Marlus Sabino

Our understanding of spatiotemporal variability in reference evapotranspiration (ETo) and its long-term trends is of paramount importance for water cycle studies, modeling, and water resource management, especially in the context of climate change. Therefore, the primary aim of this study is to critically evaluate the performance of various CMIP5 global climate models in simulating the Penman–Monteith reference evapotranspiration and its associated climate variables (maximum and minimum air temperature, incident solar radiation, relative humidity, and wind speed). This evaluation is based on data from nine climate models and 33 automatic meteorological stations (AWSs) in the state of Mato Grosso, spanning the period 2007–2020, within the areas of the biomes Amazon and Cerrado and around the Pantanal biome. The statistical metrics used for evaluation include bias, root mean square error, and Pearson and Spearman correlation coefficients. The projections of the most accurate model were then used to analyze the spatial and temporal changes and trends in ETo under the Representative Concentration Pathways (RCPs) of 2.6, 4.5, and 8.5 scenarios from 2007 to 2100. The HadGEM2-ES model projections indicate static averages similar to current conditions until the end of the century in the RCP 2.6 scenario. However, in the RCP 4.5 and 8.5 scenarios, there is a continuous increase in ETo, with the most significant increase occurring during the dry period (May to September). The areas of the Amazon biome in the north of Mato Grosso exhibit the largest increases in ETo when comparing the observed (2007–2020) and projected (2020–2100) averages. The trend analysis reveals significant changes in ETo and its variables across the state of Mato Grosso in the RCP 4.5 and 8.5 scenarios. In the RCP 2.6 scenario, significant trends in ETo are observed only in the northern Amazon areas. Despite not being observed in all AWSs, the trend analysis of the observed data demonstrates more intense changes in ETo and the existence of the evapotranspiration paradox, with an increase in the Cerrado areas and reductions in the Pantanal and southern Amazon areas.

The understanding of spatiotemporal variations in reference evapotranspiration (ETo) and its long-term trends is of paramount importance for water cycle studies, modeling, and water resource management, especially in the context of climate change. Therefore, the primary aim of this study is to critically evaluate the performance of various CMIP5 global climate models in simulating the Penman-Monteith reference evapotranspiration and its associated climate variables (maximum and minimum air temperature, incident solar radiation, relative humidity, and wind speed). This evaluation is based on data from nine climate models and 33 automatic meteorological stations (EMA) in the state of Mato Grosso, spanning the period 2007-2020. The statistical metrics used for evaluation include Bias, root mean square error, and Pearson and Spearman correlation coefficients. The projections of the most accurate model were then used to analyze the spatial and temporal changes and trends in ETo under the RCP 2.6, 4.5, and RCP 8.5 scenarios from 2007 to 2100. The HadGEM2-ES model projections indicate static averages similar to current conditions until the end of the century in the RCP 2.6 scenario. However, in the RCP 4.5 and 8.5 scenarios, there is a continuous increase in ETo, with the most significant increase occurring during the dry period (May to September). The areas of the Amazon biome in the north of Mato Grosso exhibit the largest increases in ETo when comparing the observed (2007-2020) and projected (2020-2100) averages. The trend analysis reveals significant changes in ETo and its variables across the state of Mato Grosso in the RCP 4.5 and 8.5 scenarios. In the RCP 2.6 scenario, significant trends in ETo are observed only in the northern Amazon areas. Despite not being observed in all AWSs, the trend analysis of the observed data demonstrates more intense changes in ETo and the existence of the evapotranspiration paradox with an increase in the Cerrado areas and reductions in the Pantanal and southern Amazon areas.

This paper aimed to introduce the GapMET software, developed by the authors, and evaluate the accuracy of its six methods for gap-filling the main meteorological variables monitored by weather station in the state of Mato Grosso, Brazil, using reference time series from neighbour weather station and/or remote sensing products. The methods were tested on seven different databases, with 25 to 80% artificial gaps, and their accuracy was given by the number of gaps left unfilled, the bias, the RMSE, and Pearson’s correlation. The GapMET software showed good results in filling meteorological gaps regardless of the method applied. Methods that use only one neighbour weather station as a reference series showed better results because, in the state, the minimum distance for a weather station to have at least three neighbours as reference was 350 km, reducing the climatic similarity between them and consequently the accuracy when more than one reference series were needed. The use of satellite reference series reduced the probability of unfilled gaps; however, it showed higher bias and RMSE and lower correlations.

Resumo As chuvas intensas é uma variável climática importante no planejamento de obras hidráulicas, sendo usualmente caracterizada pelas curvas de intensidade-duração-frequência (IDF) obtidas de dados pluviográficos. Em locais que não dispõem de estações pluviográficas as curvas IDF podem ser obtidas por métodos de desagregação de chuvas diárias. Assim, esse estudo ajustou os coeficientes de desagregação de chuvas de 1 dia e os parâmetros da equação de Bell no Estado de Mato Grosso e verificou qual método proporciona melhores resultados na estimativa de chuvas de diferentes durações e tempos de retorno. O ajuste dos métodos de desagregação de chuvas de 1 dia e equação de Bell foi realizado pela análise das relações entre as chuvas obtidas das curvas IDF de 14 estações pluviográficas do estado e das séries anuais de chuva máxima diária, nos mesmos locais, ajustados à distribuição generalizada de valores extremos. Devido à baixa frequência de chuvas com duração superior a 360 min, o primeiro coeficiente de desagregação de chuvas obtidos foi de 1 dia em 6 horas (0.53). Os parâmetros médios da equação de Bell (α: 0.19, β1: 0.99, β2: 0.96, β3: 0.99, γ: 0.16) apresentaram ajuste satisfatório com R2 igual 0.88. As raízes dos erros médio quadrático de ambos os métodos variaram de 3.5 mm (chuvas de 10 min) a 18.7 mm (chuvas de 360 min), com um viés inferior a 10%. O ajuste de ambos os métodos foi responsável por reduzir os erros associados quando comparado aos coeficientes nacionais, sendo assim, indicados para a obtenção de chuvas de durações inferiores a 1 dia a partir de dados pluviométricos no Mato Grosso.

Accurately identifying the interactions between large-scale land cover and regional climate in the water balance components is crucial for our understanding of how the transformation of native vegetation into agricultural areas impacts the water cycle. Yet the available regional models to access water balance components are often too complex and typically highly dependent on a large number of inputs and parameters. This inadvertently leads to relatively high uncertainty in the model components and their interactions, undermining their use for identifying controlling factor and mechanisms associated with key hydrological processes. In this work, we address the need for a parsimonious model by introducing the Soil Water Balance Modelling Environment (SWaBME). SWaBME is a novel parsimonious hydrological model used to assess the water balance partitioning of typical land cover types in Brazil, a country that is constantly affected by high rates of deforestation and agricultural expansion. The SWaBME model uses a Penman-Monteith formulation to estimate, separately and explicitly, the evapotranspiration (ET) in the three main components (bare soil evaporation, transpiration, and evaporation from canopy interception), which allow it to distinguish the effects of climate and land cover on the ET. The SWaBME model requires only five parameters to be prescribed a priori, and also contains a set of parameters which are directly provided by the recent development of global georeferenced data products. SWaBME is calibrated by following an alternative approach which evaluates hundreds of thousands of randomly generated parameter sets against observed monthly evapotranspiration and soil moisture data (when available) that are ultimately tested at a pre-defined set of soft rules to ensure model consistency. The model calibration were done individually at 10 flux sites in Brazil,  but we also investigate whether such preferred parameter combinations produce plausible model performances at the country main land-cover and land-use classes: forests, cerrado/woodlands, pasture/grasslands, and soybean and sugarcane crops. From all the parameters combinations, the model was able to satisfactorily retain about 70 to 90% of the sets for forests and cropland biomes, but appears to constrain much more strongly for pasture/grasslands and cerrado biomes with respectively 30% and 1% of the set retained. Most of the introduced soft rules have low to moderate constraining power, and we found that differences in the calibrated parameters for each biome are more pronounced only when the prior information from literature review was used to constrain specific parameters ranges. The performance with the selected parameters showed Root Mean Squared Error of about 20 to 36 mm/month [RR1] at forest and cropland biomes, 23 to 26 mm/month at the cerrado/woodland and 30 to 36 mm/month at pasture/grasslands; ranking slight better when compared to the more complex (in terms of structure and number of parameters) NOAH/GLDAS model with a RMSE ranging from 30 to 60 mm/month. Overall, SWaBME is a parsimonious model aimed at large-scale application of water balance assessment focusing on assessing the impacts of climate and land-use/land-cover changes primarily in Brazil. However, the structure and approach used here can be widely transferred to other regions of the world.

This paper aimed to evaluet the changes in the biophysical parameters and trends of the annual extremes of air temperature in Sinop, Mato Grosso, Brazil, using data from automatic meteorological stations (EMA) installed in the rural and urban areas of the municipality. The estimates of changes in soil use, surface albedo, radiation balance (Rn) and sensible heat (H) and latent heat (LE) were obtained by images from the Landsat 8 and Landsat 5 satellites in August of the years of 2007, 2011 and 2017. With the Rclimdex software, the trends of six extreme indices of the maximum, minimum and mean values of the annual maximum and minimum temperatures were calculated with least squares calibration and statistical significance considering the Fisher test with significance level equal to α: 0.05. It was observed changes in soil use and biophysical parameters like albedo increase and reduction of Rn in the rural area, while in the urban station (UFMT Sinop) occurred inversion of the ration of LE and H. The extreme indexes indicated a tendency of increase in the extreme temperatures in the urban area, being significant the changes in the indices TNx, DTR, Tn90p and Tx90p. In the last decade, with the expansion of the municipality of Sinop-MT, there have been changes in trends of temperature extremes indices, which are attributed to changes in soil use and biophysical parameters.

Intensive rainfall is an important meteorological variable that is of technical interest in hydraulic projects. This study therefore generated Intensity-Duration-Frequency equations (IDF) for 14 weather stations in Mato Grosso State, based on pluviograph analysis. Annual maximum rainfall data regarding 10-to-1440-minute long rainfall events were collected from digitized daily pluviographs. Data adherence to the generalized extreme value distribution (GEV) was checked through the Kolmogorov-Smirnov test at a 20% significance level. Next, the maximum probable rainfall for return periods such as 2, 5, 10, 20, 30, 50 and 100 years was calculated and the IDF equations were adjusted. The performance of the IDF equations was evaluated based on mean absolute error (MAE), root mean square error (RMSE), bias, Willmott's concordance index and Nash-Sutcliffe efficiency index (ENS). Adjusting the IDF equations was only possible for rainfall durations ranging from 10 to 360 min at each station due to the low frequency of longer rainfalls. High variation was present in parameters of the IDF equation and in maximum rainfall intensity between stations. The satisfactory performance of the models, as attested to by statistical indices, allows using IDF equations adjusted for rainfall durations from 10 to 360 min, and return periods from 2 to 100 years, in the regions of the Mato Grosso weather stations.

Avaliou-se a variação espaço-temporal dos parâmetros biofísicos em plantios de Eucalyptus sp, na transição Cerrado-Amazônia Mato-Grossense, por meio de sensoriamento remoto. A área localiza-se no município de Lucas do Rio Verde-MT, sendo composta por talhões de E. urophylla, E. urograndis, mata nativa e solo exposto. As imagens foram adquiridas no site do U. S. Geological Survey referentes aos meses de fevereiro 2015/16 e janeiro 2017 (estação chuvosa) e junho 2015-2017 (estação seca). O Índice de Vegetação da Diferença Normalizada (NDVI), albedo da superfície (α); temperatura da superfície (Ts); Saldo de Radiação (Rn) e evapotranspiração (ET) foram calculados em etapas do modelo R-SSEB. Os plantios de Eucalipto, comparado a floresta nativa, apresentaram aumento de 3% a 4% nos valores de NDVI, Ts, Rn e ET. A exposição de solo provocou aumento do albedo (69% a 109%) e da Ts (14% a 34%) e redução do NDVI (63% a 58%), do Rn (13% a 20%) e da ET (57% a 26%), nos períodos de chuva e seca, respectivamente. Conclui-se que as mudanças no uso e ocupação do solo alteraram os parâmetros biofísicos e a evapotranspiração, sendo estas mais acentuadas em áreas desmatadas do que em áreas com cultivo de Eucalipto.

This paper aimed to analyze the dynamics of the energy budget components: latent heat flux (LE), sensible heat flux (H) and soil heat flux (G), in the Mato Grosso Pantanal. The estimates of LE, H, and G were obtained by the Bowen ratio methods, using data from the micrometeorological tower located in the Baía das Pedras Park of SESC-Pantanal Ecological Resort, for the years 2011 to 2013. The normality of the variables Rn, LE, H and G, were tested by Kolmogorov-Smirnov test at 5% significance, and the seasonal differences of the fluxes were verified by the KruskalWallis test, α = 0.05. LE and H data from the remote sensing products MATMNXFLX and FLDAS_NOAH of the MERRA model was also acquired, and their comparison with the tower data was performed by the statistics of Spearman correlation (r), Mean Absolute Error (MAE), Root Mean Squared Erro (RMSE), bias, and Willmott's Concordance Index (d). It was observed that most of the available energy is used for evapotranspiration (latent heat), followed by sensible heat and soil heat flux. In the rainy season there is an increase in the partition of LE and G and reduction of H. Only the estimates of LE of MATMNXFLX and FLDAS_NOAH products correlate with the data observed in the meteorological tower. It is concluded that the energy partitions have a seasonal behavior and that the MATMNXFLX and FLDAS_NOAH products, after being calibrated, can be used to estimate LE in the Mato Grosso Pantanal.

Objetivou-se avaliar o crescimento inicial de Handroanthus serratifolius (Vahl) S. O. Grose. e Handroanthus ochraceus (Vahl) S.O. Grose. sob telas de sombreamento pretas e coloridas. O trabalho foi desenvolvido no Departamento de Produção Vegetal da UFMT – SINOP, com mudas produzidas seminalmente e transplantadas para vasos com 8 litros de capacidade contendo substrato comercial e fertilizante. O delineamento experimental empregado foi o inteiramente casualizado em esquema fatorial 9 x 2 (coberturas x espécies) com 16 repetições sendo os tratamentos empregados: Pleno sol, telas pretas com 35, 50, 65 e 80%; telas coloridas vermelha, azul e verde 50%; e tela aluminet prata com 50% de retenção da radiação global. As análises dos parâmetros altura, diâmetro do coleto, número de folhas e índice spad foram realizadas a cada 20 dias.