Helena Maria Ramos Alves

Forecast of coffee crop productivity by harmonic analysis, using the Fourier series in Minas Gerais State, Brazil

The objective of this work was to obtain a forecast model of coffee crop productivity in seven municipal districts of Minas Gerais State, Brazil. The harmonic analysis in Fourier series was applied on productivity series to each location. The obtained coefficients until the harmonic seventh were submitted to multiple linear regression in the first three principal components of a group of 33 inherent variables of coffee production. These variables were averages of 15 years corresponding to the same years of productivity and subdivided in four quarterly periods during the agricultural year (July to June). The model did not prove adequate, since the results presented errors of estimatives with great discrepancies evidencing the complexity of yield forecast of coffee crop.

ANÁLISE DA FRAGMENTAÇÃO FLORESTAL DA ÁREA DE PROTEÇÃO AMBIENTAL COQUEIRAL, COQUEIRAL – MG

This study analysed the forest fragmentation of Coqueiral Environmental Protected Area (APA Coqueiral), located in Coqueiral, South region of Minas Gerais state, Brazil. The objective was to evaluate the forest fragmentation of Coqueiral APA, using landscape metrics, as well as, elaborating landscape simulation models to provide future scenarios of ecological restoration, and then, to compare these simulations to the current landscape. Land use analyses were carried out through Geographic Information Systems and Remote Sensing techniques, using a SPOT 5 satellite image (SPOTMAP). Forest fragmentation was analysed by FRAGSTATS software for calculating landscape metrics such as: area, perimeter, shape, and, patch connectivity. We performed 1 and 5 m buffers maps, and a virtual restoration of the Permanent Protected Areas (APP) for landscape simulations. Landscape fragmentation analyses showed that natural vegetation is distributed within 360 patches, being 137 of them smaller than 1 ha. Landscape simulation models revealed that natural vegetation has increased from 1943.13 ha to 2299.02 ha in the restored APP simulation (natural vegetation/restored APPs = VA). The average patch size increased from 7.66 m to 15.75 m in the same simulation in comparison to the current landscape. VA showed a smaller shape value (1.93), indicating that patch shape is simpler in this simulation. This is an important result from the conservation point of view, because as simpler a shape of a patch is, smaller the edge effect is. Isolation values were not statistically different in the simulations: 38.9 m (VN); 40.64 m (VB1); 42.89 m (VB5) e 39.75 m (VA), what indicates low isolation between patches, even in the current landscape. Connectivity index was high (99%) for all simulations, indicating that landscapes have high structural connectivity. These data are relevant inputs to decision makers and to a better planning and management of the APA Coqueiral, allowing us to indicate the priority areas for conservation in this natural reserve.

Mapeamento preliminar de solos com horizonte B textural e B nítico na região de Lavras, MG

Estudos de caracterizacao de solos e estabelecimento de relacoes entre pedologia, geologia e geomorfologia permitem a elaboracao de modelos preditivos da distribuicao dos solos na paisagem. Objetivou-se, com o presente trabalho, estudar estas relacoes, com a finalidade de representar a distribuicao de solos com horizonte B textural e B nitico na paisagem da regiao de Lavras, MG, por intermedio da geracao de mapa preliminar de solos, utilizando tecnicas de geoprocessamento. Os estudos foram realizados em solos com horizonte B textural e B nitico, uma vez que esses solos apresentam caracteristicas relacionadas a variacao da composicao geoquimica das rochas igneas de origem, refletindo-se em varios atributos dos solos, enfatizando a cor e o teor de Fe2O3. Foram realizadas campanhas de campo com avaliacoes morfologicas, fisicas e quimicas de perfis de solos representativos, desenvolvidos a partir de unidades geologicas de composicoes geoquimicas distintas, estabelecendo as relacoes pedogeologicas. Verificou-se, tambem, a distribuicao dos solos na paisagem, com o estabelecimento das relacoes pedogeomorfologicas. Foi constatado que tais solos sao desenvolvidos na regiao em relevo caracterizado por classes de declividade de 12 a 45%, originando diferentes classes de solos com horizonte B textural e B nitico, diretamente relacionados a variacao do material de origem. Os criterios estabelecidos nas relacoes entre pedologia, geologia e geomorfologia permitiram avaliar a distribuicao dos solos na paisagem estudada e a geracao do mapa preliminar de solos, com individualizacao de solos com horizonte B textural e B nitico.

Digital Terrain Models Derived from SRTM Data and Kriging

The objective of this work is to define procedures to improve spatial resolution of SRTM data and to evaluate their applicability in the Serra Negra region, in the district of Patrocinio, state of Minas Gerais in Brazil. The region’s structure is a result of past tectonic processes that have arched it into a dome shape. Besides the already existing agriculture exploitation, Serra Negra also has strong tourism and mining potential. The Digital Elevation Model (DEM) was done using different interpolation methods in a resolution of 30 meters or 1 arcsec, among them kriging, ideally used to manipulate random spatial variations due to its capacity for dealing with spatially variable components. The accuracy of the resulting DEM and slope maps modelled were evaluated based on slope measured in the field. The correlation coefficients were determined from the field data and those derived from the DEM. Analyses and tests with SRTM data, divulged for South America are presented to better adequate the model to the study area. The correlation coefficients in the estimates by kriging and by bicubic interpolator were similar, with a slight difference in favour of kriging. Therefore, kriging is an interesting alternative in elaborating Digital Elevation Models that are in keeping with the dome structure of the Serra Negra region. In order to measure operational aspects of the pre-processing methods, the study area data were prepared under a resolution of 30 meters and evaluated through statistical analysis and visualizations of the DEMs and slope. The data presented strong restrictions to being used in their original form due to the low spatial resolution. However, the pre-processing allows their use in relatively detailed scales. Based on the results, a proposal for the development of a DEM with the SRTM data for the Serra Negra region is presented.