work as Distance*Elevation makes sense

Van Ginneken et al. (2008) estimate a cost of transport (COT)in kj.kg-1.km-1 do the amount of energy will be proportional to the distance covered by silver eel. The additional distance linked to altitude (water current) is relative to

Vitesse d'écoulement :

vitesse instantanée: u = dx/dt vitesse moyenne : V

Dans un chenal, relation empirique de Chezy: V= C (h S)1/2

C : coefficient de friction de Chezy h : profondeur S : pente

The additional energy due to slope is related to the current distance additional=v*t ~c(hS)1/2*t ~alpha t (E/D)1/2 with alpha a multiplying coeff depending on depth, C t is proportional to the distance so beta(DE)1/2

Energy=D+sqrt(DE)