No abstract

The demand for groundwater resources in arid and semi-arid regions has increased due to their progressive use in agriculture, industry and domestic activities. Among the difficulties and uncertainties that arise when managing groundwater resources is the calculation of groundwater withdrawals (GWW). The objective of this research work is to review the existing literature on the methods developed to estimate GWW by providing a summary of the advances, limitations and opportunities that the different methods developed on this topic could offer by identifying, categorizing and synthesizing the studies with a focus on developing a systematic guide so that researchers and practitioners conducting GWW studies can be informed of the most popular techniques, and the authors’ experiences in recent years. Therefore, a literature search was conducted in the EEE, Google Scholar, SCOPUS, SpringerLink, ScienceDirect, Taylor & Francis Group and Wiley-Blackwell databases, using the following keywords: Groundwater AND (Withdrawal OR Pumping OR Abstraction) AND (Prediction OR Estimation). Thirty-four journal articles published between 1970 and 2021 were chosen based on the selection criteria, characteristics and capabilities of the approaches used for evaluation in GWW extraction. We concluded that the different methods for groundwater pumping estimation that have been reviewed in this work have advantages and disadvantages in their application. Direct approaches are very old and are still working uncertainty in their application is presented with possible human errors or in the measurement system. On the other hand, indirect methods have evolved along with technological advances, which have brought significant improvements and accuracy to these approaches.

Palabras claveCoeficiente de pérdidas, dinámica de fluidos, modelación hidráulica, pérdidas hidráulicas. ResumenEn 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. Key words Dynamics of Fluids, Hydraulic Losses, Hydraulic Modeling, Losses CoefficientAbstract 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 as data 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.

Este trabajo obtiene expresiones analíticas para calcular el coeficiente de pérdida (K), para expansiones súbitas ó graduales de diámetro, operando bajo presión. La revisión de la literatura mostró que los métodos típicamente utilizados para evaluar la pérdida de energía en estos dispositivos no sólo proporcionan coeficientes diferentes; sino que también requiere manipular fórmulas, tablas y gráficos. Utilizando los métodos proporcionados en la literatura, determinamos los valores medios para el coeficiente local de pérdida, ajustado por regresiones lineales múltiples, para obtener una ecuación representativa para cada caso estudiado.

Una revisión de las metodologías para estimar el coeficiente de pérdidas en curvas de tuberías bajo flujo turbulento A review of the methodologies for estimating the coefficient of losses in pipe curves under turbulent flow