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In drip-irrigated systems, the understanding of the soil wetting pattern is essential in defining the area effectively irrigated, the spacing between the emitters and their installation depth, and the irrigation rate. Thus, this study aims to estimate soil hydraulic characteristics through inverse modeling of an analytical equation used in wetting bulb simulation based on soil moisture measurements obtained in the field. The parameters of the Gardner model, which describes the unsaturated soil hydraulic conductivity, and the van Genuchten model that describes the soil moisture retention curve, were estimated by inverse modeling techniques. The following options were considered: (A) estimating parameter β while considering the other parameters, Ko, θr, θs, α, n, and m, as known and obtained experimentally; (B) estimating parameters Ko and β while considering the experimental retention curve as known; (C) estimating parameters Ko, β, α, n, and m while considering the values of the θr and θs volumetric moisture as known; (D) estimating all the parameters of Gardner and van Genuchten models (Ko, θr, θs, α, n, and m). The results indicate that option D showed better concordance between the estimated and observed moisture values. Thus, the inverse modeling of the analytical equation is an important tool for irrigation design and management.

The evaluation of irrigation uniformity can be affected by the sampling pattern in the field. Thus, this work aimed to compare the water application uniformities of a Center Pivot using three sampling patterns: along the equipment radius (radial), in the direction of movement of the pivot (circular) and in a two-dimensional way (meshed). For this, samplers were positioned under the spans of a Center Pivot system, being evaluated the effects of the sampling pattern and of the span, in a 3×3 statistical factorial design, with three replications. The results showed that circular and meshed arrangements were statistically equal and had higher values of Christiansen's and Distribution Uniformity Coefficients. The mesh type arrangement represented a more uniform distribution profile of irrigation depths on the surface. For areas of flat or slightly undulating topography and when using pressure regulating valves for the emitters, sampling in a radial pattern is sufficient, but for terrains with irregular topography or when pressure head variations along the lateral line are important for the operation of the emitters, the combination of the radial and circular pattern is interesting. The meshed sampling detects the stoppage effect of the towers and drift, however, in a reduced area.

The new version of NBR 15527 (ABNT 2019) determines that any methodology used for the design of rainwater reservoirs must be performed considering the demand for rainwater resources. Thus, the objective of this study was to develop mathematical models for the design of rainwater reservoirs in residential buildings for all Brazilian states. Different use scenarios were simulated, which included drinking water demands of 100, 150, 200 and 300 litres per capita and rainwater replacement for drinking water at rates of 25, 35, 45 and 55%, according to rainfall data from the last decade. The optimal and maximal volumes of each scenario were calculated using the yield after spill (YAS) behavioural method. Based on the values of the volumes obtained, the studied municipalities were grouped, and for each group, the practical models were adjusted and evaluated using the coefficient of determination (R²) and the root mean square error (RMSE). A good adherence of the models to the observed data was observed, which simplified the estimation of the volume for rainwater reservoirs; practical applications demand that designs use discreet daily rainfall values.

RESUMO: As interaçöes entre uso e cobertura do solo e o regime hidrológico de uma bacía hidrográfica säo complexas e dinámicas. A identifıcaçâo de tendencias e mudanças nos regimes de chuva e vazäo de urna regiäo é de suma relevancia no planejamento e gestäo dos recursos hídricos para que adversidades ambientáis, económicas e sočiais sejam evitadas. Sendo assim, o objetivo desse trabalho foi identificar possíveis tendencias ñas series históricas de estaçöes pluviométricas e flnviométricas da bacía hidrográfica do Rio das Mortes. Minas Gerais, bem como relacionar as eventuāls alteraçöes no comportamento da vazäo devido as mudanças no uso e cobertma do solo na bacía entre os anos de 1985 e 2017. Para isso. foram utilizados os dados da estaçâo fluvial de IbiturunaMG e de 12 estaçöes pluviométricas. além de imagens orbitais dos satélites Landsat-5 e Sentinel. As análises do comportamento da vazäo e precipitaçâo foram realizadas por meio do teste näo paramétrico de Mann-Kendall e de Pettitt. já a classificaçâo de uso e cobertma do solo foi realizada no software eCognition Developer® 64. Observou-se tendencias significativas na média das series totais anuais de precipitaçâo e tendencias decrescentes na média das series mensais de menorvazáo ao longo dos anos de 1925 a 2014. Houve alteraçöes no uso e ocupaçâo do solo na regiäo estudada. no entanto, estas näo foram significativas a ponto de modificar o regime lúdrológico da bacía do Rio das Mortes dmante o período analisado.

The authors would like to thank the Agência Nacional de Energia Elétrica (ANEEL), Instituto Nacional de Meteorologia (INMET), Serviços e Eletricidade S/A (LIGHT) and Instituto Estadual do Ambiente (INEA) for the rainfall data. The first author would like to thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq (Brazilian National Council for Scientific and Technological Development) for the PhD Scholarship.

The lack of sub-daily rainfall data to obtain intensity-duration-frequency (IDF) relationships at a local scale is a common limitation in many countries. This study determines rainfall disaggregation coefficients using pluviographic data from several meteorological stations to adjust IDF curves for Rio de Janeiro state, Brazil. The adjusted IDF curves using the coefficients obtained show satisfactory adjustment with Nash and Sutcliffe efficiency values above 0.99 compared to the mean values proposed by Cetesb (1979). The root mean square error (RMSE) of the estimated rainfall intensities using the adjusted IDF relationships for different return periods and rainfall durations varied between 2.55 at the Eletrobrás station and 42.49 at the São Bento station. The disaggregation coefficients obtained for Rio de Janeiro state differ from the values proposed in the literature, which confirms the need to adjust values locally and for hydrologically homogeneous regions. This local and regional scale approach provides more accurate IDF curves. Keywords: extreme rainfall, IDF relationship, Rio de Janeiro.

This study created thematic heavy rainfall maps for Brazil, with durations of 5-, 30-, 60- and 120 minutes and 5 years of return period (T). The intensity-duration-frequency (IDF) relationships used were compiled from studies found in the literature (798 locations) and derived for 4411 rainfall gauges available in the Hidroweb information system, totaling 5209 rainfall data collected. To derive IDF relationships, Gumbel's probability distributions were used, with parameters estimated by the method of moments. Distribution adequacy was verified by the Kolmogorov-Smirnov test. Rainfall-intensity values obtained by IDF relationships were spatialized in Geographic Information Systems, allowing elaboration of the thematic maps. Thematic maps enable obtain rainfall intensities for places without rain gauge data and/or precarious time-series data. Therefore, these maps are a great tool for the design of hydraulic structures related to urban and rural micro-drainage.

Interactions between land use and cover and a basin hydrological regime are complex and dynamics. The identification of trends and changes in rainfall and flow regimes in a region is relevant in water resources planning and management so that environmental, economic and social adversities are avoided. Thus, this study aims to identify possible trends in the historical series of rainfall and fluviometric stations in Rio das Mortes basin, Minas Gerais, Brazil, as well as to relate the modifications in the flow rate behaviour due to changes in land use and cover in the basin between the years of 1985 and 2017. For that, hydrological data were used from the Ibituruna-MG river station and 12 rainfall stations and orbital images from Landsat-5 and Sentinel satellites. Flow rate and precipitation behavior were performed using the nonparametric Mann-Kendall test and the Pettitt’s test, while the land use and cover classification was performed in an eCognition Developer® 64 environment. Significant trends were observed in the average of total annual rainfall series and decreasing trends in the average of monthly flow rate series of lowest runoff over the years 1925 to 2014. There were changes in land use and cover in the studied region, however, these were not significant enough to modify the hydrological regime of Rio das Mortes basin during the analysed period.

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain almost ten times more of local relative abundances then constraints based on either directional or stabilizing selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics. Competing Interest Statement The authors have declared no competing interest.