Célia Alves de Souza

Evolução dos processos erosivos e aspectos granulométricos em um sistema de voçoroca no Distrito de Vila Aparecida, município de Cáceres - Mato Grosso (Evolution of erosive processes and granulometric aspects of a gully complex in the district of Vila...)

O solo e um dos recursos naturais que o homem utiliza, sem se preocupar em varios casos com sua fragilidade. Considerando a influencia do uso e ocupacao da terra nas mudancas ambientais, o estudo teve como objetivo analisar os processos erosivos no Distrito de Vila Aparecida, municipio de Caceres - Mato Grosso a partir do monitoramento de um sistema de vocorocamento. Os procedimentos utilizados foram: levantamento teorico-conceitual; trabalho de campo para coletas de amostras, instrumentalizacao da erosao pelas tecnicas de pinos e estacas; analise em laboratorio e trabalho de gabinete (analise e sistematizacao dos dados). A retirada de cobertura vegetal e a granulometria do solo no entorno da area de estudo sao fatores condicionantes aos processos erosivos. Ao analisar os dados obtidos por monitoramento, nota-se que dos quatro pontos o que apresentou maior susceptibilidade foi o Ponto 1, pois apresentou alta percentagem de areias e silte. A quantificacao da erosao indica processo remontante o que contribui para o aumento em area e ramificacao da vocoroca. Cabe salientar ainda o papel da agua ao identificar processos e feicoes nos trabalhos de campo, como: a) piping b) encrostamento nas camadas superficiais e c) lavagem do material. A B S T R A C T Soil is one of the natural resouces that humans often use without concern for its fragility. Considering the influence of land use and occupation in environmental changes, the study aimed to analyze erosive processes in the district of Vila Aparecida, Caceres Municipality, Mato Grosso, through monitoring a gully complex. We used the following procedures: theoretical-conceptual inventory; field work for sample collection; instrumentation of the erosion by pin and stake techniques; laboratory analysis and desk work (analysis and systemization of the data). Removal of vegetation cover and soil granulometry in the surroundings of the study area are determining factors of erosive processes. Analysis of the data obtained through monitoring revealed that, of the four points, Point 1 presented the greatest susceptibility, as it presented a higher percentage of sands and silt. Quantification of the erosion indicates a headward process, which contributes to the increase in area and ramification of the gully. We should also note the role of water when identifying processes and features during field work, such as a) piping, b) crusting in the surface layers, and c) washing the material. Keywords: soil degradation; granulometric composition; erosive feature.

Geomorfologia da bacia hidrográfica do Córrego Salobra, município de Porto Estrela - Mato Grosso

A pesquisa teve como objetivo verificar a geomorfologia da bacia hidrografica do corrego Salobra, MT. Os procedimentos metodologicos se deram por meio de revisao bibliografica, trabalhos de gabinete e de campo. A area da bacia foi delimitada de acordo com as cartas topograficas do Ministerio do Exercito (1975) em escalas de 1:100.000, folhas Serra da Palmeira e Barra do Bugres SD-21-Y-D-VI e SD-21-Y-D-III. O mapa de geomorfologia, foi elaborado a partir dos mapas tematicos do projeto RADAMBRASIL. Sua arte final foi realizada no programa ArcGis 10.1. Os resultados mostraram que a bacia possui tres unidades geomorfologica: Provincia Serrana, Depressao do Alto Paraguai e Planicie do rio Paraguai. No alto curso da bacia, o canal encontra-se encaixado apresentando varios segmentos retilineos. No medio curso se apresenta meandro divagante ate a foz.

Levels of As, Cd and Pb in soils and sediments from gold mining areas in the municipalities of Pontes e Lacerda and Nova Lacerda, in the Vale do Alto Guaporé, (Valley of the High Guaporé ), MT

Soils act as source or drain of trace elements (ETs) in the environment. The study was conducted in three areas of gold mining in the Valley Region of Guaporé, in the counties of Nova Lacerda and Pontes e Lacerda, in the southwestern part of the state of Mato Grosso, having the purpose of assessing the concentration of As, Cd and Pb in sediments and soils at two depths of 0-20 and 20-40 cm. The trace elements (ETs) were determined in graphite furnace after acid extraction according to USEPA SW-846-3050. The soil analysis results were compared with the resolution of CETESB n°. 195/2005 and the sediments with CONAMA 344/2004 and CCME EPC-1999. The average contents of trace elements (ETs) found in sediments were (As 0,413; Cd 0.021; Pb 1.618 mg kg) in the Lavrinha mine; (As 1,343, 0,037 Cd, Pb and 3.198 mg kg) in the Pau a Pique mine; and (As 1,093; Cd 0,020 and Pb: 2,060 mg kg) in the São Francisco mine.. The average contents in soils were (As 0,772; Cd 0,017 and Pb 2, 515 mg kg) in the Lavrinha mine; (As 2,579; Cd 0,021; and Pb 4,373 mg kg) in the Pau a pique mine and (As 0,920; Cd 0,018, and Pb 3,198 mg kg) in the São Francisco mine. The values of As, Cd and Pb in soils and sediments of these areas are below the reference values, according to the Brazilian and Canadian laws.

Atributos químicos, físicos e estoque de cálcio, magnésio, potássio e fósforo em solos de campos de murundus no Brasil

Fields of murundus (FM) are wetlands that provide numerous ecosystem services. The objectives of this study were to evaluate the chemical [organic carbon (OC), P, K + , Ca 2+ , Mg 2+ , Al 3+ and H+Al] and physical [texture and bulk density (Bd)] soil attributes and calculate the organic matter (OM) and nutrient stock (P, Ca, Mg, and K) in soils of FM located in the Guapore River basin in Mato Grosso. Thirty-six sampling points were selected, and soil samples were collected from two environments: the murundu and plain area surrounding (PAS). At each sampling point, mini trenches of 0.5 × 0.5 × 0.4 m were opened and disturbed and undisturbed soil samples were collected at depths of 0–0.1, 0.1–0.2, and 0.2–0.4 m. In the Principal Component Analysis the variables H+Al (49%) and OM (4%) were associated with the F1 component and sand content (47%) with the F2 component. The FM had lower pH values and higher concentrations of K + , P, and H+Al than PAS at all depths (p < 0.05). Additionally, FM stocked up to 433, 360, 205, and 11 kg ha -1 of Ca, Mg, K, and P, respectively, for up to a depth of 0.2 m. The murundu stored two times more K and three times more P than that in the PAS. Our results show that the FM has high sand content and Bd greater than 1.5 Mg m -3 , high acidity, low OC content, and low nutrient concentrations. Thus, special