In the Brazilian semi-arid region, the intensification of agriculture results in a change of natural vegetation by irrigated crops. To quantify the contrast between these two ecosystems, the large-scale values of water productivity components were modelled in Petrolina (PE) and Juazeiro (BA) municipalities. The SAFER (Simple Algorithm For Evapotranspiration Retrieving) algorithm was used to acquire evapotranspiration (ET), while the Monteith's radiation model was applied for estimating the biomass production (BIO). Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images were used together with agro-meteorological data. In Petrolina and Juazeiro, the mean monthly ET values for irrigated crops were 938 and 739 mm∙month⁻¹, with the corresponding ones for natural vegetation of 385 and 194 mm∙month⁻¹.Water productivity (WP) was analysed by the ratio of BIO to ET, defined here as the ratio of the net benefits from the mixed agricultural systems to the amount of water required for producing those benefits. The highest incremental WP values, as a result of the irrigated crops introduction, happened outside the rainy period. More spatial WP uniformity occurred in natural vegetation, when comparing with irrigated crops. The most frequent WP values in Petrolina were between 1.6 and 2.2 kg∙m⁻³ while in Juazeiro this range was from 1.0 to 1.6 kg∙m⁻³. The differences between the municipalities can be mainly explained by differences in precipitation and soil water storages conditions, promoting better rainfall use efficiency by the natural vegetation in the first one. The results of the current research are important for appraising the land use change impacts in situations of expanding irrigation areas.

The Cabeceira Comprida stream’s watershed, located in Santa Fé do Sul, São Paulo state, has great environmental importance. It is essential for supplying water to the population and generating surpluses for sewage dilution. This study aimed to evaluate the annual performance of the components of water productivity from Landsat-8 images of 2015, using the Simple Algorithm for Evapotranspiration Retrieving (SAFER), calculating the actual evapotranspiration (ET_a), biomass (BIO) and water productivity (WP). The annual averages of ET_a, BIO and WP were 1.03 mm day^-1, 36.04 kg ha^-1 day^-1 and 3.19 kg m-3, respectively. The average annual values of ET_a for land use and occupation were 1.40, 1.23, 1.05, 0.97 and 1.08 mm day^-1 for the remaining forest (RF), invasive species (IS), pasture (Pa), annual crop (AC) and perennial crop (PC), respectively, with BIO of 57.64, 46.10, 36.78, 32.69, 40.03 kg ha^-1 day^-1 for RF, IS, Pa, AC and PC, respectively, resulting in WP of 3.94, 3.59, 3.25, 3.09, 3.35 kg m^-3 for RF, IS, Pa, AC and PC, respectively. The ET_a, BIO and WP adjust to the seasonality of the region, and RF and IS stood out with the highest values.

MODIS images during the year 2012 were used for modelling of the radiation and energy balance components with the application of the SAFER algorithm (Simple Algorithm for Evapotranspiration Retrieving) in the Brazilian Pantanal area. Pixels from the main sub-regions of Barão de Melgaço (BR), Paiaguás (PA) and Nhecolândia (NH) were extracted in order to process microclimatic comparisons. In general, the net radiation (R_n) relied much more on the global solar radiation (R_G) levels than on water conditions and ecosystem types, in accordance with the low R_n standard deviation values. The fraction of the available energy used as latent heat flux (λE) were, on average, 65, 50 and 49% for the BR, PA and NH sub-regions, respectively. Horizontal heat advection, identified by the negative values of sensible heat flux (H), made several pixels with λE values higher than those for R_n in the middle of the year. Taking the evaporative fraction (E_f) as a surface moisture indicator, the Tree-Lined Savanna (TLS) was considered the moister ecosystem class, with 58% of the available energy being used as λE, while the driest one was the modified ecosystem Anthropogenic Changes (AC), presenting a λE/R_n fraction of 0.46. According to the spatial and temporal consistencies, and after comparisons with other previous point and large-scale studies, the SAFER algorithm proved to have sensibility to quantify and compare the large-scale radiation and energy balance components in the different ecosystems of the Brazilian Pantanal. The algorithm is useful for monitoring the energy exchange dynamics among the different terrestrial and aquatic ecosystem types throughout the seasons of the year.

WATER PRODUCTIVITY ASSESSMENTS WITH LANDSAT 8 IMAGES IN THE NILO COELHO IRRIGATION SCHEME

BALANÇO HÍDRICO E ESTIMATIVA DO CONSUMO RELATIVO DE ÁGUA DA CULTURA DA CANA-DE-AÇÚCAR NA REGIÃO NOROESTE PAULISTA¹ REGIANE DE CARVALHO BISPO2; FERNANDO BRAZ TANGERINO HERNANDEZ3 E ANTÔNIO HERIBERTO DE CASTRO TEIXEIRA4 [1] Apoio financeiro da FAPESP Processo 2.009/52.467-4. 2 Doutoranda do Programa de Pós-Graduação em Irrigação e Drenagem, Universidade Estadual Paulista “Júlio Mesquita Filho” - UNESP/FCA, Rua José Barbosa de Barros, 1780, Botucatu, SP. E-mail: regianecarvalhoks@gmail.com 3 Professor Titular, Departamento de Fitossanidade, Engenharia Rural e Solos, Universidade Estadual Paulista “Júlio Mesquita Filho”- UNESP, Ilha Solteira, SP. E-mail: fbthtang@agr.feis.unesp.br 4 Pesquisador, Embrapa Monitoramento por Satélite, Campinas, SP. E-mail: heriberto.teixeira@embrapa.br 1 RESUMO O presente trabalho teve como objetivo determinar o balanço hídrico e estimar o consumo relativo de água para a cultura da cana-de-açúcar nas diferentes fases fenológica, para o município de Sud Mennucci, visando fornecer informações úteis aos estudos de zoneamentos agroclimáticos e definição de época de menor risco para a produção dessa cultura. Os dados utilizados no estudo corresponderam ao período de 2012 a 2016, sendo calculados o balanço hídrico sequencial mensal e o balanço hídrico normal mensal, ambos utilizando a capacidade de armazenamento de água disponível no solo (CAD) de 60 mm. O Índice de Satisfação das Necessidades de Água para a cultura (ISNA), definido como a relação entre a evapotranspiração real e a evapotranspiração máxima (ETr/ETm) foi utilizado como critério na definição das fases fenológicas favorável para o cultivo. Os resultados obtidos indicam que, nas fases de perfilhamento e crescimento de colmos e nos meses entre julho e outubro são os períodos mais críticos com relação à deficiência hídrica, considerando a colheita realizada em maio, necessitando de reposição de água nestes períodos para evitar decréscimo da produtividade. PALAVRAS-CHAVE: Evapotranspiração, deficiência hídrica, Saccharum officinarum. BISPO, R. C.; HERNANDEZ, F. B. T; TEIXEIRA, A. H. C. WATER BALANCE AND RELATIVE WATER CONSUMPTION OF SUGARCANE IN THE NORTHWESTERN REGION OF SÃO PAULO 2 ABSTRACT The present work aims to determine the water balance and estimate the relative water consumption for sugarcane crop in the different phenological phases, in the municipality of Sud Mennucci, attempting to provide useful information to the agroclimatic zoning studies and to define the time of a lesser risk to production of this crop. The data used in the study corresponded to the period from 2012 to 2016, and both the monthly sequential water balance and the regular monthly water balance were calculated using 60 mm as soil water storage capacity (WSC). The Water Satisfaction Index for Culture (WSIC), defined as the relation between actual evapotranspiration and maximum evapotranspiration...

The objective of this work was to develop and apply water balance indicators to be scaled up in the wine grape (Vitis vinifera) growing regions of the municipalities of Petrolina and Juazeiro, in the states of Pernambuco and Bahia, respectively, Brazil, simulating different pruning dates along the year. Previous energy balance measurements were used to relate the crop coefficient (Kc) with the accumulated degree-days (DD_ac). This model was applied to scale up the water balance indicators during the growing seasons. When irrigation water was available, the best pruning periods were from May to July, due to the better natural thermal and hidrological conditions. More care should be taken for pruning done in other periods of the year, regarding the effect of increasing thermal conditions of wine quality. The water balance indicators, both successfully developed and applied, allow large-scale analyses of the thermohydrological conditions for wine grape production under the semiarid conditions of the Brazilian Northeast.