Evaldo de Paiva Lima

Geotecnologias aplicadas à avaliação de parâmetros biofísicos do Pantanal

The objective of this work was to evaluate surface biophysical parameters of the Pantanal biome, Brazil, by the application of geotechnologies. The Sebal algorithm, Modis imagery, and land use and land cover map were used. The obtained results for NDVI, surface temperature, albedo, daily sensible heat flux, daily net radiation and daily actual evapotranspiration were consistent with literature data for the different land use and land cover classes, and corroborate the analytical and synoptic capacity of Sebal estimates. These results show the potential of geotechnologies in the implementation of models or algorithms developed for the understanding of biophysical process dynamics related to the soil‑plant‑atmosphere interactions in Pantanal.

Geoestatística no estudo de modelagem temporal da precipitação

Geostatistics analysis is a powerful tool which has been used in studies of spatial dependence. With respect to the temporal dependence, few analysis are performed with this kind of methodology. In this study, the geostatistics technique was used to adjust a model to a series of temporal values of precipitation and its performance to predict data was also evaluated. The study was carried out at the Rio Itapemirim Basin in a series of monthly precipitation from 1940 to 2006. The adjusted model was compared to the Box and Jenkins model. The best geostatistics model adjusted was the one which used with 96 neighbors in the prediction and mean relative absolute error of 80.46. Geostatistics methodology showed better results for estimating the monthly precipitation in relation to the SARIMA model (2,1,1)(0,1,1)12.

Sazonalidade do saldo de radiação em duas sub-bacias do Paracatu por meio da utilização de produtos do sensor modis

The net radiation (Rn) represents the main source of energy for physical and chemical processes that occur in the surface-atmosphere interface, and it is used for air and soil heating, water transfer, in the form of vapor from the surface to the atmosphere, and for the metabolism of plants, especially photosynthesis. If there is no record of net radiation in certain areas, the use of information is important to help determine it. Among them we can highlight those provided by remote sensing. In this context, this work aims to estimate the net radiation, with the use of products of MODIS sensor, in the sub-basins of Entre Ribeiros creek and Preto River, located between the Brazilian states of Goias and Minas Gerais. The SEBAL (Surface Energy Balance Algorithm for Land) was used to obtain the Rn in four different days in the period of July to October, 2007. The Rn results obtained were consistent with others cited in the literature and are important because the orbital information can help determine the Rn in areas where there are not automatic weather stations to record the net radiation.

Mercury contamination in the sludge of drinking water treatment plants dumping into a reservoir in Rio de Janeiro, Brazil

Although sludge piles from drinking water treatment plants can contain harmful substances, in many countries, their disposal methods are still unregulated. Besides aluminum, which is a major constituent in these residues, many other contaminants—like trace metals—can be present and may result from the quality of the raw materials used for water treatment. The application of these chemicals for the treatment of drinking water can generate toxic sludge and contaminate the produced water. In the present work, mercury contamination in the sludge piles of two drinking water treatment plants located along the margins of the Juturnaíba Reservoir, Southeast Brazil, was evaluated to verify whether contaminants are incorporated during water treatment. In the summer 2012, five cores were collected from the piles, and were analyzed for Eh, granulometry, total carbon, total nitrogen, and total mercury. The results indicated an anoxic environment, reflecting composition of the suspended matter. Carbon and nitrogen presented elevated concentrations, but also seemed to reproduce the characteristics of the suspended matter in the raw water. The concentrations of mercury were extremely variable but presented unexpectedly high values in some of the layers, reaching 18,484 ng g−1. On the other hand, concentrations ten times lower than those observed in the natural system (8 ng g−1) could be observed. It was concluded that the only possible source for the contamination of the sludge was the chemicals used for water treatment.

Evapotranspiração real diária em sub-bacias do Paracatu, utilizando produtos do sensor Modis 1

Daily actual evapotranspiration in sub-basins of Paracatu using Modis sensor products Evapotranspiration defines the total loss of water from the soil-plant system to the atmosphere. In agricultural areas, particularly under some form of irrigation, the remote sensing-based determination of evapotranspiration is gaining increasing importance, since it provides a measure of water use ef ficiency. In this context, this study aimed to estimate the daily actual evapotranspiration (ETr) using MODIS sensor products in the sub-basins of Entre Ribeiros creek and Preto river, between the states of Goias and Minas Gerais. The Surface Energy Balance Algorithm for Land (SEBAL) was used to obtain the ETr in four different days from July to October, 2007. The results were consistent with other reports in the literature and the comparison between the evapotranspiration by SEBAL and crop evapotranspiration (ETc) showed that this algorithm can be a good option to estimate the daily evapotranspiration using MODIS sensor products in the conditions of the sub-basins of Entre Ribeiros creek and Preto river .