Debris-flow data collected in the Moscardo Torrent (eastern Italian Alps) between 1990 and 2019

2020 ◽  
Author(s):  
Lorenzo Marchi ◽  
Massimo Arattano ◽  
Marco Cavalli ◽  
Federico Cazorzi ◽  
Stefano Crema ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Flow Data ◽  
Italian Alps ◽  
Time To Peak ◽  
Flow Monitoring ◽  
Monitoring Activities ◽  
Total Event ◽  
Flow Variables ◽  
Triggering Rainfall

<p>Debris-flow research requires experimental data that are difficult to collect because of the intrinsic characteristics of these processes. Both post-event field observations and monitoring in instrumented channels are suitable to collect debris-flow field data, even if with different resolutions and purposes. Monitoring in instrumented channels enables recording data that cannot be gathered by means of post-event surveys in ungauged channels. Extending the monitoring activities over multidecadal time intervals increases the significance of collected data because longer time series permit recognizing changes in debris-flow response as a consequence of changes in controlling factors, such as climate, land use, and the implementation of control works.</p><p>This paper presents debris-flows data recorded in the Moscardo Torrent (eastern Italian Alps) between 1990 and 2019. As far as we know, the Moscardo Torrent basin was the first catchment equipped with permanent instrumentation for debris-flow monitoring in Europe. The monitoring activities in the Moscardo Torrent began in 1989-1990 and still keep on, although with some gaps due to the implementation of control works in the instrumented channel (1998-2000) and the obsolescence of the instrumentation between 2007 and 2010.</p><p>Thirty debris flows were observed between 1990 and 2019; 26 of them were monitored by sensors installed on the channel (at two measuring stations for most events), while four debris flows were documented by means of post-event observations. Monitored data consist of debris-flow hydrographs, measured by means of ultrasonic sensors, and rainfall. Debris flows in the Moscardo Torrent occur from early June to the end of September, with higher frequency in the first part of summer.</p><p>This contribution presents data on triggering rainfall, flow velocity, peak discharge and volume for the monitored hydrographs. The relatively large number of debris-flow events recorded in the Moscardo Torrent has permitted to recognize the main characteristics of the debris-flow hydrographs. We used the data related to duration and the maximum depth of the debris-flow surges to define triangular hydrographs related to different event severity. Simplified triangular hydrographs show the distinctive features of debris flows (short total event duration and very short time to peak) and can help defining realistic inputs to debris-flow propagation models. A more detailed representation of hydrographs shape was achieved by averaging the recorded hydrographs of debris-flow surges. This analysis was performed on the debris flows recorded between 2002 and 2019: data for 12 surges for each of the two flow measuring stations were available. Dimensionless hydrographs were generated normalizing the flow depth by its maximum value and the time by the total surge duration. Flow peaks were aligned to preserve the sharp shape that is a distinctive feature of debris-flow hydrographs. Finally, the ordinates were averaged, and mean debris-flow hydrographs were obtained.</p><p>Debris-flow data collected in the Moscardo Torrent dataset could contribute to further analysis, including the comparison of triggering rainfall and flow variables with those recorded in other basins instrumented for debris-flows monitoring under different climate and geolithological conditions.</p>

scholarly journals Debris flows recorded in the Moscardo catchment (Italian Alps) between 1990 and 2019

2020 ◽  
Author(s):  
Lorenzo Marchi ◽  
Federico Cazorzi ◽  
Massimo Arattano ◽  
Sara Cucchiaro ◽  
Marco Cavalli ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Time Interval ◽  
Flow Depth ◽  
Italian Alps ◽  
The Public ◽  
Time To Peak ◽  
Velocity Peak ◽  
Basic Features ◽  
Triggering Rainfall

Abstract. This paper presents debris-flows data recorded in the Moscardo Torrent (eastern Italian Alps) between 1990 and 2019. In this time interval, 30 debris flows were observed, 26 of them were monitored by sensors installed on the channel, while four were only documented through post-event observations. Monitored data consist of debris-flow hydrographs, measured utilizing ultrasonic sensors, and rainfall. Debris flows in the Moscardo Torrent occur from early June to the end of September, with higher frequency in the first part of summer. The paper presents data on triggering rainfall, flow velocity, peak discharge, and volume for the monitored hydrographs. Simplified triangular hydrographs and dimensionless hydrographs were derived to show the basic features of the debris flows in the Moscardo Torrent (time to peak, surge duration, flow depth) and permitting comparison with other instrumented catchments. The dataset is made available to the public with the following DOI: https://doi.pangaea.de/10.1594/PANGAEA.919707 .

scholarly journals Debris flows recorded in the Moscardo catchment (Italian Alps) between 1990 and 2019

2021 ◽  
Vol 21 (1) ◽  
pp. 87-97
Author(s):  
Lorenzo Marchi ◽  
Federico Cazorzi ◽  
Massimo Arattano ◽  
Sara Cucchiaro ◽  
Marco Cavalli ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Time Interval ◽  
Flow Depth ◽  
Italian Alps ◽  
The Public ◽  
Time To Peak ◽  
Velocity Peak ◽  
Basic Features ◽  
Triggering Rainfall

Abstract. This paper presents debris-flow data recorded in the Moscardo Torrent (eastern Italian Alps) between 1990 and 2019. In this time interval, 30 debris flows were observed: 26 of them were monitored by sensors installed on the channel, while four were only documented through post-event observations. Monitored data consist of debris-flow hydrographs, measured utilizing ultrasonic sensors, and rainfall. Debris flows in the Moscardo Torrent occur from early June to the end of September, with higher frequency in the first part of summer. The paper presents data on triggering rainfall, flow velocity, peak discharge, and volume for the monitored hydrographs. Simplified triangular hydrographs and dimensionless hydrographs were derived to show the basic features of the debris flows in the Moscardo Torrent (time to peak, surge duration, flow depth) and permitting comparison with other instrumented catchments. The dataset is made available to the public with the following DOI: https://doi.org/10.1594/PANGAEA.919707.

scholarly journals Triggering conditions and depositional characteristics of a disastrous debris flow event in Zhouqu city, Gansu Province, northwestern China

2011 ◽  
Vol 11 (11) ◽  
pp. 2903-2912 ◽  
Author(s):  
C. Tang ◽  
N. Rengers ◽  
Th. W. J. van Asch ◽  
Y. H. Yang ◽  
G. F. Wang
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Field Investigation ◽  
Gansu Province ◽  
Northwestern China ◽  
Catastrophic Event ◽  
Catchment Areas ◽  
Triggering Conditions ◽  
Geomorphological Features ◽  
Triggering Rainfall

Abstract. On 7 August 2010, catastrophic debris flows were triggered by a rainstorm in the catchments of the Sanyanyu and Luojiayu torrents, Zhouqu County, Gansu Province northwestern China. These two debris flows originated shortly after a rainstorm with an intensity of 77.3 mm h−1 and transported a total volume of about 2.2 million m3, which was deposited on an existing debris fan and into a river. This catastrophic event killed 1765 people living on this densely urbanised fan. The poorly sorted sediment contains boulders up to 3–4 m in diameter. In this study, the geomorphological features of both debris flow catchment areas are analyzed based on the interpretation of high-resolution remote sensing imagery combined with field investigation. The characteristics of the triggering rainfall and the initiation of the debris flow occurrence are discussed. Using empirical equations, the peak velocities and discharges of the debris flows were estimated to be around 9.7 m s−1 and 1358 m3 s−1 for the Sanyanyu torrent and 11 m s−1 and 572 m3 s−1 for the Luojiayu torrent. The results of this study contribute to a better understanding of the conditions leading to catastrophic debris flow events.

Multiple debris flow surges monitored directly by DFLP system at Kamikamihori Creek

2021 ◽  
Author(s):  
Takahiro Itoh ◽  
Takahiko Nagayama ◽  
Satoru Matsuda ◽  
Takahisa Mizuyama
Keyword(s):  
Debris Flow ◽  
Volcanic Activity ◽  
Debris Flows ◽  
Sediment Concentration ◽  
Relative Mass ◽  
Geophysical Research ◽  
Monitoring Method ◽  
Flow Measurements ◽  
Flow Monitoring ◽  
Sediment Particles

<p>The monitoring method for direct debris flow measurements using loadcells and so on, that were preliminary developed by WSL in Switzerland (McArdell et al., 2007), was firstly installed in Sakura-jima Island in Japan, where volcanic activity was severe, and many debris flows took place due to deposition of falling ash after eruptions. Debris Flow measurements with Loadcells and Pressure sensors (DFLP) system was installed referring to the method by WSL, and debris flow characteristics such as specific weight and volumetric sediment concentration have been obtained (e.g., Osaka et al., 2014).</p><p> In Japan, as well as in Sakura-jima island, attempts for debris flow monitoring were also carried out at KamiKamihori Creek since 1970s (e.g., Okuda et al., 1980), and there were a lot of debris flow events due to heavy rainfall. KamiKamihori Creek is at western side of Mt. Yake, where volcanic activity was severe at those time. The DFLP system was modified and installed there in November in 2014, because there were a lot of sediment deposition and debris flows took place though volcanic activity has been inactive. Present research could report the following results.  </p><p>(1) Multiple debris floe over five surges were monitored using DFLP system installed in 2014 during 15 minutes in debris flow events on August 29th, 2019. Rainfall intensity for 10 minutes was 12 mm and accumulated depth was 56 mm just before those events. Antecedent time before those events was 4.5 hours.</p><p>(2) The DFLP system measured multiple debris flow surges in events on August 29th, 2019, and sediment concentration was calculated temporary and continuously. Time-averaged sediment concentration and relative mass density are calculated as 0.470 and 1.73, respectively, under flow discharge obtained by images analysis of CCTV video camera. Equilibrium sediment concentration of coarse sediment particles is estimated 0.160 for bed slope of 0.141 (8 degrees) and calculated value using the DFLP system is over than the equilibrium value because of mud phase due to fine sediment particles.</p><p> </p><p>References</p><p>McArdell B.W., Bartelt P., Kowalski J. (2007). Field observations of basal forces and fluid pore pressure in a debris flow, Geophysical Research Letters, Vo. 34, L07406.</p><p>Okuda, S., Suwa, H., Okunishi, K., Yokoyama, K., and Nakano, M. (1980). Observation of the motion of debris flow and its geomorphological effects, Zeitschrift fur Geomorphology, Suppl.-Bd.35, pp. 142–163.</p><p>Osaka T., Utsunomiya R., Tagata S., Itoh T., Mizuyama T. (2014). Debris Flow Monitoring using Load Cells in Sakurajima Island, Proceedings of the Interpraevent 2014 in the Pacific Rim (edited by Fujita, M. et al.), Nov. 25-28, Nara, Japan, 2014, O-14.pdf in DVD.</p>

Debris flow monitoring in China

2020 ◽  
Author(s):  
Xiaojun Guo
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Flow Characteristics ◽  
Western China ◽  
Flow Density ◽  
Flow Depth ◽  
Jinsha River ◽  
Flow Monitoring ◽  
Jiangjia Gully ◽  
Set Up

<p><strong>Abstract: </strong>Debris flow monitoring provides valuable data for scitienfic research and early warning, however, it is of difficulty to sucessfully achive because of the great damage of debris flows and the high cost. This report introduces monitoring systems in two debris flow watersheds in western China, the Jiangjia gully (JJG) in Yunnan Province and the Ergou valley in Sichuan Province. JJG is loacted in the dry-hot valley of Jinsha River, and the derbis flows are frequent due to the semi-arid climate, deep-cut topography and highly weathered slope surface. A long-term mornitoring work has been conducted in JJG and more than 500 debris flows events has been recorded since 1965. The monitoring system consists of 10 rainfall gauges and a measuring section, with instruments to measure the flow depth and velocity; and flow density is measured through sampling the fresh debris flow body. Ergou lies in the Wenchuan earthquake affected area and the monitoring began in 2013 to investigate the characteristics and development tendency of post-earthquake debris flows. Three stations were set up in the mainstream and tributaries, with instruments to measure the flow depth, velocity, and density. Over 10 debris flow events were recorded up to date.</p><p>Based on the monitoring output, the rainfall spatial distribution and thresholds for debris flows are proposed. The debris flow dynamics characteristics are analyzed, and the relations between the parameters, e.g. density, velocity, discharge and grain compositions are presented. The debris flow formation modes and the mechanisms in different regions are discriminated and simulation methods are suggested. It is anticipated that the monitoring results will promote understanding of debris flow characteristics in the western China.</p><p><strong>Keywords:</strong> Debris flow, monitoring, rainfall, discharge, formation. </p>

Multi-parametric observations of debris-flow initiation at the headwaters of the Gadria catchment (eastern Italian Alps)

2020 ◽  
Author(s):  
Velio Coviello ◽  
Matteo Berti ◽  
Lorenzo Marchi ◽  
Francesco Comiti ◽  
Giulia Marchetti ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Debris Flow ◽  
Early Warning ◽  
Debris Flows ◽  
Lead Time ◽  
Early Warning Systems ◽  
Force Balance ◽  
Italian Alps ◽  
Alarm Systems ◽  
Debris Flow Initiation

<p>The complete understanding of the mechanisms controlling debris-flow initiation is still an open challenge in landslide research. Most debris-flow models assume that motion suddenly begins when a large force imbalance is imposed by slope instabilities or the substrate saturation that causes the collapse of the channel sediment cover. In the real world, the initiation of debris flows usually results from the perturbation of the static force balance that retains sediment masses in steep channels. These perturbations are primarily generated by the increasing runoff and by the progressive erosion of the deposits. Therefore, great part of regional early warning systems for debris flows are based on critical rainfall thresholds. However, these systems are affected by large spatial-temporal uncertainties due to the inadequate number and distribution of rain gauges. In addition, rainfall analysis alone does not explain the dynamics of sediment fluxes at the catchment scale: short-term variations in the sediment sources strongly influence the triggering of debris flows, even in catchments characterized by unlimited sediment supply.</p><p>In this work, we present multi-parametric observations of debris flows at the headwaters of the Gadria catchment (eastern Italian Alps). In 2018, we installed a monitoring network composed of geophones, three soil moisture probes, one tensiometer and two rain-triggered videocameras in a 30-m wide steep channel located at about 2200 m a.s.l. Most sensors lie on the lateral ridges of this channel, except for the tensiometer and the soil moisture probes that are installed in the channel bed at different depths. This network recorded four flow events in two years, two of which occurred at night. Specifically, the debris flows that occurred on 21 July 2018 and 26 July 2019 produced remarkable geomorphic changes in the monitored channel, with up to 1-m deep erosion. For all events, we measured peak values of soil water content that are far from saturation (<0.25 at -20 cm, <0.15 at -40 cm, <0.1 at -60 cm). We derived the time of occurrence and the duration of these events from the analysis of the seismic signals. Combining these pieces of information with data gathered at the monitoring station located about 2 km downstream, we could determine the flow kinematics along the main channel.</p><p>These results, although still preliminary, show the relevance of a multi-parametric detection of debris-flow initiation processes and may have valuable implications for risk management. Alarm systems for debris flows are becoming more and more attractive due the continuous development of compact and low-cost distributed sensor networks. The main challenge for operational alarm systems is the short lead-time, which is few tens of seconds for closing a transportation route or tens of minutes for evacuating settlements. Lead-time would significantly increase installing a detection system in the upper part of a catchment, where the debris flow initiates. The combination of hydro-meteorological monitoring in the source areas and seismic detection of channelized flows may be a reliable approach for developing an integrated early warning - alarm system.</p>

Post-earthquake changes in debris flow susceptibility in the Upper Minjiang catchment (Sichuan, China), as revealed by meteorological and hydro-meteorological thresholds

2020 ◽  
Author(s):  
Roberto Greco ◽  
Pasquale Marino ◽  
Siva Srikrishnan ◽  
Xuanmei Fan
Keyword(s):  
Water Balance ◽  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Debris Flows ◽  
Strong Increase ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
2008 Wenchuan Earthquake ◽  
Soil Storage ◽  
Triggering Rainfall

<p>On May 12, 2008, a Mw 7.9 earthquake struck Wenchuan, Longmen Shan Area, in western Sichuan, China, at the eastern margin of the Tibetan Plateau. This earthquake was the largest and most destructive event in the last 60 years, causing more than 87000 casualties. The economic loss was estimated at some 1100 billion RMB. The major fault rupture produced surface displacements up to 3-4 meters, spreading from the epicenter (near the town of Yingxiu) for 240 km along the mountain range.</p><p>The Wenchuan Earthquake triggered almost 200000 co-seismic landslides over a region larger than 110000 km<sup>2</sup>, leading to the accumulation of large volumes of loose material either along slopes or in gullies. After the earthquake, this material caused a strong increase of debris flow occurrence in the subsequent years, mainly in the worst-hit areas, such as Wenchuan, Beichuan and Mao counties. During the years immediately after the earthquake, the rainfall required for debris flow triggering resulted clearly smaller than before (Guo et al., 2016). Afterwards, the response of the debris deposits to rainfall changed, leading to a general recovery of stability and a reduction of debris flow frequency and magnitude (Domènech et al., 2019).</p><p>In this study, the assessment of debris flows occurrence throughout upper Minjiang catchment, to which Wenchuan county belongs, is modeled with two empirical approaches, both based on the available record of precipitations and debris flows in the years 2008-2015. In the first approach, a threshold to predict debris flow occurrence is defined based on intensity and duration of potentially triggering rainfall events (meteorological threshold). With the second approach, also the hydrological conditions predisposing the slopes to debris flows are considered, by assessing the water balance in the catchment with a simplified lumped hydrological model, based on the Budyko framework (Zhang et al., 2008), and defining a threshold to predict debris flows based on rainfall depth and estimated soil storage prior the onset of rainfall (hydro-meteorological threshold).</p><p>The obtained results indicate that the hydro-meteorological threshold allows catching the progressive recovery of stability of the debris deposits much better than the meteorological threshold, leading to identification of increasing thresholds, both in terms of pre-event soil storage and triggering rainfall amount, in the years from 2008 onward. Such a result shows that the adoption of process-based approaches , even empirical and strongly simplified as in the presented case, leads to predictions of debris flow occurrence more robust than those based solely on rainfall information.</p><p> </p><p>References</p><p>Domènech, G., Fan, X., Scaringi, G., van Asch, T.W.J., Xu, Q., Huang, R., Hales, T.C., 2019. Modelling the role of material depletion, grain coarsening and revegetation in debris flow occurrences after the 2008 Wenchuan earthquake. Eng. Geol. 250, 34-44.</p><p>Guo, X., Cui, P., Li, Y., Fan, J., Yan, Y., Ge, Y., 2016. Temporal differentiation of rainfall thresholds for debris flows in Wenchuan earthquake-affected areas. Environ. Earth Sci. 75, 1–12.</p><p>Zhang, L., Potter, N., Hickel, K., Zhang, Y., Shao, Q., 2008. Water balance modeling over variable time scales based on the Budyko framework – Model development and testing. J. Hydrol. 360, 117-131.</p>

Ten years of debris-flow monitoring in the Moscardo Torrent (Italian Alps)

Geomorphology ◽  
2002 ◽  
Vol 46 (1-2) ◽  
pp. 1-17 ◽  
Author(s):  
Lorenzo Marchi ◽  
Massimo Arattano ◽  
Andrea M Deganutti
Keyword(s):  
Debris Flow ◽  
Italian Alps ◽  
Flow Monitoring

scholarly journals Debris flows in the Eastern Italian Alps: seasonality and atmospheric circulation patterns

2014 ◽  
Vol 2 (12) ◽  
pp. 7197-7224 ◽  
Author(s):  
E. I. Nikolopoulos ◽  
M. Borga ◽  
F. Marra ◽  
S. Crema ◽  
L. Marchi
Keyword(s):  
Debris Flow ◽  
Atmospheric Circulation ◽  
Debris Flows ◽  
Large Scale ◽  
Rain Gauge ◽  
Italian Alps ◽  
Synoptic Pattern ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Synoptic Forcing

Abstract. The work examines the seasonality and large-scale atmospheric circulation patterns of debris flows in the Trentino-Alto Adige region (Eastern Italian Alps). Analysis is based on classification algorithms applied on a uniquely dense archive of debris flows and hourly rain gauge precipitation series covering the period 2000–2009. Results highlight the seasonal and synoptic forcing patterns linked to debris flows in the study area. Summer and fall season account for 92% of the debris flows in the record, while atmospheric circulation characterized by Zonal West, Mixed and Meridional South, Southeast patterns account for 80%. Both seasonal and circulation patterns exhibit geographical preference. In the case of seasonality, there is a strong north–south separation of summer–fall dominance while spatial distribution of dominant circulation patterns exhibits clustering, with both Zonal West and Mixed prevailing in the northwest and central east part of the region, while the southern part relates to Meridional South, Southeast pattern. Seasonal and synoptic pattern dependence is pronounced also on the debris flow triggering rainfall properties. Examination of rainfall intensity–duration thresholds derived for different data classes (according to season and synoptic pattern) revealed a distinct variability in estimated thresholds. These findings imply a certain control on debris-flow events and can therefore be used to improve existing alert systems.

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