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• 11. [Article] Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary

  Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into ...

  Citation × Citation Citation Abstract Copy Title: Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary Author: Ennis, Sara Year: 2009 Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into farmland have reduced available habitat by more than half of historical levels. Recent efforts to restore estuarine habitats include tide gate replacement, though this method has been poorly studied. As a key indicator of salmon habitat suitability, temperature was used to evaluate the effects of tide gate replacement in a tidally influenced freshwater slough in the Lower Columbia River estuary. Three tide gates in the largest slough on Tenasillahe Island were replaced in 2007 with side-hinged aluminum gates. As managed during the data collection periods, the new tide gates did not allow tidal inflow into the slough. The study employed a Before-After, Control-Impact (BACI) approach, collecting data seasonally two years before and after replacement at the impact site and at the control site, a relatively unaltered slough on nearby Welch Island. Randomized Intervention Analysis and Monte Carlo tests revealed no significant difference in slough water temperatures after tide gate replacement, although minimum temperatures dropped up and downstream of the tide gates. Although the new tide gates did not have a significant effect on water temperature, the lower minimum temperatures may have been caused by a slight increase in tidal circulation. This result suggests that slough temperatures would decrease if the tide gates were managed to increase tidal inflow, and thus improve the quality of salmon rearing habitat. Title: Effects of Tide Gate Replacement on Water Temperature ina Freshwater Slough in the Columbia River Estuary Author: Ennis, Sara Year: 2009 Dramatic declines in salmon populations in the Pacific Northwest have brought new attention to the importance of estuarine rearing habitats. Levees and tide gates used to convert estuarine wetlands into farmland have reduced available habitat by more than half of historical levels. Recent efforts to restore estuarine habitats include tide gate replacement, though this method has been poorly studied. As a key indicator of salmon habitat suitability, temperature was used to evaluate the effects of tide gate replacement in a tidally influenced freshwater slough in the Lower Columbia River estuary. Three tide gates in the largest slough on Tenasillahe Island were replaced in 2007 with side-hinged aluminum gates. As managed during the data collection periods, the new tide gates did not allow tidal inflow into the slough. The study employed a Before-After, Control-Impact (BACI) approach, collecting data seasonally two years before and after replacement at the impact site and at the control site, a relatively unaltered slough on nearby Welch Island. Randomized Intervention Analysis and Monte Carlo tests revealed no significant difference in slough water temperatures after tide gate replacement, although minimum temperatures dropped up and downstream of the tide gates. Although the new tide gates did not have a significant effect on water temperature, the lower minimum temperatures may have been caused by a slight increase in tidal circulation. This result suggests that slough temperatures would decrease if the tide gates were managed to increase tidal inflow, and thus improve the quality of salmon rearing habitat. Close

• 12. [Article] Floodplains: Balancing Nature and Human Needs

  For countless years, the interaction between climatic conditions and water flow has forged the rolling hills and rivers in the metroscape. The floods that forced a deluge of water down the Columbia River ...

  Citation × Citation Citation Abstract Copy Title: Floodplains: Balancing Nature and Human Needs Author: Shandas, Vivek, Merrick, Meg Year: 2008 For countless years, the interaction between climatic conditions and water flow has forged the rolling hills and rivers in the metroscape. The floods that forced a deluge of water down the Columbia River between 13 and 17 thousand years ago established the fertile and absorptive landscape of the Willamette Valley. The lush vegetation controlled the regional climate and stabilized the soils, while the thirsty wetlands reduced flood potential, provided habitat, and purified the water. Over geological time, these natural processes have created ideal conditions for humans. The Pacific Northwest was home to some of the most densely populated communities of Native Americans, due partly to mild climate, plentiful water, and abundant sources of food and shelter. In the 19th century, Anglo settlers flooded the region for the same amenities, which continues to create ideal conditions for all that the region is known for today, including hiking, kayaking, and sailing - not to mention the provision of climate, topography, and fertile soils for growing some of the world?s best wines! Land surveys from the 1860s suggest that the current form of the metroscape started to take shape at the end of the 19th century. The conifers, alders, and maples that covered the region were slowly removed to make way for new urban settlements, and wetlands were drained to create farms and agricultural areas. In this atlas, we journey 140 years into the past to examine how and where the metroscape has changed. Our aim is to illustrate historic flooding of the region, and ponder what changes might mean to its future. Title: Floodplains: Balancing Nature and Human Needs Author: Shandas, Vivek, Merrick, Meg Year: 2008 For countless years, the interaction between climatic conditions and water flow has forged the rolling hills and rivers in the metroscape. The floods that forced a deluge of water down the Columbia River between 13 and 17 thousand years ago established the fertile and absorptive landscape of the Willamette Valley. The lush vegetation controlled the regional climate and stabilized the soils, while the thirsty wetlands reduced flood potential, provided habitat, and purified the water. Over geological time, these natural processes have created ideal conditions for humans. The Pacific Northwest was home to some of the most densely populated communities of Native Americans, due partly to mild climate, plentiful water, and abundant sources of food and shelter. In the 19th century, Anglo settlers flooded the region for the same amenities, which continues to create ideal conditions for all that the region is known for today, including hiking, kayaking, and sailing - not to mention the provision of climate, topography, and fertile soils for growing some of the world?s best wines! Land surveys from the 1860s suggest that the current form of the metroscape started to take shape at the end of the 19th century. The conifers, alders, and maples that covered the region were slowly removed to make way for new urban settlements, and wetlands were drained to create farms and agricultural areas. In this atlas, we journey 140 years into the past to examine how and where the metroscape has changed. Our aim is to illustrate historic flooding of the region, and ponder what changes might mean to its future. Close

• 13. [Article] Alaska Spartina Prevention, Detection and Response Plan

  This Alaska Spartina Prevention and Response Plan reviews the known impacts, biology, and invasion history of Spartina on the west coast. It outlines strategies for prevention, early detection and efficient ...

  Citation × Citation Citation Abstract Copy Title: Alaska Spartina Prevention, Detection and Response Plan Author: Morgan, Vanessa Howard, Sytsma, Mark Year: 2010 This Alaska Spartina Prevention and Response Plan reviews the known impacts, biology, and invasion history of Spartina on the west coast. It outlines strategies for prevention, early detection and efficient organization of rapid response efforts following the confirmation of an infestation. The goal of the plan is to prevent the establishment of any Spartina populations and to eradicate established infestations if detected within the State’s estuaries or coastal wetlands. Five objectives and strategies are described and 31 specific tasks are outlined to achieve this goal. These include: • Prevention of establishment through vector and source population control. • Plan coordination by establishing clear procedures, authorities, and responsibilities for action, and a framework for implementation of the Plan. • Monitoring to ensure early detection of small infestations that are most easily eradicated. • Education and outreach to ensure that the public understands the threat of Spartina to Alaska’s natural resources and to recruit citizen and agency personnel in surveillance. • Research to increase understanding of vectors of introduction, susceptible habitat, and management to enhance efficacy of prevention, detection, and control. Title: Alaska Spartina Prevention, Detection and Response Plan Author: Morgan, Vanessa Howard, Sytsma, Mark Year: 2010 This Alaska Spartina Prevention and Response Plan reviews the known impacts, biology, and invasion history of Spartina on the west coast. It outlines strategies for prevention, early detection and efficient organization of rapid response efforts following the confirmation of an infestation. The goal of the plan is to prevent the establishment of any Spartina populations and to eradicate established infestations if detected within the State’s estuaries or coastal wetlands. Five objectives and strategies are described and 31 specific tasks are outlined to achieve this goal. These include: • Prevention of establishment through vector and source population control. • Plan coordination by establishing clear procedures, authorities, and responsibilities for action, and a framework for implementation of the Plan. • Monitoring to ensure early detection of small infestations that are most easily eradicated. • Education and outreach to ensure that the public understands the threat of Spartina to Alaska’s natural resources and to recruit citizen and agency personnel in surveillance. • Research to increase understanding of vectors of introduction, susceptible habitat, and management to enhance efficacy of prevention, detection, and control. Close

• 14. [Article] The Effectiveness of Vertebrate Passage and Prevention Structures: A Study of Boeckman Road in Wilsonville

  One of the most obvious impacts roads have on the natural world is direct mortality to individual animals that attempt to cross roads. A less obvious but likely more important impact of roads on many species ...

  Citation × Citation Citation Abstract Copy Title: The Effectiveness of Vertebrate Passage and Prevention Structures: A Study of Boeckman Road in Wilsonville Author: de Rivera, Catherine E., Bliss-Ketchum, Leslie L. Year: 2010 One of the most obvious impacts roads have on the natural world is direct mortality to individual animals that attempt to cross roads. A less obvious but likely more important impact of roads on many species is habitat fragmentation. The ability for individuals to travel between subpopulations is the key to genetic diversity as well as ultimately the survival of the species. Considering these impacts and management goals to increase habitat connectivity, increased attention has been given to creating road design that reduces wildlife collisions. Most studies, however, have been in other countries or regions and most focus on connectivity for just one or a few species and rarely in urban settings. This study examines the effectiveness of a variety of under-road passage structures for a community of animals in an urban wetland. Wildlife passage was taken into great consideration in the construction of the Boeckman Road Extension, the new road (2006) in Wilsonville, Oregon, examined in this study. As a result it includes a bridge, two box culverts and eleven round concrete culverts to facilitate wildlife passage as well as a mammal fence atop an amphibian/reptile wall. In order to monitor passage use we used a combination of sand-track monitoring and motion-detect cameras. We compared passage structure use to movement in the habitats surrounding the road by monitoring four habitat transects in addition to the passage structures (Road transect). We also conducted tag and release studies targeted to small mammals. Finally, camera data collected in passage structures were compared to camera monitoring at the end of the exclusionary fencing. A total of 26 species were detected in this study, 73% (19) of which were found to be using passage structures. 15% (4) of the identified species were detected on transects but not in passages and 11.5% (3) were detected in locations other than transects or passage structures. The bridge structure provided passage to the highest number of species (16), followed by the 24” and 18” culverts, which had a combined total of 11 species, and lastly the 9x4 culverts, which were flooded, with 2 species detected. Our results indicate that large and medium mammals overall did not use passages less than would be expected based on their local movement in habitats. In pit and Sherman traps sixteen of the 48 small mammals that were captured and tagged were re-caught, but only four of these moved from one transect to another, with two moving away from the road and the other two moving toward and under the road. Of the species detected with cameras at the passage structures and circumventing fencing, excluding small mammals, reptiles and amphibians (139), 19% (33) were found potentially crossing on the road surface. The proportion of deer detected using over-road crossings (23%) is of particular concern for driver safety. The bridge structure provided the greatest passage, in not only frequency of crossings but also species present. When maintenance factors, driver safety and species of greatest concern are included, the higher cost of the bridge structure would likely be even further balanced by the benefits. This study highlights the effectiveness and potential problems (and possible fixes) of some of the passage and prevention structures. Including passage and prevention structures such as these in road design is imperative for habitat connectivity and the need for this becomes even more apparent as Oregon’s native wildlife face an ever increasing urban landscape as well as the potential impacts of climate change. Title: The Effectiveness of Vertebrate Passage and Prevention Structures: A Study of Boeckman Road in Wilsonville Author: de Rivera, Catherine E., Bliss-Ketchum, Leslie L. Year: 2010 One of the most obvious impacts roads have on the natural world is direct mortality to individual animals that attempt to cross roads. A less obvious but likely more important impact of roads on many species is habitat fragmentation. The ability for individuals to travel between subpopulations is the key to genetic diversity as well as ultimately the survival of the species. Considering these impacts and management goals to increase habitat connectivity, increased attention has been given to creating road design that reduces wildlife collisions. Most studies, however, have been in other countries or regions and most focus on connectivity for just one or a few species and rarely in urban settings. This study examines the effectiveness of a variety of under-road passage structures for a community of animals in an urban wetland. Wildlife passage was taken into great consideration in the construction of the Boeckman Road Extension, the new road (2006) in Wilsonville, Oregon, examined in this study. As a result it includes a bridge, two box culverts and eleven round concrete culverts to facilitate wildlife passage as well as a mammal fence atop an amphibian/reptile wall. In order to monitor passage use we used a combination of sand-track monitoring and motion-detect cameras. We compared passage structure use to movement in the habitats surrounding the road by monitoring four habitat transects in addition to the passage structures (Road transect). We also conducted tag and release studies targeted to small mammals. Finally, camera data collected in passage structures were compared to camera monitoring at the end of the exclusionary fencing. A total of 26 species were detected in this study, 73% (19) of which were found to be using passage structures. 15% (4) of the identified species were detected on transects but not in passages and 11.5% (3) were detected in locations other than transects or passage structures. The bridge structure provided passage to the highest number of species (16), followed by the 24” and 18” culverts, which had a combined total of 11 species, and lastly the 9x4 culverts, which were flooded, with 2 species detected. Our results indicate that large and medium mammals overall did not use passages less than would be expected based on their local movement in habitats. In pit and Sherman traps sixteen of the 48 small mammals that were captured and tagged were re-caught, but only four of these moved from one transect to another, with two moving away from the road and the other two moving toward and under the road. Of the species detected with cameras at the passage structures and circumventing fencing, excluding small mammals, reptiles and amphibians (139), 19% (33) were found potentially crossing on the road surface. The proportion of deer detected using over-road crossings (23%) is of particular concern for driver safety. The bridge structure provided the greatest passage, in not only frequency of crossings but also species present. When maintenance factors, driver safety and species of greatest concern are included, the higher cost of the bridge structure would likely be even further balanced by the benefits. This study highlights the effectiveness and potential problems (and possible fixes) of some of the passage and prevention structures. Including passage and prevention structures such as these in road design is imperative for habitat connectivity and the need for this becomes even more apparent as Oregon’s native wildlife face an ever increasing urban landscape as well as the potential impacts of climate change. Close

• 15. [Article] Mapping Conservation Opportunity Areas for the Intertwine's Regional Conservation Strategy

  As part of efforts to develop the Regional Conservation Strategy (RCS) for the greater Portland-Vancouver region, Oregon State University’s Institute for Natural Resources (INR) was asked to use spatial ...

  Citation × Citation Citation Abstract Copy Title: Mapping Conservation Opportunity Areas for the Intertwine's Regional Conservation Strategy Author: Burcsu, Theresa, Kagan, James S. Year: 2011 As part of efforts to develop the Regional Conservation Strategy (RCS) for the greater Portland-Vancouver region, Oregon State University’s Institute for Natural Resources (INR) was asked to use spatial modeling to identify conservation opportunity areas (COAs). To complete the project, INR analysts proposed a strategy that would map high value areas using a landscape approach that is focused on relatively high spatial resolution data sets available for the whole metropolitan region. The approach creates 2 main metrics: one focused on terrestrial organisms and the other focused on aquatic and riparian organisms. These are combined to create a map of highly ranked land areas that can be used to formulate a map of conservation opportunity areas. The purpose of the COA mapping project was to use geographic information system methods to identify landscape patches with conservation and restoration potential. The criteria used to identify these high value patches was based on a number of base- and derived-data sets that we call “data inputs.” The data ranged from recently mapped land use and land cover types, hydrological data to indicate species habitat requirements, and road influence on habitat patches. The project identified some areas in which data gaps exist (e.g., region-wide biodiversity data collected and mapped in consistent ways) and some opportunities for improving existent data sets (e.g., land use/land cover map). The project provided several layers that can be used to guide the final Regional Conservation Strategy in selecting conservation opportunity areas. The best layer will depend upon the needs of the RCS efforts, however, in our opinion the most appropriate layer to use is COA 3.11.1 which weights wetlands fairly high, but not as highly as the second data draft. COA 3.10.1 offers similar results as well. Overall it appears that the model results corroborate corridors analysis done previously (Hennings and Soll 2010). There are some issues remaining that we feel can most adequately be addressed by updating the base land use/land cover map. Title: Mapping Conservation Opportunity Areas for the Intertwine's Regional Conservation Strategy Author: Burcsu, Theresa, Kagan, James S. Year: 2011 As part of efforts to develop the Regional Conservation Strategy (RCS) for the greater Portland-Vancouver region, Oregon State University’s Institute for Natural Resources (INR) was asked to use spatial modeling to identify conservation opportunity areas (COAs). To complete the project, INR analysts proposed a strategy that would map high value areas using a landscape approach that is focused on relatively high spatial resolution data sets available for the whole metropolitan region. The approach creates 2 main metrics: one focused on terrestrial organisms and the other focused on aquatic and riparian organisms. These are combined to create a map of highly ranked land areas that can be used to formulate a map of conservation opportunity areas. The purpose of the COA mapping project was to use geographic information system methods to identify landscape patches with conservation and restoration potential. The criteria used to identify these high value patches was based on a number of base- and derived-data sets that we call “data inputs.” The data ranged from recently mapped land use and land cover types, hydrological data to indicate species habitat requirements, and road influence on habitat patches. The project identified some areas in which data gaps exist (e.g., region-wide biodiversity data collected and mapped in consistent ways) and some opportunities for improving existent data sets (e.g., land use/land cover map). The project provided several layers that can be used to guide the final Regional Conservation Strategy in selecting conservation opportunity areas. The best layer will depend upon the needs of the RCS efforts, however, in our opinion the most appropriate layer to use is COA 3.11.1 which weights wetlands fairly high, but not as highly as the second data draft. COA 3.10.1 offers similar results as well. Overall it appears that the model results corroborate corridors analysis done previously (Hennings and Soll 2010). There are some issues remaining that we feel can most adequately be addressed by updating the base land use/land cover map. Close

• 16. [Article] Tree Cover Mapping for Assessing Greater Sage-Grouse Habitat in Eastern Oregon

  We used a predictive model to map canopy cover of vegetation over seven feet in height ("tall woody vegetation") at 30-meter resolution over nearly 29 million acres within and adjacent to the range of ...

  Citation × Citation Citation Abstract Copy Title: Tree Cover Mapping for Assessing Greater Sage-Grouse Habitat in Eastern Oregon Author: Nielsen, Eric M., Noone, Matthew D. Year: 2014 We used a predictive model to map canopy cover of vegetation over seven feet in height ("tall woody vegetation") at 30-meter resolution over nearly 29 million acres within and adjacent to the range of the greater sage-grouse in Oregon (Figure 1). Texture measures computed at various resolutions from color-infrared aerial photography provided the main source of predictor data used to produce the map. Canopy cover was treated as a categorical variable using six cover classes: absent (cover class C0), present at less than 4% (C1), 4 – 10% (C2), 10 – 20% (C3), 20 – 50% (C4), and 50% and over (C5). The map is referenced to conditions in the years 2011 and 2012. Although the specific target of the mapping was western juniper (Juniperus occidentalis), our reference data did not permit separating juniper from other tall woody vegetation during the predictive modeling process. The majority of the tall woody vegetation within the project area is western juniper. However, in high elevation regions, riparian, wetland, and residential areas, other vegetation is occasionally represented. The methodology discussed here produces raw modeled data. It is recommended that prior to use in most applications this raw tree cover product be additionally filtered or masked to eliminate false detections which often occur adjacent to agricultural areas and roads. For species-specific applications, an additional modeling phase is necessary to either eliminate tree cover detections likely to be species other than the target, or to model species importance values associated with each tree occurrence. Title: Tree Cover Mapping for Assessing Greater Sage-Grouse Habitat in Eastern Oregon Author: Nielsen, Eric M., Noone, Matthew D. Year: 2014 We used a predictive model to map canopy cover of vegetation over seven feet in height ("tall woody vegetation") at 30-meter resolution over nearly 29 million acres within and adjacent to the range of the greater sage-grouse in Oregon (Figure 1). Texture measures computed at various resolutions from color-infrared aerial photography provided the main source of predictor data used to produce the map. Canopy cover was treated as a categorical variable using six cover classes: absent (cover class C0), present at less than 4% (C1), 4 – 10% (C2), 10 – 20% (C3), 20 – 50% (C4), and 50% and over (C5). The map is referenced to conditions in the years 2011 and 2012. Although the specific target of the mapping was western juniper (Juniperus occidentalis), our reference data did not permit separating juniper from other tall woody vegetation during the predictive modeling process. The majority of the tall woody vegetation within the project area is western juniper. However, in high elevation regions, riparian, wetland, and residential areas, other vegetation is occasionally represented. The methodology discussed here produces raw modeled data. It is recommended that prior to use in most applications this raw tree cover product be additionally filtered or masked to eliminate false detections which often occur adjacent to agricultural areas and roads. For species-specific applications, an additional modeling phase is necessary to either eliminate tree cover detections likely to be species other than the target, or to model species importance values associated with each tree occurrence. Close

• 17. [Article] Estuarine Habitat Mitigation in Oregon: Policy Review, Analysis, and Recommended Improvements

  The report is organized in the following manner. After the introductory chapter (Chapter 1), Chapter Two describes Oregon’s current estuarine policy and related state and federal policies. Chapter Three ...

  Citation × Citation Citation Abstract Copy Title: Estuarine Habitat Mitigation in Oregon: Policy Review, Analysis, and Recommended Improvements Author: Buckley, Anna Year: 2006 The report is organized in the following manner. After the introductory chapter (Chapter 1), Chapter Two describes Oregon’s current estuarine policy and related state and federal policies. Chapter Three provides an inventory of recent permitted impacts and associated estuarine resource replacement. Chapter Four consists of a brief summary of the status of estuarine ecology and restoration/mitigation, with knowledge gaps identified. Chapter Five discusses wetland functional assessment tools and options for compensatory mitigation. This chapter begins with a description of the tidal Hydrogeomorphic (HGM) assessment method, how it compares to the estuarine resource replacement rules’ relative values table, and the utility of the tidal HGM in estuarine mitigation. Chapter Five, then, explores alternative mitigation options such as out-of-kind, banking, payment-in-lieu, and conservation in lieu. Chapter Six introduces the concept of incorporating compensatory mitigation into a watershed approach. Based upon the information gathered from the ecological and restoration/mitigation literature and the permit inventory, Chapter Seven outlines recommendations to change the statute, the rules, the standard operating procedures, and other aspects of Oregon’s estuarine resource replacement program. Title: Estuarine Habitat Mitigation in Oregon: Policy Review, Analysis, and Recommended Improvements Author: Buckley, Anna Year: 2006 The report is organized in the following manner. After the introductory chapter (Chapter 1), Chapter Two describes Oregon’s current estuarine policy and related state and federal policies. Chapter Three provides an inventory of recent permitted impacts and associated estuarine resource replacement. Chapter Four consists of a brief summary of the status of estuarine ecology and restoration/mitigation, with knowledge gaps identified. Chapter Five discusses wetland functional assessment tools and options for compensatory mitigation. This chapter begins with a description of the tidal Hydrogeomorphic (HGM) assessment method, how it compares to the estuarine resource replacement rules’ relative values table, and the utility of the tidal HGM in estuarine mitigation. Chapter Five, then, explores alternative mitigation options such as out-of-kind, banking, payment-in-lieu, and conservation in lieu. Chapter Six introduces the concept of incorporating compensatory mitigation into a watershed approach. Based upon the information gathered from the ecological and restoration/mitigation literature and the permit inventory, Chapter Seven outlines recommendations to change the statute, the rules, the standard operating procedures, and other aspects of Oregon’s estuarine resource replacement program. Close

• 18. [Article] Applications of Remote Sensing to the Study of Estuarine Physics: Suspended Sediment Dynamics in the Columbia River Estuary

  Estuarine circulation and its associated transport processes drive the environmental integrity of many near-shore habitats (the coastal ocean, rivers, estuaries and emergent wetlands). A thorough understanding ...

  Citation × Citation Citation Abstract Copy Title: Applications of Remote Sensing to the Study of Estuarine Physics: Suspended Sediment Dynamics in the Columbia River Estuary Author: Hudson, Austin Scott Year: 2014 Estuarine circulation and its associated transport processes drive the environmental integrity of many near-shore habitats (the coastal ocean, rivers, estuaries and emergent wetlands). A thorough understanding and consideration of this circulation is, therefore, vital in the proper management of these habitats. The aim of this study is to bring together theory and new satellite observations in the Columbia River Estuary to increase our understanding of estuarine circulation and transport. Surface reflectance measurements gathered by the Moderate Imaging Spectroradiometer (MODIS) are first compared to in situ observations to develop an empirical model for remotely derived surface turbidity. Results indicate that MODIS data significantly correlate with in situ measurements of turbidity throughout the CRE (R2 = 0.96). Remote estimates of turbidity are then used to explore the physical processes that drive their spatial distribution. Although the response to different hydrodynamic conditions varies throughout the system, global levels of turbidity are most sensitive to fluvial and tidal inputs and increase during spring tides and high river flow. As a result, the turbidity field has temporal cycles that are consistent with the frequency of these processes. The location of the estuarine turbidity maximum (ETM) is highly dynamic and typically migrates downstream as the tidal velocity or river flow increases. The ETM becomes trapped near the Megler Bridge (river kilometer 20), however, and the presence of strong topography in this region suggests there exists an interaction between bottom topography and sediment transport. A 2-D semi-analytical model, developed herein from the simplified Navier-Stokes equations, confirms that topographic features exhibit substantial influence on longitudinal turbidity distributions. The model considers the coupled, tidally-averaged velocity (composed of gravitational circulation, internal tidal asymmetry, and river flow) and salinity fields and assumes a condition of morphodynamic equilibrium to estimate the distribution of sediment for arbitrary channel configurations. Model simulations demonstrate that topographic highs tend to increase local seaward sediment fluxes, and that topographic lows increase local landward sediment fluxes. Sediment flux convergence near topographic highs compresses the local turbidity distribution, whereas flux divergence near topographic lows dilates the distribution and, under appropriate conditions, produces multiple ETMs. In summary a combination of the model and satellite data has given valuable new insights into the sediment dynamics of estuarine environments; in particular, both show that turbidity distribution and ETM location vary considerably with tidal and river flow conditions, fluctuating on a variety of timescales, and are heavily influenced by bottom topography. Title: Applications of Remote Sensing to the Study of Estuarine Physics: Suspended Sediment Dynamics in the Columbia River Estuary Author: Hudson, Austin Scott Year: 2014 Estuarine circulation and its associated transport processes drive the environmental integrity of many near-shore habitats (the coastal ocean, rivers, estuaries and emergent wetlands). A thorough understanding and consideration of this circulation is, therefore, vital in the proper management of these habitats. The aim of this study is to bring together theory and new satellite observations in the Columbia River Estuary to increase our understanding of estuarine circulation and transport. Surface reflectance measurements gathered by the Moderate Imaging Spectroradiometer (MODIS) are first compared to in situ observations to develop an empirical model for remotely derived surface turbidity. Results indicate that MODIS data significantly correlate with in situ measurements of turbidity throughout the CRE (R2 = 0.96). Remote estimates of turbidity are then used to explore the physical processes that drive their spatial distribution. Although the response to different hydrodynamic conditions varies throughout the system, global levels of turbidity are most sensitive to fluvial and tidal inputs and increase during spring tides and high river flow. As a result, the turbidity field has temporal cycles that are consistent with the frequency of these processes. The location of the estuarine turbidity maximum (ETM) is highly dynamic and typically migrates downstream as the tidal velocity or river flow increases. The ETM becomes trapped near the Megler Bridge (river kilometer 20), however, and the presence of strong topography in this region suggests there exists an interaction between bottom topography and sediment transport. A 2-D semi-analytical model, developed herein from the simplified Navier-Stokes equations, confirms that topographic features exhibit substantial influence on longitudinal turbidity distributions. The model considers the coupled, tidally-averaged velocity (composed of gravitational circulation, internal tidal asymmetry, and river flow) and salinity fields and assumes a condition of morphodynamic equilibrium to estimate the distribution of sediment for arbitrary channel configurations. Model simulations demonstrate that topographic highs tend to increase local seaward sediment fluxes, and that topographic lows increase local landward sediment fluxes. Sediment flux convergence near topographic highs compresses the local turbidity distribution, whereas flux divergence near topographic lows dilates the distribution and, under appropriate conditions, produces multiple ETMs. In summary a combination of the model and satellite data has given valuable new insights into the sediment dynamics of estuarine environments; in particular, both show that turbidity distribution and ETM location vary considerably with tidal and river flow conditions, fluctuating on a variety of timescales, and are heavily influenced by bottom topography. Close

• 19. [Article] DR7a: Changes in ecosystem services and migration in low-lying coastal areas over the next 50 years

  This paper examines the history and current status of ecosystem services in low-lying coastal areas (LLCAs), their potential changes because of wider environmental and social shifts, and the potential ...

  Citation × Citation Citation Abstract Copy Title: DR7a: Changes in ecosystem services and migration in low-lying coastal areas over the next 50 years Author: Costanza, Robert, Kubiszewski, Ida, Roman, Joe, Sutton, Paul Year: 2011 This paper examines the history and current status of ecosystem services in low-lying coastal areas (LLCAs), their potential changes because of wider environmental and social shifts, and the potential impacts of these changes on human migration. We synthesised information from a number of sources on the status and value of ecosystem services in LLCAs, including information about key ecosystems that are likely to be particularly vulnerable to environmental change. We created maps of ecosystem and human population changes in LLCAs and then estimated changes in ecosystem services. Estimating the impacts of these potential changes depends on the future scenario one assumes. For our analysis four scenarios were developed for future ecosystem and ecosystem services conditions in 2060, based on the four SRES (Special Report on Emissions Scenarios) scenarios with additional reference to the Millennium Ecosystem Assessment and the Great Transition Initiative scenarios. The two axes of the SRES scenarios are global vs. regional and material economy vs. environment foci. This allowed an assessment of the plausible range of future uncertainty about ecosystem services in LLCAs and the potential for changes in ecosystem services to drive human migration. Major findings include: ? Coastal ecosystems are among the most productive on the planet. They provide more than 70% of total global ecosystem services. ? At the same time, these systems are the most threatened by climate change, human settlement and potential coastward migration. ? In the mid-1990s, approximately 25 million people were forced to leave their homelands owing to the inability to secure a livelihood as ecosystem services declined (Myers and Kent, 2009). ? In the coming decades, one estimate puts the number at 240?525 million people globally who may feel impelled to migrate because of loss of ecosystem services (Myers and Kent, 2009). ? Risk factors for coastal populations include over-exploitation of resources, including fisheries; destruction of mangroves, wetlands, and other natural infrastructure; increased storm activity; and reduced resilience to environmental perturbations. ? Coastward population migration is largest in the globalised scenarios because of increased ease of migration in a more globalised world. ? Coastal ecosystem services decline in the material economy-focused SRES scenarios but potentially increase in the environment-focused SRES scenarios, leading to higher overall quality of life. Policies should aim to preserve and restore coastal habitats. This leads to higher and more stable coastal ecosystem services and human quality of life, along with lower vulnerability to migration pressures. Additional research and integrated modelling are needed, however, to better understand the spatial dynamics of human migration and its dependence on ecosystem services. Such models could also help illuminate the transition pathways and policies necessary to achieve the preferred future scenarios. Title: DR7a: Changes in ecosystem services and migration in low-lying coastal areas over the next 50 years Author: Costanza, Robert, Kubiszewski, Ida, Roman, Joe, Sutton, Paul Year: 2011 This paper examines the history and current status of ecosystem services in low-lying coastal areas (LLCAs), their potential changes because of wider environmental and social shifts, and the potential impacts of these changes on human migration. We synthesised information from a number of sources on the status and value of ecosystem services in LLCAs, including information about key ecosystems that are likely to be particularly vulnerable to environmental change. We created maps of ecosystem and human population changes in LLCAs and then estimated changes in ecosystem services. Estimating the impacts of these potential changes depends on the future scenario one assumes. For our analysis four scenarios were developed for future ecosystem and ecosystem services conditions in 2060, based on the four SRES (Special Report on Emissions Scenarios) scenarios with additional reference to the Millennium Ecosystem Assessment and the Great Transition Initiative scenarios. The two axes of the SRES scenarios are global vs. regional and material economy vs. environment foci. This allowed an assessment of the plausible range of future uncertainty about ecosystem services in LLCAs and the potential for changes in ecosystem services to drive human migration. Major findings include: ? Coastal ecosystems are among the most productive on the planet. They provide more than 70% of total global ecosystem services. ? At the same time, these systems are the most threatened by climate change, human settlement and potential coastward migration. ? In the mid-1990s, approximately 25 million people were forced to leave their homelands owing to the inability to secure a livelihood as ecosystem services declined (Myers and Kent, 2009). ? In the coming decades, one estimate puts the number at 240?525 million people globally who may feel impelled to migrate because of loss of ecosystem services (Myers and Kent, 2009). ? Risk factors for coastal populations include over-exploitation of resources, including fisheries; destruction of mangroves, wetlands, and other natural infrastructure; increased storm activity; and reduced resilience to environmental perturbations. ? Coastward population migration is largest in the globalised scenarios because of increased ease of migration in a more globalised world. ? Coastal ecosystem services decline in the material economy-focused SRES scenarios but potentially increase in the environment-focused SRES scenarios, leading to higher overall quality of life. Policies should aim to preserve and restore coastal habitats. This leads to higher and more stable coastal ecosystem services and human quality of life, along with lower vulnerability to migration pressures. Additional research and integrated modelling are needed, however, to better understand the spatial dynamics of human migration and its dependence on ecosystem services. Such models could also help illuminate the transition pathways and policies necessary to achieve the preferred future scenarios. Close