Risk assessment of inter-basin water transfer plans through integration of Fault Tree Analysis and Bayesian Network modelling approaches

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Hydrogeochemical Characterization and Speleogenesis of Sistema Huautla in Oaxaca, Mexico

Sierra Mazateca, Mexico is home to Sistema Huautla, the deepest cave in the Western hemisphere with 1,560 meters of depth and 90 kilometers of passage, including 26 entrances distributed in a high-relief, karstified terrain, within the Sistema Huautla Karst Groundwater Basin. Exploration of the cave has generated research questions about its evolution and geomorphology given the different vadose and phreatic zones impacted by tectonic and incision processes. Dye traces during this study of Cueva de La Peña Colorada confirmed it is a fossil resurgence of the cave system. An additional cave, Cueva Elysium, was connected hydrologically in 2019, expanding the basin and recharge area for the cave system. Four springs were monitored at high-resolution along the Rio Santo Doming for water level, temperature, and specific conductivity in 2019. The dye trace results indicate connection between the springs and that primary dissolution likely occurs at the water table and phreatic zone, due to the extreme verticality of the cave system, while flood responses are rapid and short-lived, despite seasonal storms. Results from this study also help aid in understanding and managing water resources in the region, further exploration of the cave system and potential connections, and the future evolution of Sistema Huautla under a changing climate as exploration continues

Contribution of isotopic research techniques to characterize highmountain-Mediterranean karst aquifers: The Port del Comte (Eastern Pyrenees) aquifer.

Water resources in high mountain karst aquifers are usually characterized by high rainfall, recharge and discharge that leads to the sustainability of the downstream ecosystems. Nevertheless, these hydrological systems are vulnerable to the global change impact. The mean transit time (MTT) is a key parameter to describe the behavior of these hydrologic systems and also to assess their vulnerability. This work is focused on estimating MTT by using water stable isotopes in the framework of high-mountain karst systems with a very thick unsaturated zone (USZ). To this end, it is adapted to alpine zones an existing methodology that combines in a row a semi-distributed rainfall-runoff model used to estimate recharge time series, and a lumped-parameter model to obtain through a convolution integral. The methodology has been applied to the Port del Comte Massif (PCM) hydrological system (Southeastern Pyrenees, NE Spain), a karst aquifer system with an overlying1000 m thick USZ. Six catchment areas corresponding to most important springs of the system are considered. The obtained results show that hydrologically the behavior of the system can be described by an exponential flow model (EM), with MTT ranging between 1.9 and 2.9 years. These values are shorter than those obtained by considering a constant recharge rate along time, which is the easiest and most applied aquifer recharge hypothesis when estimating through lumped-parameter models. This methodology can be useful to improve the characterization and understanding of other high mountain karst aquifers with an overlying thick USZ that are common in many alpine zones elsewhere the globe

Contribution of isotopic research techniques to characterize high-mountain-Mediterranean karst aquifers: The Port del Comte (Eastern Pyrenees) aquifer

Water resources in high mountain karst aquifers are usually characterized by high rainfall, recharge and discharge that lead to the sustainability of the downstream ecosystems. Nevertheless, these hydrological systems are vulnerable to the global change impact. The mean transit time (MTT) is a key parameter to describe the behavior of these hydrologic systems and also to assess their vulnerability. Thiswork is focused on estimating MTT by using environmental tracers in the framework of high-mountain karst systems with a very thick unsaturated zone (USZ).To this end, it is adapted to alpine zones a methodology that combines a semi-distributed rainfall runoff model to estimate recharge time series, and a lumped-parameter model to obtain ΜΤΤ. The methodology has been applied to the Port del Comte Massif (PCM) hydrological system (Southeastern Pyrenees, NE Spain), a karst aquifer system with an overlying 1000 m thick USZ. Six catchment areas corresponding to most important springs of the system are considered. The obtained results show that hydrologically the behavior of the system can be described by an exponential flow model (EM), with MTT ranging between 1.9 and 2.9 years. These ΜΤΤ values are shorter than those obtained by considering a constant recharge rate along time, which is the easiest and most applied aquifer recharge hypothesis when estimating ΜΤΤ through lumped-parameter models

Assessing the Impacts of Surface Water Removal for Use in Natural Gas Extraction on a Watershed Level

In this study, the Soil and Water Assessment Test (SWAT) was used as a tool to predict whether diffuse water removal from the Cadron Creek watershed for use with natural gas development would have an impact on downstream flow within the watershed. Cadron Creek watershed expands across four counties within Arkansas and is located in the Fayetteville Shale Gas region. This region is experiencing significant growth in natural gas development. Successful development of shale gas depends on the identification of what water supplies are available for production without interfering with community and environmental needs. The SWAT model used to evaluate hypothetical water removal scenarios was calibrated and validated for accuracy using historical observed water flow (cms) from USGS gage number 07261000 at Wolf Creek outlet. Three scenarios were evaluated using the calibrated model for the 2000 - 2009 time periods. These scenarios are hypothetical, but based on water removal permits granted by the Arkansas National Resources Commission for consumption of surface water for natural gas extraction. The first scenario set up a base level of flow for the watershed, while the second scenario simulated downstream water flow impacts if there was annually consistent water removal. Scenario three restricted water removal during the typically low water level summer months. Results from the scenarios support the conclusion that water removal should be monitored and removed at a variable rate based on a percentage of total flow at any given time, supporting the natural flow dynamics of the stream

Coupled Mixing-Cell and Mass Balance Flow Path Models of the White River Flow System, Nevada, USA

ABSTRACT: Mass balance (MB), Discrete-State Compartment (DSC) (Campana, 1975) and Discrete-State Compartment-Shuffled Complex Evolution (DSC-SCE) (Carroll et al., 2007) models are compared for the White River Flow System (WRFS), in east-southeast Nevada, using δD and δ18O to evaluate 2006 recharge-discharge (RD) estimates and two water mixing scenarios in the WRFS. DSC models use a simple mixing-cell network for regional scale problems with limited data (Campana et al., 2001). DSC-SCE models combine the DSC and a global optimization algorithm, to obtain optimal solutions (Duan et al., 1992). The 2006 RD estimates and proposed flow paths are also evaluated using δD and δ18O values in a MB model. MB model results of calculated δD and δ18O values at regional springs are within ± 2 / and ± 0.2 / of observed values, respectively, expect for Pahranagat Valley. Thus, the MB model indicates that new RD estimates and resulting inter basin flow rates and proposed flow paths are reasonable for the WRFS. DSC models were unable to match 2006 RD estimates despite calibration with isotopes. Extremely large recharge and evapotranspiration (ET) values required to achieve calibration in some cells are improbable for the system and thus are not viable. However, these non-unique solutions and their results suggest that the system cannot be entirely explained by isotopes alone without any other constraints. DSC-SCE models provide additional flux and ET values based on the recharge estimates and isotopes; thus the DSC-SCE models may help constrain future water budget estimates. DSC-SCE results also suggest that the 2006 ET estimates are reasonable. MB, DSC and DSC-SCE model results imply that ET is most likely removed from local precipitation before any remaining precipitation mixes with regional groundwater in most valleys

Water Stress : Emerging Challenges of Global Water Scarcity

Edited by: Péter Kacziba; Viktor Glied | Title: WATER STRESS : Emerging Challenges of Global Water Scarcity | Authors: Péter Kacziba; Viktor Glied; Melinda Szappanyos; Zoltán Vörös; Péter Reményi; Norbert Pap; László Kákai | Published by University of Pécs / Faculty of Humanities Department of Political Science and International Studies, Pécs, 2020 | ISBN 978-963-429-523-5 | „The volume was financed by the Higher Education Institutional Excellence Programme of the Ministry for Innovation and Technology in Hungary, within the framework of the 3. thematic programme of the University of Pécs. --- A little bit more than ten years ago a book on water conflicts was published. We authors thought, we felt that the upcoming decade brings more serious ecological problems and various global challenges than ever before. And unfortunately we were not mistaken. This book was finalised during a rather difficult period. The sudden onset of the COVID-19 crisis has not only made the work of authors and editors more challenging but also transformed our living and working environment, changed the way of casual and academic interactions, and generally, altered the way we think about certainty and reality. The pandemic highlighted the fragility of our academic, social and global system and brought back the uncertainty of previous centuries. The crisis is a forecast and a sign of warning at the same time: our current course of growth and the relative prosperity can only be sustained if we change our habits and finally began to confront the challenges of the 21st century