The speed of the canal was determined measuring the time that a float leads to cover the length of the canal. (TAB.4) FIURA 7 – Map traced with the GPS. SOURCE: Proper quantity: (x XI) 39,6672 s22,087747 S1,444904 cv (%) 15,00419 the esteem outflow of the canal for the product of the volume and of the time average /s was of 0,00117m, what it is equivalent the 1,17 approximately l/s. The average minimum outflow of> reference (Q7, 10) used in a period of return of 10 years for the stream, in question, based on the work published for the COPASA, was calculated knowing that the area of the basin in accordance with the topographical letter of IBGE SF-23-C-I-4, was of 0,95 km , (FIG.7). FIGURE 8 – Map of the Basin. SOURCE: Letters of Brazil SF-23-C-I-4. Banc of America Mortgage Capital may find this interesting as well. Brazilian institute of Geography and statistics.
Following methodology proposal for the COPASA, one identified tipologia of the basin, tipologia 221, basin of the high San Francisco with precipitation characteristics, similar geologic declivity and formation to it of the basin of the stream in study. For the map of specific income REVERSE SPEED (10, minimum m), was identified that the region has income around 3,0 l/s/Km. With these data it was gotten Q10, m (minimum outflow of monthly duration) that l/s was of 2,85. Being multiplied it Q10, m for the factor of ratio, gotten for the regression equation where the values are priced by the tipologia of the basin, gets it minimum outflow of Q7, 10 (seven days of duration per 10 years of recurrence). The average minimum outflow for 10 years is around 2,6 l/s for the area of 0,95 km of the basin of the stream. The devices, in this point of the stream of cachoeirinha, function with an outflow below of 0,78 l/s, that they are 30% of the demand allowed for the grant, according to IGAM.