A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal
Basin geomorphology is a complete system of landforms and topographic features that play a crucial role in the basin-scale flood risk evaluation. Nepal is a country characterized by several rivers and under the influence of frequent floods. Therefore, identifying flood risk areas is of paramount imp...
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MDPI AG
2021-04-01
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| Series: | ISPRS International Journal of Geo-Information |
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| Online Access: | https://www.mdpi.com/2220-9964/10/4/247 |
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| author | Til Prasad Pangali Sharma Jiahua Zhang Narendra Raj Khanal Foyez Ahmed Prodhan Lkhagvadorj Nanzad Da Zhang Pashupati Nepal |
| author_facet | Til Prasad Pangali Sharma Jiahua Zhang Narendra Raj Khanal Foyez Ahmed Prodhan Lkhagvadorj Nanzad Da Zhang Pashupati Nepal |
| author_sort | Til Prasad Pangali Sharma |
| collection | DOAJ |
| description | Basin geomorphology is a complete system of landforms and topographic features that play a crucial role in the basin-scale flood risk evaluation. Nepal is a country characterized by several rivers and under the influence of frequent floods. Therefore, identifying flood risk areas is of paramount importance. The East Rapti River, a tributary of the Ganga River, is one of the flood-affected basins, where two major cities are located, making it crucial to assess and mitigate flood risk in this river basin. A morphometric calculation was made based on the Shuttle Radar Topographic Mission (SRTM) 30-m Digital Elevation Model (DEM) in the Geographic Information System (GIS) environment. The watershed, covering 3037.29 km<sup>2</sup> of the area has 14 sub-basins (named as basin A up to N), where twenty morphometric parameters were used to identify flash flood potential sub-basins. The resulting flash flood potential maps were categorized into five classes ranging from very low to very high-risk. The result shows that the drainage density, topographic relief, and rainfall intensity have mainly contributed to flash floods in the study area. Hence, flood risk was analyzed pixel-wise based on slope, drainage density, and precipitation. Existing landcover types extracted from the potential risk area indicated that flash flood is more frequent along the major Tribhuvan Rajpath highway. The landcover data shows that human activities are highly concentrated along the west (Eastern part of Bharatpur) and the east (Hetauda) sections. The study concludes that the high human concentrated sub-basin “B” has been categorized as a high flood risk sub-basin; hence, a flood-resilient city planning should be prioritized in the basin. |
| first_indexed | 2024-03-10T12:30:49Z |
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| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-03-10T12:30:49Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
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| series | ISPRS International Journal of Geo-Information |
| spelling | doaj.art-4f25b19eb4c54602a6636ba98f8fbbe72023-11-21T14:39:56ZengMDPI AGISPRS International Journal of Geo-Information2220-99642021-04-0110424710.3390/ijgi10040247A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of NepalTil Prasad Pangali Sharma0Jiahua Zhang1Narendra Raj Khanal2Foyez Ahmed Prodhan3Lkhagvadorj Nanzad4Da Zhang5Pashupati Nepal6Key Laboratory of Digital Earth Sciences, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100094, ChinaKey Laboratory of Digital Earth Sciences, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100094, ChinaCentral Department of Geography, Tribhuvan University, Kathmandu 66613, NepalKey Laboratory of Digital Earth Sciences, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100094, ChinaKey Laboratory of Digital Earth Sciences, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100094, ChinaKey Laboratory of Digital Earth Sciences, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100094, ChinaCentral Department of Geography, Tribhuvan University, Kathmandu 66613, NepalBasin geomorphology is a complete system of landforms and topographic features that play a crucial role in the basin-scale flood risk evaluation. Nepal is a country characterized by several rivers and under the influence of frequent floods. Therefore, identifying flood risk areas is of paramount importance. The East Rapti River, a tributary of the Ganga River, is one of the flood-affected basins, where two major cities are located, making it crucial to assess and mitigate flood risk in this river basin. A morphometric calculation was made based on the Shuttle Radar Topographic Mission (SRTM) 30-m Digital Elevation Model (DEM) in the Geographic Information System (GIS) environment. The watershed, covering 3037.29 km<sup>2</sup> of the area has 14 sub-basins (named as basin A up to N), where twenty morphometric parameters were used to identify flash flood potential sub-basins. The resulting flash flood potential maps were categorized into five classes ranging from very low to very high-risk. The result shows that the drainage density, topographic relief, and rainfall intensity have mainly contributed to flash floods in the study area. Hence, flood risk was analyzed pixel-wise based on slope, drainage density, and precipitation. Existing landcover types extracted from the potential risk area indicated that flash flood is more frequent along the major Tribhuvan Rajpath highway. The landcover data shows that human activities are highly concentrated along the west (Eastern part of Bharatpur) and the east (Hetauda) sections. The study concludes that the high human concentrated sub-basin “B” has been categorized as a high flood risk sub-basin; hence, a flood-resilient city planning should be prioritized in the basin.https://www.mdpi.com/2220-9964/10/4/247morphometric analysisflash floodGeographic Information System (GIS)remote sensingSRTM |
| spellingShingle | Til Prasad Pangali Sharma Jiahua Zhang Narendra Raj Khanal Foyez Ahmed Prodhan Lkhagvadorj Nanzad Da Zhang Pashupati Nepal A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal ISPRS International Journal of Geo-Information morphometric analysis flash flood Geographic Information System (GIS) remote sensing SRTM |
| title | A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal |
| title_full | A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal |
| title_fullStr | A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal |
| title_full_unstemmed | A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal |
| title_short | A Geomorphic Approach for Identifying Flash Flood Potential Areas in the East Rapti River Basin of Nepal |
| title_sort | geomorphic approach for identifying flash flood potential areas in the east rapti river basin of nepal |
| topic | morphometric analysis flash flood Geographic Information System (GIS) remote sensing SRTM |
| url | https://www.mdpi.com/2220-9964/10/4/247 |
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