Com este trabalho objetivou-se determinar as relações entre precipitações de diferentes durações para o Estado de Santa Catarina. Foram estabelecidas as séries de máximas anuais de chuva com duração de 5 a 1440 min de treze estações pluviográficas de Santa Catarina. Para cada duração foram estimadas as precipitações máximas com período de retorno de 2 a 100 anos, com base na distribuição de Gumbel-Chow. A relação média entre a chuva de 24 h e a chuva de um dia independe do período de retorno, com média para o estado de 1,17. Ao se analisar o horário da leitura da precipitação diária verificou-se que esta relação varia de 1,12 a 1,20. Em referência à chuva de 1 h em relação à chuva de 24 h observam-se valores significativamente inferiores aos normalmente usados.
Knowledge of intensity-duration-frequency (IDF) relationships of rainfall events is extremely important to determine the dimensions of surface drainage structures and soil erosion control. The purpose of this study was to obtain IDF equations of 13 rain gauge stations in the state of Santa Catarina in Brazil: Chapecó, Urussanga, Campos Novos, Florianópolis, Lages, Caçador, Itajaí, Itá, Ponte Serrada, Porto União, Videira, Laguna and São Joaquim. The daily rainfall data charts of each station were digitized and then the annual maximum rainfall series were determined for durations ranging from 5 to 1440 min. Based on these, with the Gumbel-Chow distribution, the maximum rainfall was estimated for durations ranging from 5 min to 24 h, considering return periods of 2, 5, 10, 20, 25, 50, and 100 years,. Data agreement with the Gumbel-Chow model was verified by the Kolmogorov-Smirnov test, at 5 % significance level. For each rain gauge station, two IDF equations of rainfall events were adjusted, one for durations from 5 to 120 min and the other from 120 to 1440 min. The results show a high variability in maximum intensity of rainfall events among the studied stations. Highest values of coefficients of variation in the annual maximum series of rainfall were observed for durations of over 600 min at the stations of the coastal region of Santa Catarina.Index terms: heavy rainfall, hydrology, drainage.
R ESU M OOs dejetos suínos contribuem de forma significativa em prol da degradação dos recursos naturais e para a diminuição da qualidade de vida na região sul do estado de Santa Catarina, Brasil. O excesso de dejetos gerados pelo grande número dos suínos por unidade de área dificulta a solução do problema. Este trabalho teve como objetivo avaliar o comportamento de um sistema de tratamento de dejetos suínos, em série e em escala real, composto de unidades anaeróbias, unidades aeróbias e pós-tratamento. Os parâmetros analisados foram: DBO, DQO, PT, P-PO 4 , N-NH 3 , NTK, pH, clorofila a, biomassa algal, coliformes totais e coliformes fecais (Escherichia coli). O sistema mostrou que após um ano de funcionamento as eficiências de remoção foram satisfatórias para matéria orgânica e nutrientes, alcançando valores de 97% para DBO, 95% para DQO, 88% para N-NH 3 e 74% para PT/P-PO 4 , mesmo com as variações de vazão e de carga orgânica aplicada. Entretanto, a remoção de coliformes fecais nas unidades aeróbias foi baixa, reduzindo somente 0,86 unidades log na lagoa facultativa aerada e 0,80 unidades log na lagoa de maturação. Palavras-chave: reatores anaeróbios, lagoas de estabilização, filtro de pedrasThe evaluation of swine waste treatment system installed in Santa Catarina State A B ST R A C T The swine manure contributes significantly to the degradation of natural resources and to decrease the quality of life in the southern state of Santa Catarina, Brazil. The excess of manure produced by the large number of pigs per unit area hinders the solution of the problem. This study aimed to evaluate the behavior of a system developed to treat swine manure, in series and in real scale, composed of anaerobic units, aerobic units and post-treatment. The parameters analyzed were: BOD, COD, TP, PO 4 -P, NH 3 -N, TKN, pH, chlorophyll a, algal biomass, total coliforms and fecal coliforms (Escherichia coli). The system showed that, after one year of operation, the removal efficiencies were satisfactory for organic matter and nutrients, reaching values of 97% for BOD, 95% for COD, 88% for N-NH 3 and 74% for PT/P-PO 4 , even with variations in flow and organic load applied. However the removal of fecal coliforms in the aerobic units was low, decreasing only 0.86 log units in the aerated facultative pond and 0.80 log units in the maturation pond.
suMMary the purpose of this study was to adjust equations that establish relationships between rainfall events with different duration and data from weather stations in the state of santa catarina, Brazil. in this study, the relationships between different duration heavy rainfalls from 13 weather stations of santa catarina were analyzed. From series of maximum annual rainfalls, and using the Gumbel-chow distribution, the maximum rainfall for durations between 5 min and 24 h were estimated considering return periods from 2 to 100 years. the data fit to the Gumbel-chow model was verified by the Kolmogorov-smirnov test at 5 % significance. the coefficients of Bell's equation were adjusted to estimate the relationship between rainfall duration t (min) and the return period t (y) in relation to the maximum rainfall with a duration of 1 hour and a 10 year return period. likewise, the coefficients of Bell's equation were adjusted based on the maximum rainfall with a duration of 1 day and a 10 year return period. the results showed that these relationships are viable to estimate short-duration rainfall events at locations where there are no rainfall records.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.