No abstract

Changes resulting from land use and occupation modify the surface radioactive balance. This paper evaluated the impact on the net radiation caused by the conversion of a Cerrado area in an agricultural zone in the southern Mato Grosso using Landsat 5 TM sensor imagery acquired between June and October 2011. The analyses were performed of the following land use classes: Cerrado, riparian vegetation, sugarcane, soybean, pasture, bare soil and water. The replacement of Cerrado by agricultural areas changed the biophysical indices of the surface due to the change in biomass and the optical properties of the surface as observed in this study. The NDVI values were higher in the typical Cerrado vegetation and Riparian Forest than in agricultural areas. The surface temperature and the surface albedo showed an inverse pattern of NDVI, with lower values in the typical Cerrado vegetation and Riparian Forest and higher values in agricultural areas and bare soil. The replacement of Cerrado by cultivated crops in the south of Mato Grosso decreased the available energy at the surface, as indicated by the radiation balance.

ResumoO Pantanal apresenta períodos de inundação que modelam a paisagem e atuam como filtro ao estabelecimento e desenvolvimento de plantas. Perturbações antrópicas ou naturais podem alterar a distribuição da energia disponível no ecossistema. Diante da necessidade de compreensão da variabilidade temporal do balanço de energia em paisagens naturais inundáveis, o objetivo deste estudo foi analisar a sazonalidade do balanço de energia em área arbustiva alagável composta por Combretum lanceolatum Pohl no Pantanal Mato-grossense. As estimativas do fluxo de calor latente (LE) e sensível (H), e da evapotranspiração (ET) foram obtidas pelo método da razão de Bowen entre maio de 2012 e abril de 2013. A energia disponível foi destinada prioritariamente ao LE (64,1%), seguido ao H (35,8%) e quase zero ao fluxo de calor no solo (0,1%). Os componentes do balanço de energia apresentaram forte sazonalidade, com maior LE durante a estação chuvosa e maior H durante a estação seca. A evapotranspiração foi menor durante a estação seca devido ao baixo conteúdo de água no solo e transpiração da vegetação dominante na área de estudo. Os resultados obtidos nesse trabalho sugerem que o ambiente estudado é limitado pela disponibilidade de energia e água. Palavras chave: distribuição de energia, microclima, Combretum lanceolatum, áreas úmidas. Seasonality of Energy Balance and Evapotranspiration in a FloodedScrubland in the Pantanal of Mato Grosso AbstractThe Pantanal has flood periods that model the landscape and act as a filter to the establishment and development of plants Anthropogenic or natural disturbances can alter the available energy distribution in the ecosystem. Due to the need of understanding the temporal variability of the energy balance in flood natural landscapes, the objective of this study was to analyze the seasonality of the energy balance in flooded shrub area consisting of Combretum lanceolatum Pohl in Mato Grosso Pantanal. The estimates of latent (LE) and sensible (H) heat flux, and evapotranspiration (ET) were obtained by the method of Bowen ratio between May 2012 and April 2013.The available energy was intended primarily to LE (64.1%), followed by H (35.8%) and almost zero to heat flow in soil (0.1%). The components of the energy balance showed strong seasonality, with highest LE in the wet season and highest H in the dry season. The evapotranspiration was lower during the dry season due to the lower soil water content and transpiration of dominant vegetation in the study area. Results suggest that the study area was limited by the availability of energy and water.

A conversão da vegetação nativa para áreas agrícolas modifica a dinâmica de troca de energia no sistema soloplanta-atmosfera. Dessa forma, o objetivo deste estudo foi avaliar o efeito da conversão de uma área de Cerrado em culturas agronômicas no balanço de energia e evapotranspiração no sul do Estado de Mato Grosso. O estudo foi conduzindo em áreas de cerradão, cerrado stricto sensu, mangueiral, cultura de teca, coqueiral e pastagem. Energy Balance in Terms of Land Use Changes in the Southern of Mato Grosso State AbstractThe conversion of native vegetation to agricultural areas modifies the dynamics of energy exchange in the soil-plantatmosphere system. Thus, the objective of this study was to evaluate the effect in energy balance and evapotranspiration in the southern state of Mato Grosso due to the conversion of a Cerrado area in agronomic crops. The study was leading in areas of Cerradão, Cerrado strictu sensu, mango grove, teak culture, coconut trees and pasture. The energy balance was estimated by SEBAL (Surface Energy Balance Algorithm for Land) using weather station data and images from Landsat 5 TM sensor obtained in 2010. The net radiation showed lower values in pasture than in the Cerrado. The latent heat flux in the Cerrado was higher by 60% in relation to agronomic crops. The sensible heat flux in agricultural areas were 50% higher than Cerrado areas. The Cerradão and Mangueiral showed lower heat flux values on the ground. Although this study does not represent the entire Cerrado of Mato Grosso, the results showed the impact of the Cerrado into agricultural areas in the energy balance.

The determination of the surface energy balance fluxes (SEBFs) and evapotranspiration (ET) is fundamental in environmental studies involving the effects of land use change on the water requirement of crops. SEBFs and ET have been estimated by remote sensing techniques, but with the operation of new sensors, some variables need to be parameterized to improve their accuracy. Thus, the objective of this study is to evaluate the performance of algorithms used to calculate surface albedo and surface temperature on the estimation of SEBFs and ET in the Cerrado-Pantanal transition region of Mato Grosso, Brazil. Surface reflectance images of the Operational Land Imager (OLI) and brightness temperature (Tb) of the Thermal Infrared Sensor (TIRS) of the Landsat 8, and surface reflectance images of the MODIS MOD09A1 product from 2013 to 2016 were combined to estimate SEBF and ET by the surface energy balance algorithm for land (SEBAL), which were validated with measurements from two flux towers. The surface temperature (Ts) was recovered by different models from the Tb and by parameters calculated in the atmospheric correction parameter calculator (ATMCORR). A model of surface albedo (asup) with surface reflectance OLI Landsat 8 developed in this study performed better than the conventional model (acon) SEBFs and ET in the Cerrado-Pantanal transition region estimated with asup combined with Ts and Tb performed better than estimates with acon. Among all the evaluated combinations, SEBAL performed better when combining asup with the model developed in this study and the surface temperature recovered by the Barsi model (Tsbarsi). This demonstrates the importance of an asup model based on surface reflectance and atmospheric surface temperature correction in estimating SEBFs and ET by SEBAL.

No abstract

The morphometric analysis provides information on the hydrological response of the hydrographic basins regarding the aspects of maintenance, susceptibility to erosion and flooding that can support the planning and implementation of use and conservation measures. Thus, the objective was to understand the relationships between morphometric aspects, anthropic actions (land use and cover) and the conservation of the hydrographic basin of the Montividiu River, located in the southwest of the state of Goiás, Brazil. This hydrographic unit is the main source of water for public supply to the urban population of the municipality of Montividiu, in addition to being a water source for several irrigation projects for agricultural production. The study was carried out using the Shuttle Radar Topography Mission (SRTM) model, specific mathematical equations, Sentinel-2 image and Geographic Information System (GIS). It was observed: from the geometric results (Kc = 2.18, Kf = 0.13 and Ic = 0.21), an elongated structural arrangement that favors the conservation of the hydrographic basin, due to the reduced propensity to flooding; predominance of smooth wavy (49.05%) and flat (37.66%) reliefs, followed by wavy (12.96%) and strong wavy (0.33%); low drainage density with reduced number of river channels and highly permeable soil (Cm = 2,012 m².m-1, Dd = 0,49 km.km-2 and Eps = 1,006 km); and high altimetric amplitude (360 m). From the joint analysis of the morphometric characteristics and land use and coverage, in which there is a predominance of agricultural areas, followed by the category of native vegetation and others, it is emphasized that anthropic actions must be aligned with modern management and conservation practices from soil.Keywords: anthropic actions, geotechnologies, water resources, morphometric variables. Inteligência geoespacial aplicada à análise de aspectos morfométricos e do uso e cobertura da terra de uma bacia hidrográfica no Cerrado brasileiroR E S U M O A análise morfométrica fornece informações sobre a resposta hidrológica das bacias hidrográficas quanto aos aspectos de manutenção do corpo d’água, susceptibilidade à erosão e inundação que podem subsidiar o planejamento e implementação de medidas de uso e conservação. Assim, objetivou-se compreender as relações entre aspectos morfométricos, ações antrópicas (uso e cobertura da terra) e a conservação da bacia hidrográfica do Rio Montividiu, localizada no Sudoeste do estado de Goiás, Brasil. Essa unidade hidrográfica é a principal fonte de água para o abastecimento público da população urbana do município de Montividiu, além de ser fonte hídrica de diversos projetos de irrigação para a produção agropecuária. O estudo foi realizado por meio do modelo Shuttle Radar Topography Mission (SRTM), equações matemáticas específicas, imagem Sentinel-2 e Sistema de Informação Geográfica (SIG). Observou-se: a partir dos resultados geométricos (Kc = 2,18, Kf = 0,13 e Ic = 0,21), um arranjo estrutural alongado que favorece a conservação da bacia hidrográfica, devido a reduzida propensão a enchentes; predominância de relevos suave ondulado (49,05%) e plano (37,66%), seguidos de ondulado (12,96%) e forte ondulado (0,33%); baixa densidade de drenagem com reduzido número de canais fluviais e solo altamente permeável (Cm = 2.012 m².m-1, Dd = 0,49 km.km-2 e Eps = 1,006 km); e alta amplitude altimétrica (360 m). A partir da análise conjunta das características morfométricas e do uso e cobertura da terra, no qual há predominância de áreas agrícolas, seguidas da categoria de vegetação nativa e outras, ressalta-se que as ações antrópicas devem ser alinhadas com modernas práticas de manejo e conservação do solo.Palavras-chave: ações antrópicas, geotecnologias, recursos hídricos, variáveis morfométricas.

O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. Conselho Editorial Ciências Humanas e Sociais Aplicadas