Well soundings should also collect water temperature and barometric pressure if comparing a number of wells with water table elevations through time. A vented transducer will automatically adjust, unvented transducer needs adjustment in recording water level. One must remember with well data, water level will change with barometric pressure. By characterizing the normal well hydrograph to rainfall and water table recharge, and recession curve slope with time, it should be detectable when significant response changes occur. During periods of irrigation, with 40 pumps operating on different frequencies, it is going to be difficult to evaluate data, but if you have data at 15 minute intervals, you should be able to detect periods of rapid change as pumping. If you have estimates of hydraulic conductivity based on substrate and K testing, recognize that if wells are distant, drawdown of one well with a cone of depression, would affect adjacent wells with a rate related to the K value for the substrate. If you have no control of the 40 well users, you may have to consider timing or evaluate wells when use is low. Well drillers and hydrogeologists are familiar with the specifics of this testing to describe in detail. If the 40 wells are in close enough proximity, you could install a barometer to cover the area, and install in some, many or all wells unvented barometers to record water levels at 15 minute intervals, then use well withdrawal testing, such as might be done with hours of withdrawal as in irrigation. However, generating the subsidencedrawdown relation is critical to better understand and predict the spatial distribution of land subsidence. Excessive groundwater-level drawdown at a well may adversely affect or prevent the exercise of the groundwater right(s) associated with the well. If the question has importance, then as researchers, some degree of direct measurement or calibrating a model to the specific circumstances using well withdrawal tests may be needed. The drawdown of water levels leads to land subsidence from over-extraction of groundwater (Bell et al., 2008 Galloway and Burbey, 2011). The state engineer cannot grant an application to appropriate groundwater if the proposed appropriation will impair existing water rights (NMSA 1978, Section 72-12-3.E). We dont know if there were well logs that characterized substrates, any well pump tests, how often users pump water, are they all within the same aquifer, is it the surface aquifer or confined, are there streams or rivers adjacent to some wells that may be contributing directly, and as suggested how homogeneous are the substrate and geology. 10 years of data suggests you might have enough, but we dont know if well data is hourly, daily, weekly, etc. Maybe even they find some data that may help. He developed an analytic solution for the drawdown for a non-steady flow in a confined aquifer. ![]() Sometimes researchers need to answer questions. Theis first published in 1935 The Relation Between the Lowering of the Piezometric surface and the Rate and Duration of Discharge of a Well Using Groundwater Storage.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |