Luciano Teixeira de Oliveira

Application of LIDAR to forest inventory for tree count in stands of Eucalyptus sp

Light Detection and Ranging, or LIDAR, has become an effective ancillary tool to extract forest inventory data and for use in other forest studies. This work was aimed at establishing an effective methodology for using LIDAR for tree count in a stand of Eucalyptus sp. located in southern Bahia state. Information provided includes in-flight gross data processing to final tree count. Intermediate processing steps are of critical importance to the quality of results and include the following stages: organizing point clouds, creating a canopy surface model (CSM) through TIN and IDW interpolation and final automated tree count with a local maximum algorithm with 5 x 5 and 3 x 3 windows. Results were checked against manual tree count using Quickbird images, for verification of accuracy. Tree count using IDW interpolation with a 5x5 window for the count algorithm was found to be accurate to 97.36%. This result demonstrates the effectiveness of the methodology and its use potential for future applications.

Determinação do volume de madeira em povoamento de eucalipto por escâner a laser aerotransportado

The objective of this work was to evaluate the possibility of estimating the diameter at breast height (DBH) with tree height and number data derived from airborne laser scanning (LiDAR, light detection and ranging) dataset, and to determine the timber volume of an Eucalyptus sp. stand from these variables. The total number of detected trees was obtained using a local maxima filtering. Plant height estimated by LiDAR showed a nonsignificant tendency to underestimation. The estimate for DBH was coherent with the results found in the forest inventory; however, it also showed a tendency towards underestimation due to the observed behavior for height. The variable number of stems showed values close to the ones observed in the inventory plots. LiDAR underestimated the total timber volume in the stand in 11.4%, compared to the total volume delivered to the industry. The underestimation tendency of tree height (5% mean value) impacted the individual tree volume estimate and, consequently, the stand volume estimate. However, it is possible to obtain regression equations that estimate DBH with good precision, from the LiDAR plant height derived data. The parabolic model is the one that provides the best estimates for timber volumetric yield of eucalyptus stands.

Fire risk map for the Serra de São Domingos Municipal Park, Poços de Caldas, MG

This study constructed a fire risk map for the Serra de Sao Domingos Municipal Park (SSDMP), southern Minas GeraisSate, Brazil, which harbors Atlantic Forest remnants and endangered species. Geo-processing techniques were used for producing a preliminary risk map for altimetry (a), land slope (e), slope orientation (d), land-use/cover (u) and influence of roads and buildings (i). After, the risk maps were overlaid to produce a structural fire index (SFI)-based risk map for the Park. The SFI was calculated by using the formula SFI = 0,35i + 0,30u + 0,15d + 0,10a + 0,10e. The risks classes were classified as low (0.0-0.9), moderate (1.0 1.9), high (2.0-2.9), very high (3.0-3.9) and extreme (4.0-5.0). All data were processed with 2.5 m base spatial resolution by using the ArcView GIS. According to the SFI calculated, the SSMP area can be divided into the following fire risk zones: Low (0.93%), Moderate (61.77%), High (31.32%), Very High (4.79%) and Extreme (1.19%). The main risk factor is due to the influence of roads and buildings and most fires start due to anthropogenic causes. The low and moderate risk classes comprehend most of the rainforest area. Clearings and grasslands fit mainly the High risk class. The most vulnerable area of SSDMP was the Northern area bordering pasture, crops and eucalypt fields. The SFI map can be a valuable tool for elaborating a fire prevention plan in a small conservation unit when few climate and fire occurrence data are available.

Mapping deciduous forests by using time series of filtered MODIS NDVI and neural networks

Multi-temporal images are now of standard use in remote sensing of vegetation during monitoring and classification. Temporal vegetation signatures (i. e., vegetation indices as functions of time) generated, poses many challenges, primarily due to signal to noise-related issues. This study investigates which methods generate the most appropriate smoothed curves of vegetation signatures on MODIS NDVI time series. The filtering techniques compared were the HANTS algorithm which is based on Fourier analyses and Wavelet temporal algorithm which uses the wavelet analysis to generate the smoothed curves. The study was conducted in four different regions of the Minas Gerais State. The smoothed data were used as input data vectors for vegetation classification by means of artificial neural networks for comparison purpose. A comparison of the results was ultimately discussed in this work showing encouraging results and similarity between the two filtering techniques used.

NDVI Time Series for Mapping Phenological Variability of Forests Across the Cerrado Biome in Minas Gerais, Brazil

The constant threat that natural forests of the world have suffered over the years led to strategies that intend to prevent these from further losses in the near future. The tropical rain forest that exists in northern Brazil is the main concern of preservation, but other areas such as the “Mata Atlântica” have had losses over the years and almost 75 % of its remnants are under threat of deforestation. The main activities that lead to deforestation in the region are the expansion of agricultural frontiers, the extraction of coal and other minerals, timber exploitation, and other anthropogenic activities (Oliveira, 2004). Another area in Brazil that is under threat is the Cerrado Biome in Minas Gerais. The Cerrado biome of tropical South America covers about two million squared kilometres, representing almost 22% of the Brazilian territory. The biome was named due to its predominant vegetation type, a fairly dense woody savannah composed by shrubs and small trees. The term “cerrado” (Portuguese for closed or dense) was probably applied to this vegetation because of the difficulty of traversing it on horseback (Oliveira-Filho et al. 2002). The constant threat to the Brazilian Cerrado has led to the necessity of developing strategies and measures to promote the monitoring and mapping of this biome. The Cerrado has a rich biodiversity but its fragmentation throughout the years caused losses of a number of species from this biome (Oliveira 2004). The Cerrado has many types of phytophysiognomies, these include SemiDeciduous Forests, Deciduous Forests, Cerradao (dense Savanna), Cerrado (Savanna), Floresta Ombrofila and other more specific types of vegetation. In order to prevent further deforestation of this biome, monitoring by means of remote sensing is regarded as an efficient tool. This technique can provide accurate mapping of the occurrence of each phytophysiognomy of the Cerrado Biome and promote efficient monitoring in order to detect changes so legal actions can be taken in due time.

Methodology for planning log stacking using geotechnology and operations research

In view of the need to improve the planning of timber harvest and transportation, with both activities being the most influential in determining the final cost of timber delivered to the mill yard, this work aims to develop a new methodological proposal using operations research and geotechnology tools in order to determine optimal locations for log stacking and also the amountof timber to be allocated to each selected stack. Analysis was performed using two software applications, geographic information system (GIS) and operations research (OR). GIS spatial analyses were based on layers of the study site, which is a property owned by Votorantim Celulose e Papel, located in the municipality of Sao Jose dos Campos, in order to obtain three variables: degree of difficulty in operating forestry equipment, degree of difficulty in log stacking, and distance between log stacks and existing roadways. To obtain these variables, layers containing information on terrain inclination and existing roadways were combined in another analysis named weighted overlay. Results were then filtered and inserted into an operations research environment for maximizationof the timber volume in each selected stack. With results obtained from the geographic information system, 80 potential sites were selected for log stacking. By using operations research, 59 of these sites were ruled out, a 73% reduction in the number of potential sites, with only 21 sites remaining as potentially optimal for log storage. For each of these 21 sites, an optimal amount of timber wasdetermined to be allocated to each one of them.

Influência da idade na contagem de árvores de Eucalyptus sp. com dados de lidar

O presente trabalho foi realizado com o objetivo de analisar a influencia da idade na deteccao automatica de arvores em talhoes de Eucalyptus sp. por meio de dados LIDAR. Foram analisados 3 talhoes com as idades de 3, 5, e 7 anos. Esses talhoes tiveram os dados da nuvem de pontos do LIDAR referentes ao primeiro retorno, divididos em dois estratos verticais, o que gerou duas classes: Classe 1 (nuvem de pontos para toda a vegetacao) e Classe 2 (nuvem de pontos para a vegetacao acima de 10 metros). Os resultados da deteccao do numero de fustes para as duas classes foram comparados com o censo da area por meio de contagem visual em uma imagem de alta resolucao espacial e com dados de inventario florestal. Na comparacao com o censo, encontrouse pouca diferenca entre as idades para o numero de fustes para a Classe 1, sendo mais indicado para as idades de 3 e 5 anos e a Classe 2, apesar de se observar uma tendencia de subestimativa dos valores, e mais indicada para a idade de 7 anos. Quando se comparou com os dados do inventario florestal, observou-se uma coerencia entre o numero de fustes nos dois estratos verticais, desta forma o metodo proposto mostrou-se compativel com o inventario florestal para a intensidade amostral testada, para a obtencao da variavel numero de fustes.