Multiple flow direction algorithms are commonly thought to be a useful means for determining drainage areas from gridded elevation data. It remains however unclear whether these algorithms can be used to describe surface flow paths and gravity-driven processes across a terrain without causing unrealistic artificial dispersion of flow. To explore this issue, a unified algorithm for the determination of flow directions is developed and new methods for the validation of surface flow paths are introduced. The unified algorithm allows, by setting appropriate parameters, to perform local or path-based analyses, and to experiment different combinations of single and multiple flow directions in a morphologically significant manner. The new validation methods use drainage systems delineated from contour elevation data as a reference and consider the overlapping between these drainage systems and the corresponding drainage systems obtained from gridded elevation data. A purely morphologic analysis is carried out. The obtained results suggest that dispersive methods may be preferred over nondispersive methods if the computation of the spatial pattern of drainage area, especially along divergent terrains, is the main focus. On the other hand, the results reveal that path-based nondispersive methods should be preferred over dispersive methods if the delineation of drainage systems and surface flow paths is an important focus. Path-based nondispersive methods are found to be a reliable means for the determination of surface flow paths from gridded elevation data, and to provide therefore a sound basis for the distributed description of gravity-driven processes. Future work is needed to formulate models of physical dispersion for water, sediments and solutes upon this purely morphologic basis.
|Data di pubblicazione:||2008|
|Titolo:||On the determination of surface flow paths from gridded elevation data|
|Autori:||S. Orlandini; G. Moretti|
|Nome del convegno:||American Geophysical Union Fall Meeting 2008|
|Luogo del convegno:||San Francisco, CA, USA|
|Data del convegno:||15–19 December 2008|
|Volume:||89(53), Fall Meet. Suppl., Abstract H11H-0857|
|Appare nelle tipologie:||Abstract in Rivista|
File in questo prodotto:
I documenti presenti in Iris Unimore sono rilasciati con licenza Creative Commons Attribuzione - Non commerciale - Non opere derivate 3.0 Italia, salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris