Journal of Water Resources Planning and Management, 2019
Sampling of drinking water distribution systems is performed to ensure good water quality and pro... more Sampling of drinking water distribution systems is performed to ensure good water quality and protect public health. Sampling also satisfies regulatory requirements and is done to respond to customer complaints or emergency situations. Water distribution system modeling techniques can be used to plan and inform sampling strategies. However, a high degree of accuracy and confidence in the hydraulic and water quality models is required to support real-time response. One source of error in these models is related to uncertainty in model input parameters. Effective characterization of these uncertainties and their effect on contaminant transport during a contamination incident is critical for providing confidence estimates in model-based design and evaluation of different sampling strategies. In this paper, the effects of uncertainty in customer demand, isolation valve status, bulk reaction rate coefficient, contaminant injection location, start time, duration and rate on the size and location of the contaminant plume are quantified for two example water distribution systems. Results show that the most important parameter was the injection location. The size of the plume was also affected by the reaction rate coefficient, injection rate and the injection duration, while the the exact location of the plume was additionally affected by the isolation valve status. Uncertainty quantification provides a more complete picture of how contaminants move within a water distribution system and provides more information when using modeling results to select sampling locations.
New Mexico Geological Society Annual Spring Meeting
Total available water (TAW) is one of the most difficult to ascertain parameters necessary for pr... more Total available water (TAW) is one of the most difficult to ascertain parameters necessary for predicting water storage in the root zone. As such, a method for parametrizing TAW is necessary given the paucity of in-situ measurements that are available. TAW is determined in a novel way as a model fitting parameter. A soil water balance model, the Evaporation, Transpiration and Recharge Model, is used to simulate root zone soil moisture for an area of interest. The TAW parameter of the model is varied until agreement is found between the model simulated and remotely-sensed root zone soil moisture observations on a pixel by pixel basis. In this study, we present initial modeling efforts and a remotely sensed validation data set that will be used to optimize TAW for the area of interest: the Jornada Long Term Ecological Research station (Jornada LTER) in south central New Mexico. Within the Jornada LTER, the model predictions and remote sensing datasets of root zone soil moisture are compared to neutron probe data from an approximately 2.7 kilometer-long transect of 89 neutron soil moisture probes within the Jornada LTER.
As cosmogenic nuclide applications continue to expand, the need for a common basis for calculatio... more As cosmogenic nuclide applications continue to expand, the need for a common basis for calculation becomes increasingly important. In order to accurately compare between results from different nuclides, a single method of calculation is necessary. Calculators exist in numerous forms with none matching the needs of the CRONUS-Earth project to provide a simple and consistent method to interpret data from most commonly used cosmogenic nuclides. A new program written for this purpose, CRONUScalc, is presented here. This unified code presents a method applicable to 10 Be, 26 Al, 36 Cl, 3 He, and 14 C, with 21 Ne in testing. The base code predicts the concentration of a sample at a particular depth for a particular time in the past, which can be used for many applications. The multipurpose code already includes functions for calculating surface exposure age for a single sample or for a depth profile containing multiple samples. The code is available under the GNU General Public License agreement and can be downloaded and modified to deal with specific atypical scenarios.
Journal of Water Resources Planning and Management, 2019
Sampling of drinking water distribution systems is performed to ensure good water quality and pro... more Sampling of drinking water distribution systems is performed to ensure good water quality and protect public health. Sampling also satisfies regulatory requirements and is done to respond to customer complaints or emergency situations. Water distribution system modeling techniques can be used to plan and inform sampling strategies. However, a high degree of accuracy and confidence in the hydraulic and water quality models is required to support real-time response. One source of error in these models is related to uncertainty in model input parameters. Effective characterization of these uncertainties and their effect on contaminant transport during a contamination incident is critical for providing confidence estimates in model-based design and evaluation of different sampling strategies. In this paper, the effects of uncertainty in customer demand, isolation valve status, bulk reaction rate coefficient, contaminant injection location, start time, duration and rate on the size and location of the contaminant plume are quantified for two example water distribution systems. Results show that the most important parameter was the injection location. The size of the plume was also affected by the reaction rate coefficient, injection rate and the injection duration, while the the exact location of the plume was additionally affected by the isolation valve status. Uncertainty quantification provides a more complete picture of how contaminants move within a water distribution system and provides more information when using modeling results to select sampling locations.
New Mexico Geological Society Annual Spring Meeting
Total available water (TAW) is one of the most difficult to ascertain parameters necessary for pr... more Total available water (TAW) is one of the most difficult to ascertain parameters necessary for predicting water storage in the root zone. As such, a method for parametrizing TAW is necessary given the paucity of in-situ measurements that are available. TAW is determined in a novel way as a model fitting parameter. A soil water balance model, the Evaporation, Transpiration and Recharge Model, is used to simulate root zone soil moisture for an area of interest. The TAW parameter of the model is varied until agreement is found between the model simulated and remotely-sensed root zone soil moisture observations on a pixel by pixel basis. In this study, we present initial modeling efforts and a remotely sensed validation data set that will be used to optimize TAW for the area of interest: the Jornada Long Term Ecological Research station (Jornada LTER) in south central New Mexico. Within the Jornada LTER, the model predictions and remote sensing datasets of root zone soil moisture are compared to neutron probe data from an approximately 2.7 kilometer-long transect of 89 neutron soil moisture probes within the Jornada LTER.
As cosmogenic nuclide applications continue to expand, the need for a common basis for calculatio... more As cosmogenic nuclide applications continue to expand, the need for a common basis for calculation becomes increasingly important. In order to accurately compare between results from different nuclides, a single method of calculation is necessary. Calculators exist in numerous forms with none matching the needs of the CRONUS-Earth project to provide a simple and consistent method to interpret data from most commonly used cosmogenic nuclides. A new program written for this purpose, CRONUScalc, is presented here. This unified code presents a method applicable to 10 Be, 26 Al, 36 Cl, 3 He, and 14 C, with 21 Ne in testing. The base code predicts the concentration of a sample at a particular depth for a particular time in the past, which can be used for many applications. The multipurpose code already includes functions for calculating surface exposure age for a single sample or for a depth profile containing multiple samples. The code is available under the GNU General Public License agreement and can be downloaded and modified to deal with specific atypical scenarios.
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Papers by Brian Borchers