Artigo em anais de congresso (CNPM) https://www.alice.cnptia.embrapa.br/alice/handle/item/260 2026-06-14T19:19:22Z 2026-06-14T19:19:22Z TEIXEIRA, A. H. de C. LEIVAS, J. F. BAYMA, G. GREGO, C. R. https://www.alice.cnptia.embrapa.br/alice/handle/doc/1073556 2017-08-16T03:23:38Z 2017-01-01T00:00:00Z

Título: Índices agrometeorológicos aplicados com imagens MODIS e dados climáticos no Estado e Minas Gerais. Autoria: TEIXEIRA, A. H. de C.; LEIVAS, J. F.; BAYMA, G.; GREGO, C. R. Conteúdo: Minas Gerais state, Brazil, has experienced severe water scarcity in some areas, demanding largescale water balance studies to subsidize water policies. The reflectance bands from the MOD13Q1 MODIS product were used together with agrometeorological data to acquire water balance indices in the state, during the years from 2012 to 2015, later extracting the main agricultural growing regions, North, Northwest and Minas Triangle. Precipitation (Prec) and reference evapotranspiration (ET0) data from 36 weather stations were interpolated, while for the actual evapotranspiration (ET), the SAFER algorithm was used. A climatic water balance indicator was applied, the Water Balance Difference (WBd = Prec - ET) and, for the surface moisture, the evapotranspiration ratio (ETr = ET/ET0) was used. Higher WBd happened from the middle of October to the end of December, while the largest ETr values were between March and May.. According to the ETr values, the soil moisture storage showed a gap in relation to the WBd index, because the lapse time the soil to recover its retention capacity. Considering all studied years, ET attended the atmospheric demand by 50, 53 and 61% in the agricultural growing regions of North, Northwest and Minas Triangle. It was demonstrated the potential to monitor the water conditions for the 16-day periods on a large scale by combining weather measurements and MODIS products.

2017-01-01T00:00:00Z BAYMA, G. TEIXEIRA, A. H. de C. LEIVAS, J. F. https://www.alice.cnptia.embrapa.br/alice/handle/doc/1073573 2017-08-16T03:30:26Z 2017-01-01T00:00:00Z

Título: Estimativa de parâmetros biofísicos no bioma Cerrado do Estado de Minas Gerais. Autoria: BAYMA, G.; TEIXEIRA, A. H. de C.; LEIVAS, J. F. Conteúdo: Natural habitats decrease in extension and integrity may be considered as an indicator of biodiversity decay. Land-use and land-cover changes (LULCC), original ecosystems conversion to other anthropic uses, have direct effects on biodiversity and climate. The Cerrado biome extends over approximately 2,000,000 km2 and between 2002 and 2013 nearly 126,000 km² of its natural plant cover was suppressed (-10.7%), 11.4 thousand km² year-1. The Simple Algorithm for Evapotranspiration Retrieving (SAFER) is an agrometeorological spectral model for estimating large-scale biophysical parameters using satellite images and climate data interpolated from meteorological stations. SAFER does not require the use of the thermal band. The SAFER model was used to estimate biophysical parameters in anthropic and natural land-use classes in a portion of the Brazilian state of Minas Gerais which is covered by Cerrado vegetation. Our results show "silviculture" as the anthropic land-use class with the highest biomass (146 kg ha-1 day-1) and ET (3.3 mm day-1) values. Among the natural plant-cover classes, the highest values were estimated for "forest" (85.8 kg ha-1 day-1 and 2.4 mm day-1). We recommend that future studies apply the SAFER model to medium spatial resolution images (e.g. Landsat-8, Sentinel-2) with the aim of estimating parameters in a more detailed scale.

2017-01-01T00:00:00Z TRABAQUINI, K. BAYMA, G. SANCHES, I. D. NOGUEIRA, S. F. DORTZBACH, D. https://www.alice.cnptia.embrapa.br/alice/handle/doc/1073391 2017-08-16T01:38:13Z 2017-01-01T00:00:00Z

Título: Avaliação espaço-temporal da cultura da cana-de-açúcar no oeste paulista. Autoria: TRABAQUINI, K.; BAYMA, G.; SANCHES, I. D.; NOGUEIRA, S. F.; DORTZBACH, D. Conteúdo: This work aims to analyze the dynamics of land use change by evaluating the spatio-temporal changes of sugarcane, verified in the period between 2000 and 2015, in the western portion of the São Paulo state. The study area includes parts of the municipalities of Andradina, Muritinga do Sul, Guaraçaí and Pereira Barreto, totaling an area of 1,115 km2. From a multitemporal series of Landsat satellite images of 30 m spatial resolution, the land use information was obtained for the sixteen years, using the Spring software. Land use and land cover maps were analyzed for each date, and the expansion of sugarcane activity in the region was verified, annually, for the period analyzed. As results, it was observed that sugarcane had an expansion in area between the years 2000 and 2014. In the year 2000, about 8,000 hectares of sugarcane were already being cultivated in this area. And although between 2014 and 2015 there was no expansion, the area of sugarcane increased more than fivefold in 15 years analyzed, reaching 42,000 hectares in 2015. It is noteworthy mentioned that this expansion occurred mainly in the conversion of grazing areas, determining new regional configurations of agricultural holdings for the western region of São Paulo.

2017-01-01T00:00:00Z LEIVAS, J. F. TEIXEIRA, A. H. de C. BAYMA, G. https://www.alice.cnptia.embrapa.br/alice/handle/doc/1062767 2017-08-16T04:08:13Z 2016-01-01T00:00:00Z

Título: Evapotranspiração no perímetro irrigado de Jaíba utilizando imagens de satélite. Autoria: LEIVAS, J. F.; TEIXEIRA, A. H. de C.; BAYMA, G. Conteúdo: O objetivo do trabalho foi aplicar o modelo Simple Algorithm For Evapotranspiration Retrieving (SAFER) com a finalidade de analisar a evapotranspiração estimada na área do Perímetro Irrigado de Jaíba, na Bacia do São Francisco, com imagens de alta resolução espacial. Foram obtidos dados meteorológicos e imagens do satélite RapidEye (resolução de 5 m), referente aos dias 26 de junho de 2013 e 29 de abril de 2014. A evapotranspiração (ET) média diária de toda a cena de 2013 foi 0,43 mm ± 0,96 mm e valor máximo de 6,11 mm. Em 2014, o valor de ET médio diário foi de 2,19±2,01mm. Conforme estudos anteriores, a Caatinga converte a maior parte da energia disponível em calor sensível (H), enquanto as culturas irrigadas apresentam altos valores de ET. Com imagens de alta resolução espacial, sem a banda termal, foi possível obter a evapotranspiração em nível de pivô central e talhões de culturas irrigadas, auxiliando o uso racional da água em tempos de deficiência hídrica.

2016-01-01T00:00:00Z