In: Journal of Hydrology and Hydromechanics, vol. 65, no. 1
Christian Guzman - Seifu Tilahun - Dessalegn Dagnew - Assefa Zegeye - Tigist Tebebu - Birru Yitaferu - Tammo Steenhuis
Detaily:
Rok, strany: 2017, 1 - 17
Kľúčové slová:
Saturation excess runoff; infiltration excess (Hortonian) runoff; soil erosion; Ethiopian highlands; PED model.
URL originálneho zdroja: http://www.ih.sav.sk/jhh
O článku:
Drainage of paved and unpaved roads has been implicated as a major contributor of overland flow and erosion
in mountainous landscapes. Despite this, few watershed models include or have tested for the effect roads have on discharge
and sediment loads. Though having a model is an important step, its proper application and attention to distinct
landscape features is even more important. This study focuses on developing a module for drainage from a road and tests
it on a nested watershed (Shanko Bahir) within a larger previously studied site (Debre Mawi) that receives overland flow
contributions from a highly compacted layer of soil on an unpaved road surface. Shanko Bahir experiences a sub-humid
monsoonal climate and was assessed for the rainy seasons of 2010, 2011, and 2012. The model chosen is the Parameter
Efficient Distributed (PED) model, previously used where saturation-excess overland flow heavily influences discharge
and sediment concentration variation, though infiltration-excess occasionally occurs. Since overland flow on unpaved
surfaces emulates Hortonian flow, an adjustment to the PED model (the developed module) advances possible incorporation
of both flow regimes. The modification resulted in similar modeling performance as previous studies in the Blue
Nile Basin on a daily basis (NSE = 0.67 for discharge and 0.71 for sediment concentrations). Furthermore, the road while
occupying a small proportion of the sub-watershed (11%) contributed importantly to the early discharge and sediment
transport events demonstrating the effect of roads especially on sediment concentrations. Considerations for the dynamic
erodibility of the road improved sediment concentration simulation further (NSE = 0.75). The results show that this PED
modeling framework can be adjusted to include unpaved compacted surfaces to give reasonable results, but more work is
needed to account for contributions from gullies, which can cause high influxes of sediment.
Ako citovať:
ISO 690:
Guzman, C., Tilahun, S., Dagnew, D., Zegeye, A., Tebebu, T., Yitaferu, B., Steenhuis, T. 2017. Modeling sediment concentration and discharge variations in a small
Ethiopian watershed with contributions from an unpaved road. In Journal of Hydrology and Hydromechanics, vol. 65, no.1, pp. 1-17. 0042-790X (until 2019) .
APA:
Guzman, C., Tilahun, S., Dagnew, D., Zegeye, A., Tebebu, T., Yitaferu, B., Steenhuis, T. (2017). Modeling sediment concentration and discharge variations in a small
Ethiopian watershed with contributions from an unpaved road. Journal of Hydrology and Hydromechanics, 65(1), 1-17. 0042-790X (until 2019) .