Variation in Sediment Concentration and Water Discharge During Storm Events in Two Catchments, Northeast of Algeria

Abstract

The relation between concentration and discharge is not normally homogenous during the storm event, often producing hysteretic loops. In this study relations between sediment concentration and water discharge for hydrologic events are studied by analyzing temporal graphs (discharge and concentration versus time) in terms of spread and skewness. The hysteresis types of the discharge and concentration of 170 storm events have been analyzed to identify the relations between hysteretic loops and the associated controlling factors in the Saf Saf and Kebir West basins. Surveys of suspended sediment concentration and water discharge are being carried out at gauging stations. The selected storm events are based on samples having many sediment concentrations at water discharges. Comparing C/Q ratios at a given discharge on the rising and falling limbs of hydrographs is providing a consistent, reliable method for analyzing C-Q relations. Four common classes of such relations are determined such as single-valued line, clockwise loop, counterclockwise loop and figure eight. The plot of points has exhibited a hysteresis loop which is explained by the variability of sediment concentrations during storm events and seasonal effects. The most frequent floods at Saf Saf and Kebir West rivers are clockwise and single-valued line (62% and 59% of floods respectively) that have brought 73% and 81% of the total sediment flux. Intra-annual variability is very high. Over 31-years, the three biggest floods at each Saf Saf and Kebir West rivers have cumulated 97% and 68% of the total sediment flux and are of two classes.

Storm-Induced Dynamics of Particulate Organic Carbon in Clear Creek, Iowa: An Intensively Managed Landscape Critical Zone Observatory Story

“…Viewing the POC behavior as a function of discharge rather than time provides another perspective. Concentration-discharge (C-Q) relationships have been a useful tool to evaluate the overall processes and function of catchments (Williams, 1989;Picouet et al, 2001;Bieroza et al, 2018;Khanchoul et al, 2018), although less has been studied for particulate chemical species such as POC. The POC-Q relationship for the October 2015 storm displayed a clockwise hysteresis pattern for all three sampling stations (Figure 5).…”

On Dilemmas and Solutions for the Issues of High Seas Marine Protected Areas During the BBNJ Negotiation

“…Others suggested that the MPA definition should be sufficiently broad to encompass specific types of conservation and impact restrictions, for example, High Seas Alliance favored adapting CBD and IUCN definitions, also including cultural values. However, the North-East Atlantic Fisheries Commission (NEAFC) underscored that ABMTs by RFMOs are functioning well and that the ILBI should enhance harmony between tools of different sectoral bodies, rather than define ABMTs (Alger and Dauvergne, 2017; Khanchoul et al, 2018). It is noteworthy that Costa Rica suggested a working concept of MPAs as "a clearly defined geographic space recognized, dedicated and managed through legal and other effective means to achieve the conservation of biodiversity, ecosystem services, and other cultural values.…”

Assessing Suspended Sediment Yield in the Saf Saf Gauged Catchment, Northeastern Algeria

“…Sparse forest and shrubs (Oleo-lentiscus and Erica europa) cover 30% of the basin and are found mainly on poorly developed soils on sandstone and conglomerate. Overgrazing is observed in pasture and open shrubland, where plants are exposed to intensive grazing for extended period of time [21].…”