Embrapa Satellite Monitoring CEP

Campinas, Brazil

Embrapa Satellite Monitoring CEP

Campinas, Brazil
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De C Teixeira A.H.,Embrapa Satellite Monitoring CEP | Leivas J.F.,Embrapa Satellite Monitoring CEP | Ronquim C.C.,Embrapa Satellite Monitoring CEP | Bayma-Silva G.,Embrapa Agriculture Informatics CEP | De C Victoria D.,Embrapa Agriculture Informatics CEP
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Under land and climate change scenarios, agriculture has experienced water competitions among other sectors in the São Paulo state, Brazil. On the one hand, in several occasions, in the northeastern side of this state, nowadays sugar-cane is expanding, while coffee plantations are losing space. On the other hand, both crops have replaced the natural vegetation composed by Savannah and Atlantic Coastal Forest species. Under this dynamic situation, geosciences are valuable tools for evaluating the large-scale energy and mass exchanges between these different agro-ecosystems and the lower atmosphere. For quantification of the energy balance components in these mixed agro-ecosystems, the bands 1 and 2 from the MODIS product MOD13Q1 were used throughout SAFER (Surface Algorithm for Evapotranspiration Retrieving) algorithm, which was applied together with a net of 12 automatic weather stations, during the year 2015 in the main sugar cane and coffee growing regions, located at the northeastern side of the state. The fraction of the global solar radiation (RG) transformed into net radiation (Rn) was 52% for sugar cane and 53% for both, coffee and natural vegetation. The respective annual fractions of Rn used as λE were 0.68, 0.87 and 0.77, while for the sensible heat (H) fluxes they were 0.27, 0.07 and 0.16. From April to July, heat advection raised λE values above Rn promoting negative H, however these effects were much and less strong in coffee and sugar cane crops, respectively. The smallest daily Rn fraction for all agro-ecosystems was for the soil heat flux (G), with averages of 5%, 6% and 7% in sugar cane, coffee and natural vegetation. From the energy balance analyses, we could conclude that, sugar-cane crop presented lower annual water consumption than that for coffee crop, what can be seen as an advantage in situations of water scarcity. However, the replacement of natural vegetation by sugar cane can contribute for warming the environment, while when this occur with coffee crop there was noticed cooling conditions. The large scale modeling satisfactory results confirm the suitability of using MODIS products together with weather stations to study the energy balance components in mixed agro-ecosystems under land-use and climate change conditions. © 2016 SPIE.


De C Teixeira A.H.,Embrapa Satellite Monitoring CEP | Leivas J.F.,Embrapa Satellite Monitoring CEP | Hernandez F.B.T.,São Paulo State University | Franco R.A.M.,São Paulo State University | Nunez D.N.C.,São Paulo State University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

In the northwestern side of the São Paulo state, Brazil, irrigated areas are expanding, because rainfall is not enough to supply the crop water requirements. Under the actual climate and land-use change scenarios, large-scale evapotranspiration (ET) and biomass production (BIO) acquirements are relevant. Eleven Landsat 8 images, from May 2013 to October 2014, were used together with a net of eight agrometeorological stations for modelling these water productivity (WP) parameters in the main agricultural growing irrigated areas inside three hydrological basins in this region. Some of these areas inside of each basin were highlighted for more in-depth WP analyses. The SAFER algorithm estimated the ratio of actual (ET) to reference (ET0) evapotranspiration and this ratio was used for both, to calculate ET and to include the soil moisture effects in the Monteith's Radiation Use Efficiency (RUE) model. The highlighted agricultural growing regions were Paranapuã, Populina and Santa Rita d'Oeste in the Turvo/Grande basin; Rubinéia, Santa Fé do Sul, Suzanópolis and Ilha Solteira, in the São José dos Dourados basin; and Pereira Barreto and Sud Mennucci, in the Baixo Tietê basin. The highest averages of both ET (1.7 ± 0.9 mm d-1) and BIO (47 ± 31 kg ha-1 d-1) were for Ilha Solteira, while the lowest ones happened in Sud Mennucci (1.3 ± 0.7 mm d-1 and 40 ± 27). These ET and BIO ranges returned WP values varying from 2.2 ± 0.6 to 2.6 ± 0.8 kg m-3, with the higher end of this range happening in the Turvo/Grande hydrological basin. Considering the annual time-scale, crops will consume around 770, 828 and 786 mm yr-1 with the corresponding BIO values of 27, 26 and 25 t ha-1 yr-1, respectively in Turvo/Grande, São José do Dourados and Baixo Tietê. It was concluded that increments in agricultural irrigated areas should be stimulated in the northwestern side of the state, mainly in the first basin, to retrieve good yield with less water use. © 2016 SPIE.

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