Suspended sediment transport analysis in two Italian instrumented catchments

Abstract

Suspended sediment transport in streams is an effective indicator of soil erosion at the watershed scale. This process was studied using the data obtained from two continuous monitoring stations installed in Italian watersheds, the Rio Cordon and Torrente Carapelle. The catchments have substantially different climatic, morphological and land use characteristics. The Rio Cordon, a small Alpine watershed, has been monitored since 1986, while in the Torrente Carapelle, a medium-size Mediterranean watershed, the monitoring station has provided data since 2007. Several flood events with suspended sediment transport were isolated in the two catchments, excluding those determined by snowmelt in the Rio Cordon as this process does not affect the Carapelle watershed. Analysis of the events showed different behavior in terms of hysteresis loop trends between water discharge (m3 s-1) and suspended sediment concentration (g l-1) values, as the Rio Cordon confirms clockwise relationships most frequently, while counter-clockwise trends represent the majority of cases for the Carapelle Torrent. The different behavior of the two watersheds was further analyzed by evaluating relationships between the main hydrological parameters related to suspended sediment transport. Runoff controls the total sediment budget in both catchments. In contrast, it was noted that the runoff process does not interfere in the magnitude of the suspended sediment transport in the Rio Cordon catchment, while variations due to the larger size of the catchment area characterize the events in the Carapelle watershed. Lastly, a flow peak threshold that determines the advance or delay of the hydrograph peak with respect to the sedigraph peak was established for the Carapelle Torrent, while it was not reported in the Rio Cordon

Identifying sediment source areas in a Mediterranean watershed using the SWAT model

“…A complete description of the gauging station and equipment can be found in Gentile et al (). The highest SSC recorded in the study period is 47.83 g L −1 , corresponding to a peak flow of 19.82 m 3 s −1 (García‐Rama, Pagano, Gentile, & Lenzi, ).…”

Setting Up of an Experimental Site for the Continuous Monitoring of Water Discharge, Suspended Sediment Transport and Groundwater Levels in a Mediterranean Basin. Results of One Year of Activity

“…The floods that showed efficient measurements of both water discharge and sediment concentration were analyzed (Table 2) The sedigraph of the event nr.1 reports turbidity values (FNU), because it occurred before the calibration of the turbidity sensor, while the others indicate SSC values (g L −1 ). Though the Carapellotto is a tributary of the Carapelle torrent, its maximum water discharge peak was 66.53 m 3 s -1 in the observation period, which is quite high if compared to the 159.50 m 3 s −1 in the Carapelle [18]. The concentration peaks, instead, were very similar, with 47.99 g L −1 for the Carapellotto, and 47.83 g L −1 for the Carapelle (Table 2).…”

“…In 2007, the Department of Agro-Environmental Science of Bari University installed a continuous SSC monitoring station on the Carapelle torrent (Ponte Ordona-Castelluccio dei Sauri, drainage area 506.2 km 2 ), which worked from 2007 to 2011. The data obtained were used to analyze the sediment dynamics at the event scale [17,18,25], as well as to model erosion and transport processes [7,49,50].…”

Influences of Catchment and River Channel Characteristics on the Magnitude and Dynamics of Storage and Re-Suspension of Fine Sediments in River Beds

“…It presents yearly precipitation that ranges from 450 to 800 mm, and land use is mostly agricultural where the mean slope of main channel is 1.8% [38,47]. Continuous Q and C values have been measured from 1 January 2007 to 31 December 2011 in this catchment, which is characterized by long periods with low flows and a prevalence of counter-clockwise hysteresis [48].…”