Navegando por Assunto "Sediment production"

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Acesso aberto (Open Access)
Modelo WEPP para estimativa da produção de sedimentos em uma pequena bacia hidrográfica da Amazônia
(Universidade Federal do Pará, 2017-12-06) SAMPAIO, Liliane da Cruz; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
Erosive processes produce several economic and environmental damages. The development of mathematical models has made it possible to quantify these processes, allowing estimating the magnitude of the problem, in order to minimize it. In this sense, this work uses the WEPP (Water Erosion Prediction Project) model to simulate the sediment yield in an Amazon small catchment, igarapé da Prata catchment, located in the Municipality of Capitão Poço-PA. The calibrated main parameters of the WEPP model were: initial soil saturation (Si), erosion by runoff (Ki), erosion by channel or groove flow (Kr) and saturated hydraulic conductivity (Ke). After the calibration, it was verified that most of the sediment yield is in the plans. And as is to be expected, this production is higher in areas with predominance of agriculture and livestock. The results of the estimated sediment yield calculated by the model were compared to the observed data for the year 2012. The model presented a value of 131.99 t / km², close to the observed value, which was 121.64 t / km2. This result leads to the conclusion that the values calculated by the model are consistent with the reality of the sediment yield of the small catchment in question.
Acesso aberto (Open Access)
Modelos empíricos para estimativa de produção de sedimentos
(Universidade Federal do Pará, 2015-03-20) SILVA, Danielle Sebastiana dos Santos; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
The erosive processes that occur in a watershed have been objects of concerns associated with the planning and management of land use and water resources. In this case, the empirical models of hydrosedimentological simulation are important tools, and with low cost, in the assessment of soil erosion due to the use and management of land. Thus, the study aimed to analyze the sediments yield via three empirical models applied to a small catchment of the Amazon, the catchment of Igarapé da Prata located in the municipality of Capitão Poço-PA. The analyzed and used models were the USLE (Universal Soil Loss Equation); the Poesen model; and the Langbein-Schumm model. The results showed that the USLE model had an average sediment yield equal to 146.20 (t / km²); the Langbein-Schumm model an average production equal to 114.25 (t / km²); and the Poesen model an average yield equal to 7.57 (t / km²). The results obtained by the two first-mentioned models are of the same order of magnitude, indicating that the Langbein-Schumm model, for the case analyzed, is comparable to the classical model USLE. These results were compared with observed data of suspended sediments and the Langbein-Schumm model was the one closest to the observations.
Acesso aberto (Open Access)
Vulnerabilidade ambiental e impacto na produção de sedimentos da bacia hidrográfica do rio Itacaiúnas (BHRI) - Província Mineral de Carajás, Sudeste da Amazônia
(Universidade Federal do Pará, 2022-06-30) SILVA, Marcio Sousa da; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; HTTPS://ORCID.ORG/0000-0003-0252-808X; ROCHA, Edson José Paulino da; http://lattes.cnpq.br/2313369423727020
The development of environmental vulnerability studies in a regional context and in particular in the Amazon requires a huge human, logistical and economic effort, which when incorporated into current technologies for data acquisition and processing (remote and in situ) and publicprivate partnerships, makes such research possible. This framework was what enabled the development of this thesis in the Itacaiúnas River Watershed (IRW), which has around 42.000 km² and is located in the area called “arc of deforestation in the Amazon”. Area of many socioeconomic-environmental conflicts related to the development of the region and its different types of use and occupation of the territory. Within this context, we developed this research whose main objective was to assess how environmental vulnerability relates to the current production of suspended sediments at the IRW. First, the areas of greater or lesser vulnerability were defined and identified, having the year 2019 as a timeframe, through recognized methodologies developed for this type of study in the Amazon region. Using geoprocessing routines in ArcGIS 10.8.1 software, five thematic maps and environmental vulnerability were built (geology, geomorphology, soils, use and occupation and climate) and finally using map algebra the map of BHRI's environmental vulnerability was generated. The results showed that the BHRI is moderately stable/vulnerable in an area of 28,058 km² of extension (68% of the basin), moderately stable in 8,961 km² of extension (with 22% of the basin) and moderately vulnerable in 4,314 km² (10% of the basin). of the basin). In parallel, the study on the production of sediments at the BHRI, was based on data acquired by the hydrometeorological monitoring project by the Instituto Tecnológico Vale – ITV. Monitoring takes place in 16 hydrosedimentological control sections distributed in the six main sub-basins that make up the BHRI, with four annual campaigns (high water levels, rising water levels, falling water levels, low water levels) that took place between 2015 and 2019, and aimed at building and comparing the curves- sediment key and sediment production between these different sub-basins, data already published in the Brazilian Journal of Water Resources (RBRH) in 2021. Finally, seeking to respond to hypothesis of this study, we carried out comparative analyzes of the relationship between the environmental vulnerabilities observed and the production of sediments, identifying and demonstrating which areas, which environmental factors and how much sediment is produced in the different sub-basins of the IRW. The results obtained allowed to get an integrated and compartmentalized view of the vulnerability and production of sediments at the BHRI that confirm that the ongoing legal mineral activities within protected areas of forests do not generate significant impacts on their vulnerability or on their production of sediments. In turn, the activities related to the use and occupation of the territory in nonprotected areas, promoted an intense replacement of the forest by pastures, generating the areas of greater environmental vulnerability and are directly associated with the greater “inputs” of sediments in the IRW.
Acesso aberto (Open Access)
Vulnerabilidade ambiental e impacto na produção de sedimentos da bacia hidrográfica do rio Itacaiúnas (BHRI): província Mineral de Carajás, sudeste da Amazônia
(Universidade Federal do Pará, 2022-06-30) SILVA, Marcio Sousa da; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; https://orcid.org/0000-0003-0252-808X; ROCHA, Edson José Paulino da; http://lattes.cnpq.br/2313369423727020
The development of environmental vulnerability studies in a regional context and in particular in the Amazon requires a huge human, logistical and economic effort, which when incorporated into current technologies for data acquisition and processing (remote and in situ) and publicprivate partnerships, makes such research possible. This framework was what enabled the development of this thesis in the Itacaiúnas River Watershed (IRW), which has around 42.000 km² and is located in the area called “arc of deforestation in the Amazon”. Area of many socioeconomic-environmental conflicts related to the development of the region and its different types of use and occupation of the territory. Within this context, we developed this research whose main objective was to assess how environmental vulnerability relates to the current production of suspended sediments at the IRW. First, the areas of greater or lesser vulnerability were defined and identified, having the year 2019 as a timeframe, through recognized methodologies developed for this type of study in the Amazon region. Using geoprocessing routines in ArcGIS 10.8.1 software, five thematic maps and environmental vulnerability were built (geology, geomorphology, soils, use and occupation and climate) and finally using map algebra the map of BHRI's environmental vulnerability was generated. The results showed that the BHRI is moderately stable/vulnerable in an area of 28,058 km² of extension (68% of the basin), moderately stable in 8,961 km² of extension (with 22% of the basin) and moderately vulnerable in 4,314 km² (10% of the basin). of the basin). In parallel, the study on the production of sediments at the BHRI, was based on data acquired by the hydrometeorological monitoring project by the Instituto Tecnológico Vale – ITV. Monitoring takes place in 16 hydrosedimentological control sections distributed in the six main sub-basins that make up the BHRI, with four annual campaigns (high water levels, rising water levels, falling water levels, low water levels) that took place between 2015 and 2019, and aimed at building and comparing the curves- sediment key and sediment production between these different sub-basins, data already published in the Brazilian Journal of Water Resources (RBRH) in 2021. Finally, seeking to respond to hypothesis of this study, we carried out comparative analyzes of the relationship between the environmental vulnerabilities observed and the production of sediments, identifying and demonstrating which areas, which environmental factors and how much sediment is produced in the different sub-basins of the IRW. The results obtained allowed to get an integrated and compartmentalized view of the vulnerability and production of sediments at the BHRI that confirm that the ongoing legal mineral activities within protected areas of forests do not generate significant impacts on their vulnerability or on their production of sediments. In turn, the activities related to the use and occupation of the territory in non protected areas, promoted an intense replacement of the forest by pastures, generating the areas of greater environmental vulnerability and are directly associated with the greater “inputs” of sediments in the IRW.