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| 題 名 | 山區溪溝土砂災害類型之地貌分析=Geomorphological Analysis of Sediment-Related Disasters in Mountainous Watersheds |
|---|---|
| 作 者 | 周憲德; 游喬筑; 陳筠翰; 傅義翔; 余斌; | 書刊名 | 中華水土保持學報 |
| 卷 期 | 56:4 2025.12[民114.12] |
| 頁 次 | 頁179-191 |
| 分類號 | 434.273 |
| 關鍵詞 | 土石流潛勢溪流; 集水區險峻值; 地貌分析; 土砂災害; Potential debris-flow torrents; Melton ratio; MR; Geomorphological analysis; Sediment-related disasters; |
| 語 文 | 中文(Chinese) |
| DOI | 10.29417/JCSWC.202512_56(4).0002 |
| 中文摘要 | 土砂災害是山坡地集水區永續經營所必須面對的課題,故各類土砂災害影響範圍的評估是山區工 程治理及坡地開發利用之重要依據。本文根據數值地形資料萃取集水區地文參數並輔以現地勘查及案例分析, 建議以沿程險峻值 (MR,高程差與匯水面積平方根的比值) 判釋集水區溪溝的沿程土砂災害類型。當溪溝的 沿程險峻值大於 0.3,該處土砂運移以土石流或高含砂水流為主;小於 0.3 則為洪水。本文依計曲線法求得礫 石層溪流起點範圍介於 0.1-2.5 公頃,砂頁岩互層溪溝起點範圍則介於 0.5-20 公頃。溪溝起點以上為集水區坡 面,其土砂災害類型以崩塌或沖蝕為主。集水區沿程險峻值的分佈可歸納為六種類型,當溢流點的集水區險 峻值低於 0.3,仍應進一步分析上游主流或支流的險峻值。沿程險峻值遞增發生於陡坡及地形窄縮的河段,河 道變緩及支流匯入則使沿程險峻值遞減。本文分析平廣溪及塔羅灣溪集水區的地貌特性,所得集水區溪溝沿 程險峻值變化與現勘實際土砂災害類型相符,故此地貌分析作法可供坡地水土資源利用及聚落防災之參考。 |
| 英文摘要 | Sediment hazard zoning, such as delineating areas prone to debris flow or flooding, is a crucial task in disaster prevention and land management in mountainous watersheds. In this study, distributed Melton ratio (MR) was used as a dimensionless geomorphic parameter together with a geographic information system and digital elevation model to evaluate the types of sediment disasters. When the MR is greater than 0.3 at the local point, debris flow occurs if abundant loose sediment is located upstream. When the MR is smaller than 0.3, flooding occurs at this location. The MR values for the confluence of upstream trunk rivers and tributaries and for upstream spilling points, such as bridges or valleys, should be examined to evaluate the corresponding risk of sediment-related disasters in these locations. Typ- ically, the threshold drainage areas for channel initiation are within the ranges of 0.1-2.5 and 0.5-20.0 ha for gravelly valleys and sandstone–shale valleys, respectively. The distribution of MR values along a trunk river can be classified into six categories, with the majority of watersheds belonging to categories III and IV. Case studies of Pingguan Creek in New Taipei City and Talowan River in Nantou County revealed that distributed MR models can identify the types of sediment-related disasters that occur along the main channel in mountainous watersheds. |
本系統中英文摘要資訊取自各篇刊載內容。