Press wheels were designed to improve soil-seed contact, thus promoting good seed germination and emergence of plantules. The present investigation was aimed at studying the influence of three models of press wheel, three sowing depths and three load levels on soil temperature and moisture contents. The experiment was carried out in Uberaba, State of Minas Gerais, Brazil, in split-plot desing, 27 treatments and four repetitions. Results have shown that press wheels with bigger soil contact area provide the highest values of average soil moisture an temperature. However, load level on the press has shown no effect on soil temperature and moisture contents. | As rodas compactadoras das semadoras-adubadoras têm como principal função, propiciar o bom contato entre o solo e a semente para garantir a germinação das sementes e a emergência das plântulas. Objetivou-se, neste trabalho, estudar a influência de três modelos de rodas compactadoras, três profundidades de semeadura e três níveis de carga sobre a roda compactadora sob a temperatura e o teor de água do solo. O trabalho foi desenvolvido na pista de ensaios de semeadura, localiza em Uberaba, MG, em Latossolo Vermelho distrófico, utilizando-se o delineamento experimental de parcelas sub-subdivididas, com 27 tratamentos e quatro repetições. As rodas com maior área de contato com o solo proporcionaram maiores valores do teor médio de água e da temperatura do solo. O nível de carga sobre a roda compactadora não afetou a temperatura e o teor de água do solo.

Se describen los problemas en tres actividades de cinco del saneamiento básicos, abastecimiento de agua, disposición de las aguas residuales, excretas y disposición de los desechos sólidos. Se hace un abordaje a nivel infraestructural del sistema de agua de la comunidad Cebadilla, dicha acción fue tomada durante el proceso de trabajo de campo al observar el nivel de deterioro que el sistema de agua presentó y ante ello se espera que la investigación sirva como referencia para futuras acciones que mejoren la calidad de infraestructura del sistema de agua. El documento cuenta con cinco capítulos donde se describe la situación problemática actual en la comunidad, el porqué de la investigación, los objetivos alcanzados por el diagnostico, un marco conceptual y teórico que sustenta la investigación como referencia técnica y la presentación de los resultados obtenidos a través de la implementación de una guía de entrevista y una de observación que fueron diseñadas en base a una serie de indicadores delimitados que sirvieron para describir el problema, cabe mencionar que se acompaña un apartado donde se colocan medios de verificación donde se refleja a través de fotografías algunos momentos del proceso de trabajo de campo, realizado en la comunidad.

Managed aquifer recharge (MAR) is an efficient way to remove organic matter from raw water and, at the same time, reduce temperature variation. Two MAR sites were constructed by Karlskrona municipality on Johannishus Esker in Sweden. One of these sites, Vång, was monitored for electrical conductivity and electrical resistivity (using electrical resistivity tomography - ERT) during a 9-week tracer infiltration test. The aim of the monitoring was to map the pathways of the infiltrated water, with the overall goal to increase the efficiency of the MAR. ERT proved useful in determining both the nature of the esker formation and the water migration pathways. In Vång, the esker ridge follows a tectonically controlled paleo-valley. The fault/fracture zone in the bedrock along this paleo-valley was mapped. During the tracer test, the infiltrated water was detected in the area close to the infiltration ponds, whereas far-situated observation wells were less affected. For sequential infiltration and recharge periods in MAR, the timing of the well pumping is another important factor. Natural groundwater flow direction was a determinant in the infiltration process, as expected. ERT measurements provide supplementary data for site selection, for monitoring the functionality of the MAR sites, and for revealing the geological, hydrogeological and structural characteristics of the site.

Many coastal areas historically were inundated by seawater, but have since undergone land reclamation to enable settlements and farming. This study focuses on the coastal unconfined aquifer in the Po Plain near Ravenna, Italy. Freshwater is present as isolated thin (1–5 m) lenses on top of brackish to saline water. Historical maps show large areas of sea inundation until approximately 150–200 years ago when coastal progradation and construction of the drainage canals began. Since then, the aquifer has been freshening from recharge. A three-dimensional SEAWAT model is used to simulate a 200-year freshening history, starting with a model domain that is saturated with seawater, and applying recharge across the top model layer. Calibration to the observed concentrations for discrete depths within many monitoring wells is remarkably good. The current distribution of freshwater is largely controlled by the drainage network. Within and adjacent to the drains, the groundwater has high salinity due to up-coning of salt water. Between drains, the surface layers of the aquifer are fresh due to the flushing action of recharge. The modeling results are consistent with cation exchange processes revealed in the groundwater chemistry and with freshwater lenses identified in electrical resistivity soundings.

Optimization methods have been used in groundwater modeling as well as for the planning and management of groundwater systems. This paper reviews and evaluates the various optimization methods that have been used for solving the inverse problem of parameter identification (estimation), experimental design, and groundwater planning and management. Various model selection criteria are discussed, as well as criteria used for model discrimination. The inverse problem of parameter identification concerns the optimal determination of model parameters using water-level observations. In general, the optimal experimental design seeks to find sampling strategies for the purpose of estimating the unknown model parameters. A typical objective of optimal conjunctive-use planning of surface water and groundwater is to minimize the operational costs of meeting water demand. The optimization methods include mathematical programming techniques such as linear programming, quadratic programming, dynamic programming, stochastic programming, nonlinear programming, and the global search algorithms such as genetic algorithms, simulated annealing, and tabu search. Emphasis is placed on groundwater flow problems as opposed to contaminant transport problems. A typical two-dimensional groundwater flow problem is used to explain the basic formulations and algorithms that have been used to solve the formulated optimization problems.

The Eocene deposits of Kazan Basin in Turkey contain a rare trona mineral which is planned to be extracted by solution mining. The complex flow dynamics and mixing mechanisms as noted from previous hydraulic and hydrochemical data need to be augmented with environmental tracer and noble gas data to develop a conceptual model of the system for the assessment of the impacts of the mining and to develop sustainable groundwater management policies throughout the area. The tracers used include the stable isotopes of water (δ²H, δ¹⁸O), δ¹³C and¹⁴C of dissolved inorganic carbon (DIC), tritium (³H), the chlorofluorocarbons CFC-11 and CFC-12, and the noble gases He and Ne. The system studied consists of three aquifers: shallow, middle, and deep. CFC data indicate modern recharge in the shallow system. The estimates of ages through¹⁴C dating for the deeper aquifer system are up to 34,000 years. Helium concentrations cover a wide range of values from 5 × 10⁻⁸to 1.5 × 10⁻⁵ cm³STP/g.³He/⁴He ratios vary from 0.09RAto 1.29RA(where RAis the atmospheric³He/⁴He ratio of 1.384 × 10⁻⁶), the highest found in water from the shallow aquifer. Mantle-derived³He is present in some of the samples indicating upward groundwater movement, possibly along a NE–SW-striking fault-like feature in the basin.

Hydro-chemical and isotopic data from different aquifers in the Great Hungarian Plain (the central part of the Pannonian Basin) were evaluated down to a depth of 2,740 m. The chemical and isotopic composition of water is influenced by its origin and by chemical and mixing processes. The analytical data and chemical considerations, together with geology, pressure conditions and evolution history of the area, explain the evolution of the subsurface water. Most of the samples are of meteoric origin, but there were some samples with a non-meteoric contribution, as indicated by the water stable isotopes, and these were identified as seawater trapped during the sedimentation in Lake Pannon. The sea contribution is traceable by the shifts in δ¹⁸O and δ²H and the chemical composition of the water, and is explained with an upward-driving force. Chemical considerations and spatial variability of the dissolved components suggest that distinct water bodies, each with a specific origin and chemical evolution, can be separately identified. Although in the Quaternary layers there are water bodies that can be considered to display complete flow systems (from recharge to discharge), in most water bodies present infiltration was not identified. The lack of recent recharge to several water bodies in various places and depths suggests a separation of the recharge and the discharge that occurred not in space, but in time. A possible explanation of the cessation of recharge is a significant change in the hydraulic circumstances, probably the surface elevation.

Using a water balance to estimate groundwater recharge through the use of remotely sensed evapotranspiration offers a spatial and temporal density of data that other techniques cannot match. However, the estimates are uncertain and therefore ground truthing of the recharge estimates is necessary. This study, conducted in the south-east of South Australia, demonstrated that the raw water-balance estimates of recharge had a negative bias of 45 mm/yr when compared to 190 recharge estimates using the water-table fluctuation method over a 10-year period (2001–2010). As this bias was not related to the magnitude of the recharge estimated using the water-table fluctuation method, a simple offset was used to bias-correct the water-balance recharge estimates. The bias-corrected recharge estimates had a mean residual that was not significantly different from an independent set of 99 historical recharge estimates but did have a large mean absolute residual indicating a lack of precision. The value in this technique is the density of the data (250-m grid over 29,000 km²). The relationship between the water-table depth and net recharge under different vegetation types was investigated. Under pastures, there was no relationship with water-table depth, as the shallow roots do not intercept groundwater. However, under plantation forestry, there was a relationship between net recharge and water-table depth. Net recharge under plantation forestry growing on sandy soils was independent of the water table at around 6 m depth but, under heavier textured soils, the trees were using groundwater from depths of more than 20 m.

Atlantic salmon (Salmo salar) and Rainbow trout (Oncorhynchus mykiss) are two fish species that spawn in fresh water (FW) and, during development, acclimate to seawater (SW) by secreting excess NaCl to the environment. The salmon industry measures Na+/K+ ATPase (NKA) activity as a molecular marker to determine the timing of smolt transfer from FW to SW. However, the lack of other accurate molecular markers of smoltification remains a major issue for the fish farming industry. The molecular mechanism of NaCl secretion in gills from SW-acclimated fish has a thermodynamic requirement to recycle K+ out of the cell via potassium channels therefore we hypothesised that potassium channel expression in gills may be a suitable candidate to monitor the smoltification process. In support of this hypothesis, we observed increased expression of BK potassium channel mRNA in gills from S. salar under conditions of high salinity (1.2%) compared to animals in FW. In this work, we designed a real-time PCR analysis in order to quantify mRNA levels of BK potassium channels in S. salar organ samples. We found differences in mRNA expression among gills, kidney and intestine. We also found a unique real-time PCR product in S. salar gills through melting curve analysis, agarose gel electrophoresis and cDNA sequencing. This PCR product showed a 98% of identity with the BK channel portion recorded by the NCBI Database and was differentially expressed in gills, kidney and intestine. This real-time PCR assay may become an important tool to study BK potassium channels expressed in the gills of S. salar and its changes during smoltification as putative new candidate to monitor this process. | El salmón del Atlántico (Salmo salar) y la trucha arcoíris (Oncorhynchus Mykiss) son especies que se reproducen en agua dulce y durante la smoltificación deben aclimatarse para vivir en agua de mar, gracias a la secreción del exceso de NaCl al ambiente. La industria salmonera utiliza la medición de la actividad de la Na+/K+ ATPasa como marcador molecular para determinar el tiempo de transferencia de los smolts al mar. Sin embargo, la baja precisión de este marcador es un importante problema en la industria. Como el mecanismo molecular de secreción de NaCl en las branquias en peces aclimatados al mar tiene el requisito termodinámico de reciclar el K+ fuera de las células por medio de canales de potasio, nosotros hipotetizamos que canales de potasio expresados en branquias podrían ser candidatos a potenciales nuevos marcadores para monitorear el proceso de smoltificación. En este trabajo se utilizó la técnica de PCR en tiempo real para medir la expresión de ARNm del canal de potasio BK. Se encontró expresión en branquias, riñón e intestino en animales aclimatados a agua dulce, así como también se encontró, de forma interesante, un aumento de la expresión del canal de potasio BK al aumentar la salinidad al día 7 específicamente en branquia. El producto amplificado por PCR en tiempo real es único y su secuencia posee un 98% de identidad con la porción del canal BK descrito en la base de datos del NCBI. Este ensayo de PCR en tiempo real podría ayudar al monitoreo de los cambios de expresión del canal de potasio BK durante la smoltificacion para estudiar si es posible usar este canal como marcador molecular en el futuro.

Sustainable development and management of groundwater resources require application of scientific principles and modern techniques. An integrated approach is implemented using remote sensing and geographic information system (GIS)-based multi-criteria evaluation to identify promising areas for groundwater exploration in Raya Valley, northern Ethiopia. The thematic layers considered are lithology, lineament density, geomorphology, slope, drainage density, rainfall and land use/cover. The corresponding normalized rates for the classes in a layer and weights for thematic layers are computed using Saaty’s analytical hierarchy process. Based on the computed rates and weights, aggregating the thematic maps is done using a weighted linear combination method to obtain a groundwater potential (GP) map. The GP map is verified by overlay analysis with observed borehole yield data. Map-removal and single-parameter sensitivity analyses are used to examine the effects of removing any of the thematic layers on the GP map and to compute effective weights, respectively. About 770 km²(28 % of the study area) is designated as ‘very good’ GP. ‘Good’, ‘moderate’ and ‘poor’ GP areas cover 630 km²(23 %), 600 km²(22 %) and 690 km²(25 %), respectively; the area with ‘very poor’ GP covers 55 km²(2 %). Verification of the GP map against observed borehole yield data shows 74 % agreement, which is fairly satisfactory. The sensitivity analyses reveal the GP map is most sensitive to lithology with a mean variation index of 6.5 %, and lithology is the most effective thematic layer in GP mapping with mean effective weight of 52 %.