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• 1. [Article] Statistical Analysis for Groundwater / Surface Water Interaction at a Drinking Water Well

  Drinking water at a certain groundwater well is located at the confluence of a north fork and south fork of a major river. Data was collected to determine if the well is under direct influence by surface ...

  Citation × Citation Citation Abstract Copy Title: Statistical Analysis for Groundwater / Surface Water Interaction at a Drinking Water Well Author: Garlitz, John Year: 2008 Drinking water at a certain groundwater well is located at the confluence of a north fork and south fork of a major river. Data was collected to determine if the well is under direct influence by surface water. Direct influence and the extent of the correlation was determined by statistically analyzing the well turbidity with surface water flow and temperature variability. The surface water flow and was lagged per period and with a weighted average to determine the highest correlation. Logistic regression models were developed to determine if a predictive model can predict permit conditions based on the data collected. Title: Statistical Analysis for Groundwater / Surface Water Interaction at a Drinking Water Well Author: Garlitz, John Year: 2008 Drinking water at a certain groundwater well is located at the confluence of a north fork and south fork of a major river. Data was collected to determine if the well is under direct influence by surface water. Direct influence and the extent of the correlation was determined by statistically analyzing the well turbidity with surface water flow and temperature variability. The surface water flow and was lagged per period and with a weighted average to determine the highest correlation. Logistic regression models were developed to determine if a predictive model can predict permit conditions based on the data collected. Close

• 2. [Article] Convergent Surface Water Distributions in U.S. Cities

  Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface ...

  Citation × Citation Citation Abstract Copy Title: Convergent Surface Water Distributions in U.S. Cities Author: Steele, Meredith K., Heffernan, James B., Bettez, Neil D., Cavender-Bares, Jeannine, Groffman, Peter M., Grove, J. Morgan, Hall, Sharon J., Hobbie, Sarah E., Larson, Kelli L., Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Polsky, Colin, Chowdhury, Rinku Roy Year: 2014 Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface water redistribution at broad spatialscales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US cities with their surrounding undeveloped land. We evaluated differences in areal ( A) and numeric densities ( N) of water bodies (lakes, wetlands, and so on), the morphological characteristics of water bodies (size), and the density ( D) of surface flow channels (that is, streams and rivers). The variance of urban A, N, and D across the 100 MSAs decreased, by 89, 25, and 71%, respectively, compared to undeveloped land. These data show that many cities are surface water poor relative to undeveloped land; however, in drier landscapesurbanization increases the occurrence of surface water. This convergence pattern strengthened with development intensity, such that high intensityurban development had an areal water body density 98% less than undeveloped lands. Urbanization appears to drive the convergence of hydrological features across the US, such that surface water distributions of cities are more similar to each other than to their surrounding landscapes. Title: Convergent Surface Water Distributions in U.S. Cities Author: Steele, Meredith K., Heffernan, James B., Bettez, Neil D., Cavender-Bares, Jeannine, Groffman, Peter M., Grove, J. Morgan, Hall, Sharon J., Hobbie, Sarah E., Larson, Kelli L., Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Polsky, Colin, Chowdhury, Rinku Roy Year: 2014 Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface water redistribution at broad spatialscales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US cities with their surrounding undeveloped land. We evaluated differences in areal ( A) and numeric densities ( N) of water bodies (lakes, wetlands, and so on), the morphological characteristics of water bodies (size), and the density ( D) of surface flow channels (that is, streams and rivers). The variance of urban A, N, and D across the 100 MSAs decreased, by 89, 25, and 71%, respectively, compared to undeveloped land. These data show that many cities are surface water poor relative to undeveloped land; however, in drier landscapesurbanization increases the occurrence of surface water. This convergence pattern strengthened with development intensity, such that high intensityurban development had an areal water body density 98% less than undeveloped lands. Urbanization appears to drive the convergence of hydrological features across the US, such that surface water distributions of cities are more similar to each other than to their surrounding landscapes. Close

• 3. [Article] Groundwater-Surface Water Interactions near Mosier, Oregon

  The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater ...

  Citation × Citation Citation Abstract Copy Title: Groundwater-Surface Water Interactions near Mosier, Oregon Author: Jones, Cullen Brandon Year: 2016 The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that has received relatively little attention is the interaction between groundwater and surface waters at locations where interflow zones are intersected by the surface waters. The objective of my research is to investigate how CRBG interflow zone exposures in Mosier Creek may be controlling groundwater elevations in the area. The methods used include: (1) geochemical analysis of well cuttings and detailed geologic mapping along area streams to identify interflow zones of individual CRBG flows, (2) analysis of stream discharge data and groundwater elevation data to confirm exchange of groundwater and surface waters, and (3) collection and analyses of 31 water samples from area wells, streams, and springs, to determine if waters from individual CRBG aquifers can be hydrochemically identified and to further constrain understanding of surface and groundwater interactions. My study confirms that the general elevation of the Pomona Member and Basalt of Lolo interflow zone creek exposure is coincident with the elevation where a change in slope of the decline trend in 2004 is seen in Mosier area well hydrographs. Furthermore, the results of stream discharge data indicated a close connection between drawdown from groundwater pumping during irrigation season and groundwater- surface water interaction. At the time of drawdown in the upper-most CRBG aquifer (Pomona), the stream transitions from gaining to losing water into the groundwater system. Elemental chemistry data indicates the Frenchman Springs Sentinel Gap aquifer waters are the most evolved waters in this study. Stable isotopic data reinforced this determination as the Sentinel Gap waters are the lightest, or most negative, with regard to δD and δ18O. Sentinel Gap samples were more depleted than other aquifer samples by 4.38 to 6.89 0/100 for δD and 0.39 to 0.59 0/100 for δ18O. The results of the general chemistry and isotope data reveal a more evolved chemical signature in lower watershed groundwater versus a less evolved signature for waters from wells located higher up on the Columbia Hills anticline. This was interpreted to be the result of the major structural features in the area providing for a more regional pathway of recharge in lower watershed groundwaters, versus a more local source of recharge for upper watershed groundwaters. There was also a pronounced commingled signature in the elemental ratios of lower watershed aquifer waters. The suspected mechanism of recharge to lower watershed wells is through younger Cascadian deposits upslope from the local watershed. The findings of this study reveal the importance of a detailed understanding of CRBG stratigraphy and its relation to surface waters, especially for other areas within the Yakima Fold Belt or Oregon and Washington. Studies that do not consider the influence that individual CRBG flows can have on groundwater-surface water interactions, and the groundwater system as a whole, run the risk of improperly assessing the groundwater resource for a region. Title: Groundwater-Surface Water Interactions near Mosier, Oregon Author: Jones, Cullen Brandon Year: 2016 The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that has received relatively little attention is the interaction between groundwater and surface waters at locations where interflow zones are intersected by the surface waters. The objective of my research is to investigate how CRBG interflow zone exposures in Mosier Creek may be controlling groundwater elevations in the area. The methods used include: (1) geochemical analysis of well cuttings and detailed geologic mapping along area streams to identify interflow zones of individual CRBG flows, (2) analysis of stream discharge data and groundwater elevation data to confirm exchange of groundwater and surface waters, and (3) collection and analyses of 31 water samples from area wells, streams, and springs, to determine if waters from individual CRBG aquifers can be hydrochemically identified and to further constrain understanding of surface and groundwater interactions. My study confirms that the general elevation of the Pomona Member and Basalt of Lolo interflow zone creek exposure is coincident with the elevation where a change in slope of the decline trend in 2004 is seen in Mosier area well hydrographs. Furthermore, the results of stream discharge data indicated a close connection between drawdown from groundwater pumping during irrigation season and groundwater- surface water interaction. At the time of drawdown in the upper-most CRBG aquifer (Pomona), the stream transitions from gaining to losing water into the groundwater system. Elemental chemistry data indicates the Frenchman Springs Sentinel Gap aquifer waters are the most evolved waters in this study. Stable isotopic data reinforced this determination as the Sentinel Gap waters are the lightest, or most negative, with regard to δD and δ18O. Sentinel Gap samples were more depleted than other aquifer samples by 4.38 to 6.89 0/100 for δD and 0.39 to 0.59 0/100 for δ18O. The results of the general chemistry and isotope data reveal a more evolved chemical signature in lower watershed groundwater versus a less evolved signature for waters from wells located higher up on the Columbia Hills anticline. This was interpreted to be the result of the major structural features in the area providing for a more regional pathway of recharge in lower watershed groundwaters, versus a more local source of recharge for upper watershed groundwaters. There was also a pronounced commingled signature in the elemental ratios of lower watershed aquifer waters. The suspected mechanism of recharge to lower watershed wells is through younger Cascadian deposits upslope from the local watershed. The findings of this study reveal the importance of a detailed understanding of CRBG stratigraphy and its relation to surface waters, especially for other areas within the Yakima Fold Belt or Oregon and Washington. Studies that do not consider the influence that individual CRBG flows can have on groundwater-surface water interactions, and the groundwater system as a whole, run the risk of improperly assessing the groundwater resource for a region. Close

• 4. [Article] Occurrence of Synthetic Amino-Polycarboxylate Chelating Compounds in Oregon Surface Waters

  Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial ...

  Citation × Citation Citation Abstract Copy Title: Occurrence of Synthetic Amino-Polycarboxylate Chelating Compounds in Oregon Surface Waters Author: Hersey, Nathan A Year: 2014 Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial settings. When chelating compounds are present, the activity and transport of metal cations in the environment and the uptake of metals in natural systems can be affected. Surface water samples from across the United States were analyzed, as well as local collection and analysis of surface waters and wastewater treatment plant effluent from around Northwest Oregon. Results indicate presence of synthetic chelating compounds in areas with human activity, and absence in areas that are less populated. As a stable and water soluble compound, monitoring for chelates could have potential use as an effective indicator of further anthropogenic effects. Title: Occurrence of Synthetic Amino-Polycarboxylate Chelating Compounds in Oregon Surface Waters Author: Hersey, Nathan A Year: 2014 Cation sequestering compounds are contained in many industrial, commercial and personal care products. The most widely used chelating agents, EDTA and DTPA, are commonly found in natural and industrial settings. When chelating compounds are present, the activity and transport of metal cations in the environment and the uptake of metals in natural systems can be affected. Surface water samples from across the United States were analyzed, as well as local collection and analysis of surface waters and wastewater treatment plant effluent from around Northwest Oregon. Results indicate presence of synthetic chelating compounds in areas with human activity, and absence in areas that are less populated. As a stable and water soluble compound, monitoring for chelates could have potential use as an effective indicator of further anthropogenic effects. Close

• 5. [Article] Groundwater Surface Trends in the North Florence Dunal Aquifer, Oregon Coast, USA

  The North Florence Dunal Aquifer is the only feasible source for drinking water for the coastal city of Florence, Oregon and Florence's Urban Growth Boundary. High infiltration rates and a shallow groundwater ...

  Citation × Citation Citation Abstract Copy Title: Groundwater Surface Trends in the North Florence Dunal Aquifer, Oregon Coast, USA Author: Doliber, Sarah Rebecca Year: 2012 The North Florence Dunal Aquifer is the only feasible source for drinking water for the coastal city of Florence, Oregon and Florence's Urban Growth Boundary. High infiltration rates and a shallow groundwater table leave the aquifer highly susceptible to contamination from septic tank effluent, storm runoff, chemical fertilizers and recreational ATV use throughout the dunes. Public interest in the quality and quantity of the aquifer water has been sparked since the City of Florence received a grant from the Environmental Protection Agency for a watershed protection and restoration project. Delineation of the shallow groundwater surface and its relationship to the surface water bodies within the dunes is crucial in protecting this drinking water source from contamination. This thesis project created a GIS representation of the shallow groundwater elevation and associated prediction error map. Surface water bodies were confirmed as window lakes into the dunal aquifer and no signs of perched aquifer conditions were observed between Holocene and Pleistocene dunes. Ground Penetrating Radar, well data provided by the city of Florence and LiDAR were the primary sources for data collection. Title: Groundwater Surface Trends in the North Florence Dunal Aquifer, Oregon Coast, USA Author: Doliber, Sarah Rebecca Year: 2012 The North Florence Dunal Aquifer is the only feasible source for drinking water for the coastal city of Florence, Oregon and Florence's Urban Growth Boundary. High infiltration rates and a shallow groundwater table leave the aquifer highly susceptible to contamination from septic tank effluent, storm runoff, chemical fertilizers and recreational ATV use throughout the dunes. Public interest in the quality and quantity of the aquifer water has been sparked since the City of Florence received a grant from the Environmental Protection Agency for a watershed protection and restoration project. Delineation of the shallow groundwater surface and its relationship to the surface water bodies within the dunes is crucial in protecting this drinking water source from contamination. This thesis project created a GIS representation of the shallow groundwater elevation and associated prediction error map. Surface water bodies were confirmed as window lakes into the dunal aquifer and no signs of perched aquifer conditions were observed between Holocene and Pleistocene dunes. Ground Penetrating Radar, well data provided by the city of Florence and LiDAR were the primary sources for data collection. Close

• 6. [Article] Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2)

  One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. ...

  Citation × Citation Citation Abstract Copy Title: Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2) Author: Shojaei, Nasim Year: 2014 One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. To better understand the effects of external and internal nutrient and organic loading and the effects of reservoir operation, a model is often developed, calibrated, and used for sensitivity and management simulations. The importance of modeling and simulation in the scientific community has drawn interest towards methods for automated calibration. This study addresses using an automatic technique to calibrate the water quality model CE-QUAL-W2 (Cole and Wells, 2013). CE-QUAL-W2 is a two-dimensional (2D) longitudinal/vertical hydrodynamic and water quality model for surface water bodies, modeling eutrophication processes such as temperature-nutrient-algae-dissolved oxygen-organic matter and sediment relationships. The numerical method used for calibration in this study is the particle swarm optimization method developed by Kennedy and Eberhart (1995) and inspired by the paradigm of birds flocking. The objective of this calibration procedure is to choose model parameters and coefficients affecting temperature, chlorophyll a, dissolved oxygen, and nutrients (such as NH4, NO3, and PO4). A case study is presented for the Karkheh Reservoir in Iran with a capacity of more than 5 billion cubic meters that is the largest dam in Iran with both agricultural and drinking water usages. This algorithm is shown to perform very well for determining model parameters for the reservoir water quality and hydrodynamic model. Implications of the use of this procedure for other water quality models are also shown. Title: Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2) Author: Shojaei, Nasim Year: 2014 One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. To better understand the effects of external and internal nutrient and organic loading and the effects of reservoir operation, a model is often developed, calibrated, and used for sensitivity and management simulations. The importance of modeling and simulation in the scientific community has drawn interest towards methods for automated calibration. This study addresses using an automatic technique to calibrate the water quality model CE-QUAL-W2 (Cole and Wells, 2013). CE-QUAL-W2 is a two-dimensional (2D) longitudinal/vertical hydrodynamic and water quality model for surface water bodies, modeling eutrophication processes such as temperature-nutrient-algae-dissolved oxygen-organic matter and sediment relationships. The numerical method used for calibration in this study is the particle swarm optimization method developed by Kennedy and Eberhart (1995) and inspired by the paradigm of birds flocking. The objective of this calibration procedure is to choose model parameters and coefficients affecting temperature, chlorophyll a, dissolved oxygen, and nutrients (such as NH4, NO3, and PO4). A case study is presented for the Karkheh Reservoir in Iran with a capacity of more than 5 billion cubic meters that is the largest dam in Iran with both agricultural and drinking water usages. This algorithm is shown to perform very well for determining model parameters for the reservoir water quality and hydrodynamic model. Implications of the use of this procedure for other water quality models are also shown. Close

• 7. [Article] Effects of Beaver Dams on Surface Water Flow During Storm Events in an Urban Landscape

  Urban land-use generally alters the hydrologic cycle, leading to changes in the natural flow regime of local streams. Runoff from impervious surfaces and routing of stormwater to streams causes urban streams ...

  Citation × Citation Citation Abstract Copy Title: Effects of Beaver Dams on Surface Water Flow During Storm Events in an Urban Landscape Author: Poor, Erin Year: 2017 Urban land-use generally alters the hydrologic cycle, leading to changes in the natural flow regime of local streams. Runoff from impervious surfaces and routing of stormwater to streams causes urban streams to respond quickly and more intensely to storm events-more so than then would be observed in a less urbanized landscape. The rapid pulse of water that is routed to streams during precipitation events can degrade the physical structure of the channel and alter water quality and habitat availability. To manage these common urban stream issues, agencies have been seeking alternative ways of restoring and enhancing resilience in urban stream networks within the constraints of existing infrastructure. One potential strategy may be to support beaver recolonization of urban streams. This is because beaver dam building activity has been found to attenuate streamflow in areas that have experienced minimal human impact. Currently, however, no studies have been published that examine how beaver dams affect stream flow in altered urban systems. This study seeks to determine if the presence of beaver dams and ponds in urban stream reaches in the Tualatin River basin, Oregon, modifies the stream’s response to storm events. Continuous surface water levels are being collected upstream and downstream of two beaver affected reaches in order to determine how the presence of dams and ponds affect the flow regime, and whether this more closely resembles a less degraded state. Title: Effects of Beaver Dams on Surface Water Flow During Storm Events in an Urban Landscape Author: Poor, Erin Year: 2017 Urban land-use generally alters the hydrologic cycle, leading to changes in the natural flow regime of local streams. Runoff from impervious surfaces and routing of stormwater to streams causes urban streams to respond quickly and more intensely to storm events-more so than then would be observed in a less urbanized landscape. The rapid pulse of water that is routed to streams during precipitation events can degrade the physical structure of the channel and alter water quality and habitat availability. To manage these common urban stream issues, agencies have been seeking alternative ways of restoring and enhancing resilience in urban stream networks within the constraints of existing infrastructure. One potential strategy may be to support beaver recolonization of urban streams. This is because beaver dam building activity has been found to attenuate streamflow in areas that have experienced minimal human impact. Currently, however, no studies have been published that examine how beaver dams affect stream flow in altered urban systems. This study seeks to determine if the presence of beaver dams and ponds in urban stream reaches in the Tualatin River basin, Oregon, modifies the stream’s response to storm events. Continuous surface water levels are being collected upstream and downstream of two beaver affected reaches in order to determine how the presence of dams and ponds affect the flow regime, and whether this more closely resembles a less degraded state. Close

• 8. [Article] Estimation of Surface Water Temperature of the Tigris River System in Iraq

  Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering ...

  Citation × Citation Citation Abstract Copy Title: Estimation of Surface Water Temperature of the Tigris River System in Iraq Author: Al-Murib, M., Wells, Scott A., Talke, Stefan A. Year: 2017 Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering the saturation concentration of dissolved oxygen (DO), and influencing the susceptibility of fish to disease. Temperatures in the Tigris River, one of the largest rivers in the Middle East, are influenced by factors such as heat fluxes at the air-water and human activities such as direct discharge of water to the river. However, modeling and management of water temperature is limited by a paucity of in-situ data, which prevents calibration of models. In this study, we infill data gaps by estimating Tw using the thermal bands of both the Landsat 5 TM and Landsat 7 ETM+ sensors. These satellite-based estimates, typically measured once or twice a month with 60-120m resolution, are then used to develop a regression model that relates daily water temperature to daily air temperature and river flow. These estimates are used to define the Tw boundary conditions for a hydrodynamic and water quality model of the Tigris River based on a 2D implementation of the CE-QUAL-W2 (W2) numerical model. Initial results suggest that there is a significant agreement between modeled and remotely estimated data of Tw. Results suggest that short-wave solar radiation is the most important factor that controls seasonal Tw variations. However, anthropogenic influence is observed as a result of return irrigation flows and flows from Tharthar Lake. Title: Estimation of Surface Water Temperature of the Tigris River System in Iraq Author: Al-Murib, M., Wells, Scott A., Talke, Stefan A. Year: 2017 Monitoring surface water temperatures (Tw) in lakes, rivers, and reservoirs is a key component of environmental management and influences water quality by affecting bio-geo chemical reaction rates, altering the saturation concentration of dissolved oxygen (DO), and influencing the susceptibility of fish to disease. Temperatures in the Tigris River, one of the largest rivers in the Middle East, are influenced by factors such as heat fluxes at the air-water and human activities such as direct discharge of water to the river. However, modeling and management of water temperature is limited by a paucity of in-situ data, which prevents calibration of models. In this study, we infill data gaps by estimating Tw using the thermal bands of both the Landsat 5 TM and Landsat 7 ETM+ sensors. These satellite-based estimates, typically measured once or twice a month with 60-120m resolution, are then used to develop a regression model that relates daily water temperature to daily air temperature and river flow. These estimates are used to define the Tw boundary conditions for a hydrodynamic and water quality model of the Tigris River based on a 2D implementation of the CE-QUAL-W2 (W2) numerical model. Initial results suggest that there is a significant agreement between modeled and remotely estimated data of Tw. Results suggest that short-wave solar radiation is the most important factor that controls seasonal Tw variations. However, anthropogenic influence is observed as a result of return irrigation flows and flows from Tharthar Lake. Close

• 9. [Article] Stable Isotope Variations (δ18O and δD) in Modern Waters Across the Andean Plateau

  Environmental parameters that influence the isotopic composition of meteoric water (δ18O and δD) are well characterized up the windward side of mountains, where orographic precipitation results in a predictable ...

  Citation × Citation Citation Abstract Copy Title: Stable Isotope Variations (δ18O and δD) in Modern Waters Across the Andean Plateau Author: Bershaw, John, Saylor, Joel E., Garzione, Carmala N., Leier, Andrew Year: 2016 Environmental parameters that influence the isotopic composition of meteoric water (δ18O and δD) are well characterized up the windward side of mountains, where orographic precipitation results in a predictable relationship between the isotopic composition of precipitation and elevation. The topographic and climatic evolution of the Andean Plateau and surrounding regions has been studied extensively by exploiting this relationship through the use of paleowater proxies. However, interpretation on the plateau itself is challenged by a poor understanding of processes that fractionate isotopes during vapor transport and rainout, and by the relative contribution of unique moisture sources. Here, we present an extensive dataset of modern surface water samples for the northern Andean Plateau and surrounding regions to elucidate patterns and causes of isotope fractionation in this continental environment. These data show a progressive increase in δ18O of stream water west of the Eastern Cordillera (∼1‰/70 km), almost identical to the rate observed across the Tibetan Plateau, attributed to a larger fraction of recycled water in precipitation and/or increased evaporative enrichment downwind. This may lead to underestimates of paleoelevation, particularly for sites deep into the rainshadow of the Eastern Cordilleran crest. That said, elevation is a primary control on the isotopic composition of surface waters across the entire Andean Plateau and its flanks when considering the most negative δ18O values, highlighting the need for sufficiently large datasets to distinguish minimally evaporated samples. There is a general increase in δ18O on the plateau from north to south, concomitant with an increase in aridity and decrease in convective moistening (amount effect). Lastly, stable isotope and seasonal precipitation patterns suggest easterlies provide the vast majority of moisture that falls as precipitation across the Andean Plateau and Western Cordillera, from Peru to northern Bolivia (−13° to −20° latitude), with Pacific-derived moisture contributing a minor amount at low elevations near the coast. Title: Stable Isotope Variations (δ18O and δD) in Modern Waters Across the Andean Plateau Author: Bershaw, John, Saylor, Joel E., Garzione, Carmala N., Leier, Andrew Year: 2016 Environmental parameters that influence the isotopic composition of meteoric water (δ18O and δD) are well characterized up the windward side of mountains, where orographic precipitation results in a predictable relationship between the isotopic composition of precipitation and elevation. The topographic and climatic evolution of the Andean Plateau and surrounding regions has been studied extensively by exploiting this relationship through the use of paleowater proxies. However, interpretation on the plateau itself is challenged by a poor understanding of processes that fractionate isotopes during vapor transport and rainout, and by the relative contribution of unique moisture sources. Here, we present an extensive dataset of modern surface water samples for the northern Andean Plateau and surrounding regions to elucidate patterns and causes of isotope fractionation in this continental environment. These data show a progressive increase in δ18O of stream water west of the Eastern Cordillera (∼1‰/70 km), almost identical to the rate observed across the Tibetan Plateau, attributed to a larger fraction of recycled water in precipitation and/or increased evaporative enrichment downwind. This may lead to underestimates of paleoelevation, particularly for sites deep into the rainshadow of the Eastern Cordilleran crest. That said, elevation is a primary control on the isotopic composition of surface waters across the entire Andean Plateau and its flanks when considering the most negative δ18O values, highlighting the need for sufficiently large datasets to distinguish minimally evaporated samples. There is a general increase in δ18O on the plateau from north to south, concomitant with an increase in aridity and decrease in convective moistening (amount effect). Lastly, stable isotope and seasonal precipitation patterns suggest easterlies provide the vast majority of moisture that falls as precipitation across the Andean Plateau and Western Cordillera, from Peru to northern Bolivia (−13° to −20° latitude), with Pacific-derived moisture contributing a minor amount at low elevations near the coast. Close

• 10. [Article] Impact of Groundwater Contamination in East Multnomah County on the Interlachen Community

  The Friends of Blue and Fairview Lake through the Environmental Protection Agency (EPA) Technical Assistance Grant (TAG) program contracted with Portland State University faculty and staff to provide an ...

  Citation × Citation Citation Abstract Copy Title: Impact of Groundwater Contamination in East Multnomah County on the Interlachen Community Author: Wells, Scott A., Li, ShuGuang, Beeson, Marvin, Cummings, Michael, Pratt, Richard, Annear, Robert Leslie, Brandt, Karann Year: 1996 The Friends of Blue and Fairview Lake through the Environmental Protection Agency (EPA) Technical Assistance Grant (TAG) program contracted with Portland State University faculty and staff to provide an independent review of the groundwater contamination problem at the Boeing-Cascade site in East Multnomah County. An independent consultant, Karann Brandt, of PRC Environmental Management, Inc., was also assisting the panel with the review. The region of groundwater contamination is a 2.5 square mile region bounded by NE Halsey Blvd. to the Columbia River and NE 178th to NE 223rd (see Figure 1). The groundwater contamination is primarily of volatile organic compounds (like trichloroethylene or TCE). The approximate plume extent is shown in Figure 2 in one of the principal aquifers, the Troutdale Sandstone Aquifer (TSA). Since the Interlachen community in the area of Blue and Fairview Lakes uses groundwater as a community water supply and the lakes as a recreation resource, there are concerns that the groundwater contamination could seriously affect the community by contaminating their water supply and surface water bodies (Fairview Lake, Blue Lake, Columbia Slough) in their vicinity. Much work has been accomplished already by responsible parties (Boeing and Cascade Corporations and their conconsultants. The community was able to secure the EPA TAG to provide an independent review of the contamination problem facing their community and to assist the community in understanding the nature of the contamination problem. Issues of concern identified from this review will be recommended for incorporation in the Department of Environmental Quality’s (DEQ) final Record of Decision concerning site remediation efforts. This review will help assure remediation strategies that protect groundwater and surface water for the Interlachen community will be pursued by the responsible parties. Title: Impact of Groundwater Contamination in East Multnomah County on the Interlachen Community Author: Wells, Scott A., Li, ShuGuang, Beeson, Marvin, Cummings, Michael, Pratt, Richard, Annear, Robert Leslie, Brandt, Karann Year: 1996 The Friends of Blue and Fairview Lake through the Environmental Protection Agency (EPA) Technical Assistance Grant (TAG) program contracted with Portland State University faculty and staff to provide an independent review of the groundwater contamination problem at the Boeing-Cascade site in East Multnomah County. An independent consultant, Karann Brandt, of PRC Environmental Management, Inc., was also assisting the panel with the review. The region of groundwater contamination is a 2.5 square mile region bounded by NE Halsey Blvd. to the Columbia River and NE 178th to NE 223rd (see Figure 1). The groundwater contamination is primarily of volatile organic compounds (like trichloroethylene or TCE). The approximate plume extent is shown in Figure 2 in one of the principal aquifers, the Troutdale Sandstone Aquifer (TSA). Since the Interlachen community in the area of Blue and Fairview Lakes uses groundwater as a community water supply and the lakes as a recreation resource, there are concerns that the groundwater contamination could seriously affect the community by contaminating their water supply and surface water bodies (Fairview Lake, Blue Lake, Columbia Slough) in their vicinity. Much work has been accomplished already by responsible parties (Boeing and Cascade Corporations and their conconsultants. The community was able to secure the EPA TAG to provide an independent review of the contamination problem facing their community and to assist the community in understanding the nature of the contamination problem. Issues of concern identified from this review will be recommended for incorporation in the Department of Environmental Quality’s (DEQ) final Record of Decision concerning site remediation efforts. This review will help assure remediation strategies that protect groundwater and surface water for the Interlachen community will be pursued by the responsible parties. Close