圖解數化地籍圖套合1/1000數值地形圖之研究

A Study on Digitization Product of Cadastral Map Overlaid with 1/1000 Topographic Information

地政機關自86年度起積極推動圖解地籍圖數值化工作，並於94年度全部完成，惟數值化成果僅能保持地籍圖數化當時的原貌，對於其因圖紙伸縮所損失之精度，無法有效克服，加上環境變遷等因素，容易產生與實地使用現況的不一致的情形。本研究選定3個已辦地籍圖重測之地段為實驗區，依據經驗判斷，於數化地籍圖及1/1000數值地形圖上，選取相對應的界址點位，利用適當測量平差演算方式，將兩者予以套合，其結果與重測後之地籍線互相檢核，研究評估兩者間精度、面積之差異，分析比較地籍線與現況地物相對關係，以提供地籍圖重測或土地複丈作業之參考。經研究結果，以點對點約制條件實施坐標轉換整合圖解地籍圖與地形圖作業，係屬可行。另轉換後之數化地籍圖與重測成果相較，其結果仍有些許差異，但比起未轉換前，已較接近重測成果。 The land administrative organizations in Taiwan have overall made their effort to perform the digitization of graphical cadastral maps from 1997 to 2005. The product, stored in media with individual file for every cadastral map sheet, was requested to be kept matching up with the original shape and precision of boundary lines on cadastral maps.The concealed lost precision i.e. not match of boundaries between map and on the spot that might be caused by uneven shrinkage and/or extension throughout the whole sheet of map paper after long-term uses is not solved simultaneously. In this study, 3 sites with different distribution types of ground features were chosen for the tests. Also, 1:1000 scale digital topographic maps and digitization of cadastral map were just finished not long ago. The cadastral maps resurvey was on going in these areas. Proper survey adjustment algorithms were chosen to overlie cadastral map and topographic map. By using point to point constrained conditions, the individual cadastral boundary line was shift to be along the edges of ground features. The result was satisfactorily very close to that of cadastral map resurvey. That is because cadastral resurvey results were mostly based on the sites indicated by the landowners according to the practical situations. Making overlay in advance before the beginning of cadastral resurvey is helpful for a surveyor to realize the possible situation of boundary sites around a certain area and have an integrated planning of boundary site investigation of resurvey.

The land administrative organizations in Taiwan have overall made their effort to perform the digitization of graphical cadastral maps from 1997 to 2005. The product, stored in media with individual file for every cadastral map sheet, was requested to be kept matching up with the original shape and precision of boundary lines on cadastral maps.The concealed lost precision i.e. not match of boundaries between map and on the spot that might be caused by uneven shrinkage and/or extension throughout the whole sheet of map paper after long-term uses is not solved simultaneously. In this study, 3 sites with different distribution types of ground features were chosen for the tests. Also, 1:1000 scale digital topographic maps and digitization of cadastral map were just finished not long ago. The cadastral maps resurvey was on going in these areas. Proper survey adjustment algorithms were chosen to overlie cadastral map and topographic map. By using point to point constrained conditions, the individual cadastral boundary line was shift to be along the edges of ground features. The result was satisfactorily very close to that of cadastral map resurvey. That is because cadastral resurvey results were mostly based on the sites indicated by the landowners according to the practical situations. Making overlay in advance before the beginning of cadastral resurvey is helpful for a surveyor to realize the possible situation of boundary sites around a certain area and have an integrated planning of boundary site investigation of resurvey.