Infiltração da água em viveiros escavados para a aquicultura com diferentes tempos de uso

Abstract

The following paper work aimed on evaluation of the water loss by soil infiltration in excavated (ponds), with different time of usage in a pisciculture in the State of Goiás. To carry out the experiment, 3 old ponds and 3 new ones were used, which were numbered from 1 to 6. Metrical tapes were disposed inside the ponds to measure the infiltration. The measurements were made in 3 periods of the day (from 8 a.m. to 11 a.m., from 11 a.m. to 2 p.m. and from 14 p.m. to 17 p.m.) for a period of 3 days, until they’ve obtained the stable value of the infiltration rate. In respect to the evaporation measurement, a water box with a ruler was installed on the side of the ponds which was measured at the same time as the measurements of the infiltration. For the soil analysis 3 samples were collected from the bottom of the newly built ponds and a granulatory analisys was made on the Physics of Soils laboratory (UFGD). The results were submitted to analysis of variance and Turkey’s test. According to the results, it is possible to observe that on the older ponds (1, 2 and 3) the infiltration rate was lower, due to the presence of organic matter which promotes a sealing of the pores, decreasing the infiltration. In those ponds, the infiltration rate ranged from 2,93 to 6,22 mm h -1 , which leads to losses from 70,32 to 149,2 mm day -1 ; being those values higher compared with the international reference values. On the ponds recently built (4, 5 and 6) the average infiltration rate ranged from 9,52 to 37,45 mm h -1 ; which leads to losses from 228 to 898 mm day -1 . Depending on the pond area, the consumption of water is high, making this activity together with agriculture one of the big water consumers on the planet.