404 research outputs found
The water cycle in Reccopolis
Reccopolis was a new city built in Visigothic Spain in the late 6th c. CE. Even rarer than this
example of an ex novo urban foundation in the post-Roman West is the fact that the city was equipped
with a brand-new aqueduct. The aqueduct has, until now, only been partially studied, but in this
paper we update and re-assess the original, preliminary results. We consider the city’s whole water
cycle, including usage and drainage, employing new engineering calculations and GIS analyses.
The results show that the aqueduct was an integral part of the city. Finally, we set our conclusions
within their wider context, looking not only at the roles of aqueducts in the ideal of a city at this
time, but also at urban water culture in the Late Antique West
Drainage estimation to aquifer and water use irrigation efficiency in semi-arid zone for a long period of time
Water requirements for different crop types according to soil type and climate conditions play not only an important role in agricultural efficiency production, though also for water resources management and control of pollutants in drainage water. The key issue to attain these objectives is the irrigation efficiency. Application of computer codes for irrigation simulation constitutes a fast and inexpensive approach to study optimal agricultural management practices. To simulate daily water balance in the soil, vadose zone and aquifer the VisualBALAN V. 2.0 code was applied to an experimental area under irrigation characterized by its aridity. The test was carried out in three experimental plots for annual row crops (lettuce and melon), perennial vegetables (artichoke), and fruit trees (citrus) under common agricultural practices in open air for October 1999-September 2008. Drip irrigation was applied to crops production due to the scarcity of water resources and the need for water conservation. Water level change was monitored in the top unconfined aquifer for each experimental plot. Results of water balance modelling show a good agreement between observed and estimated water level values. For the study period, mean drainage obtained values were 343 mm, 261 mm and 205 mm for lettuce and melon, artichoke and citrus respectively. Assessment of water use efficiency was based on the IE indicator proposed by the ASCE Task Committee. For the modelled period, water use efficiency was estimated as 73, 71 and 78 % of the applied dose (irrigation + precipitation) for lettuce and melon, artichoke and citrus, respectively.Peer ReviewedPostprint (published version
Drainage estimation to aquifer and water use irrigation efficiency in semi-arid zone for a long period of time
Water requirements for different crop types according to soil type and climate conditions play not only an important
role in agricultural efficiency production, though also for water resources management and control of pollutants in drainage water. The key issue to attain these objectives is the irrigation efficiency. Application of computer codes for irrigation simulation constitutes a fast and inexpensive approach to study optimal agricultural management
practices. To simulate daily water balance in the soil, vadose zone and aquifer the VisualBALAN V. 2.0 code was applied to an experimental area under irrigation characterized by its aridity. The test was carried out in three experimental
plots for annual row crops (lettuce and melon), perennial vegetables (artichoke), and fruit trees (citrus) under common agricultural practices in open air for October 1999-September 2008. Drip irrigation was applied to crops production due to the scarcity of water resources and the need for water conservation. Water level change
was monitored in the top unconfined aquifer for each experimental plot. Results of water balance modelling show a good agreement between observed and estimated water level values. For the study period, mean drainage obtained values were 343 mm, 261 mm and 205 mm for lettuce and melon, artichoke and citrus respectively. Assessment of water use efficiency was based on the IE indicator proposed by the ASCE Task Committee. For the modelled period, water use efficiency was estimated as 73, 71 and 78 % of the applied dose (irrigation + precipitation) for
lettuce and melon, artichoke and citrus, respectively.Peer ReviewedPostprint (published version
Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils
Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation
management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a
first measure. For this purpose, the control of volumetric water content, ¿, and pressure head, h, is required. This study adopted two
types of monitoring strategies in the same experimental plot to control ¿ and h in the vadose zone: i) non-automatic and more timeconsuming;
ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both
acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit
results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of ¿
and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely
estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, ¿s, and
the n and a van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient
of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic
data acquisition as data variability was lower and accuracy was higher.Peer ReviewedPostprint (author's final draft
Electrochemical treatment of aluminium alloy 7075 in aqueous solutions of imidazolium phosphonate and phosphate ionic liquids and scratch resistance of the resultant materials
The abilitiy of 1-ethyl-3-methylimidazolium ethylphosphonate ([ImPhosphonate]) and 1-ethyl-3-methylimidazolium diethylphosphate ([ImPhosphate]) ionic liquids (ILs) to interact with anodized Al7075 T6 aluminium alloy has been studied via electrochemical techniques under different applied potentials, inside and outside the passivation regions. SEM, EDX and XPS analysis have been used to study the composition of the surface coatings. The abrasion resistance after treatment with the ILs has been studied by scratch tests under progressive load, and compared with the performance of the unprotected material and the anodized alloy. While conventional anodization only improves the abrasion resistance of Al7075 in a 30%, the maximum reduction of the penetration depth, 86% with respect to Al7075 and 79% with respect to the anodized alloy, is obtained for the material treated with [ImPhosphonate] at 1 V, in the passivation region. Under these conditions, a phosphorus-containing alumina layer is formed. Applied voltages outside the passivation region for each IL activate the dissolution of the alumina layer and reduce abrasion resistance, not only with respect to the anodized material, but also with respect to the unprotected alloy.This work received the financial support of the Ministerio de Economía y Competitividad (MINECO, Spain) and the EU FEDER Program (Grant MAT2014-55384-P), and the Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia for a “Ayuda a las Unidades y Grupos de Excelencia Científica de la Región de Murcia (Programa Séneca 2014)” (Grant 19877/GERM/14)
Tackling Uncertainties of Species Distribution Model Projections with Package mopa
Species Distribution Models (SDMs) constitute an important tool to assist decision-making in environmental conservation and planning in the context of climate change. Nevertheless, SDM projections are affected by a wide range of uncertainty factors (related to training data, climate projections and SDM techniques), which limit their potential value and credibility. The new package mopa provides tools for designing comprehensive multi-factor SDM ensemble experiments, combining multiple sources of uncertainty (e.g. baseline climate, pseudo-absence realizations, SDM techniques, future projections) and allowing to assess their contribution to the overall spread of the ensemble projection. In addition, mopa is seamlessly integrated with the climate4R bundle and allows straightforward retrieval and post-processing of state-of-the-art climate datasets (including observations and climate change projections), thus facilitating the proper analysis of key uncertainty factors related to climate data.We acknowledge the ENSEMBLES project (GOCE-CT-2003-505539), supported by the European Commission’s 6th Framework Program for providing publicly the RCM simulations and observational data used in this study. We are also grateful to Rémy Petit and François Ehrenmann for providing the distribution of Oak phylogenies
Background sampling and transferability of species distribution model ensembles under climate change
Species Distribution Models (SDMs) constitute an important tool to assist decision-making in environmental conservation and planning. A popular application of these models is the projection of species distributions under climate change conditions. Yet there are still a range of methodological SDM factors which limit the transferability of these models, contributing significantly to the overall uncertainty of the resulting projections. An important source of uncertainty often neglected in climate change studies comes from the use of background data (a.k.a. pseudo-absences) for model calibration. Here, we study the sensitivity to pseudo-absence sampling as a determinant factor for SDM stability and transferability under climate change conditions, focusing on European wide projections of Quercus robur as an illustrative case study. We explore the uncertainty in future projections derived from ten pseudo-absence realizations and three popular SDMs (GLM, Random Forest and MARS). The contribution of the pseudo-absence realization to the uncertainty was higher in peripheral regions and clearly differed among the tested SDMs in the whole study domain, being MARS the most sensitive ? with projections differing up to a 40% for different realizations ? and GLM the most stable. As a result we conclude that parsimonious SDMs are preferable in this context, avoiding complex methods (such as MARS) which may exhibit poor model transferability. Accounting for this new source of SDM-dependent uncertainty is crucial when forming multi-model ensembles to undertake climate change projections.We acknowledge the ENSEMBLES project, funded by the European Commission's EU 6th Framework Programme through contract GOCE-CT-2003-505539. The first author has a research contract from the EU-funded project FP7- SEC-2013-1 (INTACT)
Tributos y presupuestos
Dentro del apartado correspondiente a las novedades normativas referentes a la Comunidad Autónoma de Aragón, las normas que afectan a la materia aquí examinada –y que, por ello, deben ser objeto de comentario en las páginas sucesivas– son las leyes siguientes: a) Ley 1/2016, de 28 de enero, de Presupuestos de la Comunidad Autónoma de Aragón para el ejercicio 2016; b) La Ley 2/2016, de 28 de enero, de Medidas Fiscales y Administrativas de la Comunidad Autónoma de Aragón; c) La Orden de 22 de julio de 2015, por la que se modifica el anexo II del Reglamento regulador del Impuesto sobre la Contaminación de las Aguas de la Comunidad Autónoma de Aragón y d) La Orden de 3 de agosto de 2015, por la que se regula la transferencia de la información que deben proporcionar las entidades suministradoras de agua al Instituto Aragonés del Agua para la recaudación del Impuesto sobre la Contaminación de las Aguas
Temporal scaling of groundwater discharge in dual and multicontinuum catchment models
This paper presents a multicontinuum approach to model fractal temporal scaling of catchment response in hydrological systems. The temporal scaling of discharge is quantified in frequency domain by the transfer function (), which is defined as the ratio between the spectra of catchment response and recharge time series. The transfer function may scale with frequency as ()approximate to-. While the classical linear and Dupuit models predict exponents of =2 and =1, observations indicate scalings with noninteger exponents . Such behaviors have been described by multifractal models, which, however, often lack a relation to the medium characteristics. We revisit and extend the classical linear Dupuit aquifer models and discuss their physical meanings in the light of the resulting aquifer dynamics. On the basis of these classical models, we derive a multicontinuum approach that provides physical recharge models which are able to explain fractal behaviors with exponents 1/2<<2. Furthermore, this approach allows to link the fractal dynamics of the discharge process to the physical aquifer characteristics as reflected in the distribution of storage time scales. We systematically analyze the catchment responses in the proposed multicontinuum models, and identify and quantify the time scales which characterize the dynamics of the catchment response to recharge.Peer ReviewedPostprint (published version
Hacia una política de desarrollo agropecuario y campesino en el Municipio de El Carmen de Viboral – Antioquia
El documento “hacia una política de desarrollo agropecuario y campesino en el Municipio de El Carmen de Viboral”, presenta el diagnóstico y el análisis situacional del sector agropecuario del municipio del Carmen de Viboral, así como los lineamientos para la política pública municipal para el sector. El análisis se basó en fuentes primarias y secundarias y en un proceso metodológico de marco lógico y talleres participativos para construir el árbol de problemas y el árbol de objetivos. El problema central se definió como “rezago socioeconómico del sector agropecuario, familias, organizaciones y productores campesinos (as) en el Municipio de El Carmen de Viboral”, del cual se destacaron cinco (5) grandes causas: deterioro de condiciones productivas del sector agropecuario en el Municipio, bajo acceso a crédito, subsidios y programas de apoyo a la producción agropecuaria, bajo acceso a desarrollos tecnológicos para el sector agropecuario, deficiencia en la infraestructura vial y en los equipamientos de apoyo a la distribución y comercialización y desprotección social de productores campesinos.
En relación con el análisis de objetivos se definió junto con las comunidades que es necesario orientar la política municipal hacia la “recuperación social y económica del sector agropecuario, sus productores, familias y organizaciones campesinas en el Municipio de El Carmen de Viboral.” Para avanzar en este sentido se proponen cinco (5) alternativas: implementar eficientemente el servicio de extensión agropecuaria, generar condiciones que contribuyen a mejorar la productividad del sector agropecuario, facilitar el acceso a desarrollos tecnológicos para el sector agropecuario, disposición de equipamientos, infraestructuras y servicios que permiten mejorar procesos de distribución y de comercialización de productos agropecuarios y finalmente, mejorar los servicios de protección social al campesinado.
Al final se plantea la matriz de planificación con estrategias y acciones de política pública por cada lineamiento, así como recomendaciones para actores estratégicos.The document "Towards a policy of agricultural and peasant development in the Municipality of El Carmen de Viboral", presents the diagnosis and situational analysis of the agricultural sector of the municipality of El Carmen de Viboral, as well as the guidelines for municipal public policy for the sector. The analysis was based on primary and secondary sources and a methodological process of logical framework and participatory workshops to build the problem tree and the objective tree. Thecentral problem was defined as "socioeconomic backwardness of the agricultural sector, families, organizations and peasant producers in the Municipality of El Carmen de Viboral", of which five (5) major causes were highlighted: deterioration of productive conditions of the agricultural sector in the municipality, low access to credit, subsidies and support programs for agricultural production, accessto technological developments for the agricultural sector, deficiency in road infrastructure and equipment to support distribution and marketing and lack of social protection of peasant producers.
In relation to the analysis of objectives, it was defined together with the communities that it is necessary to orient municipal policy towards the "social and economic equality of the agricultural sector, its producers, families and peasant organizations in the Municipality of El Carmen de Viboral." To advance in this direction, five (5) alternatives are proposed: efficiently implement the service of energy to bus, generate conditions that contribute to improving the productivity of the agricultural sector, facilitate access to technological developments for the agricultural sector, provision of equipment, infrastructures and services that allow improving distribution processes and marketing of agricultural products and finally, improving social protection services for farmers.
At the end, the planning matrix is proposed with strategies and public policy actions for each guideline, as well as recommendations for strategic actors
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