Modelling nitrogen fluxes from the land surface to the coastal zone in European systems: the perspective of the INCA project

This paper describes the results and conclusions of the INCA (Integrated Nitrogen Model for European CAtchments) project and sets the findings in the context of the ELOISE (European Land-Ocean Interaction Studies) programme. The INCA project was concerned with the development of a generic model of the major factors and processes controlling nitrogen dynamics in European river systems, thereby providing a tool (a) to aid the scientific understanding of nitrogen transport and retention in catchments and (b) for river-basin management and policy-making. The findings of the study highlight the heterogeneity of the factors and processes controlling nitrogen dynamics in freshwater systems. Nonetheless, the INCA model was able to simulate the in-stream nitrogen concentrations and fluxes observed at annual and seasonal timescales in Arctic, Continental and Maritime-Temperate regimes. This result suggests that the data requirements and structural complexity of the INCA model are appropriate to simulate nitrogen fluxes across a wide range of European freshwater environments. This is a major requirement for the production of coupled fiver-estuary-coastal shelf models for the management of our aquatic environment. With regard to river-basin management, to achieve an efficient reduction in nutrient fluxes from the land to the estuarine and coastal zone, the model simulations suggest that management options must be adaptable to the prevailing environmental and socio-economic factors in individual catchments: 'Blanket approaches' to environmental policy appear too simple. (c) 2004 Elsevier B.V. All rights reserved.

Impacts of forestry on nitrogen in upland and lowland catchments: a comparison of the River Severn at Plynlimon in mid-Wales and the Bedford Ouse in south-east England using the INCA Model

The impacts of afforestation at Plynlimon in the Severn catchment, mid-Wales. and in the Bedford Ouse catchment in south-east England are evaluated using the INCA model to simulate Nitrogen (N) fluxes and concentrations. The INCA model represents the key hydrological and N processes operating in catchments and simulates the daily dynamic behaviour as well as the annual fluxes. INCA has been applied to five years of data front the Hafren and Hore headwater sub-catchments (6.8 km(2) area in total) of the River Severn at Plytilimon and the model was calibrated and validated against field data. Simulation of afforestation is achieved by altering the uptake rate parameters in the model. INCA simulates the daily N behaviour in the catchments with good accuracy as well as reconstructing the annual budgets for N release following clearfelling a four-fold increase in N fluxes was followed by a slow recovery after re-afforestation. For comparison, INCA has been applied to the large (8380 km(2)) Bedford Ouse catchment to investigate the impact of replacing 20% arable land with forestry. The reduction in fertiliser inputs from arable farming and the N uptake by the forest are predicted to reduce the N flux reaching the main river system, leading to a 33% reduction in N-Nitrate concentrations in the river water.

An assessment of the fine sediment dynamics in an upland river system: INCA-Sed modifications and implications for fisheries

There is a need for better links between hydrology and ecology, specifically between landscapes and riverscapes to understand how processes and factors controlling the transport and storage of environmental pollution have affected or will affect the freshwater biota. Here we show how the INCA modelling framework, specifically INCA-Sed (the Integrated Catchments model for Sediments) can be used to link sediment delivery from the landscape to sediment changes in-stream. INCA-Sed is a dynamic, process-based, daily time step model. The first complete description of the equations used in the INCA-Sed software (version 1.9.11) is presented. This is followed by an application of INCA-Sed made to the River Lugg (1077 km2) in Wales. Excess suspended sediment can negatively affect salmonid health. The Lugg has a large and potentially threatened population of both Atlantic salmon (Salmo salar) and Brown Trout (Salmo trutta). With the exception of the extreme sediment transport processes, the model satisfactorily simulated both the hydrology and the sediment dynamics in the catchment. Model results indicate that diffuse soil loss is the most important sediment generation process in the catchment. In the River Lugg, the mean annual Guideline Standard for suspended sediment concentration, proposed by UKTAG, of 25 mg l− 1 is only slightly exceeded during the simulation period (1995–2000), indicating only minimal effect on the Atlantic salmon population. However, the daily time step simulation of INCA-Sed also allows the investigation of the critical spawning period. It shows that the sediment may have a significant negative effect on the fish population in years with high sediment runoff. It is proposed that the fine settled particles probably do not affect the salmonid egg incubation process, though suspended particles may damage the gills of fish and make the area unfavourable for spawning if the conditions do not improve.

A semi-distributed ntegrated itrogen model for multiple source assessment in tchments (INCA): Part I — model structure and process equations

A new model has been developed for assessing multiple sources of nitrogen in catchments. The model (INCA) is process based and uses reaction kinetic equations to simulate the principal mechanisms operating. The model allows for plant uptake, surface and sub-surface pathways and can simulate up to six land uses simultaneously. The model can be applied to catchment as a semi-distributed simulation and has an inbuilt multi-reach structure for river systems. Sources of nitrogen can be from atmospheric deposition, from the terrestrial environment (e.g. agriculture, leakage from forest systems etc.), from urban areas or from direct discharges via sewage or intensive farm units. The model is a daily simulation model and can provide information in the form of time series at key sites, or as profiles down river systems or as statistical distributions. The process model is described and in a companion paper the model is applied to the River Tywi catchment in South Wales and the Great Ouse in Bedfordshire.

Controls on inorganic nitrogen leaching from Finnish catchments assessed using a sensitivity and uncertainty analysis of the INCA-N model

The semi-distributed, dynamic INCA-N model was used to simulate the behaviour of dissolved inorganic nitrogen (DIN) in two Finnish research catchments. Parameter sensitivity and model structural uncertainty were analysed using generalized sensitivity analysis. The Mustajoki catchment is a forested upstream catchment, while the Savijoki catchment represents intensively cultivated lowlands. In general, there were more influential parameters in Savijoki than Mustajoki. Model results were sensitive to N-transformation rates, vegetation dynamics, and soil and river hydrology. Values of the sensitive parameters were based on long-term measurements covering both warm and cold years. The highest measured DIN concentrations fell between minimum and maximum values estimated during the uncertainty analysis. The lowest measured concentrations fell outside these bounds, suggesting that some retention processes may be missing from the current model structure. The lowest concentrations occurred mainly during low flow periods; so effects on total loads were small.

PERSiST: a flexible rainfall-runoff modelling toolkit for use with the INCA family of models

Runoff generation processes and pathways vary widely between catchments. Credible simulations of solute and pollutant transport in surface waters are dependent on models which facilitate appropriate, catchment-specific representations of perceptual models of the runoff generation process. Here, we present a flexible, semi-distributed landscape-scale rainfall-runoff modelling toolkit suitable for simulating a broad range of user-specified perceptual models of runoff generation and stream flow occurring in different climatic regions and landscape types. PERSiST (the Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport) is designed for simulating present-day hydrology; projecting possible future effects of climate or land use change on runoff and catchment water storage; and generating hydrologic inputs for the Integrated Catchments (INCA) family of models. PERSiST has limited data requirements and is calibrated using observed time series of precipitation, air temperature and runoff at one or more points in a river network. Here, we apply PERSiST to the river Thames in the UK and describe a Monte Carlo tool for model calibration, sensitivity and uncertainty analysis

As crônicas do Inca Garcilaso de La Vega: um discurso de legitimação

A literatura latino-americana está marcada pela heterogeneidade existente na América Latina, e a crônica é considerada o início desta heterogeneidade, devido ao fato de narrar um mundo desconhecido a leitores que fazem parte de outra realidade, gerando assim, uma situação de conflito. Os relatos escritos das civilizações andinas, em sua maioria, são de cronistas espanhóis, no entanto, também nos deparamos com alguns cronistas “índios” e mestiços, como o Inca Garcilaso de la Vega. Ele se destaca não somente por representar esta pequena parcela, ou seja, por ser um mestiço, mas, principalmente por ser herdeiro de duas nobrezas: a nobreza espanhola e a nobreza incaica. O cronista Inca Garcilaso era filho do capitão espanhol Garcilaso de la Vega, que possuía uma família que se destacava na guerra e na literatura; e de Chimpu Ocllo, uma princesa Inca, neta do Imperador Túpac Inca Yupanqui. Porém, este privilégio em relação aos outros mestiços, não lhe garantia o reconhecimento como nobre diante da coroa espanhola. Por isso, veremos neste trabalho que um dos seus intuitos ao escrever as crônicas Comentarios Reales de los Incas e Historia General del Perú, era o de tentar legitimar o seu status social diante dos espanhóis por meio de relatos que descrevem todos os feitos e avanços dos Incas, bem como afirmar, como uma de suas justificativas, que a colonização foi aceita pelos indígenas e estes estavam aptos à catequização, sendo uma maneira do Rei da Espanha e a Igreja Católica “salvarem” este povo da barbárie. Desta maneira, o Inca Garcilaso cria um discurso contraditório, pois, ao mesmo tempo que defende os espanhóis, ele glorifica o Império Inca

La anticuaria y la filología renacentista en los Comentarios Reales del Inca Garcilaso de la Vega. Una cuestión de evidencia

Este texto es una tentativa crítica acerca del uso de los métodos historiográficos renacentistas en los Comentarios Reales del Inca Garcilaso en relación con el concepto de la evidentia de la retórica clásica y la prueba (evidence) moderna. No es ajeno el Inca Garcilaso de la Vega a las implicaciones historiográficas que la elección de un método suponía. Aún más, es justamente la presunción en su escritura acerca del buen método lo que ubica nuestra pesquisa tras los pasos de un historiador mestizo que anuncia en el siglo XVI los modos de investigación de la disciplina en sentido moderno. La composición del ?discurso de la historia? de los Comentarios Reales no señala menos un proceso de escritura de acuerdo a las reglas del decoro y la fineza que una ostentación de ?pruebas? en relación con los documentos escritos y orales de su archivo de filólogo y con los testimonios materiales de su colección de anticuario. Pues tanto la filología como la anticuaria hacen de la "prueba" ya no, o al menos no con prioridad, el resultado de la "vividez" (enargeia) del relato sino una pieza argumentativa fundamental de la composición discursiva de los hechos pasados: una operación crítica mediante la yuxtaposición, confrontación y diálogo de las ?fuentes? y una mostración de objetos materiales que oficien como testimonios de ese pasado cuya legibilidad se resiste a la escritura de un discurso

Los Comentarios reales del Inca Garcilaso de la Vega : una poética de la historia

Puede resultar algo desconcertante la forma en que el Inca Garcilaso encara la escritura de la historia del incario en los Comentarios reales. Lejos de naturalizar esa práctica, de considerarla como la única forma posible de narrar la historia, nos proponemos rastrear algunos de los modelos que le sirvieron para generar la escritura de su obra. Nuestro trabajo se propone rastrear esos modelos en los que el Inca abrevó para la construcción de su obra mayor. Conocemos a partir de las investigaciones de Durán -fundamentalmente aquella en la que nos revela los nombres que poblaban la biblioteca del Inca- algunos libros que pueden haberle resultado decisivos a la hora de adoptar un modo de escritura. A partir de esos datos y del cotejo de la obra del Inca con otras obras y autores que conocía (Plinio, la Historia general de las Indias de Francisco López de Gómara, la Historia natural y moral de las Indias del padre José de Acosta), indagaremos en una serie de tradiciones que sirvieron de modelo para la escritura de la historia del incario: la recurrencia a la autoridad de los antiguos y, vinculada a ella, la consideración de aspectos de la historia natural; la influencia de una concepción judeo-cristiana de la historia; la autoridad otorgada al haber visto, proveniente de la historiografía griega; la vigencia del modelo historiográfico renacentista.

La anticuaria y la filología renacentista en los Comentarios Reales del Inca Garcilaso de la Vega. Una cuestión de evidencia

Este texto es una tentativa crítica acerca del uso de los métodos historiográficos renacentistas en los Comentarios Reales del Inca Garcilaso en relación con el concepto de la evidentia de la retórica clásica y la prueba (evidence) moderna. No es ajeno el Inca Garcilaso de la Vega a las implicaciones historiográficas que la elección de un método suponía. Aún más, es justamente la presunción en su escritura acerca del buen método lo que ubica nuestra pesquisa tras los pasos de un historiador mestizo que anuncia en el siglo XVI los modos de investigación de la disciplina en sentido moderno. La composición del ?discurso de la historia? de los Comentarios Reales no señala menos un proceso de escritura de acuerdo a las reglas del decoro y la fineza que una ostentación de ?pruebas? en relación con los documentos escritos y orales de su archivo de filólogo y con los testimonios materiales de su colección de anticuario. Pues tanto la filología como la anticuaria hacen de la "prueba" ya no, o al menos no con prioridad, el resultado de la "vividez" (enargeia) del relato sino una pieza argumentativa fundamental de la composición discursiva de los hechos pasados: una operación crítica mediante la yuxtaposición, confrontación y diálogo de las ?fuentes? y una mostración de objetos materiales que oficien como testimonios de ese pasado cuya legibilidad se resiste a la escritura de un discurso

Los Comentarios reales del Inca Garcilaso de la Vega : una poética de la historia

Puede resultar algo desconcertante la forma en que el Inca Garcilaso encara la escritura de la historia del incario en los Comentarios reales. Lejos de naturalizar esa práctica, de considerarla como la única forma posible de narrar la historia, nos proponemos rastrear algunos de los modelos que le sirvieron para generar la escritura de su obra. Nuestro trabajo se propone rastrear esos modelos en los que el Inca abrevó para la construcción de su obra mayor. Conocemos a partir de las investigaciones de Durán -fundamentalmente aquella en la que nos revela los nombres que poblaban la biblioteca del Inca- algunos libros que pueden haberle resultado decisivos a la hora de adoptar un modo de escritura. A partir de esos datos y del cotejo de la obra del Inca con otras obras y autores que conocía (Plinio, la Historia general de las Indias de Francisco López de Gómara, la Historia natural y moral de las Indias del padre José de Acosta), indagaremos en una serie de tradiciones que sirvieron de modelo para la escritura de la historia del incario: la recurrencia a la autoridad de los antiguos y, vinculada a ella, la consideración de aspectos de la historia natural; la influencia de una concepción judeo-cristiana de la historia; la autoridad otorgada al haber visto, proveniente de la historiografía griega; la vigencia del modelo historiográfico renacentista.