量(距離、方向) 36 第四章 分析結果與結果討論 38 4.1分析目的 38 4.2 分析方法 38 4.3實驗結果與分析 45 4.3.1 分析結果 47 4.3.2 實驗影像結果分析 49 第五章 結論與建議 55 5.1 結論 55 5.2 建議 56 參考文獻 58 表 目 錄 表2.1 台灣地區取得之各式遙測影像特性表 5 表4.1 分析樣區之遙測影像資料項目 40 表4.2 樣區坡度分布表 40 表4.3 樣區之遙測影像狀況資料表 46 表4.4(A) 工程施作類之紋理描述子統計表 47 表4.4(B) 自然崩塌類之紋理描述子統計表 47 表4.4(C) 開挖整地類之紋理描述子統計表 48 表4.4(D) 農業使用類之紋理描述子統計表 48 圖 目 錄 圖2.1 一般衛星波長範圍圖 4 圖2.2 坡地土地利用監測流程圖 14 圖2.3 方向性紋理 16 圖2.4 週期性紋理 17 圖2.5 隨機性紋理 17 圖3.1 位移向量圖 26 圖3.2 3*3視窗中心像元與八鄰域像元編號 27 圖4.1 研究分析流程圖 39 圖4.2 研究區坡度分佈圖 41 圖4.3 樣區塊點位分布圖 42 圖4.4(a) 工程施作類實驗影像 43 圖4.4(b) 自然崩塌類實驗影像 43 圖4.4(c) 開挖整地類實驗影像 44 圖4.4(d) 農業使用類實驗影像 44 圖4.5 不同類別紋理特徵值平均統計圖 49 圖4.6 不同類別紋理特徵值標準偏差統計圖 50 圖4.7 角二次矩(ASM)紋理特徵值統計圖 51 圖4.8 熵(ENT)紋理特徵值統計圖 51 圖4.9 熵總和(SE)紋理特徵值統計圖 51 圖4.10 熵差(DE)紋理特徵值統計圖 52 圖4.11 對比(CON)紋理特徵值統計圖 52 圖4.12 相關度(COR)紋理特徵值統計圖 52 圖4.13 同質度(HOMO)紋理特徵值統計圖 53 圖4.14 不相似度(DIS)紋理特徵值統計圖 53 圖4.15 群聚傾向度(CLU)紋理特徵值統計圖 53 圖4.16 行長機率(PRL)紋理特徵值統計圖 5

    Delineation of Optimal Subdivision and Landslide Risk Assessment in a Watershed

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    Abstract This study aims to evaluate risk and optimal management area for a watershed scale based on the relationship among the optimal zoning, risk management and crisis management of the catchment area. The optimal analysis unit is obtained by dividing the catchment area and extracting the local factors and the landslide ratio to evaluate the relationship between the local factors and the landslide area within the catchment using principal component analysis, discriminant analysis and cluster analysis, and then explores the optimal management unit of catchment area through topographic factor analysis. Finally, this study also developed a systematic and operational risk assessment framework for any given watershed division to deal with disaster-induced crisis. In order to understand the relationship between the occurrence of landslides and the topological factors, the eigenvalues and eigenvectors of each principal component axis for topological factors were calculated using the conceptual view of the homogeneous zone cupled with principal component analysis. The classified landslide ratio could be use to distinguish future landslide potential of study area in spatial scale. Study results show that the classification accuracy of landslide ratio is decreasing with the increase of the number of subdivision, which means that the classification accuracy decreases gradually due to the dilution of the transition information. The unmber of the optimal subdivision could be derived by the concept of species-area curve. This study developed a systematic and operational risk assessment framework based on the environmental indices of event rainfall, road construction, and vegetation recovery. According to the result of risk classification, the mean value of the risk areas of each homogenous zone is divided by the total number of grids, and the average risk value of the mean area is obtained by K-means clustering analysis. Finally, the remediation priority can be separate into immediate treatment, priority treatment and natural recovery respectively.摘要 本研究以集水區最適分區、風險管理及危機處理等三相關係,做為研究主軸,藉由均質區劃分求得最適之分析單元,並萃取地文因子及崩塌率等資訊,應用主成分分析、判別分析與群集分析等多變量統計分析,探討地文因子與崩塌之關係,再透過坡地地文因子之分析,探索集水區劃分最適管理單元。進而依其集水區特性、風險影響因子及保護對象等相關資料,研擬具系統化及可操作性之風險評估架構,供面對災害所引致危機處理之用。 以集水區均質區之觀點,配合統計方法,計算各主成份軸之特徵值與特徵向量,瞭解影響崩塌發生與地文因子相互關係,並藉由區別分析予以將崩塌率進行分類,以瞭解研究樣區崩塌潛勢空間分布狀況。研究成果顯示,藉由區別分析可以發現,輸入集水分區個數愈多,其崩塌率分類準確度呈逐漸遞減之趨勢,表示劃分過多之集水區因指標過度稀釋,導致分類準確度逐漸下降,由種數-面積曲線可求出集水分區最佳個數單元。 另以事件降雨、道路開發、植生綠劣等環境指標,進行正規化後相加產製研究範圍之脆弱度。依據風險分級結果,以集水區均值區分別予以統計,將其各均值區之風險分級總分除以總網格數,得到均值區之總風險平均值,以K-means群集分析將集水區均值區,依治理優先順序分為立即處理、優先處理以及自然復育等。目錄 摘要 i Abstract ii 表目錄 vi 圖目錄 viii 第一章 緒論 1 第一節 研究動機與目的 1 第二節 研究內容與流程 2 第二章 文獻回顧 5 第一節 崩塌地定義與類型 5 一、崩塌地名詞與定義 5 二、崩塌地發生原因 7 三、崩塌地運動類型 11 四、崩塌地判釋方法 14 第二節 最適分析單元劃分 22 一、均質區劃分因子 24 二、均質區劃分方法 24 第三節 集水區劃定及影響因子 26 一、集水區定義與範圍界定 26 二、集水區地文因子 28 三、集水區劃定方法 31 第四節 集水區崩塌災害風險管理 33 一、風險定義 33 二、風險計算 36 三、危害度 37 四、脆弱度 39 五、崩塌風險 39 第三章 研究材料與方法 44 第一節 樣區介紹 44 一、地文資料 45 二、水系與氣象 52 三、人文資料 57 第二節 研究材料 60 一、航照影像 60 二、衛星影像及崩塌地判釋 61 三、數值地形 64 四、崩塌地判釋成果 65 第三節 研究方法 67 一、自動化劃分架構 67 二、地文因子箤取 70 四、主成分分析 78 五、判別分析 80 六、群集分析 83 七、風險評估方法 84 第四章 結果與討論 93 第一節 集水區均質區劃分 93 第二節 集水區均質區崩塌與地文因子關連性 96 一、崩塌率分類 96 二、崩塌區位分類 100 三、崩塌地離散程度 104 第三節 集水區均質區受災風險評估108 一、危害度指標 108 二、脆弱度指標 108 三、崩塌規模潛勢指標 115 四、危險度分級 118 第四節 水土保持管理及防減災策略122 一、水土保持管理 122 二、防減災策略 123 第五章 結論與建議 129 第一節 結論 129 第二節 建議 131 參考文獻 133 附錄 14

    A Study on Positional Accuracy Assessment of Scanned Cadastral Maps

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    地籍圖是地政單位業務中的一項重要的基本資料,在國土資訊系統之九大資料庫中又以地籍圖之精度要求最高,然而舊圖因皺折破損嚴重,故數值化地籍圖之建置與供應,實為保存圖籍資料與推動國土資訊系統之首要工作。 本論文針對目前各界較常用之原圖掃瞄影像之地籍圖數化的作業過程,研究探討其可能之誤差來源,包含地籍圖定向之誤差、儀器之誤差、掃瞄圖籍影像向量化之誤差等,以誤差傳播原理推估地籍圖掃瞄數化之精度,並評估地籍圖本身皺折變形情形之影響。研究實驗成果可提供從事地籍數化之工作者及終端使用者一組量化的誤差分析數據,作為其後續運用時的細部考量、評估與決策的重要考慮因素。Cadastral maps play dominant roles in land administration as their accuracy requirement is the highest among the nine databases in the National Geographical Information Systems (NGIS). However, old cadastral maps usually get wrinkled and destroyed, the establishment and supply of digital cadastral date are the most primary work for preserving cadastral map data and implementing NGIS. This paper examines possible sources of error in the processes of digitizing cadastral maps , including errors caused by orientating cadastral maps, instruments, and vectorizing on the scanned images of cadastral maps, etc, in order to estimate the accuracy of digitizing on the scanned images of cadastral maps based on error propagation principles. Meanwhile, the influence of using wrinkled cadastral maps was also evaluated. Empirical results should provide quantified information about errors digitizing cadastral map workers and end-users for their application, evaluation and decision-making in using these data .第一章 緒論 1.1 前言1 1.2 研究動機與目的2 1.3 研究方法3 第二章 文獻回顧 2.1圖解地籍圖資料現況及數化作業執行-----4 2.1.1圖解地籍圖資料背4 2.1.2圖解地籍圖數化工作執行概6 2.2地籍圖數值化作業流程與數化步驟8 2.2.1地籍圖數值化作業流程8 2.2.2圖解地籍圖數化作業步驟11 2.3地籍圖數化方法之比較13 2.3.1 原圖直接數化法14 2.3.2原圖掃瞄影像數化法15 2.4圖解地籍圖數值化作業品質之檢核17 2.4.1地理資料庫的建置程序-----17 2.4.2資料品質的檢核----------18 2.4.3資料精度----------20 2.4.4錯誤資料的檢核------------20 2.4.5數值化品質的控制-------21 2.5 數化作業的資料處理作業------24 2.5.1數化作業的輸出入資料----24 2.5.2成果資料整合之處理------26 2.6 掃瞄儀原理與精度評-----29 2.6.1 掃瞄儀的基本原理-----29 2.6.2 掃瞄儀精度評估---29 第三章 掃瞄數化的理論分析 3.1坐標轉換的模31 3.1.1四參數轉換32 3.1.2六參數轉換34 3.2原圖掃瞄影像處理36 3.2.1影像追蹤向量化處理流程36 3.2.2圖籍的掃瞄與處理38 3.2.3影像二元化---39 3.2.4細線化40 3.2.5圖形向量化44 3.3 線段交點之計算46 3.3.1向量資料中之線段交點46 3.3.2網格資料中之線段交點48 第四章 實驗方法與結果分析 4.1實驗目的-----51 4.2 實驗方法與內容---51 4.2.1 研究範圍-51 4.2.2研究流程55 4.2.3 實驗方法55 4.2.3.1 圖籍定向誤差實驗------55 4.2.3.2地籍圖掃瞄流程---------58 4.3實驗結果與討論63 4.3.1地籍圖定向誤差63 4.3.2向量化誤差實驗66 4.3.3精度檢核分析----------76 4.3.4誤差來源分析76 第五章 結論與建議 5.1 結論77 5.2 建議78 參考文獻8

    泥岩區地滑監測與分析之探討

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    莫拉克風災後位於臺南市南化區玉山里柚仔腳聚落發生邊坡滑動,對當地居民及鄰近聚落造成威脅。本研究遂針對該地區辦理崩塌地調查、監測與穩定分析,以做為後續整治規劃之參考。由於地質上屬台灣西南部泥岩分布區,本滑動邊坡由厚層泥岩所組成,地表面則由崩積層或風化泥岩所覆蓋。調查顯示研究區滑動體受地下水位影響顯著,未來辦理相關治理工程規劃,應著重於地表水及地下水之排除。調查結果發現,本崩塌地主裂隙整體呈馬蹄形,延伸性相當良好,為一典型之地滑裂隙型態。崩塌原因初步推論因新鮮岩盤屬不透水之泥岩,大量之降雨入滲後,累積於新鮮岩盤以上之地表覆蓋層、舊有崩積層或風化泥岩中,造成自重增加及孔隙壓力上升,終導致邊坡破壞而發生地層滑動。Settlement occurs slope slip on local residents and threatens neighboring settlements at Yo-Tzu-Chao, Yuli district of NanHua area in Tainan city after typhoon Morakot. In this study, then apply for the collapse of the region to investigate, monitor and stability analysis to be used as a reference for subsequent remediation plan. Survey shows that the sliding slope composed by a thick layer of mud, the ground surface by colluvium or weathered mudstone covered. Geologically the study area is located in southwestern Taiwan mudstone, sliding body significantly affected by groundwater, the survey found that the collapse of the whole horseshoe-shaped fissure landlords, extensibility quite well for a typical fracture patterns of the slippery floor. Causes of Collapse preliminary inferences because fresh rock is impermeable to the mudstone, a lot of rainfall infiltration, the cumulative in fresh rock above the surface cover, old colluvium or weathered mudstone, causing weight increase and pore pressure rise, eventually leading edge slope landslides occurred damage. Future for the relevant management project planning should focus on surface water and groundwater are excluded

    大肚台地水砂災害潛勢區位之評估

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    Under climate change, the extreme rainfall event increases obviously and leads to sediment disaster on the slopeland. The excessive rainfall also would cause flood in the lowlands. The property and safety of resident are threatened by the disaster. This study was based on the delineation of sub-watersheds to analyze the landslide risk and scale on the Dadu Terrace. In addition, the curve number of pre- and/or postdevelopment in a sub-watershed can be evaluated using maps of landuse and soil, and then changes of potential maximum amount of water retention in a sub-watershed could be calculated. Hotspot screening and conservation planning in soil and water resources can be effectively carried out using the methodologies of this study. Results could be references for the related authorities in the disasters of debris and/or flood prevention.受近年氣候變遷影響下,極端降雨事件有明顯增加之趨勢,並常導致山坡地崩塌之土砂災 害,超滲之地表逕流水亦會引發下游地區淹水,嚴重威脅下遊地區居民之生命財產安全,據此, 本研究以大肚山台地為研究樣區,透過集水區分析單元劃定,進行崩塌風險度及崩塌規模分析, 評估大肚山台地大規模崩塌潛勢,並透過土地利用及土壤圖套疊,得到土地開發前後之 CN(Curve Number)值,進而利用開發前後 CN 差值,比較開發前、後之最大蓄水量,進行水源 涵養能力評估,並以大規模崩塌規模潛勢劃定及水源涵養能力評估,作為大肚山台地土砂及淹 水災害防治之參考

    阿里山溪集水區源頭崩塌機制之探討

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    本研究目的係以Strahler's 河川級序之概念劃定源頭集水區並探討其崩塌發生機制。利用數位地形模型及遙測影像處理技術,萃取樣區之地文水文資訊,藉由河道輸砂量與坡面泥砂產量之比值,建立源頭崩塌潛勢指標。結果顯示源頭崩塌潛勢指標可有效反映集水區源頭土砂堆積能量狀況,若逢極端事件來臨時,源頭崩塌潛勢較高之區位可能發生大規模土砂災害,可做為源頭集水區監測及管理之參考。This study focused on the mechanisms of landslides which occurred in the headwater watershed to establish the index of potential headwater landslides. The index of potential headwater landslide is defined as a ratio of the amount of channel sediment output to the slopeland sediment yield for a given storm event in the headwater watershed. The spatial distribution of headwater watershed was delineated in the interested watershed according to the rule of Strahler's stream order and a conceptual model (index of potential headwater landslide) is introduced to quantitatively measure the potential headwater landslide for the references of policy and decision making

    2009 年莫拉克颱風中南部災區災害調查分析

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    2009 年莫拉克颱風造成台灣中南部地區嚴重受災,災害型態由洪水或崩塌等單一形式災害,轉變為崩塌、洪水、堰塞湖之複合型災害,本分析藉著「全流域管理」的精神、「尊重大自然」的思維及「國土復育」的理念,使集水區有專業知識以整體治理。 本研究主要針對降雨因子造成的「超大洪水量」、「崩塌災害」及「土石流災情」,進行探討分析,以有效減輕災害之發生。並以中部災區為例進行集水區歷史災害調查分析演算。直接探討莫拉克颱風災害前後崩塌與延時雨量的關係;分析水土保持現行策略對土砂整治率、水土保持構造物、區域性避難規劃及聚落區之合適性。 在無法預知之極端氣候發生機率增加清況下,策略目標應以聚落安全為核心,評估各類災害的影響範圍;除加強軟硬體減災措施外,更應著重於土石流防災監測及預報等非工程措施。2009 Typhoon Morakot resulted in serious disasters in central and southern Taiwan. The type of disaster is changed from single flooding or landslide to compound disasters, which includes avalanches, floods and barrier lakes. This analysis is based on the spirit of 'Total Catchment Management (TCM)', the thought of 'Respect to Nature' and the idea of 'Land Restoration', so that the watershed area could be comprehensively governed by professional knowledge. This study focuses on the rainfall factors of 'Tremendous Floods,' 'Collapse Hazard' and 'Mudslide', to take an effective approach to reduce the occurrence frequency of disasters. Taking Taiwan Central Disaster Area as an example to investigate, analyze and to perform calculation of historical watershed disaster data. Directly investigate the relationship between the collapse and rainfall before and after Typhoon Morakot. Analyze the appropriateness of the current policy to the 'Ratio of Sediment, 'Soil and Water Conservation Structures' and 'Regional Refuge Planning and Settlement District of Soil and Water Conservation.' Under the increasingly possibility of unpredictable extreme weather, the core of the strategic objectives should be the 'Settlement Security' to evaluate all influence of disasters. In addition to strengthening the hardware and software mitigation measures and also emphasis on the debris flow monitoring and forecasting
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