Fluvial Geomorphology and Basin Development of Karra Khola Basin, Hetauda, Central Nepal

• 作者: Manju Subedi Naresh Kazi Tamrakar
• 来源期刊: 地质研究(英文)
• 学科: 地球科学
• 关键词: Morphometric analysis Stream classification Hypsometric analysis Geomorphic development Drainage density Dissection index Natural hazards EROSION
• 年，卷（期）: 2020,（4）
• 页码范围: 1-13
• 页数: 13页
• 分类号: P61

摘要

Geomorphological study of a basin is important for understanding theoverall basin characteristics which are helpful for the management of waterresources, construction along the river bank and natural hazard mitigationwithin the area. The study was carried out in the Karra Khola Basin, oneof the prominent basins in the Eastern extreme of the Hetauda Dun Valley,Central Nepal, to investigate geomorphic characteristics of the mainstream of the basin, categorize them into various stream types and studybasin development through drainage basin’s morphometric parameters.Geographical Information System (GIS) and Remote sensing techniquesusing satellite images were used as a tool to make the morphometricanalysis of the basin along with its major 13 sub-basin and delineate streamclassification following the Rosgen’s Level I hierarchical inventory. Themain stream of the Karra Khola is characterized as A-, B- and C-typeand the tributaries segments as B- and F-type. The basin is structurallyunaffected and has the permeable surface area and elongated shape. Thehypsometric analysis indicates that the basin is mostly at the old stage ofgeomorphic development while four out of 13 sub-basin being at maturestage. The Karra Khola sub-basin have higher risk to flash flooding(Lg=0.1-0.16km). Drainage density value reveals that the basin is highlysusceptible to flooding, gully erosion, etc. Similarly, dissection index valueimplies that the north eastern region of the basin is highly vulnerable toerosion as it at the younger stage of geomorphic development. Since thestudy area is highly sensitive to future natural hazards, further study andappropriate measures should be followed for safeguarding against thefuture risk along the Karra Khola basin and its tributaries.