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• 1. [Article] Calibration and verification of HSPF model for Tualatin River Basin Water Quality

  The Tualatin River Basin is located in the Washington County, Oregon. The river was detected having high chlorophyll a concentration and low dissolved oxygen concentration during summer time, which violated ...

  Citation × Citation Citation Abstract Copy Title: Calibration and verification of HSPF model for Tualatin River Basin Water Quality Author: Tang, Fei The Tualatin River Basin is located in the Washington County, Oregon. The river was detected having high chlorophyll a concentration and low dissolved oxygen concentration during summer time, which violated DEQ water quality standards. A mathematical model (HSPF) was used to simulate physical, chemical and biological processes in the basin and to evaluate the effect of the 'best management practice' (BMP) strategy on improving water quality of the basin. Calibration of the model was focused on water temperature, total suspended solids, dissolved oxygen, dissolved ammonia, dissolved nitrate, dissolved phosphate, and chlorophyll a. Comparison against observed data (1990) showed that the model predictions were accurate for most of the constituents. After verification, the model was used to evaluate the strategy of the Best Management Practice (BMP) on the agricultural land at Gales Creek basin, a major sub-basin of the study area. The results showed that the effect of BMP on nutrients loading from land segment is not significant at Gales Creek. Title: Calibration and verification of HSPF model for Tualatin River Basin Water Quality Author: Tang, Fei The Tualatin River Basin is located in the Washington County, Oregon. The river was detected having high chlorophyll a concentration and low dissolved oxygen concentration during summer time, which violated DEQ water quality standards. A mathematical model (HSPF) was used to simulate physical, chemical and biological processes in the basin and to evaluate the effect of the 'best management practice' (BMP) strategy on improving water quality of the basin. Calibration of the model was focused on water temperature, total suspended solids, dissolved oxygen, dissolved ammonia, dissolved nitrate, dissolved phosphate, and chlorophyll a. Comparison against observed data (1990) showed that the model predictions were accurate for most of the constituents. After verification, the model was used to evaluate the strategy of the Best Management Practice (BMP) on the agricultural land at Gales Creek basin, a major sub-basin of the study area. The results showed that the effect of BMP on nutrients loading from land segment is not significant at Gales Creek. Close

• 2. [Image] Yarkon River - Drowning in Sewage

  	Citation × Citation Citation Abstract Copy Title: Yarkon River - Drowning in Sewage Year: 1987 Title: Yarkon River - Drowning in Sewage Year: 1987 Close

• 3. [Image] Hydrologic Data Collection for River Basin Management

  	Citation × Citation Citation Abstract Copy Title: Hydrologic Data Collection for River Basin Management Year: 2008 Title: Hydrologic Data Collection for River Basin Management Year: 2008 Close

• 4. [Image] High pH Water in Maqarin Area, Jordan (Occurence, Mineralization, Genesis)

  	Citation × Citation Citation Abstract Copy Title: High pH Water in Maqarin Area, Jordan (Occurence, Mineralization, Genesis) Author: Salāmah, Ilyās Year: 1985 Title: High pH Water in Maqarin Area, Jordan (Occurence, Mineralization, Genesis) Author: Salāmah, Ilyās Year: 1985 Close

• 5. [Image] Libyan Great Man-Made River Project Phase 1 Paper 6. Storage reservoirs: design and construction.

  	Citation × Citation Citation Abstract Copy Title: Libyan Great Man-Made River Project Phase 1 Paper 6. Storage reservoirs: design and construction. Year: 1994 Title: Libyan Great Man-Made River Project Phase 1 Paper 6. Storage reservoirs: design and construction. Year: 1994 Close

• 6. [Article] Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter

  Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM ...

  Citation × Citation Citation Abstract Copy Title: Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter Author: Lee, Baek Soo P. Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems. Title: Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter Author: Lee, Baek Soo P. Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems. Close