Predictions in Ungauged Basins: Promise and Progress (Proceedings of symposium S7 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 303, 2006, 187-194.

 

Role of spatial aggregation over runoff calculations on southeast France catchments

 

NABIL J. EID1,2, FLAVIE CERNESSON2, NATHALIE FOLTON3 & PASCAL KOSUTH2

1       Depto. Eng. Civil e Ambiental/FT/UnB, 70910-900 Brasília-DF, Brazil

njeid@unb.br

2       UMR TETIS Cemagref, ENGREF-CIRAD, Maison de la Télédétection, 500 rue JF Breton,
34093 Montpellier Cedex 5, France 

3         UR Ouvrages Hydrauliques et Equipements pour l’Irrigation, CEMAGREF BP31, Le Tholonet, 13612 Aix on Provence Cedex 1, France

 

Abstract The paper investigates the catchment area extension calculations as a function of the adopted spatial resolution and the effect of these spatial resolutions on the runoff calculations, for a number of catchments. Calcula­tions were done with hypothetical and constant amounts of precipitation over space. Adopted grid size varied from 3000 to 2 m. Area estimate errors were computed in respect to 2 m grid resolution and the SCS method used for excess precipitation calculations. Results have shown that 75% of the catch­ments have errors of <15% of its area at any resolution and that the surface estimation errors are < ±1% for a 200 m spatial resolution. For any catchment effective precipitation presented, small variations occurred when 300 m spatial resolution was used and at 100 m spatial resolution almost no variations were observed.

 

Key words  Corine Land Cover; French Mediterranean catchments; SCS; spatial resolution