Integration of Erosion Control Practices to Reduce Sediment Loads in Furrow Irrigation

Effects of vegetation as an ecosystem service on the changes in runoff and sediment yield in a Mediterranean semi-arid basin

10.5194/egusphere-egu21-4239 ◽

2021 ◽

Author(s):

María Rosario Vidal-Abarca Gutiérrez ◽

Alberto Martínez-Salvador ◽

Carmelo Conesa-García ◽

María Luisa Suárez-Alonso ◽

Francisco Alonso-Sarria ◽

...

Keyword(s):

Sediment Yield ◽

Ecosystem Service ◽

Vegetation Cover ◽

Pressure Sensors ◽

Erosion Control ◽

Water Levels ◽

Event Scale ◽

Dynamic Component ◽

Sediment Loads ◽

Runoff And Sediment Yield

<p>Semiarid basins contribute significantly to sediment loads, as they are often characterized by torrential flows, source areas with high sediment-producing rates, great availability of erodible material subjected to intense weathering processes, and poor vegetation cover. Vegetation, despite its scarce presence, is a dynamic component of this environment, which provides a range of important ecosystem services such as biodiversity, flood retention, nutrient sink, erosion control and groundwater recharge. This study examines the vegetation responses to the magnitude of peak flows and its contribution to the changes in runoff and sediment yield during the period 1997-2020 in a catchment Mediterranean semiarid basin: The Rambla de la Azoh&#237;a (southeastern Spain).Vegetation type, density, preferred location and degree of permanence in each sub-basin were analyzed in order to determine their degree of influence on surface runoff and erosion control. Changes in riparian vegetation cover was quantified at large scale for the analysis period (1997-2020), using remotely sensed spatial information, such as satellite images and aerial photographs separated by two years on average (at scales from 1:15000 to 1:30000, and resolution between 0.22 and 0.50 m/pixel). A geo-spatial erosion prediction model was applied to estimate the runoff and sediment load generated at the event scale, taking into account the variability of the vegetation cover in each sub-basin. The simulated outputs of this model were previously calibrated with water levels measured by pressure sensors and suspended sediment records.The results showed both a poor response of vegetation (low incidence in the runoff coefficient) in steep metamorphic watersheds, capable of supplying large sediment loads, and functioned as an efficient ecosystem service (stabilization of slopes and decrease in peak flow) in less steep sub-basins with slopes in the shadow, composed of limestone formations and alluvial fans. This suggests important spatial differences in the vegetation impact, according to other environmental conditions intrinsic to each sub-basin, but also a low overall influence on the temporal variability of sediment fluxes at the event scale. This research was funded by FEDER/Spanish Ministry of Science, Innovation and Universities&#8212;State Research Agency (AEI)/Projects CGL2017-84625-C2-1-R and CGL2017-84625-C2-2-R; State Program for Research, Development and Innovation Focused on the Challenges of Society.</p>

Download Full-text

Erosion modelling towards, and sediment transport modelling in unnavigable watercourses in Flanders, Belgium

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-367-349-2015 ◽

2015 ◽

Vol 367 ◽

pp. 349-356

Author(s):

B. Ferket ◽

M. Van De Broek ◽

T. Van Hoestenberghe ◽

J. Degerickx ◽

R. De Sutter ◽

...

Keyword(s):

Sediment Transport ◽

Erosion Control ◽

Control Measures ◽

River Engineering ◽

Transport Models ◽

Transport Modelling ◽

Sediment Loads ◽

Erosion Modelling ◽

Sediment Transport Modelling ◽

Sediment Export

Abstract. Antea Group and KULeuven were awarded a project in Flanders to identify the regions exporting high sediment loads to unnavigable watercourses and the sedimentation zones within them. Two types of models are applied: hydrological sediment export models (SEM) and hydraulic sediment transport models (STM). The influence of erosion control measures on sediment export as well as river engineering measures needs to be taken into account. A concept will be developed to connect the SEM and STM, enabling the sediment to be routed from upstream to the sedimentation zones. Results of the study will be used by the Flemish government to plan erosion control measures, estimate future sedimentation volumes, steer sedimentation and optimize river engineering and dredging works. Finally, model results could also be used to obtain better insights to the re-suspension risks of contaminated sediment in watercourses.

Download Full-text