Pérdidas por intercepción de la vegetación y su efecto en la relación intensidad, duración y frecuencia (IDF) de la lluvia en una cuenca semiárida

López-Lambraño, A. A., Fuentes, C., González-Sosa, E., & López-Ramos, A. A. (julio-agosto, 2017). Pérdidas por intercepción de la vegetación y su efecto en la relación intensidad, duración y frecuencia (IDF) de la lluvia en una cuenca semiárida. Tecnología y Ciencias del Agua, 8(4), 37-56. Se cuantifica el componente hidrológico de la intercepción en vegetación semiárida y se evalúa el efecto en la relación intensidad-duración-frecuencia de la precipitación. La intercepción se determina mediante la simulación de lluvias a diferentes intensidades sobre muestras con cubierta vegetal herbácea; se obtienen los componentes del balance  hidrológico, como lámina precipitada, lámina escurrida, lámina almacenada en un espesor de suelo a un contenido de humedad inicial dado y lámina drenada. A partir de precipitaciones máximas, en 24 horas se obtienen las curvas intensidad-duración-frecuencia (IDF) de la precipitación para periodos de retorno de 2, 5, 10, 25, 50 y 100 años,  estableciendo cuatro escenarios con diferentes cubiertas vegetales para evaluar el efecto del componente de la intercepción en dichas curvas. De las simulaciones de lluvia que se realizan, se encuentra que el porcentaje interceptado en vegetación herbácea tiene un valor promedio de 2.33% del total de la precipitación incidente. Las curvas IDF son  afectadas en un 2.89% para el escenario que se conforma sólo por cubierta vegetal herbácea; para  el escenario con cubierta vegetal arbórea se tiene un efecto de 11.15%, y un 19.85% para el escenario que se conforma por vegetación herbácea y arbórea. Lo anterior da origen a que los caudales de diseño o volúmenes de escurrimiento directo en una cuenca disminuyan de manera significativa

Analytical Expressions of the Coefficient of Energy Losses in Diameter Reduction Devices on Forced Regime

En este artículo se obtienen expresiones analíticas del coeficiente de pérdidas de energía para dispositivos de reducción brusca y reducción gradual del diámetro, que operan en conductos bajo régimen forzado. Se observó que los métodos tradicionales para evaluar las pérdidas por dispositivos, requieren el empleo de fórmulas, tablas y gráficos al estimar el coeficiente de pérdida K. Se obtuvieron curvas de valores promedio para K y se ajustaron con métodos de regresiones lineales múltiples hasta obtener una ecuación representativa para cada caso estudiado. Se concluyó que las ecuaciones pueden ser utilizadas confiablemente para determinar el coeficiente de pérdida K sin necesidad de manipular tablas y gráficos.Analytical expressions of the energy loss coefficient for abrupt and gradual diameter reduction devices, operating in ducts on forced regime are obtained. For this approach, a state of the art was carried out where it was identified that the traditionally utilized methods (that assess the loss of the devices) needed formulas, tables and/or graphs when estimating the K coefficient. These results were used asdata in multiple linear regression methods until a representative equation for each case study was obtained. These equations constitue a reliable tool to determine the loss of the K coefficient without having to manipulate tables and graphs

Methodologies for the evaluation of seismic vulnerability in masonry structures

Para la evaluación del riesgo sísmico existen procedimientos cada vez más complejos y elaborados para su cálculo, siendo una herramienta fundamental las funciones de fragilidad y vulnerabilidad. En los últimos 30 años se han desarrollado varios métodos para el análisis de vulnerabilidad sísmica en estructuras de mampostería. En este artículo se han revisado algunas de las metodologías empíricas y analíticas más comunes y se explican de una manera concisa, lo que ayudara a decidir a otros investigadores del área a elegir cual es el método más adecuado dependiendo de la información disponible en el estudio que se está realizandoFor the evaluation seismic risk, there are evermore complex and elaborate procedures, the functions of fragility and vulnerability a fundamental tool. In the last 30 years, various methods have been developed for the analysis of seismic vulnerability in masonry structures. In this article, some of the most common empirical and analytical methodologies have been revised and are explained in a concise manner, which will help other investigators in the field to decide which method is the most suitable, depending on the available information in the study that is being carried out

Santa Ana Winds: Fractal-Based Analysis in a Semi-Arid Zone of Northern Mexico

A fractal analysis based on the time series of precipitation, temperature, pressure, relative humidity, and wind speed was performed for 16 weather stations located in the hydrographic basin of the Guadalupe River in Baja California, Mexico. Days on which the phenomenon known as Santa Ana winds occurs were identified based on the corresponding criteria of wind speed (≥4.5 m/s) and wind direction (between 0° and 90°). Subsequently, the time series was formed with data representing the days on which this phenomenon occurs in each of the analyzed weather stations. A time series was additionally formed from the days in which the Santa Ana winds condition does not occur. Hurst exponents and fractal dimension were estimated applying the rescaled range method to characterize the established time series in terms of characteristics of persistence, anti-persistence, or randomness along with the calculation of the climate predictability Index. This enabled the behavior and correlation analysis of the meteorological variables associated with Santa Ana winds occurrence. Finally, this type of research study is instrumental in understanding the regional dynamics of the climate in the basin, and allows us to establish a basis for developing models that can forecast the days of occurrence of the Santa Ana winds, in such a way that actions or measures can be taken to mitigate the negative consequences generated when said phenomenon occurs, such as fires and droughts

Santa Ana Winds: Fractal-Based Analysis in a Semi-Arid Zone of Northern Mexico

A fractal analysis based on the time series of precipitation, temperature, pressure, relative humidity, and wind speed was performed for 16 weather stations located in the hydrographic basin of the Guadalupe River in Baja California, Mexico. Days on which the phenomenon known as Santa Ana winds occurs were identified based on the corresponding criteria of wind speed (≥4.5 m/s) and wind direction (between 0° and 90°). Subsequently, the time series was formed with data representing the days on which this phenomenon occurs in each of the analyzed weather stations. A time series was additionally formed from the days in which the Santa Ana winds condition does not occur. Hurst exponents and fractal dimension were estimated applying the rescaled range method to characterize the established time series in terms of characteristics of persistence, anti-persistence, or randomness along with the calculation of the climate predictability Index. This enabled the behavior and correlation analysis of the meteorological variables associated with Santa Ana winds occurrence. Finally, this type of research study is instrumental in understanding the regional dynamics of the climate in the basin, and allows us to establish a basis for developing models that can forecast the days of occurrence of the Santa Ana winds, in such a way that actions or measures can be taken to mitigate the negative consequences generated when said phenomenon occurs, such as fires and droughts

Supply and Demand Analysis of Water Resources. Case Study: Irrigation Water Demand in a Semi-Arid Zone in Mexico

To sustainably use water resources, it is important to quantify water availability in a certain region. Due to climate change, population increase, and economic development, water demand increases continuously. Consequently, the difference between supply and demand of water becomes a significant issue, especially in arid and semi-arid regions. In this research, the Soil and Water Assessment Tool (SWAT) model has been applied to the Guadalupe river basin, to assess supply and demand analysis of water resources in this area, specifically for the irrigation of agricultural crops and municipal uses. From the land use, soil type, and terrain slope maps, 763 Hydrostatic Release Units (HRU) were estimated, distributed in the diverse relief types making up the basin, featured by mountains, hills, plateaus, plains, and valleys. For the crop area, 159 HRU were found with the three slope classification types, where 57 HRU represent 91% of the cultivated area on slopes, from 0 to 15%, located in the Ojos Negros and Guadalupe Valleys. The Soil Conservation Service method (SCS) was used to estimate the average monthly runoff and soil moisture content. As a result, water resource parameters related to the supply were determined with this, e.g., runoff, aquifer recharge, flow, infiltration, and others. Crop coefficient values (Kc) were used to determine crop evapotranspiration (ETc), to estimate the water demand of these for each month, using the multi-year monthly average reference evapotranspiration (ETo) calculated with the SWAT model. Overall good performance was obtained considering average monthly discharges data from the Agua Caliente gauging station. The model was calibrated, modifying the parameters chosen according to sensitivity analysis: SCS curve number, base-flow factor, ground-flow delay, and the threshold for return-flow occurrence. The Soil and Water Assessment Tool–Calibration and Uncertainty Programs SWAT-CUP has different goodness-of-fit indicators for the model e.g., determination coefficient (R2), standard deviation of the measured data (RSR), Nash–Sutcliffe coefficient of efficiency (NSE), and others. Multiple iterations were performed, resulting in a ratio between the root mean square error and the standard deviation of the measured data (RSR) of 0.61, a coefficient of determination (R2) of 0.70, and a Nash–Sutcliffe efficiency coefficient (NSE) of 0.63. A supply–demand analysis of the volume generated by the runoff from the basin was performed using the method of estimating useful volume for a reservoir. It is observed in these results that only positive deviations were obtained, implying that runoff in this basin is not enough to meet monthly demand. Finally, the need to establish actions to ensure water management efficiency is highlighted, both for irrigation of agricultural crops and for supply to the region population

Assessment of Morphometric Parameters as the Basis for Hydrological Inferences in Water Resource Management: A Case Study from the Sinú River Basin in Colombia

The geomorphology of a basin makes it possible for us to understand its hydrological pattern. Accordingly, satellite-based remote sensing and geo-information technologies have proven to be effective tools in the morphology analysis at the basin level. Consequently, this present study carried out a morphological analysis of the Sinú river basin, analyzing its geometric characteristics, drainage networks, and relief to develop integrated water resource management. The analyzed zone comprises an area of 13,971.7 km2 with three sub-basins, the upper, the middle, and the lower Sinú sub-basins, where seventeen morphometric parameters were evaluated using remote sensing (RS) and geographical information system (GIS) tools to identify the rainwater harvesting potential index. The Sinú basin has a dendritic drainage pattern, and the results of the drainage network parameters make it possible for us to infer that the middle and lower Sinú areas are the ones mainly affected by floods. The basin geometry parameters indicate an elongated shape, implying a lesser probability of uniform and homogeneous rainfall. Additionally, the hypsometric curve shape indicates that active fluvial and alluvial sedimentary processes are present, allowing us to conclude that much of the material has been eroded and deposited in the basin’s lower zones as it could be confirmed with the geological information available. The obtained results and GIS tools confirm the basin’s geological heterogeneity. Furthermore, they were used to delimit the potential water harvesting zones following the rainwater harvesting potential index (RWHPI) methodology. The research demonstrates that drainage morphometry has a substantial impact on understanding landform processes, soil characteristics, and erosional characteristics. Additionally, the results help us understand the relationship between hydrological variables and geomorphological parameters as guidance and/or decision-making instruments for the competent authorities to establish actions for the sustainable development of the basin, flood control, water supply planning, water budgeting, and disaster mitigation within the Sinú river basin

Assessment of Morphometric Parameters as the Basis for Hydrological Inferences in Water Resource Management: A Case Study from the Sinú River Basin in Colombia

The geomorphology of a basin makes it possible for us to understand its hydrological pattern. Accordingly, satellite-based remote sensing and geo-information technologies have proven to be effective tools in the morphology analysis at the basin level. Consequently, this present study carried out a morphological analysis of the Sinú river basin, analyzing its geometric characteristics, drainage networks, and relief to develop integrated water resource management. The analyzed zone comprises an area of 13,971.7 km2 with three sub-basins, the upper, the middle, and the lower Sinú sub-basins, where seventeen morphometric parameters were evaluated using remote sensing (RS) and geographical information system (GIS) tools to identify the rainwater harvesting potential index. The Sinú basin has a dendritic drainage pattern, and the results of the drainage network parameters make it possible for us to infer that the middle and lower Sinú areas are the ones mainly affected by floods. The basin geometry parameters indicate an elongated shape, implying a lesser probability of uniform and homogeneous rainfall. Additionally, the hypsometric curve shape indicates that active fluvial and alluvial sedimentary processes are present, allowing us to conclude that much of the material has been eroded and deposited in the basin’s lower zones as it could be confirmed with the geological information available. The obtained results and GIS tools confirm the basin’s geological heterogeneity. Furthermore, they were used to delimit the potential water harvesting zones following the rainwater harvesting potential index (RWHPI) methodology. The research demonstrates that drainage morphometry has a substantial impact on understanding landform processes, soil characteristics, and erosional characteristics. Additionally, the results help us understand the relationship between hydrological variables and geomorphological parameters as guidance and/or decision-making instruments for the competent authorities to establish actions for the sustainable development of the basin, flood control, water supply planning, water budgeting, and disaster mitigation within the Sinú river basin