O presente estudo objetivou a caracterização hidrogeoquímica ao longo da bacia de drenagem do rio Sorocaba - São Paulo, em cinco estações de amostragens, localizadas desde a região de nascentes, estação S5- Ibiúna, passando por áreas com maior influencia urbana e agrícola (S4 - Votarantim, S3 - Itavuvu e S2 - Tatuí), até a foz da bacia em estudo, S1 - Laranjal Paulista, utilizando-se modelos de transporte de materiais nas fases dissolvidas e particuladas. Para tal, foram realizadas coletas ao longo de 18 meses, de amostras de águas fluviais, pluviais, sedimento fino em suspensão (FSS) e dos principais tipos solos integrantes da bacia. Importantes parâmetros físico-quimicos e a caracterização das cargas dissolvida e particulada foram determinados. As características hidroquímicas das águas fluviais mostraram que as espécies químicas SiO2, Ca2+, Mg2+, K+, HCO3- e TDS indicaram possíveis aportes difusos e as espécies Na+, Cl-, SO42-, PO43-, NH4+ e NO3-indicaram origens pontuais. O elemento químico dissolvido que mais contribuiu no transporte específico fluvial junto à foz do rio Sorocaba (S1- Laranjal Paulista), foi o Na+ para os cátions (24,25, kg km-2 d-1) e para os ânions foi o HCO3- com 53,97 kg km-2 d-1. Já no transporte pluvial o Ca2+ foi a espécie química que apresentou maior contribuição na carga do rio com 54,89 %. Com relação ao material particulado, representada pelo FSS, o transporte específico variou de 22,68 a 55,70 t km-2 a-1, desde a região das nascentes até a foz, respectivamente. O rio Sorocaba foi classificado como médio transportador de sedimento fino em suspensão e a erosão mecânica foi de 37,88 m.Ma-1 / This study aimed to characterize the hydrogeochemical along the Sorocaba river basin (SP), in five sampling stations, located from the headwaters region, S5-Ibiúna station, passing through areas with higher urban and agricultural influences (S4 - Votorantim, S3 - Itavuvu and S2 and Tatuí, to the mouth of the basin under study, S1 - Laranjal Paulista, using models of transport on dissolved and particulate phases. Samples of river water, pluvial, fine suspended sediment (FSS) and the main soils types were collected over 18 months. Important physico-chemical characterization of dissolved and particulate loads were determined. The hydrochemical features of the river water showed that the chemical species SiO2, Ca2 +, Mg2+, K +, HCO3-and TDS indicated possible diffuse contributions and species Na +, Cl-, SO42-, PO43-, NH4+ and NO3-indicated origin contributions. The dissolved chemical element who more contributed in transport dissolved specific in S1-Laranjal Paulista), was Na+ for cations, with 24,25 kg km-2 d-1 and for anions was HCO3- with 53.97 kg km-2 d-1. In the rain Ca2+ was the chemical species with the highest contribution to the river load with 54.89%. The suspended particulate matter, represented by the FSS, the specific transport ranged from 22.68 to 55.70 t km-2 a-1, from the region of the headwaters to the mouth, respectively. The river was classified as medium transporting fine sediment in suspension and the mechanical erosion was the 37.88 m .Ma-1

O presente estudo objetivou a caracterização hidrogeoquímica ao longo da bacia de drenagem do rio Sorocaba - São Paulo, em cinco estações de amostragens, localizadas desde a região de nascentes, estação S5- Ibiúna, passando por áreas com maior influencia urbana e agrícola (S4 - Votarantim, S3 - Itavuvu e S2 - Tatuí), até a foz da bacia em estudo, S1 - Laranjal Paulista, utilizando-se modelos de transporte de materiais nas fases dissolvidas e particuladas. Para tal, foram realizadas coletas ao longo de 18 meses, de amostras de águas fluviais, pluviais, sedimento fino em suspensão (FSS) e dos principais tipos solos integrantes da bacia. Importantes parâmetros físico-quimicos e a caracterização das cargas dissolvida e particulada foram determinados. As características hidroquímicas das águas fluviais mostraram que as espécies químicas SiO2, Ca2+, Mg2+, K+, HCO3- e TDS indicaram possíveis aportes difusos e as espécies Na+, Cl-, SO42-, PO43-, NH4+ e NO3-indicaram origens pontuais. O elemento químico dissolvido que mais contribuiu no transporte específico fluvial junto à foz do rio Sorocaba (S1- Laranjal Paulista), foi o Na+ para os cátions (24,25, kg km-2 d-1) e para os ânions foi o HCO3- com 53,97 kg km-2 d-1. Já no transporte pluvial o Ca2+ foi a espécie química que apresentou maior contribuição na carga do rio com 54,89 %. Com relação ao material particulado, representada pelo FSS, o transporte específico variou de 22,68 a 55,70 t km-2 a-1, desde a região das nascentes até a foz, respectivamente. O rio Sorocaba foi classificado como médio transportador de sedimento fino em suspensão e a erosão mecânica foi de 37,88 m.Ma-1 / This study aimed to characterize the hydrogeochemical along the Sorocaba river basin (SP), in five sampling stations, located from the headwaters region, S5-Ibiúna station, passing through areas with higher urban and agricultural influences (S4 - Votorantim, S3 - Itavuvu and S2 and Tatuí, to the mouth of the basin under study, S1 - Laranjal Paulista, using models of transport on dissolved and particulate phases. Samples of river water, pluvial, fine suspended sediment (FSS) and the main soils types were collected over 18 months. Important physico-chemical characterization of dissolved and particulate loads were determined. The hydrochemical features of the river water showed that the chemical species SiO2, Ca2 +, Mg2+, K +, HCO3-and TDS indicated possible diffuse contributions and species Na +, Cl-, SO42-, PO43-, NH4+ and NO3-indicated origin contributions. The dissolved chemical element who more contributed in transport dissolved specific in S1-Laranjal Paulista), was Na+ for cations, with 24,25 kg km-2 d-1 and for anions was HCO3- with 53.97 kg km-2 d-1. In the rain Ca2+ was the chemical species with the highest contribution to the river load with 54.89%. The suspended particulate matter, represented by the FSS, the specific transport ranged from 22.68 to 55.70 t km-2 a-1, from the region of the headwaters to the mouth, respectively. The river was classified as medium transporting fine sediment in suspension and the mechanical erosion was the 37.88 m .Ma-1

The coupled effects of thermochemical and thermomechanical erosion are investigated. A quasi-steady ablation model with finite rate surface chemistry is developed and applied to a solid carbon combustion scenario to investigate the system’s behavior in situations in which surface reactions are not in equilibrium. It is found that in this regime, the system can be described effectively in terms of the B number and the Damkohler number, and a useful algebraic relationship between these parameters is determined for nonequilibrium behavior. The thermochemical ablation model is then expanded by considering mechanical removal of thermochemically weakened material from the ablating surface. A model is developed for a randomly oriented carbon fiber preform material, like that used in the production of phenolic impregnated carbon ablator (PICA), and this model is incorporated into the previously developed ablation code. It is found that for PICA in realistic reentry scenarios, the removal of individual fibers from the ablating surface by mechanical erosion is not an important mass loss mechanism, although hypothetical situations exist where this mechanism for mechanical removal of material is non-negligible. The thermo-chemo-mechanical erosion mechanism is then extended to address brand generation in wildland fire scenarios. A model is developed to predict the size and number distribution of embers generated from a tree with fractal geometry. This model is coupled to a simple plume and propagation model similar to those existing in the literature, and a case study is performed for a realistic wildfire scenario. The presence of an optimal branch diameter for brand propagation is identified, and areas for future work in thermo-chemo-mechanical degradation are discussed. / text

Os rios Jundiaí e Capivari são importantes efluentes do rio Tietê, e estão localizados em regiões que possuem municípios de grande potencial sócio/econômico, para o estado se São Paulo, por esse motivo estão sobre constantes pressões antrópicas causando deteriorização de suas águas, que são usadas para abastecimento humano. O presente estudo teve por objetivo realizar o levantamento das características hidrogeoquímicas das bacias de drenagem dos rios Jundiaí e Capivari, buscando caracterizar os aspectos das influências antrópicas nas cargas dissolvidas e particuladas transportadas fluvialmente nas referidas bacias de drenagem. Para tal foram determinadas quatro estações de amostragem, JUN0 e JUN1 para o rio Jundiaí, e CAP0 e CAP1 para o rio Capivari, sendo coletadas amostras fluviais no período de abril de 2011 a dezembro de 2012, distribuídas em 15 excursões. Os estudos das dinâmicas das cargas fluviais particuladas, representadas pelos sedimentos finos em suspensão (FSS), evidenciaram para ambos os rios, a influência da sazonalidade, com significativo transporte de sedimentos, principalmente nos períodos chuvosos. O rio Jundiaí apresentou uma erosão média e o rio Capivari uma erosão considerada alta. As relações estabelecidas entre os COP (carbono orgânico particulado), NOP (nitrogênio orgânico particulado), COD (carbono orgânico dissolvido), NOD (nitrogênio orgânico dissolvido) e respectivas assinaturas isotópicas (?13C e ?15N) para os rios Jundiaí e Capivari, revelaram que a origem da matéria orgânica esteve associada ao material erosivo (solos da bacia) nos períodos chuvosos e aos efluentes domésticos no período de estiagem. A caracterização hidroquímica fluvial revelou que para a maioria das espécies químicas presentes na carga dissolvida dos rios Jundiaí e Capivari sofreram os processos de diluição em consonância com o aumento da vazão. Quando comparadas às respectivas curvas de diluição teórica, as curvas dos íons Na+ e Cl-, se mostraram oriundos de uma única fonte ou origem de entrada nas bacias, nas regiões de foz, relativas ao lançamento de esgotos domésticos. O modelo geoquímico conceitual simples de alteração química de rochas permitiu de modo satisfatório avaliar a alteração de rochas dos rios Jundiaí e Capivari, evidenciando a contribuição dos aportes antrópicos na química das águas dos rios estudados / The Jundiaí and Capivari River are important Tietê river tributaries, and are located in regions with potential social/economic cities of São Paulo state, for this reason they are on influence of countless water impacts that is used for human supply. This study has the main objective survey the hidrogeochemical characteristic of the Capivari and Jundiaí rivers basins drainage, looking for describing anthropogenic influence in dissolved and suspended sediment transported in the basins. Four local were determined, JUN0 and JUN1 for Jundiaí river, and CAP0 and CAP1 for Capivari river where fluvial water samples were collected from April of 2011 to December of 2012, divided in 15 sampling. The suspended sediments dynamics studies, represented by the fine sediments in suspension (FSS), proved for both rivers the seasonality influence with expressive suspended sediment transport mainly during rainy periods. Jundiaí river showed medium erosion and Capivari river a considered high erosion. The relation established among COP (particulate organic carbon), NOP (particulate organic nitrogen), COD (dissolved organic carbon), NOD (dissolved organic nitrogen) and isotopic signature (?13C e ?15N) for Jundiaí and Capivari rivers indicated that the organic matter has been associated with erosive materials (basins soils) during rainy periods and sewage during dry season. The fluvial hydrochemical characterization appeared that for the majority of chemical species presents are dissolved in the Jundiaí and Capivari rivers where the dilution happened according to the water flow increase. Comparing with corresponding theoretical dilution curves, both Na and Cl ions curves have shown to be from a single or input source in the mount basins for the sewage release. The geochemical simple model of chemical of rocks allowed consider Jundiaí and Capivari rocks alteration showing the anthropic rivers water influence

Os rios Jundiaí e Capivari são importantes efluentes do rio Tietê, e estão localizados em regiões que possuem municípios de grande potencial sócio/econômico, para o estado se São Paulo, por esse motivo estão sobre constantes pressões antrópicas causando deteriorização de suas águas, que são usadas para abastecimento humano. O presente estudo teve por objetivo realizar o levantamento das características hidrogeoquímicas das bacias de drenagem dos rios Jundiaí e Capivari, buscando caracterizar os aspectos das influências antrópicas nas cargas dissolvidas e particuladas transportadas fluvialmente nas referidas bacias de drenagem. Para tal foram determinadas quatro estações de amostragem, JUN0 e JUN1 para o rio Jundiaí, e CAP0 e CAP1 para o rio Capivari, sendo coletadas amostras fluviais no período de abril de 2011 a dezembro de 2012, distribuídas em 15 excursões. Os estudos das dinâmicas das cargas fluviais particuladas, representadas pelos sedimentos finos em suspensão (FSS), evidenciaram para ambos os rios, a influência da sazonalidade, com significativo transporte de sedimentos, principalmente nos períodos chuvosos. O rio Jundiaí apresentou uma erosão média e o rio Capivari uma erosão considerada alta. As relações estabelecidas entre os COP (carbono orgânico particulado), NOP (nitrogênio orgânico particulado), COD (carbono orgânico dissolvido), NOD (nitrogênio orgânico dissolvido) e respectivas assinaturas isotópicas (?13C e ?15N) para os rios Jundiaí e Capivari, revelaram que a origem da matéria orgânica esteve associada ao material erosivo (solos da bacia) nos períodos chuvosos e aos efluentes domésticos no período de estiagem. A caracterização hidroquímica fluvial revelou que para a maioria das espécies químicas presentes na carga dissolvida dos rios Jundiaí e Capivari sofreram os processos de diluição em consonância com o aumento da vazão. Quando comparadas às respectivas curvas de diluição teórica, as curvas dos íons Na+ e Cl-, se mostraram oriundos de uma única fonte ou origem de entrada nas bacias, nas regiões de foz, relativas ao lançamento de esgotos domésticos. O modelo geoquímico conceitual simples de alteração química de rochas permitiu de modo satisfatório avaliar a alteração de rochas dos rios Jundiaí e Capivari, evidenciando a contribuição dos aportes antrópicos na química das águas dos rios estudados / The Jundiaí and Capivari River are important Tietê river tributaries, and are located in regions with potential social/economic cities of São Paulo state, for this reason they are on influence of countless water impacts that is used for human supply. This study has the main objective survey the hidrogeochemical characteristic of the Capivari and Jundiaí rivers basins drainage, looking for describing anthropogenic influence in dissolved and suspended sediment transported in the basins. Four local were determined, JUN0 and JUN1 for Jundiaí river, and CAP0 and CAP1 for Capivari river where fluvial water samples were collected from April of 2011 to December of 2012, divided in 15 sampling. The suspended sediments dynamics studies, represented by the fine sediments in suspension (FSS), proved for both rivers the seasonality influence with expressive suspended sediment transport mainly during rainy periods. Jundiaí river showed medium erosion and Capivari river a considered high erosion. The relation established among COP (particulate organic carbon), NOP (particulate organic nitrogen), COD (dissolved organic carbon), NOD (dissolved organic nitrogen) and isotopic signature (?13C e ?15N) for Jundiaí and Capivari rivers indicated that the organic matter has been associated with erosive materials (basins soils) during rainy periods and sewage during dry season. The fluvial hydrochemical characterization appeared that for the majority of chemical species presents are dissolved in the Jundiaí and Capivari rivers where the dilution happened according to the water flow increase. Comparing with corresponding theoretical dilution curves, both Na and Cl ions curves have shown to be from a single or input source in the mount basins for the sewage release. The geochemical simple model of chemical of rocks allowed consider Jundiaí and Capivari rocks alteration showing the anthropic rivers water influence

En Guinée, la disponibilité des ressources en eau est soumise à de graves problèmes de gestion avec des conséquences importantes pour les populations, notamment à Kankan où la plupart des puits tarissent pendant la saison sèche, et où la fourniture régulière de l’eau à partir de la rivière Milo n'est pas assurée dans tous les quartiers de la ville. Le Milo et son bassin versant représente donc un enjeu important pour les habitants de cette ville. Le Milo (480 km de long) qui draine un bassin versant 13 810 km2 est le plus important des affluents rive droite du Niger. Pour évaluer l’impact du bassin versant du Milo et de la ville de Kankan sur la qualité des eaux et des sédiments de ce cours d’eau, 30 échantillons de sédiments de fond ont été prélevés au cours d’une première campagne (juin-juillet 2013) sur l’ensemble des cours d’eau du bassin versant, tandis que durant une deuxième campagne (avril 2014-mai 2015), un suivi régulier a été mis en place sur le Milo en amont et en aval de Kankan. Au cours de cette dernière, 232 échantillons d’eau du Milo (dont 116 utilisés pour l’isotopie), et 26 échantillons de sédiments de fond ont été prélevés sur les stations de Bordo (amont de Kankan) et de Karifamoriah (aval de Kankan). Les concentrations en éléments majeurs et traces, terres rares, COP, COD, pH, alcalinité, l’azote organique, les isotopes de l’oxygène et de l’hydrogène, ainsi que la micro-granulométrie des sédiments ont été mesurés. Les résultats obtenus durant le cycle hydrologique 2014-2015 ont permis d’estimer le flux de matières exportées en solution par le Milo à Kankan à 47 863 t.an-1 et le flux de matières particulaires à 76 759 t.an-1. 92% de ce tonnage est exporté durant la période des hautes eaux. Ces flux permettent d’estimer des vitesses moyennes d’érosion physique (8 t.km-2.an-1) et d’altération chimique (5 t.km-2.an-1) du bassin relativement faibles. Le flux spécifique de CO2 consommé par l’altération chimique est lui aussi relativement faible (76.103 mole.km-2.an-1), mais il reste dans la moyenne des flux de CO2 mesurés sur les bassins couverts de sols latéritiques. Le degré de contamination des sédiments et sa variation spatio-temporelle ont été évalués grâce au calcul du facteur d’enrichissement (FE), en normalisant les concentrations en éléments traces par rapport à Al, Sc et Ti et en prenant le PAAS et l’UCC comme matériaux de référence. La quasi-totalité des éléments traces proviennent essentiellement des processus d’altération et sont d’origine naturelle. Toutefois, un enrichissement modéré à significatif (5 < FE < 20) a été mis en évidence pour Zr et Hf (enrichissements naturels) et As et Sb (impacts anthropiques). Finalement, l’apport anthropique en éléments traces, quand il existe, reste modéré. Les profils de concentrations en terres rares ont permis de montrer que la signature géochimique des sédiments de fond du Milo est homogène sur l’ensemble du bassin et caractéristique des sols latéritiques, non perturbée par la ville de Kankan et elle est proche des signatures du PAAS et de l’UCC. Pour l’ensemble des éléments traces et des terres rares la contribution anthropique reste faible et les fractions disponibles (phases labiles) sur les sédiments (extraction à l’EDTA) sont également faibles, confirmant ainsi que l’essentiel de ces éléments rentrent principalement dans la composition des phases résiduelles. / In Guinea, the availability of water resources is subjected to serious problems of management with important consequences for the populations, particularly in Kankan city where most of the wells dry up during the dry season and where the water supply from the Milo river is not assured for all the districts. Then the Milo river and its watershed represent an important issue for the inhabitants of Kankan. The Milo river (480 km in length) which drains an area of 13 810 km2 is the most important right-bank tributary of the Niger river. To evaluate the impact of the Milo watershed and of the Kankan city on the water and sediments of this river, 30 samples of bottom sediments have been collected during a first campaign (June-July 2013) on the main course from upstream to downstream and on the main tributaries, whereas during a second campaign (April 2014-May 2015) a regular monitoring was set up on the Milo river, upstream and downstream Kankan city. During this campaign, 232 river water samples (of which 116 for isotopic analyses) and 26 bottom sediment samples have been collected at Bordo (upstream) and Karifamoriah (downstream) stations. The concentrations of major and trace elements, rare earth elements, POC and PON, DOC, pH, alkalinity, the isotopic composition of O, H and the micro-granulometry of sediments have been measured. The results obtained during the hydrological cycle 2014-2015 allowed to estimate the fluxes of dissolved (47 863 t.y-1) and particulate (76 759 t.y-1) matters exported by the Milo river at Kankan. 92% of these fluxes are exported during the high flow period. These fluxes allowed us to estimate very low average rates of physical erosion (8 t.km-2.y-1) and chemical weathering (5 t.km-2.y-1) of the Milo catchment. The specific flux of CO2 consumed by chemical weathering (76.103 mole.km-2.y-1) is relatively low but within the range of CO2 fluxes measured in catchments draining lateritic soils. The degree of sediment contamination and its spatio-temporal variation have been assessed using the enrichment factor (EF), by normalizing the trace element concentrations with Al, Sc and Ti and by taking PAAS and UCC as the reference materials. Almost all the trace elements mainly originate from weathering processes and are of natural origin. Nevertheless, moderate to significant enrichments (5 < EF < 20) have been calculated for Zr and Hf (natural enrichments) and As and Sb (anthropogenic impacts). Finally, the anthropogenic contribution of trace elements, when it exists, remains moderate. The rare earth concentration patterns allowed to show the geochemical signature of river bottom sediments is homogeneous within the Milo catchment and characteristic of lateritic soils, non- perturbed by the city of Kankan and close to the PAAS and UCC patterns. For most of the trace and rare earth elements, the anthropogenic contribution remains low and the available fractions (labile phases) in the sediment (EDTA extraction) are also low, confirming that the main part of these elements are mainly in the residual phases.