Techniques de l’eau et calcul des réseaux

Présentation au sujet: "Techniques de l’eau et calcul des réseaux"— Transcription de la présentation:

1 Techniques de l’eau et calcul des réseaux
Les termes du bilan d’eau que nous aurons à manipuler en calcul des réseaux Michel Verbanck 2015

2

3 Stream ordering Quantitative way of studying streams. Developed by Horton and then modified by Strahler. Each headwater stream is designated as first order stream When two first order stream combine, they produce second order stream Only when two streams of the same order combine, the stream order increases by one When a lower order stream combines with a higher order stream, the higher order is retained in the combined stream

4 Routing a hillslope hydrograph through the network
3. When these are combined, the outlet hydrograph is more drawn out, and the peaks from A, B, C do not coincide 1: Rainfall is transformed by the hillslopes into a hydrograph which is delivered throughout the network . 2: Hydrographs from A take longer to travel to the outlet than those from B, and those from C arrive sooner still.

5 Potential evapotranspiration (PET) is the amount of water that could be evaporated and transpired if there was sufficient water available. Evapotranspiration can never be greater than PET, but can be lower if there is not enough water to be evaporated or plants are unable to readily transpire.

6

7 nous pouvons jouer sur:
- connaissance des principaux postes, - choix des especes ligneuses à planter, - intensification des préc (cf projet Geshem par exemple).

8 the Penman-Monteith equation requires daily mean temperature, wind speed, relative humidity, and solar radiation to predict net evapotranspiration. principe de parsimonie (dans la démarche de modélisation).

9

10 Répartition des volumes à écouler pendant l´année
Débits Qd , m3 j-1 Précipitations, mm j-1 40 50000 100000 150000 80 Jan Feb Mar Avr Mai Jun Jul Aug Sep Oct Nov Dec

11

12

13