13 research outputs found
Drought Mitigation and Effect on Perennial and Deferred Perennial Yield Strategies, Case Study: Cache Valley
No full textGroundwater users are often the last to be affected by drought. Also, groundwater users are the last to experience a return to normal water levels. Less than average precipitation will affect the sustainability of the aquifer use and the hydraulically connected surface water. We examine the effect of drought on perennial and deferred perennial yield strategies developed for long-term average conditions. An optimal perennial yield strategy gives areal distribution of groundwater pumping rates that will cause acceptable consequences to the aquifer and hydraulically connected surface water bodies. Such strategies have relatively constant annual pumping rates and check for annual average conditions. Deferred perennial yield strategies differ from perennial yield strategies in that pumping rates can initially be high while aquifer mining is allowed for hydrological or economic reasons. Afterwards, pumping rates are reduced allowing for aquifer recovery. Reconnaissance optimization problems or scenarios are constructed to help explore the options for mitigating drought (less than average) effect on groundwater. One scenario computes the maximum allowed junior water rights to be granted if less-than average precipitation exists. Another scenario will be invoked if junior rights can not be granted and unacceptable consequences are still noticed. This scenario computes an optimal unified reduction percentage in background pumping or shaving groundwater senior water rights. The third scenario will reduce senior water rights by an optimal proportion and prevent junior water rights from pumping more than their perennial yield pumping rates. Cache Valley aquifer system will be used as a representative aquifer to evaluate the results of the three scenarios. Drought with PDSI (Palmer Drought Severity Index) of -1 or less (absolute value \u3e 1) has not hit Utah for hundreds of years. However, normal fluctuation in climatic conditions can be observed in Cache Valley. Precipitation depth between 11 and 21 inches has a cumulative distribution of 81%. Such statistics will be used in conjunction with a USGS Cache Valley transient simulation model to test the effect of using less-than-average conditions on a previously developed perennial yield strategy. Bassel Timani and Richard C. Peralt
Innovative and Efficient Simulation-Optimization Tools for Successful Groundwater Management and Conflict Resolution
No full textSimulation-Optimization (S-O) models are exemplary for strategic groundwater management planning. The two components of an S-O model serve different purposes. The simulation component models the aquifer and computes state variables resulting from stimuli such as extraction or diversion while the optimizor computes an optimal set of stimuli that maximize an objective function and satisfy a set of constraints. With the increased use of S-O model for larger and more complex real-world study areas, the use of fast and efficient S-O models has risen. Response matrix methods (RMMs) are usually used as substitute simulators within an S-O to solve the posed optimization problem. To increase the chances of a groundwater management plan to be a success employed S-O models should represent sustainability concepts and quantify the ability of the aquifer to replenish from a climatic anomaly such as drought. Aquifers are usually modeled using a single simulation model. However, there exist cases in which stakeholders’ disagreement about the conceptual model leads to different simulation models for the same aquifer.
We propose a hybrid RMM that uses the strengths of existing RMM. The proposed RMM that is most efficient for situations in which optimizable stimuli can vary through consecutive periods of uniform duration interspersed with periods of different duration. Tested scenarios indicate that the hybrid RMM requires as much or 63-89% less computation time than other RMMs.
Ensuring the acceptability of the aquifer states, including seepage losses to surface waters, on sub-annual (less than a year) basis (sustained yield) and quantifying the aquifer’s ability to acceptably recover from an anomaly such as drought are integral for successful groundwater management. We evaluate sustained yield strategies (SYS) and quantify the resilience of a computed SYS for Cache Valley, Utah (USA). We maximize the number of new residents who can have their indoor and outdoor uses satisfied while maintaining acceptable aquifer-surface waters seepage losses, and limiting new residents to projected increases in population (PIiP). Because the optimal solution can be influenced by many factors, we examine the optimal solution as affected by optimizing: (1) population versus pumped volume; (2) optimizing indoor and outdoor water demand (traditional housing development) versus optimizing indoor population (apartment dwellers) then the portion of that population whose outdoor water demand can be met too; (3) optimizing in the presence of temporally-lagged spatially distributed return flow that is a function of optimal groundwater use versus optimizing in its absence; and (4) annual versus quarter-annual time evaluation of acceptability. Results indicate that Cache Valley aquifer has the capacity to sustain the outdoor water demand of 74%- 83% and the indoor water demand of 83%-100% of the PIiP. Aquifer conditions can rebound from a 2-year drought to within 7% and 5% of acceptable levels in three and eight years, respectively, after the drought has ceased. Reducing pumping rates by 25% allows the aquifer conditions to be rebound to 96% of acceptable levels or rates within 3 years.
To circumvent the necessity that stakeholders reach an agreement on a single simulation model for an aquifer, we propose Multi-Conceptual Model Optimization (MCMO). Unlike the traditional S-O models, MCMO computes optimal strategies that simultaneously satisfy analogous constraints and bounds in multiple numerical models differing by more than parameter values. Applying MCMO to Cache Valley (Utah, USA) reveals that protecting local ecosystem limits the increased groundwater pumping to satisfy only 40% of projected water demand increase using both models simultaneously
An Improved and Efficient Surrogate Simulator for Groundwater S/O Models
No full textContinual developments and advances in Simulation/Optimization (S/O) models have led to the development of cost-effective and improved groundwater management implementations. S/O models eliminate the excessive time consumed by trial-anderror use of simulation models to reach a “good” strategy. S/O models of groundwater studies have historically used one of two Response Matrix-based surrogate simulators (here termed ICGO1 and ICGO2). This research will enrich these S/O models with an innovative and efficient methodology (ICDUAH). The main difference among the different surrogate simulators is in the handling of the stress periods of stimulation and observation. ICDUAH combines the capabilities of ICGO1 and ICGO2 and enhances the composite. ICDUAH can employ stress periods of different durations while requiring fewer unitstimulus simulations than ICGO2. Also, ICDUAH uses a time varying unit stimulus for each stimulus location to increase efficiency. ICDUAH groups consecutive stress periods of equal durations into a management era. Moreover, it allows users, if they wish, to set up their own management eras irrespective of the relative duration of stress periods. All stress periods of a management era must be of equal duration. Each steady-state stress period must have its own management era. A unit stimulus will be applied at the first stress period of each management era. This research compares ICGO1, ICGO2 and ICDUAH performance for an optimization problem that maximizes groundwater extraction from a hypothetical study area subject to constraints on state variables. The simulation model of the hypothetical study area uses 12 transient stress periods. The S/O model optimizes for two formulations that differ only in the stress period setup. Posed bounds resemble those for protecting senior surface water or groundwater rights, from proposed management actions. Cycling used in conjunction with the Response Matrix approach allows linearly solving non-linear systems with acceptable accuracy and stability. The result is a better and more efficient surrogate simulator for solving non-linear groundwater management problems. The proposed tool is an improvement over the traditional response matrix algorithm (ICGO1) because it is capable of handling a broader spectrum of situations. The created surrogate simulator is more efficient than the ICGO2 approach because it does not require a unit-stimulus simulation at each stress period
Groundwater safe yield versus sustained yield planning
No full textGroundwater Safe Yield versus Sustained Yield Planning Many governments have policies to assure the safe yield of groundwater from important aquifers. Safe yield strategies are defined to avoid unacceptable aquifer states from year to year. However, they often allow undesirable states to occur within a year. Sustained yield strategies are intended to overcome that weakness. To achieve that, sustained yield strategies often allow less groundwater pumping than safe yield strategies. Contrasted Cache Valley safe yield and sustained yield strategies demonstrate this generality
Final Report for Irrigation water quality monitoring of the Jordan River, 2008
No full textThe goal of the Jordan River Water Quality Project is to assess the quality of irrigation water removed from the Jordan River at three diversion locations: Jordan Narrows (JN), Cahoon and Maxfield (CM), and Jordan & Salt Lake Canal (JSLC). During 2008, Salt Lake City Corporation personnel took water samples on 12 dates from April 18 to September 25, 2008. Utah State University Analytical Laboratories (USUAL), an EPAcertified laboratory, performed water analyses on the samples. USUAL is located at Utah State University (USU) in Logan, Utah
Groundwater contamination transport modeling in Andean river aquifer in Peru
No full textNote, this revised abstract replaces one entitles Groundwater contamination transport modeling in coastal Peru. Pacific coastal rivers of Peru receive snowmelt runoff from the Andes. These rivers recharge coastal aquifers to which they are hydraulically connected. The quality of the river and ground water differs from basin to basin. Many aquifers demonstrate the general Chebotarev sequence of bicarbonate to sulfate to chloride to sulfate, as one progresses from the Andes to the ocean. North of Lima, Chillon River aquifer groundwater sulfate concentrations exceed health advisory limits, before chloride concentrations begin to dominate. Water managers have been concerned about significant changes in measured concentrations. Being able to predict groundwater sulfate concentrations is important for the increasing population. Developing a pilot groundwater contaminant transport model involved intensive data and simulation model evaluation, and included re-positioning and re-calibrating an existing groundwater flow model for the Chillon River aquifer. Flow model re-calibration significantly improved calibration head-matching statistics. An equilibrium-concentration approach guided sulfate contaminant transport model calibration. Because the flow-related data were known with more certainty than the transport-related data, the newly developed flow model parameters were not varied during transport model calibration. Transport model calibration optimization identified seepage water sulfate concentrations, that would produce a quasi-steady-state concentration distribution, to best match field measurements. Both the flow model and the transport model are as accurate as the data upon which they are based. They can be improved by enhanced positioning of pumping wells within the model grid, and increased horizontal and vertical discretization
Groundwater contamination transport modeling in coastal Peru
No full textDeveloping a pilot groundwater contaminant transport model involved intensive data and simulation model evaluation, and included re-calibrating the Antea-Amsa groundwater flow model for the Chillon River aquifer. Flow model re-calibration significantly \u27improved head-matching statistics for the 1985-1997 era. An equilibrium-concentration approach guided sulfate contaminant transport model calibration. Because the flow-related data were known with more certainty than the transport-related data, the newly developed flow model parameters were not varied during transport model calibration. Transport model calibration optimization identified seepage water sulfate concentrations, that would produce a quasi-steady-state concentration distribution, that best matches field measurements of 1993-1997. Project circumstances dictated the brevity of the history-matching era. Both the flow model and the transport model are as accurate as the data upon which they are based. They can be improved by enhanced positioning of pumping wells within the model grid, and increased horizontal and vertical discretization
Aggregated surrogate simulator for groundwater-surface water management via simulation-optimization modeling: Theory, development and tests
No full textDeveloped pumping strategies for Mather AFB TCE plume
No full textAccomplishments prior to BCT Meeting/Phone Conference of 14 October 2004 Prior to 14 October 2004, the best pumping strategy USU achieved manually completely contains both PCE and TCE1 (within revised containment zones proposed by USU on that date), at the end of years 2, 3, 4, 5 and 5-year intervals thereafter. This strategy uses two new extraction wells (USUE3 and USUE4). The strategy did not utilize a recently constructed well EW-12B. USU did not previously know about EW-12B and the well package USU received did not indicate a well at its location, cell (3,58,43). On 14 October, USU also learned of new aquifer parameter field data near well EW-12B
Cache Valley: Optimizing Sustainable Water Use and Ecosystems While Considering Water Rights
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