The objective of this paper is to simulate flow frequency distribution curves for Amazon catchments with the aim of scaling power generation from small hydroelectric power plants. Thus, a simple nonlinear rainfall-runoff model was developed with sigmoid-variable gain factor due to the moisture status of the catchment, which depends on infiltration, and is considered a factor responsible for the nonlinearity of the rainfall-runoff process. Data for a catchment in the Amazon was used to calibrate and validate the model. The performance criteria adopted were the Nash-Sutcliffe coefficient (R²), the RMS, the Q 95% frequency flow percentage error, and the mean percentage errors ranging from Q 5% to Q 95%. . Calibration and validation showed that the model satisfactorily simulates the flow frequency distribution curves. In order to find the shortest period of rainfall-runoff data, which is required for applying the model, a sensitivity analysis was performed whereby rainfall and runoff data was successively reduced by 1 year until a 1.5-year model application minimum period was found. This corresponds to one hydrological year plus the 6-month long "memory". This analysis evaluates field work in the ungauged sites of the region. Cieľom tohto príspevku je simulácia čiar rozdelenia prietokov pre povodia rieky Amazonka pre potreby hodnotenia premeny energie v malých hydroelektrárňach. Preto bol vyvinutý jednoduchý nelineárny zrážko-odtokový model so sigmoidálne sa meniacim zdrojovým faktorom v závislosti od obsahu vody v povodí, ktorý závisí od infiltrácie a je považovaný za faktor, spôsobujúci nelinearitu zrážkoodtokových procesov. Pre kalibráciu a validizáciu modelu boli použité údaje z povodí rieky Amazonka. Použili sme tieto hodnotiace kritériá: Nashov-Sutcliffov koeficient (R²), RMS, Q 95% , chyba určenia odtoku v percentách, a priemerná percentuálna chyba v rozsahu od Q 5% do Q 95% . Kalibrácia a validizácia ukázala, že model simuluje čiary rozdelenia prietokov uspokojivo. Aby bolo možné nájsť najkratšie obdobie pre nájdenia závislosti zrážky -odtok, ktorá je potrebná pre aplikáciu v modeli, použili sme citlivostnú analýzu tak, že údaje zrážky -odtok boli postupne redukované o jeden rok, až kým nebolo nájdené minimálne obdobie pre aplikáciu vzťahu zrážky -odtok 1,5 roka. Toto obdobie zodpovedá jednému hydrologickému roku, plus 6 mesiacov dlhá "pamäť". Touto analýzou boli vyhodnotené výsledky terénnych meraní v oblastiach, kde neboli k dispozícii merania odtoku.KĽÚČOVÉ SLOVÁ: hydrologické modelovanie, čiara rozdelenia prietokov, malé povodia riekyAmazonka.

The protection of urban channels becomes increasingly necessary when the levels of degradation of water resources tend to increase worldwide. This article deals with an evaluation of the water quality of the main channels (São Joaquim channel, Pirajá channel, Antônio Baena channel and Una channel) that depart from the Una hydrographic basin in the municipality of Belém, Pará State-Brazil. For the evaluation, three measurement campaigns were carried out at four points determined in the channels of the Una hydrographic basin, in the period considered mostly rainy, from April to June 2012, with the following physical-chemical parameters being surveyed: dissolved oxygen, water temperature, biochemical oxygen demand, Nitrate, pH, turbidity, Total Phosphate and fecal Coliform, for the determination of the Water Quality Index (WQI) of the channels, in addition to determining the flow of the basin using the ADCP (Acoustic Doppler Current Profiler). In general, the WQI of the main channels had a regular result, only the Antônio Baena Channel had a bad WQI. The work contributes to the management and planning of water resources in the region.

RESUMO Estuda-se o comportamento hidráulico do sistema de drenagem da Bacia do Paracuri, no município de Belém (PA), com o uso do código computacional livre Storm Water Management Model (SWMM), sendo simulados dois cenários, ambos referentes à ocorrência de uma chuva de 82 mm de precipitação e duração de 6 horas. O primeiro cenário consiste no canal projetado, em perfeitas condições, e nesse caso não ocorrem alagamentos. O segundo cenário simula o mesmo canal com assoreamento de 50 cm, e ocorre inundação. Assim, verifica-se a utilidade do SWMM para simular o comportamento hidráulico dos sistemas de drenagem com dados de precipitações reais, diferentes das chuvas de projeto.

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O artigo faz parte de um estudo mais amplo que mapeia os impactos do turismo, considerando aspectos ambientais e sociais. Neste artigo, objetiva-se a apresentar e discutir resultados de um estudo sobre a relação entre produção de resíduos sólidos e atividade do turismo, em zona turística litorânea na cidade de Barreirinhas, no estado do Maranhão, que é a porta de acesso a uma beleza singular - o Parque Nacional dos Lençóis Maranhenses. Neste sentido, coletaram-se resíduos sólidos gerados ao longo da principal avenida litorânea local e na maior praça pública adjacente, ambas caracterizadas como espaços públicos plurais, frequentados por turistas que pousam na cidade antes e após a visitação ao Parque nacional mas também por moradores locais. A partir da coleta e da caracterização física do resíduo em dois períodos distintos, alta e baixa temporada turística, foi possível identificar seus constituintes e distribuição gravimétrica, bem como correlacionar a sua ocorrência com atividades turísticas. Os resultados obtidos apontam que há pouca relação entre atividade turística e a produção de resíduos no local, além de evidenciar práticas de gestão públicas conscientes e maior conscientização ambiental dos atores envolvidos no processo. The relations of the Tourism with the garbage’s question at the Barreirinhas’ city (MA, Brazil) ABSTRACT This paper is part of a greater investigation targeting tourism impacts, based on environmental and social aspects. It presents and discusses results from a study on the relationship between solid waste productions and tourism activity in a touristic area in Barreirinhas city, in Maranhão State, which gives access to Lençois Maranhenses National Park, place of unique beauty. In this scenario, waste sampling was carried out on two different touristic seasons, high and low, along main city avenue and square, both places holding touristic and local infrastructures. Physical characterization was performed in waste samples collected to identify gravimetric content, and eventual correlations with touristic activities. Results show little degree of correlation between two aspects investigated in this paper, and also a good public management, and population environmental understanding and involvement in the process. KEYWORDS: Tourism; Impacts; Garbage; Barreirinhas; Maranhão.