Pumping test is the most reliable method for determining the hydraulic conductivity and tracer test is the most reliable way to determine the hydraulic connection. Pumping test involves imposing a perturbation such as pumping in a well and measuring the response of the aquifer, for example in terms of head variations (Renard et al. 2009). Those data are then interpreted with the help of analytical or numerical models in order to infer the hydraulic properties (hydraulic conductivity, transmissivity and storage coefficient) of the aquifer (Renard et al. 2009).
Tracer tests are frequently used at the regional scale to delineate the difference between the hydrogeologic and topographic watersheds. Watersheds with very distinct and permanent boundaries are rare in karst. For this reason, tracer tests in different hydrological stages are strongly recommended (Milanović 2011). For regional tracer tests, the most commonly used dyes are fluorescein and Rhodamin B, lycopodium spores, inorganic salts, and radioactive salts (Milanović 2011). Longitudinal and transverse dispersivity and the ratio of hydraulic conductivity and effective porosity can be determined by tracer tests.
Concomitant use of these two methods, the first time by Laguna (1970) reported that two jugate sandy aquifers were pumped simultaneously, and a forced gradient tracer tests was used to determine what proportion of the pumped water was coming from each sandy aquifer. Then, the results of pumping and tracer tests have been compared for hydraulic conductivity (Niemann and Rovey 2000; Rovey and Niemann 2005; Thorbjarnarson et al. 1998).
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In most studies, tracer tests are considered to be more accurate because they would better implement the hete...
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...racteristics of the fractured aquifer system (Lee and Lee 1999).
The geometric mean of the hydraulic conductivity is 30.50 m/day for pumping test and 106.339 m/day for tracer test in dam sit of Salman Farsi. The geometric mean of the hydraulic conductivity based on the tracer test is more than the geometric mean of the hydraulic conductivity based on pumping test. Because, in this area, conduit routes is abundant (Refrence ????) and in tracer test transmission is done mainly from conduit routes. But, in pumping test transmission is done from conduit and matrix routes.
In dam site of Salman Farsi with abundant conduit routes, observed tracers following high conductivity conduits and noted that using an average K value from an aquifer pump test to predict solute transport would result in considerable underestimation of transport distances for a given time period.
When test results don’t have accuracy, additional testing may be needed to authenticate the results.
...s strength in the experiment rather than a limitation which future studies should also monitor.
In most archaeological surveys, one of the probes is used to conduct the current through the ground and another probe is used to measure the potential difference across the circuit of the current. The resistance of the soil between both probes can be then calculated by using the equation:
In industry, the performance specifications for a particular pump may be known, but the tests are usually based on water as the pumping medium. For liquids of significantly higher viscosity than water, these performance curves may only be accurate at certain flow rates, or they might not be valid at all, and it might be necessary to recalibrate the specifications for higher viscosity liquids.
.... Without knowledge of the reliability and validity of these two instruments we are unable to know if the instruments are consistent or if they measure what they intend to measure.
Ros Barcelo A., Calderon A. and Munoz R. (1994). Measuring water conductivity coefficients in plant tissues. Journal of Biological Education, 28 (2), p 83 – 85. from: http://www.tandfonline.com/doi/abs/10.1080/00219266.1994.9655371 [Access date: April 12, 2014]
Comments and recommendations made in this technical review note are as a result of careful screening of many hydraulic and hydrological modeling methodologies, hydrological and hydraulic modeling software programs and design procedures available to the drainage engineer today.
Soil and rock – Record and describe any exposed soils or rocks that are present. Samples should be taken to determine the rock and soil type. If there is soft soil you can dig shallow holes using an auger to get an idea of the soil characteristics. The auger is held vertically and is driven into the ground by rotating its handle. At every 30 cm of depth, the auger is taken out and the soil samples collected.Any holes created should be made good to prevent possible injury.
According to Slabbert (2007), inter-basin water transfer is the “artificial withdrawal of water by ditch, canal or pipeline from its source in one basin (catchment) for use in another.” Since South A...
The permeability of a reservoir can be measured in many ways including wire line log analysis
As there are many assessment technique of hydration measurements are available, they are differ in their applicability due to their kind of methodological significance. Each method has different limitations as per their methodological synthesis techniques such as necessary circumstances for measurement, sensitivity and accuracy, installation of the system, ease and cost of system.
Water logging is caused by excessive irrigation on poorly drained soils, i.e. water enters the soil faster than it drains away. It occurs even worse where there is compaction of subsoil layers; where water quickly enters the topsoil but is then blocked by a water-resistant clay layer, which may occur naturally or may be induced through excessive use of agricultural machinery. Irrigation water and/or seepage from canals eventually raise the water table in the ground.
The hydrogeology of a particular area is mostly determined by geology, geomorphlogy and climatic conditions. The document compiled by MWIE (2003)indicated that the hydrogeology of a country is characterized by regional factors such as geological processes (the swell, rifting and volcanism), the stratigraphy of alternating pervious and impervious formations, the development of secondary porosity and permeability through the fracturing and jointing of rocks and, the development of thermal groundwater and steam,mostly associated with rift valley. These factorsare ground to be putting serious impact on characterizing the challenges and problems in the catchments and the hydrogeological conditions of the study area.
Production changes, carried out during a transient well test, induce pressure disturbances in the wellbore and surrounding rock. This disturbances extend into the formation and are affected in various ways by the rock features. For example, a low permeable rock will restrict the pass of the pressure wave. Therefore, a record of the pressure response over time produces a curve whose shape is defined by the reservoir’s unique characteristics.
Water table is refers to the upper level of which all the openings of rock are saturated with water, also called “the zone of saturation ” (http://imnh.isu.edu/digitalatlas/hydr/concepts/gwater/wattable.htm) As the water table diminished, the “upward water transport” also diminished. (Yuan,2009).