An innovative mode of groundwater recharge to a buried esker aquifer is considered. The current conceptual model affords a natural safeguard to underlying aquifers from the overlying muds. A hypothesis of groundwater recharge to a buried esker aquifer via preferential pathways across its overlying muds is tested here by heuristic numerical one-dimensional and two-dimensional modeling simulations. The hypothesis has been tested against two other conventionally accepted scenarios involving: (1) distal esker outcrop areas and (2) remote shallow-bedrock recharge areas. The main evidence comes from documented recharge pressure pulses in the overlying mud aquitard and in the underlying esker hydraulic-head time series for the Vars-Winchester esker aquifer in Eastern Ontario, Canada. These perturbations to the potentiometric surface are believed to be the aquifer response to recharge events. The migration rate of these pressure pulses is directly related to the hydraulic diffusivity of the formation. The measured response time and response amplitude between singular radar precipitation events and well hydrographs constituted the heuristic model calibration targets. The main evidence also includes mud-layering deformation (water escape features) which was observed in seismic surveys of the over-esker muds. These disturbed stratigraphic elements provide a realistic mechanism for migrating water to transit through the muds. The effective hydraulic conductivities of these preferential pathways in the muds were estimated to be between 2 × 10⁻⁶ and 7 × 10⁻⁶ m/s. The implications of these findings relate to the alleged natural safeguard of these overlying muds.

The Regional Deep Cretaceous Aquifer (RDCA) is the principal groundwater resource in Syria. Isotope and hydrochemical data have been used to evaluate the geographic zones in terms of renewable and non-renewable groundwater and the inter-relation between current and past recharge. The chemical and isotopic character of groundwater together with radiometric ¹⁴C data reflect the existence of three different groundwater groups: (1) renewable groundwater, in RDCA outcropping areas, in western Syria along the Coastal and Anti-Lebanon mountains. The mean δ¹⁸O value (−7.2 ‰) is similar to modern precipitation with higher ¹⁴C values (up to 60–80 pmc), implying younger groundwater (recent recharge); (2) semi-renewable groundwater, which is located in the unconfined section of the RDCA and parallel to the first zone. The mean δ¹⁸O value (−7.0 ‰) is also similar to modern precipitation with a ¹⁴C range of 15–45 pmc; (3) non-renewable groundwater found in most of the Syrian interior, where the RDCA becomes confined. A considerable depletion in δ¹⁸O (−8.0 ‰) relative to the modern rainfall and low values of ¹⁴C (<15 pmc) suggest that the large masses of deep groundwater are non-renewable and related to an older recharge period. The wide scatter of all data points around the two meteoric lines in the δ¹⁸O-δ²H diagram indicates considerable variation in recharge conditions. There is limited renewable groundwater in the mountain area, and most of the stored deep groundwater in the RDCA is non-renewable, with corrected ¹⁴C ages varying between 10 and 35 Kyr BP.

The aim was to study density-driven groundwater flow and analyse groundwater mixing because of seasonal changes in groundwater temperature. Here, density-driven convection in groundwater was studied by numerical simulations in a subarctic climate, i.e. where the water temperature was <4 °C. The effects of soil permeability and groundwater temperature (i.e. viscosity and density) were determined. The influence of impermeable obstacles in otherwise homogeneous ground was also studied. An initial disturbance in the form of a horizontal groundwater flow was necessary to start the convection. Transient solutions describe the development of convective cells in the groundwater and it took 22 days before fully developed convection patterns were formed. The thermal convection reached a maximum depth of 1.0 m in soil of low permeability (2.71 · 10⁻⁹ m²). At groundwater temperature close to its density maximum (4 °C), the physical size (in m) of the convection cells was reduced. Small stones or frost lenses in the ground slightly affect the convective flow, while larger obstacles change the size and shape of the convection cells. Performed simulations show that “seasonal groundwater turnover” occurs. This knowledge may be useful in the prevention of nutrient leakage to underlying groundwater from soils, especially in agricultural areas where no natural vertical groundwater flow is evident. An application in northern Sweden is discussed.

One way to see a change in environmental process is the use of appropriate parameters to tell us before and after these processes. With this we address primarily the study of climate change, particularly in coastal areas. Therefore, we have established a base of quality parameters of seawater coastline in order to evaluate the possible relation to climate change and its effects on marine environments in the Pacific and the Caribbean, the Isthmus of Panama. Therefore, samples of coastal seawater at Galeta, Playa Teta, Playa Hermosa and Playa La Marinera, four times a year, twice per season since 2013. These samples were analyzed by physical, chemical and microbiological parameters, following standard methodologies. The results allow carrying out a descriptive analysis of the coastal marine water quality sampling at each site on a given time and space. We conclude that there exists a possible link between the coastal marine water quality and the influence of climatic conditions on the concentration of the parameters and their seasonal pattern in the Pacific and Caribbean coasts of Panama. This study allows to establish a long-term research that contributes to scientific knowledge about water quality off the coast of Panama, promoting new research on these ecosystems and allowing to know the vulnerability to which they are exposed to prevent and mitigate the possible effects of climate change. | Una de las formas de ver un cambio en un proceso ambiental, es la utilización de parámetros adecuados que nos indiquen un antes y un después de estos procesos. Con esto abordamos principalmente el estudio del cambio climático, específicamente en zonas costeras. Por ello, se ha establecido una línea base de parámetros de calidad de agua marina costera con el fin de evaluar la posible relación con el cambio climático y sus efectos sobre los ambientes marinos en las costas del Pacífico y el Caribe del istmo de Panamá. Por consiguiente, se colectaron muestras de aguas marinas costeras en Punta Galeta, Playa Teta, Playa Hermosa y Playa La Marinera, cuatro veces al año, dos veces por temporada desde el año 2013. Estas muestras fueron analizadas según parámetros físico-químicos y microbiológicos, siguiendo metodologías estandarizadas. Los resultados obtenidos permiten la realización de un análisis descriptivo de la calidad del agua marina costera en cada sitio de muestreo en un tiempo y espacio determinado. Se concluye que sí existe una posible relación entre la calidad del agua marina costera y la influencia de las condiciones climáticas sobre la concentración de los parámetros y su comportamiento estacional en las costas del Pacífico y Caribe de Panamá. Este estudio permite establecer una investigación a largo plazo que contribuye al conocimiento científico sobre la calidad del agua en las costas de Panamá, impulsando nuevos estudios de investigación sobre estos ecosistemas y permitiendo conocer la vulnerabilidad a la que están expuestas para prevenir y mitigar los posibles efectos del cambio climático.

Subsidence due to groundwater overexploitation has been recognized in the metropolitan area of Murcia (25 km²) in south-eastern Spain since the early 1990s. Previous published works have focused their attention on land subsidence that occurred during the drought period between 1995 and 2008. This work first analyzes the groundwater recovery that has occurred since 2008 and then determines the kind of associated ground deformation detected by the new extensometric data. Subsequently, subsidence time series are computed on 24 geotechnical boreholes scattered throughout the study area by means of a hydro-mechanical finite element code and a linear-elastic constitutive law. A spatio-temporal interpolation of the numerically modeled surface displacements is performed over the whole domain and compared with extensometers and DInSAR-derived displacement maps in two different periods: the drought period from 2004 to 2008, and the recovery period from 2008 to 2012. In spite of the limited information on the geomechanical parameters characterizing the modelled geological formations, the proposed approach is able to discriminate areas where the soils have an elastic behavior (small differences in the comparisons) or an elasto-plastic behavior (large differences in the comparisons). This zonation enhances the understanding of the subsidence phenomenon in Murcia City and could prevent, from a quantitatively point of view, future severe subsidence due to aquifer overexploitation.

The thermal profile of a streambed is affected by a number of factors including: temperatures of stream water and groundwater, hydraulic conductivity, thermal conductivity, heat capacity of the streambed, and the geometry of hyporheic flow paths. Changes in these parameters over time cause changes in thermal profiles. In this study, temperature data were collected at depths of 30, 60, 90 and 150 cm at six streambed wells 5 m apart along the thalweg of Little Kickapoo Creek, in rural central Illinois, USA. This is a third-order low-gradient baseflow-fed stream. A positive temperature gradient with inflection at 90-cm depth was observed during the summer period. A negative temperature gradient with inflection at 30 cm was observed during the winter period, which suggests greater influence of stream-water temperatures in the substrate during the summer. Thermal models of the streambed were built using VS2DHI to simulate the thermal profiles observed in the field. Comparison of the parameters along with analysis of temperature envelopes and Peclet numbers suggested greater upwelling and stability in temperatures during the winter than during the summer. Upwelling was more pronounced in the downstream reach of the pool in the riffle and pool sequence.

The Technical University of Cotopaxi with coordination to Agricultural Engineering Career and Researching Direction carried out the kraft papper obtainment process which had two day process from the moment the fiber gets wet to improve its characteristics and softeness after the cooking process, liquefied, sheet formation, pressing and drying. Two outstanding treatments were obtained on the investigation that meet the physical ranges by 1 429 INEN regulation. As the treatment case is: t7 (Sisalana agave fiber, calcium carbonate, chlorine dioxide). Meet with the indicators and objectives. | La Universidad Técnica de Cotopaxi en coordinación con la Dirección de Investigación y la Carrera de Ingeniería Agroindustrial. Realizó el proceso de obtención de papel kraft, el cual tuvo un proceso de dos días, desde el momento en que se humecta a la fibra para mejorar sus características y suavizarla, consiguiente al proceso de cocción, licuado, formación de la hoja, prensado y secado. Se obtuvieron dos tratamientos sobresalientes en la investigación que cumplen con los rangos físicos establecidos por la normativa INEN 1 429, como es el caso de los tratamientos: t7 (Fibra de Agave Sisalana, Carbonato de calcio, Dióxido de cloro) y t1 (Fibra de Agave Americana, Sulfato de sodio, Dióxido de cloro). Cumplen de esta manera con los indicadores y objetivos planteados, se realizó un balance de materiales utilizados en el proceso que demostró, que podemos optimizar recursos y volver a reutilizar el agua residual del proceso de humectación de la fibra.

In southern Iran’s Gareh Bygone Plain, water-supply qanats in four mixed farming communities were desiccated by over-pumping of illegal dug wells throughout the area. Emergency situations developed, resulting in city-ward migration. Since 1983, 193 million m³ of water has been supplied to those communities by floodwater spreading (FWS) to facilitate spate irrigation of sandy rangeland (2,034 ha) and artificial recharge of groundwater (ARG), of which 76 % has recharged the aquifer. This resulted in a reverse migration of the population. The irrigated area in the 2010–2011 growing season increased 13.2 fold when compared to the pre-FWS period, and year-round forage for about 700 sheep has been provided since 1991. The ARG is a logical alternative to building large dams in Iran; 420,000 km² of coarse-grained alluvium provides capacity to store 5,000 km³ of water, representing more than ten times the annual precipitation of the whole country. As the equivalent cost for building dams to accommodate that volume is estimated at US$12.5 × 10¹², the potential value of the alluvium may be realized. ARG on the recharge areas of 33,000 of the desiccated qanats eventually could rejuvenate them. As agricultural commodities absorb 19 % of the monetary value of Iran’s imports, and ARG activities could supply the water to produce them, alluvium is even more valuable than oil, which provides foreign exchange. More importantly, ARG on 140,000 km² of the alluvium could strengthen the capacity to adapt to droughts and reduce the number and impact of water-related emergency situations.

Environmental tracers (noble gases, tritium, industrial gases, stable isotopes, and radio-carbon) and hydrogeology were interpreted to determine groundwater transit-time distribution and calculate mean transit time (MTT) with lumped parameter modeling at 19 large springs distributed throughout the Upper Colorado River Basin (UCRB), USA. The predictive value of the MTT to evaluate the pattern and timing of groundwater response to hydraulic stress (i.e., vulnerability) is examined by a statistical analysis of MTT, historical spring discharge records, and the Palmer Hydrological Drought Index. MTTs of the springs range from 10 to 15,000 years and 90 % of the cumulative discharge-weighted travel-time distribution falls within the range of 2−10,000 years. Historical variability in discharge was assessed as the ratio of 10–90 % flow-exceedance (R ₁₀/₉₀%) and ranged from 2.8 to 1.1 for select springs with available discharge data. The lag-time (i.e., delay in discharge response to drought conditions) was determined by cross-correlation analysis and ranged from 0.5 to 6 years for the same select springs. Springs with shorter MTTs (<80 years) statistically correlate with larger discharge variations and faster responses to drought, indicating MTT can be used for estimating the relative magnitude and timing of groundwater response. Results indicate that groundwater discharge to streams in the UCRB will likely respond on the order of years to climate variation and increasing groundwater withdrawals.