1,720,972 research outputs found
Applying GIS and fine-resolution digital terrain models to assess three-dimensional population distribution under traffic impacts
No full textMonitoring of Landscape Change on Unlawful Cultivated Forestland
No full text摘 要
森林地景變遷監測之目的在掌握過去及現在地景結構的變化過程，並進一步推估未來演變趨勢，以提供森林經營管理之依據。相關研究目前已成為國內外林業科學之重點方向。本研究利用與人為干擾有關之八項量化地景結構指數，比較蓮華池研究中心民國12年、60年及87年三期之地景結構變遷情形，並以Shannon多樣性指數t檢定法評估各期間民墾干擾程度之差異，最後整合馬可夫鏈模式與二項式logit廻歸之分析結果，預測未來之地景變遷和模擬民墾地發生之空間分佈情形，並進而探討民墾地干擾對未來地景之影響效應，提供蓮華池研究中心未來經營管理之參考。本研究結果如下：
1. 三期地景結構分析之結果顯示，由於受到民墾地干擾的影響，造成區塊總數、區塊密度、邊緣密度、形狀指數、碎形維度、Shannon多樣性及Shannon均勻度指數值上升，而平均區塊面積指數值下降之趨勢，惟就Shannon多樣性指數之t測驗檢定結果顯示，雖然三期的Shannon多樣性指數有差異，但其地景變遷在5%顯著水準時，均未達顯著差異，此說明了該期間之民墾地干擾並未達顯著的差異程度。
2. 使用馬可夫鏈模式預測未來之地景變遷結果顯示，根據民國60年至87年間之資料所建立的馬可夫鏈模式，經模式確認與驗證後，適合應用於預測民國141年、195年及249年之地景結構，並發現林業用地面積從民國60年的88.36%和民國87年的85.87%，降為民國141年的81.41%、民國195年的77.18%及民國249年的73.17%；而民墾地面積則由原來的0.90%和3.39%依序增加為7.85%、12.08%及16.09%。至於應用二項式logit廻歸分析模擬民墾地發生之空間分佈結果顯示，民墾地的發生與海拔、坡度、距民墾地、道路及河流的距離均有密切的關係，但其中以距民墾地和距道路的遠近最有相關。
3. 在探討民墾地干擾對未來地景之影響效應方面顯示，民國141年、195年及249年之Shannon多樣性指數隨著民墾地面積之增加而增加，分別為0.61，0.70和0.76，同時，由Shannon多樣性指數之t測驗檢定結果顯示，雖然到民國141年仍未發生民墾地干擾的情形，但到了民國195年，其干擾程度則已達5%顯著水準，而到了民國249年甚至達到1%的極顯著水準。
綜合以上結果可知，整合馬可夫鏈模式和二項式logit廻歸分析預測未來之地景變遷和模擬民墾地發生之空間分佈情形，確實為一有效、可行的方法，此外，Shannon多樣性指數之t測驗檢定亦可用以監測和評估民墾地干擾對未來地景之影響效應，因此，本研究所得結果可提供蓮華池研究中心經營管理之參考。ABSTRACT
The purpose of monitoring forest landscape change is not only to understand the change of past and present landscape structure, but also to predict the future trend for providing the reference of forest management. Therefore, the related research has been growing concern by forester. This study applied eight qualified landscape structure indices, which are related to human disturbance, to compare the landscape change of Lien-Hwa-Chih Research Center among 1923, 1971, and 1998. The t-test based on Shannon diversity index was also used to examine the disturbance differences caused by unlawful cultivated forestland. In addition, the mathematical models such as Markov chain and binomial logit regression analysis were applied to predict the future overall landscape structure and to simulate the spatial distribution of unlawful cultivated forestland. Again, the t-test was applied to monitor the future effect of disturbance caused by unlawful cultivated forestland. The results are as follows.
1. The comparison of landscape structure among three different dates indicated that patch number, patch density, edge density, shape index, fractal dimension, Shannon diversity index, and Shannon evenness index were increased due to the disturbance effect of unlawful cultivated forestland. Conversely, the mean patch was decreased. As for the t-test examination using Shannon diversity index, the landscape change among 1923, 1971, and 1998 showed no differences at the 5% significance level, that is, there was no significant differences about the disturbance caused by unlawful cultivated forestland.
2. The prediction of future landscape change using the Markov chain model indicated that the Markov chain developed by the time step (1971-1998) was matched well after model verification and validation. The projection of overall landscape structure from 1971 to 2052, 2106, and 2160, respectively showed that forestland was decreased from 88.36% in 1971 and 85.87% in 1998 to 81.41% in 2052, 77.18% in 2106, and 73.17% in 2160. The unlawful cultivated forestland was increased from 0.90% and 3.39% to 7.85%, 12.08%, and 6.09%, respectively. As for the spatial distribution using binomial logit regression analysis, the result showed that the occurrence of unlawful cultivated forestland had the relationship with elevation, slope, and the distance of road, river, and previous unlawful cultivated forestland. However, it was strongly correlated with the distance of road and previous unlawful cultivated forestland, and less correlated with elevation, slope, and the distance of river.
3. On the aspect of monitoring the future disturbance effect caused by unlawful cultivated forestland, the Shannon diversity indices among three predicted time steps were increased. They are 0.61, 0.70, and 0.76, respectively. Meanwhile, the Shannon t-test indicated that although there’s no disturbance effect in 2052, it would occur at the 5% significance level in 2106 and had the significant effect of disturbance at the 1% significance level in 2160.
From the result, obviously the integration of Markov chain and binomial logit regression analysis is a feasible approach to predict the overall landscape change in future and to simulate the spatial distribution of unlawful cultivated forestland. Also, the Shannon t-test is a good way to monitor and assess the disturbance effect of unlawful cultivated forestland on future landscape. The above result can be provided to Lien-Hwa-Chih Research Center for the reference of forest management in order to prevent the occurrence of unlawful
cultivated forestland.目 錄
表目錄
圖目錄
中文摘要
英文摘要
第一章、前言 ………………………………………………………… 1
第二章、研究動機與目的 …………………………………………… 2
壹、研究動機 ……………………………………………………… 2
貳、研究目的 ……………………………………………………… 3
第三章、前人研究……………………………………………………… 4
壹、地景生態學……………………………………………………… 4
一、基質…………………………………………………………… 6
二、區塊…………………………………………………………… 6
三、廊道…………………………………………………………… 6
貳、干擾因子與地景結構之關係…………………………………… 7
參、干擾指數 ……………………………………………………… 8
肆、地景結構量化分析 ……………………………………………13
伍、地景變遷研究 ………………………………………………… 19
一、地景變遷預測模式-馬可夫鏈模式…………………………22
（一）馬可夫鏈模式之發展及應用……………………………23
（二）馬可夫鏈模式之數學表示………………………………24
（三）馬可夫特性之檢定………………………………………25
（四）馬可夫鏈模式使用上之限制……………………………26
二、地景變遷空間分析模式-多項式logit廻歸模式……………27
（一）多項式logit廻歸模式之數學表示式……………………28
（二）logit模式之應用…………………………………………30
第四章、研究材料與方法………………………………………………32
壹、研究試區概述 ………………………………………………… 32
一、經營概況………………………………………………………32
（一）氣候………………………………………………………33
（二）土壤………………………………………………………33
（三）植群組成…………………………………………………33
（四）生物資源…………………………………………………34
二、蓮華池地區民墾情形…………………………………………34
貳、研究材料………………………………………………………35
一、圖籍資料………………………………………………………35
二、區塊類型圖……………………………………………………36
三、數值地型模型…………………………………………………38
參、研究方法…………………………………………………………39
一、地景結構分析…………………………………………………39
二、地景變遷模式建立……………………………………………40
（一）地景變遷預測模式………………………………………41
1、樣本取樣…………………………………………………41
2、馬可夫特性檢定…………………………………………41
3、模式建立…………………………………………………42
4、模式檢核…………………………………………………43
5、模式評估…………………………………………………43
（二）空間變遷機率模式………………………………………43
1、影響因子之選擇…………………………………………44
(1)海拔高…………………………………………44
(2)坡度……………………………………………44
(3)距民墾地距離…………………………………44
(4)距道路距離……………………………………45
(5)距河流距離……………………………………45
2、變數的度量………………………………………………45
(1)因變數…………………………………………46
（2）解釋變數……………………………………………46
3、空間資訊分析……………………………………46
4、空間變遷機率模式之建立………………………………49
5、模式驗證…………………………………………………50
三、未來民墾干擾程度之評估……………………………………51
第五章、研究結果…………………………………………………… 52
壹、地景結構分析……………………………………………………52
一、一般性指數……………………………………………………54
二、邊緣密度指數…………………………………………………55
三、形狀性指數……………………………………………………56
四、地景多樣性指數………………………………………………57
貳、地景變遷模式之建立……………………………………………60
一、蓮華池地景變遷預測模式……………………………………60
（一）樣本取樣結果……………………………………………60
（二）馬可夫特性之檢定………………………………………62
（三）抽樣資料與全區資料所建預測模式之比較……………65
（四）模式檢核…………………………………………………68
1、民國12~60年預測模式檢核……………………………68
2、民國60~87年預測模式檢核……………………………69
（五）模式評估…………………………………………………70
二、蓮華池空間變遷機率模式……………………………………71
（一）空間資訊樣本取樣………………………………………71
（二）地景變遷之多項式logit廻歸分析………………………71
參、未來民墾干擾程度之評估………………………………………76
第六章、討論……………………………………………………………81
壹、地景結構分析結果之探討………………………………………81
一、地景結構量化結果與圖籍資料比例尺之關係………………81
貳、地景變遷模式建立結果之探討…………………………………81
一、馬可夫鏈模式評估……………………………………………81
二、民墾干擾影響因子……………………………………………82
三、地景變遷空間分析之準確度…………………………………82
參、未來干擾程度評估結果之探討…………………………………83
一、未來干擾程度評估在生態保育上之意義……………………83
二、未來干擾程度評估對政策制定之影響……………………83
第七章、結論……………………………………………………………85
第八章、展望與建議……………………………………………………87
第九章、參考文獻 ……………………………………………………8
Study on the Hydrologic Cycle of the Northern Taiwan Using Remote Sensing Techniques
No full text環境變遷與集水區水文循環之間的關係已成為環境規劃的重要課題。國內外已有許多專家學者結合大氣環流模式 (General Circulation Models, GCMs) 與GWLF河川流量模式 (Generalized Watershed Loading Functions, GWLF)，探討氣候變遷對集水區水資源的衝擊效應。但大部份的研究除受限於大尺度地表蒸發散量的調查不易之外，在蒸發散覆蓋係數 (Evapotranspiration Cover Coefficient, CV) 之設定方面，亦大多根據GWLF手冊中所列之參考值進行設定。然真實地表之土地使用類別甚為複雜，如僅依手冊中之參考值進行參數設定，可能會影響分析結果之正確性。此外，土地使用型態和蒸發散量的逐年變化，亦會影響集水區之未來水文狀態，而傳統的流量模擬研究甚少針對此兩項因子之影響效應加以探討。
有鑑於此，本研究以台灣北部地區為試區，旨在利用遙測技術推估真實地表的蒸發散量與CV值，以提昇流量模擬之正確性，進而結合SEBAL模式 (Surface Energy Balance Algorithm for Land, SEBAL)、CGCM1大氣環流模式 (The First Version of the Canadian Global Coupled Model; CGCM1) 與Markov模式，模擬未來土地使用型及蒸發散量的變化，並分析其對未來流量模擬之影響，最後再綜合氣候、土地使用及蒸發散量等環境變遷因子，進一步評估台灣北部地區未來水文循環可能遭受之衝擊效應。研究方法首先利用遙測混合式分類方法進行台灣北部地區之大地資源衛星(Landsat-5)的土地使用分類，並配合數值地形模型(Digital Terrain Model, DTM)與SEBAL能量平衡模式，先計算與蒸發散量有關之16項環境參數，再推估地表蒸發散量，並比較各土地使用型之蒸發散量，過程中為評估空間尺度和生態分類系統二因子對環境參數之影響，乃選定兩種空間尺度 (台灣北部地區及其轄內的7個集水區)和兩種生態分類系統 (12個地理氣候分區及7個集水區)，透過多變量逐步判別分析方法，探討該二因子對環境參數之影響效應；其次，在利用SEBAL模式計算蒸發散量和應用遙測方法推估CV值之後，進而應用GWLF模式模擬淡水河集水區之河川流量，目的除了驗證流量模式之適用性之外，並評估傳統查表方法和遙測方法所推估之CV的流量模擬差異；最後，以兩期土地使用資料為基礎，整合Markov模式與CGCM1模式，預測未來短、中、長期之土地使用變遷、並推估其CV，再經由GWLF之流量分析，分析土地變遷及蒸發散變化對於未來河川流量之影響，進而評估北台灣地區水文系統可能遭遇到的衝擊效應。
研究結果指出，北台灣地區經混合式影像分類後，計分為森林、建地、水體、耕作農地、休耕農地、雲及陰影7類土地使用型，其整體分類準確度經檢核區檢定後為89.00%；在土地使用型之蒸發散量方面，以森林最大 (一月：0.723cm；七月：0.395cm)，建地為最小 (一月：0.220cm；七月：0.088cm)；在空間尺度和生態分類系統對環境參數之影響分析方面顯示，使用不同生態分類系統和空間尺度來區分5種土地使用型 (森林、建地、水體、耕作農地及休耕農地) 所需要的環境參數與參數數目皆不盡相同，但常態化差異植生指標與地表熱紅外光放射率兩項參數，不管在那一種生態分類系統，均為重要的判別參數；在利用蒸發散量和土地使用兩因子模擬河川流量之結果顯示，利用遙測推估之CV值(濕季：1.245；乾季：0.851) 與查表所得之CV值 (濕季：0.842; 乾季：0.717) 確實有差異。若透過流量站的觀測資料，並結合Watershed hydrology, especially stream flow, is expected to be highly sensitive to the influences of global climate change. Traditional studies have integrated the General Circulation Models (GCMs) with the Generalized Watershed Loading Function (GWLF) model to estimate stream flow rates. However, using these models in the context of a transitioning climate and on a large spatial is problematic, particularly for the estimation of two important parameters, evapotranspiration (ET) and cover coefficient (CV).
This study focuses on an integrated analysis of the hydrological cycle using remote sensing techniques to estimate the ET and the CV. Furthermore, we improved on older studies by integrating the Surface Energy Balance Algorithm for Land (SEBAL) model, the First Version of the Canadian Global Coupled Model (CGCM1), and the Markov model which allows us to predict land-use and ET change. The results were applied to assess the future impacts of global warming on hydrological cycles of northern Taiwan. Our methods include applying hybrid image classification to generate the land-use maps of the northern Taiwan using Landsat-5 images; using digital terrain model (DTM) and the SEBAL model to calculate 16 environmental parameters relevant to ET. We then compared the differences among different land-use types; (1) investigating the effects of two ecosystem classification systems (i.e., watershed division method and geographic climate method) at various spatial scales on environmental parameters using stepwise discriminant analysis; (2) comparing stream flow simulations according to the GWLF model with two CV values derived from remote sensing and traditional methods; (3) integrating the Markov model and the CGCM1 model to predict future land-use and CV parameters for evaluating the effect of land-use change and ET change; and (4) finally, assessing the future impacts on hydrological cycle of the northern Taiwan.
The results indicated that the study area was classified into seven land types (i.e., forest, building, water, farmland, fallow farmland, cloud-covered, and shadow-covered) with 89.09% classification accuracy. These last two land types could not be analyzed further. A comparison of daily ET values among different land-use types revealed differences. In this study, forest ET is the largest (January: 0.723cm; November: 0.395cm) while building is the smallest (January: 0.220cm; November: 0.088cm). These differences contrive to exist for ecosystem classification systems at various scales, but depend on the selected environmental parameters and the number of parameters included in the model. Two parameters, a normalized difference vegetation index and an emissivity are important factors for discriminating land types. On the aspect of land-use and ET effects on hydrological simulations, the stream flows simulated by two estimated CVs were different. The stream flow simulation using the remote sensing approach (wet season: 1.245; dry season: 0.851) presented more accurate hydrological characteristics than the traditional approach (wet season: 0.842; dry season: 0.717). Meanwhile, according to the result of regression analysis, the flow simulation using RSCV (remote sensing based CV; regression coefficient = 0.877) would represent truer flow characteristics than the use of REFCV (reference CV; regression coefficient = 0.853). In the prediction of future land-use and ET, due to the increase of building area from 13.36% in 1995 and 14.05% in 2002 to 38.91% in 2030, 52.13% in 2052, and 62.36% in 2086, the predicated CV values for next three periods display a decreasing trend no matter under which climatic change storyline. In addition, land-use and ET change indeed affect the predicted stream flows. The predicted flows with consideration of these two factors were lower than those without consideration. Finally, the impact assessment on the hydrology of the northern Taiwan indicated that the flow volumes increase due to urban expansion, ET decline, and climate change, and it will lead to the increase of stream flow.
From above results, obviously the integration of remote sensing, the SEBAL model, the CGCM1 model, and the Markov model is a feasible scheme to predict future land-use, ET change, and stream flows. Therefore, it can be extended to the further studies in water resource management and global environmental change
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
