The concept of doing hydrology backwards, introduced in the literature in the last decade, relies on the possibility to invert the equations relating streamflow fluctuations at the catchment outlet ...to estimated hydrological forcings throughout the basin. In this work, we use a recently developed set of equations connecting streamflow oscillations at the catchment outlet to baseflow oscillations at the hillslope scale. The hillslope-scale oscillations are then used to infer the pattern of evaporation needed for streamflow oscillations to occur. The inversion is illustrated using two conceptual models of movement of water in the subsurface with different levels of complexity, but still simple enough to demonstrate our approach. Our work is limited to environments where diel oscillations in streamflow are a strong signal in streamflow data. We demonstrate our methodology by applying it to data collected in the Dry Creek Experimental Watershed in Idaho and show that the hydrology backwards principles yield results that are well within the order of magnitude of daily evapotranspiration fluctuations. Our analytic results are generic and they encourage the development of experimental campaigns to validate integrated hydrological models and test implicit parameterization assumptions.
We investigate how channel flow dynamics on real river networks produces scaling in peak flows. Scaling relations have been defined by log–log linearity between peak flow statistics and drainage ...areas for idealized mean self-similar networks like Peano and Mandelbrot Viscek. Unlike idealized basins, drainage areas and link lengths in real basins vary statistically. We use Horton–Strahler order as scale parameter instead of drainage area, and use the Hortonian framework to analyze these network structures. A river-network oriented GIS is used to extract the drainage network for the Walnut Gulch basin, Arizona in the United States. It provides the link connectivity structure and the geometric variables for numerically solving coupled link-based mass and momentum conservation equations. The equations are solved for spatially uniform and instantaneous injection of runoff under three different scenarios of flow in the channels: (1) Constant Velocity, (2) Constant Friction, and (3) Spatially Variable Friction. We find that Hortonian scaling in peak flows does not hold for the constant friction scenario. The scaling exponents of peak flows for the other two cases are larger than the scaling exponent of the peaks of the width functions. This property of scaling exponents for a real network is opposite to previous findings for idealized mean self-similar networks. An empirical scaling analysis of peak flows on the Walnut Gulch basin is briefly explained to provide preliminary empirical support to our theoretical findings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
El presente artículo muestra cómo ha sido el desarrollo de Claro S.A. y como sus estrategias han influenciado el sector de las telecomunicaciones en Colombia, las regulaciones iniciales a las que fue ...sometido el sector y como poco a poco se ha ido consolidando como uno de los sectores económicos más importantes del país.
Se realiza una prospectiva en general del negocio de las telecomunicaciones a nivel mundial y en particular en Colombia y como estas tendencias afectarían las decisiones a futuro de la empresa Claro y cuáles serían los retos a los cuales se enfrentaría.
Para la realización del presente artículo en forma de estudio de caso se utilizó una metodología cualitativa con alcance descriptiva, basada en el rastreo bibliográfico, encontrando que Claro Colombia es reconocida por ser una de las empresas más importantes y solidas del país, no solo por la prestación de sus servicios, ayudando a que los rincones más apartados del país se encuentren comunicados con las principales ciudades, sino que también es considerada como una de las empresas generadoras de empleo predilecta por los colombianos.
Además, Claro Colombia desde sus inicios ha sentado las bases de la transformación tecnológica del negocio de telecomunicaciones en el país, se ha caracterizado por estar a la vanguardia en prestación de servicios, infraestructura de telefonía móvil y fija, convirtiéndola
en un elemento accesible a toda la población colombiana, ratificándose como la principal empresa de telecomunicaciones por su amplia cobertura.
•Antecedent SMAP soil moisture (SM) has a significant relationship with runoff ratio.•Probability of higher runoff ratios increases as event total rainfall increase.•SM-deficit-normalized rainfall ...has a better predictive power than SM and rainfall.•Vegetation has significant effect on runoff in an agricultural region.
Following results by Crow et al. (2017) Geophys. Res. Lett. 44, 5495–5503 on the impact of antecedent soil moisture on runoff production, we investigate total runoff production during individual rainfall-runoff events in agricultural landscapes as a function of antecedent soil moisture, total rainfall, and vegetation cover for catchments with drainage areas ranging from 80 to 1000 km2 in the state of Iowa, USA. For our study, we use Enhanced SMAP soil moisture estimates, the MODIS enhanced vegetation index (EVI), gauge-corrected Stage IV radar rainfall, and USGS streamflow data. We analyze the event runoff ratio as a function of event-scale rainfall, antecedent SMAP soil moisture and soil-moisture-deficit-normalized rainfall for the events in a period from March 31, 2015 to October 31, 2018. Our goal is to confirm the relationships identified by Crow et al. (2017) in heavily managed agricultural landscapes and to refine some of their methodological steps to quantify the role of additional variables controlling runoff production. To this end, we define three different strategies to identify rainfall-runoff events and add a baseflow separation step to better insulate event scale stormflow runoff. We test the effects of antecedent soil moisture, rainfall, and vegetation on the event-scale runoff ratio. The antecedent SMAP soil moisture and event-scale rainfall are found to have significant predictive power in estimating event runoff ratio. Soil moisture deficit-normalized rainfall, introduced as the ratio of event-scale rainfall to available space in top soil before initiation of the event, exhibited a more distinct relationship with runoff ratio. The long-term analysis of runoff ratio, rainfall, and MODIS EVI indicated that, in an agricultural region, vegetation plays a significant role in determining event-scale runoff ratios. The methodology and outcome of our study have direct implications on real-time flood forecasting and long-term hydrologic assessments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
La era digital y los continuos avances tecnológicos generan cambios en la forma de vivir, actuar y pensar, exigiendo nuevas habilidades para ser competitivo e innovador. Los avances originan nuevas ...habilidades; inventos como la rueda, la bombilla, el automóvil, la computadora y la Internet, fueron estableciendo varios tipos de analfabetismo. Inicialmente el término comprendía a la incapacidad de leer y escribir; después la necesidad de una segunda lengua, y finalmente, destrezas mínimas para atender los retos de la sociedad del conocimiento con nuevos recursos digitales. Para el siglo XXI se llama alfabetización digital, con cambios obligatorios en la forma de pensar, actuar y resolver problemas. Como respuesta surge el pensamiento computacional, visto como la capacidad para resolver problemas con apoyo de la tecnología e informática. En el abanico de estrategias para lograr su desarrollo, se presentan los resultados acumulados en 2 años, desde un semillero de investigación.
•We evaluate HLM performance comparing simulated and observed streamflow at 150 locations in Iowa.•We explore the effect of including an interflow component in model structure.•We test a routing ...model adapted to the flow velocity of each stream order.•We study the effect of bias correction in radar rainfall products.
This study evaluates the performance of Iowa Flood Center’s real-time distributed hydrologic model, Hillslope-Link Model (HLM). The HLM provides information about current and future streamflow conditions for over 1000 locations in Iowa, including small communities and stream gauge locations. The HLM uses a calibration-free approach in which a system of ordinary nonlinear differential equations represents the processes of rainfall to runoff translation as well as the transport of water in the river network. The authors developed a comprehensive evaluation framework to improve the model performance through modification of its structure, and not by parameter calibration. The authors explored modifications to the runoff generation modeling, and to the approach for routing water in channels. Model performance was assessed using different metrics: Nash Sutcliffe efficiency (NSE); Kling Gupta efficiency (KGE); mean absolute error of river stages (MAE); percent bias (PB); annual peak difference; ratio of hits, misses and false alarms, and timing difference. The inclusion of an interflow component alleviated problems of volume underestimation. Timing of model simulations was found to be more accurate when the routing component considered the channel stream order. In the study, effect of rainfall input on the model performance was verified with Stage IV, which includes bias adjustment using gauge information, and a radar rainfall product created in real-time by IFC without bias correction. Open-loop simulations obtained with Stage IV and IFC rainfall show similar performance. Out of all the simulations obtained with Stage IV, 88% have NSE > 0; 95% have KGE > 0; 65% have MAE < 1 foot; 83% have |PB| < 40; 35% have hit rate >40%; average peak estimation errors are below 5% at large basins and below 20% at small basins; and the average timing difference is smaller than three hours. The characteristics of landforms and the impact of agricultural practices in the region are related to the spatial distribution of model performance. The study provides the basis for future improvements of the model.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
La educación tiene por tarea preparar individuos para retos, necesidades y oportunidades de un mundo globalizado; ahora con tecnología permeando las actividades del ser humano, teorías de aprendizaje ...tradicionales sin reconocer elementos de la alfabetización digital (conductismo, cognitivismo y constructivismo). Demandan cambios de pensamiento y más aún con la presencia del COVID-19, pandemia que impulsó aislamientos físicos sociales; aumentando la necesidad de dominar escenarios digitales. Lo anterior resalta al pensamiento computacional, como estrategia efectiva aplicada con el modelo presentado por el MIT-Harvard, con marco teórico definido y aplicado desde el año 2012. El objetivo de la investigación es diagnosticar el nivel de formación de competencias del pensamiento computacional para resolver problemas; y establecer desde un estudio cuantitativo con diseño no experimental transeccional la correlacional entre: las dimensiones conceptual, práctica y perspectiva computacional, con el desarrollo de competencias en pensamiento computacional para resolver problemas, implementado en un colegio público de Colombia con 133 estudiantes de educación media. El instrumento de diagnóstico, validado y categorizado por 32 problemas, dimensiona las habilidades para generar competencias, con similitudes al sistema educativo colombiano que promueve los aprendizajes con: el saber, saber hacer y saber ser; lo anterior se consolida como insumos para la generación de un ecosistema virtual de aprendizaje.
A series of numerical experiments were conducted to test the connection between streamflow hydrographs at the outlet of large watersheds and the time series of hillslope-scale runoff yield. We used a ...distributed hydrological routing model that discretizes a large watershed (∼ 17 000 km2) into small hillslope units (∼ 0.1 km2) and applied distinct surface runoff time series to each unit that deliver the same volume of water into the river network. The numerical simulations show that distinct runoff delivery time series at the hillslope scale result in indistinguishable streamflow hydrographs at large scales. This limitation is imposed by space-time averaging of input flows into the river network that are draining the landscape. The results of the simulations presented in this paper show that, under very general conditions of streamflow routing (i.e., nonlinear variable velocities in space and time), the streamflow hydrographs at the outlet of basins with Horton–Strahler (H–S) order 5 or above (larger than 100 km2 in our setup) contain very little information about the temporal variability of runoff production at the hillslope scale and therefore the processes from which they originate. In addition, our results indicate that the rate of convergence to a common hydrograph shape at larger scales (above H–S order 5) is directly proportional to how different the input signals are to each other at the hillslope scale. We conclude that the ability of a hydrological model to replicate outlet hydrographs does not imply that a correct and meaningful description of small-scale rainfall–runoff processes has been provided. Furthermore, our results provide context for other studies that demonstrate how the physics of runoff generation cannot be inferred from output signals in commonly used hydrological models.
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•Proposed model captures range of observed soil moisture (SM) in time.•SMAP estimes are drier than modeled & observed SM during summer.•SM model was able to generate observed SM ...spatial statistics.•Observed and modeled average SM has highest variability at intermediate range.•SM skewness is positive and negative for dry and wet average SM, respectively.
This study focused on the utility of coarse surface soil moisture observations for applications that require high resolution surface soil moisture information. This was accomplished by quantifying the information content of average soil moisture for three different spatial scales of 81 km2, 790 km2, and 4400 km2. In situ point observations of soil moisture from 31 stations in Iowa were used to develop a spatial stochastic model that assumes hillslope-scale model parameters are independent. Soil moisture dry-downs and wetting regimes were analyzed using rain gauge and soil moisture sensor data. The statistical nature of dry-downs were parameterized using a power-law decay, and soil moisture increases due to rainfall were parameterized using a non-dimensional logistic curve that is a function of soil moisture deficit. The resulting stochastic model is used to quantify the magnitude of the standard deviation, σ(θ), and skewness G(θ) as a function of the areal average. We show that the greatest information content (small spatial standard deviation) of average observation corresponded to values near the minimum or the maximum soil moisture with σ(θ)<5%, while average observations for intermediate soil moisture values had the lowest information content with σ(θ)>20%. The differences in information content as a function of the areal average were consistent with the statistical nature of soil moisture that can be interpreted as small range bounded variable. However, this study provides quantitative estimates for the magnitude of the sub-grid and basin scale variability, documenting the utility for applications that require high resolution information. These results form the basis for the investigation of spatial runoff production in response to rainfall and to inform plot scale agriculture applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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