Técnica geoestatística na avaliação de atributos físico-hídricos dos solos da sub-bacia hidrográfica Santa Rita, Pelotas/RS

Abstract

With the increasing of population, further electric energy and food are required, thereby the maintenance and preservation of this resource becomes a very important subject for the sustainability of the species over time, In this context, increases relevance the planning, management and protection of natural courses. Therefore, the study of soil physical-hydric attributes combined to the sub-basin scale support the understanding the soil management situation, water dynamics and hydrological processes in the region. The objective of this work was to evaluate the spatial variability of soil physical-hydric attributes in the 0-0,20m layer, aiming to identify and mapping its condition, with the help of indicator kriging, in the Santa Rita sub-basin, inserted in the basin of the Arroio Moreira / Fragata, located in the south of Rio Grande do Sul, Soil samples were collected in a grid in the sub-basin, with a sample distance of 300m for each point, where the following soil attributes were analyzed: sand, silt, clay, total porosity, macroporosity, microporosity, bulk density, saturated hydraulic conductivity and soil organic carbon, For the analysis of the behavior of these soil attributes, descriptive statistics and subsequent application of geostatistics were performed, Indicator kriging was used to support the understanding of the physical-hydrological phenomena of the sub-basin, and thus to identify areas with a greater or less probability of occurrence of a given event, The cut-offs applied at this work were based on classical values and widely widespread in soil sciences, It was possible to characterize and quantify the spatial dependence structure of the physical-hydic attributes studied. The indicative kriging method proved to be an efficient tool for mapping the soil physical-hydric attributes.