An improved correlation model for sediment delivery ratio assessment

Abstract

In the present work, a new simplified model approach for sediment delivery ratio (SDR) assessment is proposed. Modelling and assessing SDR is still an open question. Difficulties rise from the lack of sufficient data availability, on one side, and, on the other, from the inherent uncertainties including spatial variability and temporal discontinuity of the land cover, climatic, hydrological and geomorphological variables involved. The proposed SDR SIM model tries to skip over the limitations observed in other models generally adopted. A comparison with two different selected models amongst the most widespread simplified models, i.e. the area-model and the slope-model, is showed in application to a wide range of catchments extensions across different landscapes of Italy. The SDR SIM estimates were also evaluated against observed SDR over a validation dataset of 11 basins sparse over different regions of the world. The results showed the effectiveness of the proposed model approach based on easily available catchment parameters.

Comparison of conceptual landscape metrics to define hillslope-scale sediment delivery ratio

“…Fraser et al, 1998;McHugh et al, 2002;Verstraeten et al, 2007;Boomer et al, 2008;Diodato and Grauso, 2009;Vigiak et al, 2009;Ali and De Boer, 2010). This interest stems partly from the recognition of the limits of empirical models developed at the plot/ field scale in performing acceptably at the catchment scale (Jetten et al, 1999); and even more importantly, from the shift in natural resource management focus from on-site effects of erosion (i.e.…”

“…regionalisation). Catchment SDR has been related to upslope area, climatic conditions, or shape and slope of the catchment (Maner, 1958;Vanoni, 1975;Walling, 1983;Wasson, 1994;Ferro and Minacapilli, 1995;Lu et al, 2006;Diodato and Grauso, 2009). Several algorithms have also been proposed to account more explicitly for topography (Ferro and Minacapilli, 1995;Mitasova et al, 1996;Yagov et al, 1998) as well as hydrologic conditions, vegetation, surface roughness, and sediment properties (Fraser et al, 1998;Rustomji and Prosser, 2001;McHugh et al, 2002;Lu et al, 2006;Borselli et al, 2007Borselli et al, , 2008.…”

“…Boomer et al (2008) found that the application of five SDR algorithms (three lumped at the catchment scale, and two spatially distributed) did not improve the performance of a USLE-based sediment budget model, particularly for uncalibrated watersheds. Other studies report that regionalisation of SDR or sediment transport capacity can improve catchment model assessment of sediment yields (Lenhart et al, 2005;Borselli et al, 2007Borselli et al, , 2008Verstraeten et al, 2007;Diodato and Grauso, 2009). Interpretation of these contrasting findings on the benefits of adopting a regionalised SDR parameter is difficult because sediment yields measured at gauging stations result from complex interactions of several erosion and deposition processes, such as hillslope erosion (comprising sheet, interrill, and rill erosion), gully or streambank erosion, or floodplain deposition (e.g.…”

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“…(Auerswald, 1992). SDR tidak hanya dipengaruhi oleh luas DAS tapi juga faktor-faktor lain, diantaranya kondisi hidrologi, geomorfologi, sifat sedimen (Vigiak, Borselli, Newham, McInnes, & Roberts, 2012) (Diodato & Grauso, 2009). Nilai SDR yang hanya mempertimbangkan luas DAS akan lebih besar dibandingkan dengan penentuan SDR dengan pendugaan laju erosi menggunakan USLE dan hasil pengukuran muatan sedimen (Tunas, 2008).…”

PERBANDINGAN PREDIKSI HASIL SEDIMEN MENGGUNAKAN PENDEKATAN MODEL UNIVERSAL SOIL LOSS EQUATION DENGAN PENGUKURAN LANGSUNG (Comparison of sediment yield from prediction using Universal Soil Loss Equation with direct measurement)

“…Peta kemiringan lereng (Slope steepness map) (Auerswald, 1992). SDR tidak hanya dipengaruhi oleh luas DAS tapi juga faktor-faktor lain, diantaranya kondisi hidrologi, geomorfologi, sifat sedimen (Vigiak, Borselli, Newham, McInnes, & Roberts, 2012) (Diodato & Grauso, 2009). Nilai SDR yang hanya mempertimbangkan luas DAS akan lebih besar dibandingkan dengan penentuan SDR dengan pendugaan laju erosi menggunakan USLE dan hasil pengukuran muatan sedimen (Tunas, 2008).…”