Research developments in debris flow monitoring, modelling and hazard assessment in Italian mountain catchments

Lenzi, Mario Aristide

doi:10.2495/deb060141

Cited by 8 publications

(6 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This paper deals with the morphological evolution and the associated island dynamics of the middle course of the Brenta River (from Bassano Del Grappa to Piazzola sul Brenta) over the last 30 years. Previous studies in this river basin have analysed (i) the morphological changes of the river channel (Surian and Cisotto, 2007;Surian et al, 2009b;Moretto et al, 2011), (ii) land use changes within the fluvial corridor and the abundance of in-channel wood Rigon et al, 2008Rigon et al, , 2012Vitti et al, 2011) and (iii) sediment transport and sediment budget in the headwaters (Lenzi, 2006, Mao and Lenzi, 2007. The evolution of the reach between Bassano Del Grappa and Piazzola sul Brenta is interesting to be explored because it was heavily affected by human pressure due to a dense hydropower scheme in the basin and severe past gravel mining activity.…”

Section: Introductionmentioning

confidence: 99%

Channel Adjustments and Island Dynamics in the Brenta River (Italy) Over the Last 30 years

et al. 2013

Self Cite

View full text Add to dashboard Cite

Many gravel bed rivers in the European Alpine area suffered different ranges and types of human pressure that modified their morphology and altered their processes. This work presents the case of the middle portion of the Brenta River, historically impacted by human activities such as floodplain occupations, bank protection, gravel mining, hydropower schemes and water diversion. Dam operation and gravel mining have produced considerable modifications in the natural sediment regime generating important morphological channel responses (narrowing and incision). Large areas of the former active channel have been colonized by riparian vegetation, both as islands and as marginal woodlands. Overall, the river changed its morphological pattern from braided to wandering. The present study analyses the timing and extent of the planform morphological changes that occurred over the last 30 years along the middle portion of the river (20 km long) through the examination of aerial photos, repeated topographic measurements and hydrological data. A series of recent aerial photos (1981, 1990, 1994, 1999, 2003, 2006, 2008, 2010 and 2011) have been used to assess the medium and short‐term morphological changes of the floodplains and the active channel area. As to the medium‐term modification, the recent changes in in‐channel gravel mining have determined a new trend of active channel widening through erosion of vegetated areas. The analysis has also allowed to assess the morphological effect of single flood events. Only floods with recurrence interval higher than 8–10 years appear to be able to determine substantial erosion of floodplain and island margins. Copyright © 2013 John Wiley & Sons, Ltd.

show abstract

Section: Introductionmentioning

confidence: 99%

Channel Adjustments and Island Dynamics in the Brenta River (Italy) Over the Last 30 years

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Also, between the 1960s and 1990s, intense gravel mining was carried out in the main channel and in its main tributaries. Finally, effective erosion and torrent control works started in the upper basin in the 1930s [9,[16][17][18][19].…”

Section: Methodsmentioning

confidence: 99%

Riparian forest structure, vegetation cover and flood events in the Piave River

Picco

Mao

Rigon

et al. 2012

Monitoring, Stimulation, Prevention and Remediation of Dense and Debris Flows IV

Self Cite

View full text Add to dashboard Cite

Until very recently, rivers have been considered as the result of the interaction between water and sediments, thus simplifying this very complex system. In doing so, one important component was missed. This is vegetation, namely trees growing on banks, floodplains, and bars/islands. The pattern of riparian vegetation in gravel bed rivers depends on the climate, hydrological regime, floods, sediment transport and the morphological settings of the river. Also, the marked spatial variability of density, height, species diversity, age, and rates of growth reflects the very complex nature of bed colonization, the strong influence of sequences and magnitude of floods, and the feedbacks between morphology, vegetation and hydraulics. Furthermore, a wide array of human impacts acting at either the basin or river network scales can influence substantially the morphodynamics and thus the characteristics, types and distribution of vegetation within the river corridor. The aim of the work is to analyze the relationship between the vegetation structure and the morphological characteristics of two sub-reaches of the Piave river which suffered both floods and intense and multiple human impacts especially due to dam building and inchannel gravel mining. Six cross sections were surveyed and vegetation, soil variables and sediment deposited were measured on 214 plots, (4 x 4 m each one and 10 m spaced). Each vegetation plot were recognized on a recent aerial photo (2009) and its ages were calculated performing both a multi-temporal analysis of older photos (1960, 70, 80, 91, 99, 2006 and 2009) analysis. The Piave River shows a complex pattern of vegetation distribution along the cross-sections with no clear relationship between the elevation and the plant communities. However later successional plant communities cover older surfaces and the thickness of the sand layer helps explaining differences in areas dominated by different species (e.g. Salix alba and Salix eleagnos).

show abstract

“…This is because floating LW elements can represent a hazard during intense flood events [ Fischer , 2006; Waldner et al , 2007; Comiti et al , 2008b]. LW may increase flood risk by a variety of processes, such as flow and sediment surges following the collapse of temporary wood dams [ Castiglioni , 1974], inclusion in debris flows [ Ishikawa , 1990; Lancaster et al , 2003; Lenzi , 2006], clogging of bridges and other structures [ Diehl , 1997; Bezzola et al , 2002; Lyn et al , 2007; Mao and Comiti , 2010; Mazzorana et al , 2011], and local bank erosion [ Daniels and Rhoads , 2004].…”

Section: Introductionmentioning

confidence: 99%

Large wood storage in streams of the Eastern Italian Alps and the relevance of hillslope processes

Rigon¹,

Comiti²,

Lenzi³

2012

Water Resources Research

Self Cite

View full text Add to dashboard Cite

[1] An understanding of the dynamics of large wood (LW) in mountain channels provides the basis for evaluating natural morphological patterns as well as managing potentially hazardous wood transport during flood events. Few studies have investigated the distribution of LW in managed streams of the Alps across a wide spatial scale. This paper presents extensive field measurements of LW storage and channel morphology carried out in 13 channels of the Eastern Italian Alps with drainage areas ranging from 1.2 to 70 km 2 , mean bed slope between 0.03 and 0.38, and channel width between 2 and 20 m. More than 9000 LW elements were measured in the 33 reaches surveyed. A geostatistical, geographic information system (GIS)-based model for wood recruitment from hillslope instabilities was also developed and applied to the study basin. LW storage in the study channels results as being much lower than in seminatural basins of comparable size and climate, and only basins characterized by extensive mass wasting processes contain high wood loads with relevant morphological consequences. The statistical analysis of LW storage at the reach scale indicates that unit stream power is apparently the most significant hydromorphological factor influencing LW storage, in agreement with studies in other world regions. However, we argue that the effect of unit stream power on LW storage is not only linked to flow transport capacity but also derives from its association with LW supply and valley morphology. Both the GIS model and statistical tests on field data indicate that hillslope instabilities connected to the channel network dominate the LW recruitment volume and the distribution of in-channel wood storage.Citation: Rigon, E., F. Comiti, and M. A. Lenzi (2012), Large wood storage in streams of the Eastern Italian Alps and the relevance of hillslope processes, Water Resour. Res., 48, W01518,

show abstract

Research developments in debris flow monitoring, modelling and hazard assessment in Italian mountain catchments

Cited by 8 publications

References 29 publications

Channel Adjustments and Island Dynamics in the Brenta River (Italy) Over the Last 30 years

Channel Adjustments and Island Dynamics in the Brenta River (Italy) Over the Last 30 years

Riparian forest structure, vegetation cover and flood events in the Piave River

Large wood storage in streams of the Eastern Italian Alps and the relevance of hillslope processes

Contact Info

Product

Resources

About