查詢結果分析
來源資料
頁籤選單縮合
題名 | 集水區邊界自動劃定之研究=A Study on Automatic Watershed Boundary Delineation |
---|---|
作者 | 陳文福; 洪文傑; | 書刊名 | 水土保持學報 |
卷期 | 29:1 1997.03[民86.03] |
頁次 | 頁27-39 |
分類號 | 436.124 |
關鍵詞 | 集水區劃定; 影像處理; 數值地形模型; Watershed delineation; Image processing; Digital terrain model; DTM; |
語文 | 中文(Chinese) |
中文摘要 | 集水區之劃定為水文演算及防洪工程等不可或缺之基礎工作,更是國土資訊系統 中基本地理資料庫建立之先驅工作。為改善以人為方式劃定集水區所常面臨之種種缺失、節 省工作所耗費之時間及符合客觀之原則,乃以出水口位於大安溪中上游地區地勢較陡之鯉魚 潭集水區及出水口在出海口而涵蓋上、中、下游範圍較廣且地勢陡緩均具之中港溪全流域, 以解析度均為 40 公尺之數位地形模型 (DTM), 利用加拿大 PCI 公司出版之影像處理軟體 EASI ╱ PACE 進行集水區自動劃定,並將其結果與由人為依 1 ╱ 25,000 地形圖審慎判釋 所得之集水區進行比較,其間之差異多在可以接受的範圍內,因此大面積之集水區若行自動 劃定, 不但比人為劃定快速且具客觀性,其劃定結果更能直接建立關聯式 GIS 檔,頗具時 效性及價值性。惟所產生之一些較重要的問題則在文中加以探討。所得結果為:在地勢平緩 處或因 DTM 之解析度比地形變化粗略之情形下,容易造成自動劃定的錯誤; 另外,在切取 DTM 之範圍不正確、門限值之大小設定不當、受到集水區自動劃定演算法基本定義的限制以 及來源資料之格式為向量式或網格式之情況下 (因資料須進行格式轉換 ),均會影響集水區 自動劃定的結果。 |
英文摘要 | Watershed delineation is essential to hydrologic routing, flood control engineering, and geographic data base establishment in the national land information system. For time-saving of data processing and reducing the disadvantage of delineating watershed by manual operation, the DTM (with resolution: 40m ) of Liyutan watershed and Chungkongshi watershed were used to automatically delineate with canadian image processing software EASI/PACE of PCI Co. The results of watersheds delineated via computer with DTM were compared to the results done carefully by manual operation with topographic map (with scale 1/25,000). The differences were almost negligible. Therefore automatically delineating a large watershed with DTM, one may get more objective results, faster and erect relational GIS files directly. Some existing problems are discussed. In case that the resolution of DTM is worse than that of topographic variation or if the zone belongs to a mild slope, mistakes are more likely in delineating the watershed automatically. On the other hand, the delineation results would be less accurate if the watershed boundary is wrong and the threshold is set unsuitably. The limitation of basic definition of routing approach or the structural format (such as raster or vector) of resource data is different. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。