| Abstract: | Abstract The analysis of the exchanges of vapour and heat above a small water table, situated in the middle of a more or less dry region, leads them to be expressed in function of the thermic and hydric changes of the environment, by which the measured, screened data are influenced. This analysis allows us,—among other results,—to observe the variation from simple to the double of the evaporation. This has come to evidence already in cases when the evaporating surface diminishes. The application was carried out under two exceedingly different climates: in a Sahelian zone, on a pan type “Colorado”, situated in the middle of a bare surface, with very poor evaporation; and in an equatorial zone, on a “Colorado” pan, in the center of a humid zone, where the vegetation could dispose of water in sufficient quantity. The results confirm the hypothesis set up, and allow us to take into consideration the use of the pans corrected data for expressing the potential evaporation. |
