Abstract The present research aimed to demonstrate the feasibility of using image segmentation for better drainage extraction, automated drainage network hierarchization and main channel definition based on Horton (1945). The test area for the applications was the Bandeirinha Stream Hydrographic Basin (BSHB), which is located in the municipality of Formosa, in the state of Goiás, Brazil. The study used the Shuttle Radar Topography Mission (SRTM), with a spatial resolution of 1" x 1" (one arc second). The SRTM segmentation was performed using the Python language ODR_Obia algorithm, inserted with a QGIS plugin. Through the QGIS platform, the ODR_Hidro plugin was used to perform the delimitation of the BSHB, the extraction of the drainages and the definition of the main channel. The results were validated in the field and evaluated from the manual definition of the main channel. That was done using both the data produced by the application and the drainage data contained in the vector base of the topographic maps of the Army of Geographic Service (AGS), at the scale of 1:100,000 and 1:25,000. From the results obtained, it can be inferred that the ODR_Hidro model used for the delimitation of the BSHB, the automated hierarchization of the drainages and the definition of the main channel from the segmented SRTM image is very efficient. The field validation demonstrated its effectiveness by proving the existence of first-order drainages which are not mapped on the DSG chart at a scale of 1:100.000. This leads to the conclusion that the use of the proposed tools and the inclusion of image segmentation, aiming for the extraction of drainage network and geomorphometric characterization of watersheds, can efficiently contribute to the provision of morphometric data.

School feeding is part of for million students' routine worldwide. Schools' closure during the COVID-19 pandemic brought to the fore the challenge of providing food for children and adolescents by alternative means, through food programs, whether governmental or otherwise. In Brazil, approximately 40.1 [1] million children and adolescents enrolled in basic public education were affected and went without their daily meal during this period. To provide them food, most local governments chose to transfer financial resources to their parents. The challenge of knowing if children are receiving these meals adequately during school closures, which can be lengthy, is the target of this study. The current situation in the 27 Brazilian federated entities regarding the transfer of funds and delivery of meals is presented herein. A monitoring model is proposed for children and adolescents to be followed during the pandemic, in order to guarantee their adequate nutrition.

A alimentação escolar faz parte da rotina de milhões de estudantes em todo o mundo. O fechamento das escolas durante a pandemia da COVID-19 trouxe à tona o desafio de fornecer alimentos para crianças e adolescentes de forma alternativa, por meio de programas alimentares, governamentais ou não. No Brasil, aproximadamente 40,1 [1] milhões de crianças e adolescentes matriculados na educação básica da rede pública foram afetadas e estão sem essa refeição diária. Para suprir a demanda deles, a maioria dos governos estaduais fez opção pelo repasse de recursos financeiros a seus pais. O desafio de saber se as crianças estão recebendo essas refeições adequadamente durante o fechamento da escola, que pode ser demorado, é o objeto deste estudo. A situação atual nos 27 entes federados brasileiros em relação à transferência de fundos e entrega de refeições é apresentada aqui. Um modelo de monitoramento é proposto para crianças e adolescentes a serem seguidos durante a pandemia, a fim de garantir uma nutrição adequada.

Abstract: This research aims to determine the vertical accuracy of the Interferometric Digital Elevation Model (DEM) obtained from the processed Shuttle Radar Topographic Mission (SRTM) data. The research compared the SRTM-GL1 (Shuttle Radar Topographic Mission-Global 1) with 30-meter resolution and the following 90-meter resolution models: (a) EMBRAPA; (b) Hydrological data and maps based on Shuttle Elevation Derivatives at multiple Scales (HydroSHEDS) (HydroSHEDS), provided by the United States Geological Survey (USGS); (c) Consultative Group for International Agricultural Research-Consortium for Spatial Information (CGIAR-CSI); and (d) Jonathan de Ferranti. The accuracy analysis considered the diverse Brazilian regions, adopting 1,087 field points from the Global Navigation Satellite System (GNSS) trackers or topography methods. The Jonathan de Ferranti model achieved the best accuracy with RMSE of 9.61m among the 90-meter resolution models. Most SRTM models at 1:100,000 scale reached Grade A of the Cartographic Accuracy Standard. However, the accuracy at the 1: 50,000 scale did not achieve the same performance. SRTM errors are linearly related to slope and the most significant errors always occur in forest areas. The 30-meter resolution SRTM showed an accuracy of around 10% better (RMSE of 8.52m) than the model of Jonathan de Ferranti with 90-meter resolution (RMSE of 9.61m).

A água tem importante papel na sociedade humana, especialmente no Brasil. Seus usos são múltiplos, incluindo o abastecimento, produção energética e lazer, entre outros. A própria Política Nacional de Recursos Hídricos (Lei nº 9.433/97) traz entre seus artigos a sua importância segundo os seus usos múltiplos, priorizando o abastecimento humano e a dessedentacão de animais. Neste enfoque é importante considerar a qualidade físico-química da água para atender a estas demandas, escopo do enquadramento dos corpos d'água segundo seus usos preponderantes, com o objetivo de garantir qualidade compatível com os usos mais exigentes a que for destinada e diminuir os custos de combate à poluição mediante ações preventivas permanentes. Entre os vários parâmetros que buscam analisar a qualidade físico-química da substância busca-se entender a distribuição espacial da turbidez na superfície do lago, uma vez que a variação dos componentes que alteram este parâmetro pode ser detectada por meio do sensoriamento remoto passivo. A aplicação do Modelo linear de mistura espectral permitiu, de forma satisfatória, identificar a distribuição espacial da turbidez no espelho de água.

The water has an important role in human society, especially in Brazil. Its uses are multiple, including supply, energy production, recreation and others. The National Policy for Water Resources (Law Nº 9.433/97) states in its articles the importance of water use in accordance to their multiple uses, prioritizing the supply for humans and animals. In this approach, it is important to consider the physical and chemical quality of water to meet these demands, scope of the legal framework applied to the Brazilian water bodies according to their main uses, in order to guarantee the water quality compatible with the most demanding uses and to reduce the costs of pollution control through ongoing preventive actions. Among the various parameters that seek to analyze the physical and chemical quality of water it is intended to understand the spatial distribution of turbidity in the lake's surface, since the variation of the components that alter this parameter can be detected by means of passive remote sensing. The application of the Linear spectral mixture model allowed, satisfactorily, the identification of turbidity spatial distribution patterns in the lake.