The D8, D8-LTD, D∞-LTD, D∞, MD∞, and MD8 flow direction methods are evaluated against field observations of overland flow dispersion obtained from novel experimental methods. Thin flows of cold water were released at selected points on a warmer slope and individual overland flow patterns originating from each of these points were observed using a terrestrial laser scanner and a thermal imaging camera. Land microtopography was determined by using laser returns from the dry land surface, whereas overland flow patterns were determined by using either laser returns or infrared emissions from the wetted portions of the land surface. Planar overland flow dispersion is found to play an important role in the region lying immediately downslope of the point source, but attenuates rapidly as flow propagates downslope. In contrast, existing dispersive flow direction methods are found to provide a continued dispersion with distance downslope. Predicted propagation patterns, for all methods considered here, depend critically on the size h of grid cells involved. All methods are found to be poorly sensitive in extremely fine grids (h ≤ 2 cm), and to be poorly specific in coarse grids (h = 2 m). Satisfactory results are, however, obtained in grids having resolutions h that approach the average flow width (50 cm), with the best performances displayed by the MD8 method in the finest grids (5 cm ≤ h ≤ 20 cm), and by the MD∞, D∞, and D∞-LTD methods in the coarsest grids (20 cm < h ≤ 1 m).

Evaluation of flow direction methods against field observations of overland flow dispersion / Orlandini, Stefano; Moretti, Giovanni; Corticelli, Mauro Alessandro; Santangelo, Paolo Emilio; Capra, Alessandro; Rivola, Riccardo; Albertson, John D.. - ELETTRONICO. - (2012), pp. 1-12. ((Intervento presentato al convegno XXXIII Convegno di Idraulica e Costruzioni Idrauliche tenutosi a Brescia, Italia nel 10-15 settembre 2012.

Evaluation of flow direction methods against field observations of overland flow dispersion

Orlandini, Stefano;Moretti, Giovanni;Corticelli, Mauro Alessandro;Santangelo, Paolo Emilio;Capra, Alessandro;Rivola, Riccardo;
2012

Abstract

The D8, D8-LTD, D∞-LTD, D∞, MD∞, and MD8 flow direction methods are evaluated against field observations of overland flow dispersion obtained from novel experimental methods. Thin flows of cold water were released at selected points on a warmer slope and individual overland flow patterns originating from each of these points were observed using a terrestrial laser scanner and a thermal imaging camera. Land microtopography was determined by using laser returns from the dry land surface, whereas overland flow patterns were determined by using either laser returns or infrared emissions from the wetted portions of the land surface. Planar overland flow dispersion is found to play an important role in the region lying immediately downslope of the point source, but attenuates rapidly as flow propagates downslope. In contrast, existing dispersive flow direction methods are found to provide a continued dispersion with distance downslope. Predicted propagation patterns, for all methods considered here, depend critically on the size h of grid cells involved. All methods are found to be poorly sensitive in extremely fine grids (h ≤ 2 cm), and to be poorly specific in coarse grids (h = 2 m). Satisfactory results are, however, obtained in grids having resolutions h that approach the average flow width (50 cm), with the best performances displayed by the MD8 method in the finest grids (5 cm ≤ h ≤ 20 cm), and by the MD∞, D∞, and D∞-LTD methods in the coarsest grids (20 cm < h ≤ 1 m).
XXXIII Convegno di Idraulica e Costruzioni Idrauliche
Brescia, Italia
10-15 settembre 2012
1
12
Orlandini, Stefano; Moretti, Giovanni; Corticelli, Mauro Alessandro; Santangelo, Paolo Emilio; Capra, Alessandro; Rivola, Riccardo; Albertson, John D.
Evaluation of flow direction methods against field observations of overland flow dispersion / Orlandini, Stefano; Moretti, Giovanni; Corticelli, Mauro Alessandro; Santangelo, Paolo Emilio; Capra, Alessandro; Rivola, Riccardo; Albertson, John D.. - ELETTRONICO. - (2012), pp. 1-12. ((Intervento presentato al convegno XXXIII Convegno di Idraulica e Costruzioni Idrauliche tenutosi a Brescia, Italia nel 10-15 settembre 2012.
File in questo prodotto:
File Dimensione Formato  
17a-1238_ORLANDINI_STEFANO.pdf

non disponibili

Tipologia: Post-print dell'autore (bozza post referaggio)
Dimensione 4.32 MB
Formato Adobe PDF
4.32 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/798289
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact