Heinrich Hasenack

Decision trees for digital soil mapping on subtropical basaltic steeplands

When soil surveys are not available for land use planning activities, digital soil mapping techniques can be of assistance. Soil surveyors can process spatial information faster, to assist in the execution of traditional soil survey or predict the occurrence of soil classes across landscapes. Decision tree techniques were evaluated as tools for predicting the ocurrence of soil classes in basaltic steeplands in South Brazil. Several combinations of types of decicion tree algorithms and number of elements on terminal nodes of trees were compared using soil maps with both original and simplified legends. In general, decision tree analysis was useful for predicting occurrence of soil mapping units. Decision trees with fewer elements on terminal nodes yield higher accuracies, and legend simplification (aggregation) reduced the precision of predictions. Algorithm J48 had better performance than BF Tree, RepTree, Random Tree, and Simple Chart.

Mamíferos carnívoros e sua relação com a diversidade de hábitats no Parque Nacional dos Aparados da Serra, sul do Brasil

Carnivore mammals and their relation with habitat diversity in Aparados da Serra National Park, southern Brazil. A survey of carnivore mammals was accomplished in Aparados da Serra National Park from February 1998 to March 2000. The park has 10,250 ha and is considered a biodiversity core area of the Atlantic Forest Biosphere Reserve in the Rio Grande do Sul State, Brazil. The landscape is characterized by relatively well preserved relicts of Araucaria angustifolia (Bertol.) Kuntze forest, grasslands and Atlantic Forest, which have contributed for the survival of endangered carnivore mammals. The National Park was divided in a grid of 16 km 2 cells using a 1:50,000 scale map. The animals were recorded using indirect methods, by identifying signs (scats, tracks) and direct observation in 2.5 km long and 5 m wide transects, with 10 replicates in each grid cell. Interviews with local people were also used to confirm the animal presence. A total of 13 species was recorded: Procyon cancrivorus (Cuvier, 1798), Pseudalopex gymnocercus (G. Fischer, 1814), Leopardus pardalis (Linnaeus, 1758) and Cerdocyon thous (Linnaeus, 1766) were the most frequent species registered. Nasua nasua (Linnaeus 1766), Herpailurus yaguarondi (Lacepede, 1809), Chrysocyon brachyurus (Illiger, 1815), Eira barbara (Linnaeus, 1758), Leopardus sp., Puma concolor (Linnaeus, 1771), Galictis cuja (Molina, 1782), Conepatus chinga (Molina, 1892) and Lontra longicaudis (Olfers, 1818) showed lower frequencies. The Park presented areas with significant differences (Mantel Test, P< 0.05) in species richness and composition related to habitat classes. Areas with high habitat richness presented high species richness. The Araucaria forest was the habitat that presented the higher carnivore richness. The border areas of the Park are influenced by several environmental degradation factors that could be affecting the distribution of carnivores.

Traffic Crashes and Alcohol Outlets in a Brazilian State Capital

Objective: Restricting alcohol outlets is being considered as a measure for preventing alcohol-related crashes. However, in many developing countries, alcohol availability is not regulated and its influence on motor vehicle traffic crashes is unknown. This study explores the association between traffic crashes and alcohol outlets in a Brazilian city. Method: Data were geocoded and exploratory analysis was conducted using the kernel density estimator. Two generalized additive models (GAMs) were implemented to predict the factors associated with alcohol-related crashes. Results: For 78 percent of the 3840 traffic crashes where the driver was a victim, there was at least one bar located within a 300-m radius. The median distances between an outlet were 124.4 and 130.7 m for a non-alcohol- and alcohol-related crashes, respectively (P =.13). The GAMs did not make evident any significant association between the outlet locations and alcohol-related crashes: the presence of at least one outlet was associated with alcohol-related crashes with an odds ratio (OR) of 0.94 (95% confidence interval [CI] = 0.75–1.17). Alcohol crashes are more likely to be observed among males (OR = 1.58; 95% CI = 1.21–2.06), young drivers vs. those aged 50 years+ (OR = 3.4; 95% CI = 1.79–6.43), and crashes with fatalities (OR = 1.73; 95% CI = 0.98–3.04). Conclusions: Density of alcohol outlets was high all over the city and both alcohol- and non-alcohol-related crashes occurred near an outlet. The study helps to better understand the relationship between alcohol availability and traffic crashes in a middle-income country where licensing/zoning is absent and suggests that measures for restricting the physical availability of alcohol are necessary, even though further studies are still needed.

Prediction of soil orders with high spatial resolution: response of different classifiers to sampling density

O objetivo deste trabalho foi avaliar a densidade de amostragem na acuracia de predicao de ordens de solos, com alta resolucao espacial, em area viticola da Serra Gaucha. Para isso, utilizou-se modelo digital de elevacao (MDE) do terreno, base cartografica, mapa convencional de solos e o programa Idrisi. Sete variaveis preditoras foram calculadas e lidas junto com as classes de solo, em pontos aleatoriamente distribuidos, nas densidades de 0,5, 1, 1,5, 2 e 4 pontos por hectare. Os dados foram usados para treinar uma arvore de decisao (Gini) e tres redes neurais artificiais: teoria da ressonância adaptativa, fuzzy ARTMap; mapa auto‑organizavel, SOM; e perceptron de multiplas camadas, MLP. Os mapas estimados foram comparados com o mapa de solos convencional para calcular erros de omissao e de inclusao, exatidao geral, e erros de quantidade e de alocacao. A arvore de decisao foi menos sensivel a densidade de amostragem e apresentou maior acuracia e consistencia. O SOM foi a rede neural com menor sensibilidade e maior consistencia. O MLP apresentou minimo critico e maior inconsistencia, enquanto fuzzy ARTMap apresentou maior sensibilidade e menor acuracia. Os resultados indicam que densidades de amostragem usadas em levantamentos convencionais podem servir de referencia para estimar ordens de solos na Serra Gaucha.

Sistema de informação geográfica como apoio ao levantamento detalhado de solos do Vale dos Vinhedos

This study proposes the use of geotechnologies to support detailed soil surveys, from field surveys to the delimitation of mapping units and later the drawing of the final map. The study area corresponds to a topographic map on a scale of 1:5,000 of the Vale dos Vinhedos, in the Serra Gaucha region, State of Rio Grande do Sul, Brazil. The material used consists of planialtimetric data derived from aerial photographs, navigation GPS (Global Positioning System), and GIS (Geographical Information System) software. The GIS program was used to integrate field data with cartographic information and with a DTM (Digital Terrain Model). Results show that the methodology can generate a georreferenced digital map in which soil mapping units are strongly associated with relief phases, improving the consistency and reliability as well as making the use in further applications easier.

Composition of mixed-species bird flocks in forest fragments of southern Brazil

The present study aimed to evaluate the composition of mixed-species bird flocks in a fragmented landscape of the Atlantic Forest in southern Brazil. We recorded 117 species in 218 mixed-species flocks. The correspondence analysis showed two distinct groups of fragments according to degree of connectivity with other fragments. The percentage of original cover surrounding a sampled fragment area up to a ratio of 2.5 and 1 km was the variable that presented highest correlation with the formation of different composition of mixed-species bird flocks, followed by altitude. Based on these results, we concluded that, in landscapes with low levels of fragmentation, the composition of mixed flocks reflects the local species pool. Thus, future studies comparing composition of mixed-specie flocks should concentrate their efforts in areas where some of these variables remain constant, as for example where fragments are at similar altitudes.

Forest–grassland biodiversity hotspot under siege: land conversion counteracts nature conservation

Abstract We report extent and rate of land use/land cover change in a forest–grassland mosaic of Rio Grande do Sul, Brazil, during a recent period of increasing conflicts between native habitat protection and conversion. The area is part of the Atlantic rain forest biome, a Global Biodiversity Hotspot. Analyzing Landsat and Google Earth imagery, and calculating an effective conservation risk index () as ratio of converted to remnant area, we specifically compared the effectiveness of designated fully protected areas (-s) and Sustainable Use areas (-s) in preventing conversion of native forest and grassland habitats for agri- and silviculture, relative to areas outside. Grassland area decreased by 17%, corresponding to a net loss of 59,671 ha, in the entire area. Forest gains exceeded losses, and was zero inside Full Protection s. Non-native tree plantation area increased by 94% over the entire study area; cropland increased by 7%. Conversion for silviculture predominated outside the designated s and conversion for agriculture predominated inside the designated s. was generally higher for grassland than forest, and in -s, grassland was several times higher than in areas without any protection status. These developments are in stark contrast to the high standards of the Brazilian protected area system and corresponding International Union for Conservation of Nature and Natural Resources categories. They are due to protracted regularization of land conversion and establishment of designated protection areas. Furthermore, they reveal the dilemma of previously managed grasslands in strictly protected areas being eventually succeeded by forest, and the hazards of broad interpretation of the term “sustainable development”.

GIS as a Support to Soil Mapping in Southern Brazil

Traditional soil surveys follow a specific methodology to identify, characterize, and fit mapping units in a classification system and to spatialize them in order to produce soil maps. The need for observation and characterization on field, associated with the physical and chemical analyses, makes the surveys expensive and therefore scarce. The low number of surveys stimulated the development of models for digital soil mapping, whose results proved to be possible to predict and spatialize many soil characteristics. However, conventional soil surveys remain important as a basis for the development of digital soil mapping models, setting a reason to continue the development of methodologies to improve the conventional surveys. Technologies like GPS and GIS contribute to make field observation and soil sampling more objective and make the mapping process and the production of hardmaps easier and faster. The objective of this study was to develop methodologies to integrate cartographic base elements with field work, using GIS and GPS in an area corresponding to 20 topographic charts in scale 1:50,000 in the State of Rio Grande do Sul, Southern Brazil, to obtain soil mapping based on the Brazilian Soil Classification System. The result obtained was a georeferenced digitized soil map, continuous for the whole region, free of inconsistency among neighbor map sheets and with attributes associated with the mapping units. These characteristics allow the use and application of the soil map for many purposes like zoning, diagnosis, suitability analysis as well as serving as a basis to the development of models for digital soil mapping.

Caracterização de mapas legados de solos: uso de indicadores em mapas com diferetens escalas no Rio Grande do Sul

Mapas convencionais de solos tem adquirido importância crescente como entrada para diversas aplicacoes, muitas vezes sem levar em conta a sua qualidade deles. O objetivo deste estudo foi descrever e comparar mapas de solos usando indicadores quantitativos de facil determinacao. Foram utilizados nove mapas elaborados em diferentes escalas no Rio Grande do Sul e o software ArcGIS. Calcularam-se a escala efetiva, o numero de poligonos menores que a area minima mapeavel e um indice de complexidade de forma, e quantificaram-se o numero de classes taxonomicas, de tipos de solos e de unidades de mapeamento e a fracao da area com dados nao uniformes. Os resultados evidenciaram que a qualidade de mapas de solos tende a ser inferior ao presumido para sua escala de apresentacao, o que demonstra a importância e a necessidade de avaliacoes previas ao seu uso. Indicadores computados a partir dos poligonos e da legenda possibilitam avaliacao rapida e objetiva, com potencial de aplicacao na sistematizacao e documentacao de dados legados de solos no Brasil.

Identification of foot and mouth disease risk areas using a multi-criteria analysis approach

Foot and mouth disease (FMD) is a highly infectious disease that affects cloven-hoofed livestock and wildlife. FMD has been a problem for decades, which has led to various measures to control, eradicate and prevent FMD by National Veterinary Services worldwide. Currently, the identification of areas that are at risk of FMD virus incursion and spread is a priority for FMD target surveillance after FMD is eradicated from a given country or region. In our study, a knowledge-driven spatial model was built to identify risk areas for FMD occurrence and to evaluate FMD surveillance performance in Rio Grande do Sul state, Brazil. For this purpose, multi-criteria decision analysis was used as a tool to seek multiple and conflicting criteria to determine a preferred course of action. Thirteen South American experts analyzed 18 variables associated with FMD introduction and dissemination pathways in Rio Grande do Sul. As a result, FMD higher risk areas were identified at international borders and in the central region of the state. The final model was expressed as a raster surface. The predictive ability of the model assessed by comparing, for each cell of the raster surface, the computed model risk scores with a binary variable representing the presence or absence of an FMD outbreak in that cell during the period 1985 to 2015. Current FMD surveillance performance was assessed, and recommendations were made to improve surveillance activities in critical areas.