Geomorphological slope units of the Himalayas
Slope units represent surface slopes by means of polygons delimited by drainage and divide lines obtained on a digital topography. Objective slope unit delineation for a given digital elevation model is still an open issue and, often, a limitation that may dictate the use of a more traditional pixel...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2022-05-01
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| Series: | Journal of Maps |
| Subjects: | |
| Online Access: | https://www.tandfonline.com/doi/10.1080/17445647.2022.2052768 |
| _version_ | 1811252038575587328 |
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| author | Massimiliano Alvioli Ivan Marchesini Badal Pokharel Kaushal Gnyawali Samsung Lim |
| author_facet | Massimiliano Alvioli Ivan Marchesini Badal Pokharel Kaushal Gnyawali Samsung Lim |
| author_sort | Massimiliano Alvioli |
| collection | DOAJ |
| description | Slope units represent surface slopes by means of polygons delimited by drainage and divide lines obtained on a digital topography. Objective slope unit delineation for a given digital elevation model is still an open issue and, often, a limitation that may dictate the use of a more traditional pixel-based approach for spatial analysis. Availability of slope unit maps facilitates many kinds of studies and allows scholars to focus on specific scientific issues rather than on preparing sound mapping units from scratch for their research. Here, we present a slope unit map of a large portion of the Himalayas. The map is prepared following a widely tested, parameter-free optimization algorithm. The area encompassed by the map is relevant to studies of the well-known 2015 Gorkha earthquake and monsoons, which makes it relevant to a vast portion of the scientific community working in natural hazards including, but not limited to, landslide scientists and practitioners. The map contains 112,674 polygons with average area of 0.38 km[Formula: see text] and is published in vector form. The map is accompanied by a selection of data including morphometric and thematic quantities. In addition to describing the rationale behind the delineation of the polygonal map and selected data, we describe an application devoted to unsupervised terrain classification. We applied a k-means clustering procedure with two strategies: one at (coarser) basin scale and one at (finer) slope unit scale. We show similarities and differences between the two classification strategies, highlighting the role of the slope unit subdivision in the two cases. |
| first_indexed | 2024-04-12T16:28:55Z |
| format | Article |
| id | doaj.art-0f987b28820a4ffab55754a4c5135b8b |
| institution | Directory Open Access Journal |
| issn | 1744-5647 |
| language | English |
| last_indexed | 2024-04-12T16:28:55Z |
| publishDate | 2022-05-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Journal of Maps |
| spelling | doaj.art-0f987b28820a4ffab55754a4c5135b8b2022-12-22T03:25:15ZengTaylor & Francis GroupJournal of Maps1744-56472022-05-0111410.1080/17445647.2022.2052768Geomorphological slope units of the HimalayasMassimiliano Alvioli0Ivan Marchesini1Badal Pokharel2Kaushal Gnyawali3Samsung Lim4Consiglio Nazionale delle Ricerche, Istituto di Ricerca per la Protezione Idrogeologica, Perugia, ItalyConsiglio Nazionale delle Ricerche, Istituto di Ricerca per la Protezione Idrogeologica, Perugia, ItalySchool of Civil and Environmental Engineering, University of New South Wales, Sydney, AustraliaSchool of Engineering, The University of British Columbia, Kelowna, BC, CanadaSchool of Civil and Environmental Engineering, University of New South Wales, Sydney, AustraliaSlope units represent surface slopes by means of polygons delimited by drainage and divide lines obtained on a digital topography. Objective slope unit delineation for a given digital elevation model is still an open issue and, often, a limitation that may dictate the use of a more traditional pixel-based approach for spatial analysis. Availability of slope unit maps facilitates many kinds of studies and allows scholars to focus on specific scientific issues rather than on preparing sound mapping units from scratch for their research. Here, we present a slope unit map of a large portion of the Himalayas. The map is prepared following a widely tested, parameter-free optimization algorithm. The area encompassed by the map is relevant to studies of the well-known 2015 Gorkha earthquake and monsoons, which makes it relevant to a vast portion of the scientific community working in natural hazards including, but not limited to, landslide scientists and practitioners. The map contains 112,674 polygons with average area of 0.38 km[Formula: see text] and is published in vector form. The map is accompanied by a selection of data including morphometric and thematic quantities. In addition to describing the rationale behind the delineation of the polygonal map and selected data, we describe an application devoted to unsupervised terrain classification. We applied a k-means clustering procedure with two strategies: one at (coarser) basin scale and one at (finer) slope unit scale. We show similarities and differences between the two classification strategies, highlighting the role of the slope unit subdivision in the two cases.https://www.tandfonline.com/doi/10.1080/17445647.2022.2052768GeomorphometryGorkhamapping unitsterrain classificationnatural hazardsautomatic delineation |
| spellingShingle | Massimiliano Alvioli Ivan Marchesini Badal Pokharel Kaushal Gnyawali Samsung Lim Geomorphological slope units of the Himalayas Journal of Maps Geomorphometry Gorkha mapping units terrain classification natural hazards automatic delineation |
| title | Geomorphological slope units of the Himalayas |
| title_full | Geomorphological slope units of the Himalayas |
| title_fullStr | Geomorphological slope units of the Himalayas |
| title_full_unstemmed | Geomorphological slope units of the Himalayas |
| title_short | Geomorphological slope units of the Himalayas |
| title_sort | geomorphological slope units of the himalayas |
| topic | Geomorphometry Gorkha mapping units terrain classification natural hazards automatic delineation |
| url | https://www.tandfonline.com/doi/10.1080/17445647.2022.2052768 |
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