Pedro Roberto de Azambuja Madruga

Desintensificação do uso da terra e sua relação com a erosão do solo

Conservation of natural resources such as soil and water should be a concern of governments and institutions. Erosion processes are responsible for the degradation of these important resources in many parts of the globe. The aim of this study was to assess the land cover dynamics in a region of complex landscape and employ the modified universal soil loss equation (RUSLE) to quantify soil loss due to erosion. The land use in the district of Vale Veneto, Sao Joao do Polesine in central region of Rio Grande do Sul, was evaluated in Landsat images of 1988, 2000 and 2007. The spatial and temporal analysis of the land use indicates that the forest areas had a 16.2% increase over the 19 years period. Areas under agriculture had a decrease of 57.5% over the same period. The gross erosion suffered a 44% reduction from 1988 to 2007. The study showed that land use disintensification leads to a more favorable configuration for soil conservation and erosion mitigation. It is believed that changes in land use are related to diminishing number of rural families who previously cultivated areas unsuitable for agriculture in this region.

Geoprocessamento e sensoriamento remoto aplicados à análise de recursos florestais

This study presents a methodology for survey and analysis of the forestal resources of natural and implanted populating located in the topographic leaf SH.22Y-A, Cachoeira do Sul, RS, (Brazil) by using geoprocessing and remote sensing technics. For this purpose, the Geographic Information Systems, associated to satellite images, processed by digital classification and mathematics’ functions were used. In so doing data gathering and quantification of different thematic bases of the studied area. Variables and thematic bases eere accomplished the satellite images, assessed in the field and topographic maps and the geospacials crossings obtaining the land use, implanted species, taken area, besides the localization of the forest concerning slope, edaphic, hydrographic and road availability. Thus, these information obtained by comparing these variables, made it possible to analyze the forestal cover of the study area, supplying subsidy to the forestal resources management and the environmental preservation.

GEOPROCESAMIENTO APLICADO AL ANALISIS DEL USO DE LA TIERRA EN EL MUNICIPIO DE SAN PEDRO DE YCUAMANDYYÚ, PARAGUAY

San Pedro of Ycuamandyyu is located in the northwest of the oriental region of Paraguay. The objectives of this work were the elaboration and the analysis of the map of the land use for the planning of forest activities in the place, for which were used techniques of cartography, remote sensing and (GIS) Geographical Information’s Systems, that facilitated the analysis of information coming from satellites images LANDSAT TM 5, topographical chart and (GPS) Global Position System, that allowed the processing of data in the program Idrisi 2.0 for the map manufactoring that facilitated the analysis on the situation of the land use in the municipality. Some predominant categories were distinguished as the high meadows or natural fields, agricultural use and low meadows, being the forest covering less than 25%. As general conclusion the municipality presents enough areas of natural fields and agricultural use that could be used for reforestation activities, lither native or exotic species of rapid growth with the purpose of obtaining values of forest covering in balance with the other categories of land use.

Modelagem numérica em mapa temático: sítios florestais

The objective of this work was to utilize programs of geoprocessing and treatment of images, considerated to be well-knowm and easily operated, for numerical modelling of a thematical map. This modelling is carried out from feeding a digital base bank, for forest planning and cadaster. More specifically, a methodology that uses the numerical modelling for tridimensional visualization of a layer of geoindicated forest sites has been designed to permit the crossing (superposition) with other layers, also, related to the forest area. The following materiais have been used in order to reach the goals: a map of natural sites in the National Forest of Passo fundo, hardware (microcomputer, ink jet printer, table scanner), software (Idrisi 4.1 and Aldus PhotoStyler 2.0). The employed methodology based geoindication for posterior numerical modelling and tridimensional visualization of the different site represented in the plannimetrical map of the National Forest of Passo fundo. As a result, representative archives about the employed methodology were obtainde to help in identifying, through different heights, the site where the most adequated species to their natural characteristics can be implanted, showing, the viability of the application of the present methodology in forest.