Measuring runoff by plots at different scales : understanding and analysing the sources of variation
| Autor: | Harouna Karambiri, Jean-Emmanuel Paturel, Lawani Adjadi Mounirou, Gil Mahé, Hamma Yacouba |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
COUVERT VEGETAL
Range (biology) SOL CULTIVE Drainage basin Soil science PARCELLE TRAVAIL DU SOL SOL DEGRADE ETAT DE SURFACE DU SOL MESURE Scale effect Hydrology Global and Planetary Change geography geography.geographical_feature_category SURFACE DU SOL Vegetation Soil type COEFFICIENT DE RUISSELLEMENT EFFET D'ECHELLE BASSIN VERSANT PLUIE Soil water VARIATION SPATIALE General Earth and Planetary Sciences Environmental science Scale (map) Surface runoff |
| Popis: | The decrease of runoff with the increase in area is not a new fact. The scale effect depends on the spatial and temporal variability of different factors, including the surface characteristics and hydrodynamic properties of the soil and the vegetation development. The purpose of our work is to study the relative influence of the sources of variation of runoff from a small Sahelian catchment on several types of soil surfaces features. Plots of different sizes (1, 50 and 150 m 2 ) on cultivated soils and degraded soils (non-cultivated with three different types of crusts) were monitored for two consecutive years. The results show that the runoff coefficients of rainfall events range from 4 to 65% on cultivated soils and 16 to 96% on uncultivated bare and degraded soils. A statistical and dimensionless analysis shows that in degraded environments, the processes generating runoff on plots of 50 and 150 m 2 are identical and significantly different from the unit plot (1 m 2 ). The decrease in runoff with increasing scale becomes more pronounced when rainfall duration decreases. In cultivated areas, this result is not observed. Additional measurements are needed to better understand the differences in functioning at various scales of observations. |
| Databáze: | OpenAIRE |
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