Modelling Hydrology and Sediment Transport in a Semi-Arid and Anthropized Catchment Using the SWAT Model: The Case of the Tafna River (Northwest Algeria)

Abstract

Sediment deposits in North African catchments contribute to around 2%-5% of the yearly loss in the water storage capacity of dams. Despite its semi-arid climate, the Tafna River plays an important role in Algeria's water self-sufficiency. There is continuous pressure on the Tafna's dams to respond to the demand for water. The Soil and Water Assessment Tool (SWAT) was used to evaluate the contribution of different compartments in the basin to surface water and the dams' impact on water and sediment storage and its flux to the sea in order to develop reservoir management. The hydrological modelling fitted well with the observed data (Nash varying between 0.42 and 0.75 and R 2 varying between 0.25 and 0.84). A large proportion of the surface water came from surface runoff (59%) and lateral flow (40%), while the contribution of groundwater was insignificant (1%). SWAT was used to predict sediments in all the gauging stations. Tafna River carries an average annual quantity of 2942 t·yr −1 to the Mediterranean Sea. A large amount of water was stored in reservoirs (49%), which affected the irrigated agricultural zone downstream of the basin. As the dams contain a large amount of sediment, in excess of 27,000 t·yr −1 (90% of the sediment transported by Tafna), storage of sediment reduces the lifetime of reservoirs.

Hydrological modeling using the SWAT model based on two types of data from the watershed of Beni Haroun dam, Algeria

“…In a study of the R'dom watershed in North-West of Morocco the land cover parameter was the most sensitive parameter with the value of NSE, R 2 of the daily time steps in the calibration period is 0.58, 0.79 [BROUZIYNE et al 2017]. In another study in the Tafna watershed in the simulation of the runoff the groundwater parameter have a big influence on the simulation result with value of NSE and R 2 of the flow simulation is NSE between 0.42 and 0.75, and R 2 was in the interval from 0.25 to 0.84 [ZETTAM et al 2017].…”

Why and How Do We Study Sediment Transport? Focus on Coastal Zones and Ongoing Methods

“…Scientific issues are common, and digital communication has allowed researchers to multiply worldwide collaborations, disrupting the production of knowledge. This special issue thus reflects the ongoing international cooperation between northern and southern countries on sensitive topics of common interest, thanks to the support of scientific research organizations such as the Institute of Research for Development in France, or through dedicated projects [57,351,[353][354][355][356].…”

“…Zettam, et al [356] use a coupled hydrological-erosion-transport model within a watershed (SWAT) to evaluate the contribution of different sub-basins to surface water and sediment flux, the dam's impact on water and sediment storage, and fluxes to the estuary, necessary for forcing estuarine and coastal studies. In their model, erosion is estimated using the modified universal soil loss equation (MUSLE) and sediment routing is based on a modified sediment transport equation from Bagnold.…”

Origin, distribution, and behaviour of rare earth elements in river bed sediments from a carbonate semi-arid basin (Tafna River, Algeria)

“…In the Mouillah sub-catchment, the slope is estimated to be < 5%, with an erosion rate of 400 t km −2 yr −1 . In the upstream Tafna basin, the slope is > 25% and it exceeds 30% in the Isser sub-catchment with an erosion rate of 1000 t km −2 yr −1 (Tidjani et al, 2006;Zettam et al, 2017).…”