Random forest for spatialization of daily evapotranspiration (ET0) in watersheds in the Atlantic Forest.

The importance of daily data on reference evapotranspiration (ET0) has increased in recent years due to its relevance in planning and decision making regarding irrigated agriculture, water production, and forest restoration. Facing the scarcity of this information measured in loco, the study of interpolation methods capable of representing ET0 becomes important. Therefore, this study aimed to evaluate the adequacy of the Random Forest (RF) method in the spatialization of ET0 in the watersheds of the Mid-South region of the Espírito Santo State, located within the Atlantic Forest biome, Brazil. From this study, it was found that the RF method is the most suitable one for ET0 spatialization when compared to the Angular distance weighting (ADW) and the inverse distance weighting (IDW) techniques. Also, the spatializations carried out by this method were transformed into databases in a grid format and made available online. Furthermore, the RF database was also compared to other ET0 grid databases, and it was concluded that the RF database also carried out a better performance than the other ones.

Selecting models for the estimation of reference evapotranspiration for irrigation scheduling purposes.

Alternative models for the estimation of reference evapotranspiration (ETo) are typically assessed using traditional error metrics, such as root mean square error (RMSE), which may not be sufficient to select the best model for irrigation scheduling purposes. Thus, this study analyzes the performance of the original and calibrated Hargreaves-Samani (HS), Romanenko (ROM) and Jensen-Haise (JH) equations, initially assessed using traditional error metrics, for use in irrigation scheduling, considering the simulation of different irrigation intervals/time scales. Irrigation scheduling was simulated using meteorological data collected in Viçosa-MG and Mocambinho-MG, Brazil. The Penman-Monteith FAO-56 equation was used as benchmark. In general, the original equations did not perform well to estimate ETo, except the ROM and HS equations used at Viçosa and Mocambinho, respectively. Calibration and the increase in the time scale provided performance gains. When applied in irrigation scheduling, the calibrated HS and JH equations showed the best performances. Even with greater errors in estimating ETo, the calibrated HS equation performed similarly or better than the calibrated JH equation, as it had errors with greater potential to be canceled during the soil water balance. Finally, in addition to using error metrics, the performance of the models throughout the year should be considered in their assessment. Furthermore, simulating the application of ETo models in irrigation scheduling can provide valuable information for choosing the most suitable model.

Prognoses of diameter and height of trees of eucalyptus using artificial intelligence.

Models of individual trees are composed of sub-models that generally estimate competition, mortality, and growth in height and diameter of each tree. They are usually adopted when we want more detailed information to estimate forest multiproduct. In these models, estimates of growth in diameter at 1.30m above the ground (DBH) and total height (H) are obtained by regression analysis. Recently, artificial intelligence techniques (AIT) have been used with satisfactory performance in forest measurement. Therefore, the objective of this study was to evaluate the performance of two AIT, artificial neural networks and adaptive neuro-fuzzy inference system, to estimate the growth in DBH and H of eucalyptus trees. We used data of continuous forest inventories of eucalyptus, with annual measurements of DBH, H, and the dominant height of trees of 398 plots, plus two qualitative variables: genetic material and site index. It was observed that the two AIT showed accuracy in growth estimation of DBH and H. Therefore, the two techniques discussed can be used for the prognosis of DBH and H in even-aged eucalyptus stands. The techniques used could also be adapted to other areas and forest species.

Qualidade da água de nascentes do Assentamento Paraíso / Quality of the water from the springs of the Paraíso settlement

RESUMO Este estudo teve por objetivo avaliar a influência de diferentes usos do solo no entorno de nascentes sobre alguns parâmetros de qualidade das águas de oito nascentes localizadas no Assentamento Paraíso, Alegre, Espírito Santo. As nascentes avaliadas consistiram em uma em meio à floresta remanescente de Mata Atlântica; seis cercadas e em diferentes estágios de recomposição florestal; e uma sem cerca e com acesso livre dos animais de criação. Três amostras de água foram coletadas em cada nascente entre 2011 e 2012, sendo analisados 17 parâmetros. Os valores determinados foram comparados com os padrões normativos para qualidade da água e correlacionados linearmente por meio do coeficiente de correlação. As águas das nascentes se mostraram aptas para o consumo, desde que previamente tratadas, e, quanto maior foram os trabalhos de proteção às nascentes, melhores foram os valores de qualidade de água.

ABSTRACT The objective of this study was to evaluate the influence of land use in the surrounding of the springs on some of the parameters of water quality in eight springs located in the Paraíso settlement in the city of Alegre, Espírito Santo, Brazil. The springs evaluated were: one in the Atlantic forest remnant; six fenced ones and in different stages of forest recovery; and one without a fence and with free livestock access. Three samples of water were collected in each spring in 2011 and 2012, and 17 parameters were analyzed. The determined values were compared to the normative standards for water quality and linearly correlated through the correlation coefficient. Water from the springs showed to be consumable, if previously treated, and the more protected the springs, the better the water quality values.