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Cobrança pelo uso dos recursos hídricos na bacia hidrográfica do rio São Francisco no decênio 2011 a 2020

2023-05-30T00:00:00Z

Título: Cobrança pelo uso dos recursos hídricos na bacia hidrográfica do rio São Francisco no decênio 2011 a 2020 Autor(es): Oliveira, Luiz Ricardo Santos de Abstract: Charging for the use of water resources can be understood to encourage the rational use of water, in addition to raising financial resources for investments in environmental recovery and conservation actions. However, its implementation involves technical, political, and social challenges. In the face of that, this work aimed to analyze the charging for the use of water in the San Francisco River basin (BHSF), between the years 2011 and 2020 and, in particular, to analyze the hydro-environmental recovery projects carried out in the states of Minas Gerais and Sergipe. This research was based on master's and doctoral research related to the study of water resources, in addition to scientific articles, laws, application plans, management reports, deliberations and information on charging, collection and projects executed in the BHSF, through website of the San Francisco River basin committee and of the Peixe Vivo Basin Agency. The results of the present research demonstrate that the collection in this river basin is effectively and institutionally achieving its goals, however, the available resources are not sufficient to attend the investment demands necessary to reduce the main challenges of the San Francisco River basin. It was also observed that there was a constant increase in the collection of resources from different uses between 2011 and 2018, as well as a significant growth in collection with the new methodology started in 2019, mainly in uses for irrigation and transposition. Besides, it was verified that Sergipe actively contributes to the collection of the river basin, but needsinvestment in hydro-environmental recovery projects, in contrast to Minas Gerais, which has several projects financed by the water charging and has a significant participation in the total collection of the region. Finally, although the efforts and commitment of the management organizations of the San Francisco River basin, this water resource faces significant obstacles, set by the high demand for the use of water, as well as the irregular distribution of projects to recover the river basin.

Perfil da ictiofauna e níveis de mercúrio em peixes capturados na região do baixo rio São Francisco

2023-02-27T00:00:00Z

Título: Perfil da ictiofauna e níveis de mercúrio em peixes capturados na região do baixo rio São Francisco Autor(es): Santos, Érica Alves de Oliveira Abstract: Mercury contamination has increased its importance in research, due to the risks to organisms, and requires accurate knowledge about the impacts on the environment and health. The objective of the present study was to investigate Hg contamination in muscle tissues of fish captured in the Lower São Francisco region, with the aim of using them as bioindicators. To capture the specimens, a set of gillnets was used, with meshes of 3 to 16 cm between opposite nodes. Two collections were carried out, dry season and rainy season, where about 1,606 specimens were captured in the Lower São Francisco, belonging to a group of 25 species of fish with different eating habits, 13 omnivores, 6 carnivores, 4 detritivores, 1 herbivore and 1 1 plankton, to determine Hg concentrations in muscle tissue, evaluating the influence of trophic position, seasonality and biometrics. The analysis method used to determine the total mercury concentration in the samples was based on thermal decomposition, amalgamation and detection by atomic absorption spectrometry, using the DMA-80 equipment (Direct Mercury Analyzer, Milestone), with direct mercury analysis. To certify the analytical method, analyzes were carried out on the reference material composed of fish protein (DORM-4), with known mercury content (0.410 ± 0.055 mg kg-1), where the agreement was 98.2 ± 2, 4%. The results obtained showed that in the dry period the species Acestrorhynchus lacustris with a carnivorous feeding habit presented the highest average concentration of mercury in the muscle, with a concentration of 0.1183 ± 0.0737 mg kg-1. However, in the rainy season, the species Bryconops affinis with an omnivorous feeding habit was the one that presented the highest levels, with a concentration of 0.1541 ± 0.1053 mg kg-1. Considering the mean concentrations, all species studied in both periods had mercury levels below the maximum limit of 0.5 mg kg-1 in non-predatory fish and 1.0 mg kg-1 in predatory fish, established by the National Agency of Sanitary Surveillance - ANVISA. It was possible to verify that the specimens evaluated both in the dry and in the rainy season had a Risk Quotient lower than 1, not presenting a risk of contamination by Hg capable of causing damage to human health. It should be noted that, even without presenting risks, it should be considered that riverside communities consume fish more frequently, requiring the integration of public power with academia, so that such analyzes in fish are monitored with greater assiduity.

Modelagens do balanço hídrico em larga escala com uso de sensoriamento remoto e dados climáticos : aplicações em áreas de crescimento agrícola da região costeira do Nordeste do Brasil

2023-02-24T00:00:00Z

Título: Modelagens do balanço hídrico em larga escala com uso de sensoriamento remoto e dados climáticos : aplicações em áreas de crescimento agrícola da região costeira do Nordeste do Brasil Autor(es): Farias, Franzone de Jesus Abstract: The SAFER algorithm (Simple Algorithm for Evapotranspiration Retrieving) was applied with satellite images together with precipitation grids, to test the monitoring of water balance (WB) components in the agricultural growth region of SEALBA, agriculture growing region limited by the states of Sergipe (SE), Alagoas (AL), and Bahia (BA), in the coast of Northeast Brazil, classifying the Atlantic Forest (AF) and Caatinga (CT) biomes inside this region. The MODIS MOD13Q1 reflectance product and weather data upscaled to the 16-days satellite timescale were used to retrieve the actual (ET) and reference (ET0) evapotranspiration along the years 2007 to 2021, analyzing the average results for this period. Expressive differences on P, ET, WB (P – ET), and the evaporative fraction (ETf = ET/ET0) are noticed along the year in the region and between the biomes. The period of the highest P is in May, when the 16-day values are above 90 mm in AF and larger than 70 mm in CT. Considering the annual scale, the mean total P in CT, with 772 mm, is 83% of that for AF (927 mm). Regarding ET, the highest rates occur between July and September, when the 16-day average exceeds 2.70 mm d-1 in the FA biome and 2.90 mm d-1 in CT. At the annual scale, the average ET totals were 760 and 601 mm yr-1 for the AF and CT biomes within SEALBA, respectively, being the rates in CT being 79% of those for AF. Accounting P and ET, the CT biome, the CT biome has a slightly rainfall more water availability than the FA biome, with an annual WB being 2% larger, because even FA having a higher P, its higher ET rates reduce WB. The highest P values together with the lowest ET rates from March to August, increasing the positive WB values (P > ET) in both biomes, confirm suitability for rainfed agriculture, as well as high possibilities for rainfall water storage. However, from July to December happen the negative WB values (P < ET), indicating irrigation needs during the critical crop stages. Inferring the root-zone moisture conditions through the daily values of ETf, it is noted that the best levels are from April to September in the whole SEALBA region, with some cases the species of the CT biome with better conditions than those for AF. The lowest ETf values from October to April in CT. The lower ETf values from October to April in CT, when comparing with AF, are directly related to lower amounts of rainfall under greater atmospheric demand. Crossing the WB and ETf values it is evident a delay regarding the moment when the rains satisfy the water consumptions with that when the root-zone moisture levels reach to optimum levels after the driest periods. Although the modelling being carried out in a specific Brazilian region, the suitability of the joint use of the MOD13Q1 product and gridded Weather data shows potential for implementation of an operational system to monitor the water balance components in any environmental conditions. The large-scale accountings of precipitation, evapotranspiration, and the root-zone moisture conditions are highlighted as of strong support for public policies regarding the management and conservation of water resources, mainly under the actual scenarios of climate and land use changes, with possibility of replication of the methods to other regions from Brazil and the World, after calibrations of the modelling regression coefficients.

Produção de cladódios jovens de genótipos de palma forrageira sob salinidade da água

2023-02-24T00:00:00Z

Título: Produção de cladódios jovens de genótipos de palma forrageira sob salinidade da água Autor(es): Santos, Gabriéli Meneses dos Abstract: Water is the most limiting factor for agricultural production, especially in arid and semiarid regions, to enable cultivation in these areas, then. biosaline agriculture can be used. However, we must find species that are able to produce, even at high salinity levels, which can be obtained by identifying forage palm genotypes with greater tolerance, since the effects may vary between genotypes. Thus, the objective was to study the production of young cladodes of forage palm genotypes under water salinity levels. The experimental design used was in randomized blocks, with treatments formed from a split-plot scheme, where five levels of salinity were studied (0,14 dS m-1; 1,50 dS m-1; 3,00 dS m-1, 4,50 dS m-1 e 6,00 dS m-1) in the plots and two species of forage palm “Miuda” or Doce; ‘IPA Sertânia’, both of genus Napolea, in the subplots, with three plants per sample unit and repeated in five blocks. The plants were cultivated in vases filled with soil-based substrate, the plants were irrigated weekly, and the water demand was estimated through weighing lysimetry. Sprout samples between 10 and 20 cm in length were collected weekly, the morphometric variables were analyzed, at 114 days, the growth, chemical, and production variables of the mother plant (PM) were determined. The salinity reduces sprout production from 3,0 dS m-1 in both genotypes of forage palm. The “Miúda” palm has better performance than “IPA Sertânia” in saline water cultivation.