| Popis: |
The Paracatu River is the largest affluent of the Sao Francisco River, Brazil. The main water use in the Paracatu river basin is irrigation, which occupies an area of 37,150 ha. The objective in this study was to obtain water indicators at irrigated areas using the SAFER (Simple Algorithm For Evapotranspiration Retrieving) and the Penman-Monteith models with images of SPOT 6 satellite (without the thermal band). The parameters obtained are evapotranspiration (ET), albedo (α), biomass (BIO), surface temperature (Tsup) and water productivity (PA) in irrigated areas of Paracatu River Basin. We used 2 satellite images by the sensor SPOT6 (by Astrium Company) with a spatial resolution of 6 m (August 8, 2014 and August 23, 2015) and data from meteorological stations. In irrigated areas, the NDVI reached values higher than 0.76, due the response of vegetation to irrigation. The daily average albedo was 0.18 ± 0.01 and 0.02 ± 0.17 respectively. In the analysis of the surface temperature (Tsup), it can be observed that in the image of 2015, mean values higher than those observed in the image of 2014 (303.03 ± 1.97 K and 299.34 ± 3.47 K, respectively). In 2015, due to increased atmospheric evaporative demand, ET reached values higher than those seen in the scene in 2014. The average daily evapotranspiration rate in Paracatu for 2014 scene was of 0.81±1.49 mm, with a maximum value of 8.96 mm at the irrigated areas. In image of 2015 the average evapotranspiration (ET) values was 1.87±1.27 mm. The results obtained in this study may assist in the monitoring of irrigated agriculture to face a trend of scarcity of water resources and of increasing conflicts over water use as occurs in the Paracatu River Basin. |
