Because of their profound influence on water movement and nutrient cycling in salt marshes, the t... more Because of their profound influence on water movement and nutrient cycling in salt marshes, the two key physical properties of hydraulic conductivity and compressibility were studied in the Great Sippewissett Marsh and in the Ebben Creek Marsh in Massachusetts. Hydraulic conductivity was the most variable property: most frequently observed conductivities were of the order of 10−3 cm s−1 in both marshes, but extremes ranged from about 10−1 to 10−5 cm s−1. Compressibility was much less variable, and contributed of the order of 10−3 cm−1 to the specific storativity of marsh sediment, making compression a major mechanism for changes in water storage in the sediment. Surface sediments frequently exhibited below‐average conductivity, in contrast to freshwater bog peats which are usually most conductive at the surface. These measured properties may be applied to estimate the importance of many critical processes, such as the extent of infiltration occurring on the marsh surface, the hydrol...
Climate change poses a threat to the performance and resiliency of flexible pavement systems arou... more Climate change poses a threat to the performance and resiliency of flexible pavement systems around the world and can lead to inadequate designs or shortened service life which, in turn, tax the already limited budgets of transportation agencies and increase user costs. This paper aims to provide a high-level overview of three common approaches (scenario-based, asset-based and hybrid) that can be used to incorporate climate change in pavement design and rehabilitation practices. Examples of each approach for a flexible pavement system are presented along with a discussion of their advantages and limitations. Additionally, select results from a pavement life cycle assessment (LCA) case-study comparing the use of simulated future climate projections instead of historical observed climate data is included to demonstrate impacts on maintenance and rehabilitation budgeting and planning. Current knowledge gaps and research needs are identified and discussed to promote future collaboration towards designing and maintaining more resilient flexible pavements under a changing climate.
Greenhouse gas emissions have caused global temperatures to rise since the mid-20th century accom... more Greenhouse gas emissions have caused global temperatures to rise since the mid-20th century accompanied by sea-level rise (SLR). Temperature increases and SLR-induced groundwater rise have been shown to cause premature pavement failure in many roadway structures. Hybrid bottom-up/top-down (hybrid) adaptation approaches have shown promise by initially investigating an asset’s response to incremental environmental change and then identifying the timing of critical effects for budgetary planning. This improves practitioners’ understanding of the asset’s climate resiliency and informs adaptation-plan development to minimize both cost and risk. In this study, a hybrid approach to pavement adaptation with climate-change-induced temperature and groundwater rise is demonstrated at a case-study site in coastal New Hampshire. The hot-mix-asphalt (HMA) thickness that achieves a minimum of 85% reliability is calculated for 70 combinations of incremental temperature and groundwater rise. Increas...
Transportation Research Record: Journal of the Transportation Research Board, 2019
Pavements are vulnerable to reduced life with climate-change-induced temperature rise. Greenhouse... more Pavements are vulnerable to reduced life with climate-change-induced temperature rise. Greenhouse gas emissions have caused an increase in global temperatures since the mid-20th century and the warming is projected to accelerate. Many studies have characterized this risk with a top-down approach in which climate-change scenarios are chosen and applied to predict pavement-life reduction. This approach is useful in identifying possible pavement futures but may miss short-term or seasonal pavement-response trends that are essential for adaptation planning. A bottom-up approach focuses on a pavement’s response to incremental temperature change resulting in a more complete understanding of temperature-induced pavement damage. In this study, a hybrid bottom-up/top-down approach was used to quantify the impact of changing pavement seasons and temperatures on pavement life with incremental temperature rise from 0 to 5°C at a site in coastal New Hampshire. Changes in season length, seasonal ...
ABSTRACT Knott, J.F.; Jacobs, J.M.; Daniel, J.S., and Kirshen, P., 2019. Modeling groundwater ris... more ABSTRACT Knott, J.F.; Jacobs, J.M.; Daniel, J.S., and Kirshen, P., 2019. Modeling groundwater rise caused by sea-level rise in coastal New Hampshire. Journal of Coastal Research, 35(1), 143–157. Coconut Creek (Florida), ISSN 0749-0208. Coastal communities with low topography are vulnerable from sea-level rise (SLR) caused by climate change and glacial isostasy. Coastal groundwater will rise with sea level, affecting water quality, the structural integrity of infrastructure, and natural ecosystem health. SLR-induced groundwater rise has been studied in coastal areas of high aquifer transmissivity. In this regional study, SLR-induced groundwater rise is investigated in a coastal area characterized by shallow unconsolidated deposits overlying fractured bedrock, typical of the glaciated NE. A numerical groundwater-flow model is used with groundwater observations and withdrawals, LIDAR topography, and surface-water hydrology to investigate SLR-induced changes in groundwater levels in New Hampshire's coastal region. The SLR groundwater signal is detected more than three times farther inland than projected tidal flooding from SLR. The projected mean groundwater rise relative to SLR is 66% between 0 and 1 km, 34% between 1 and 2 km, 18% between 2 and 3 km, 7% between 3 and 4 km, and 3% between 4 and 5 km of the coastline, with large variability around the mean. The largest magnitude of SLR-induced groundwater rise occurs in the marine and estuarine deposits and peninsulas with tidal water bodies on three sides. Groundwater rise is dampened near streams. Groundwater inundation is projected to contribute 48% of the total inundated area from both SLR-induced groundwater rise and marine tidal flooding in the city of Portsmouth, with consequences for built and natural resources. Freshwater wetlands are projected to expand 3% by the year 2030, increasing to 25% by the end of the century, coupled with water-depth increases.
Transportation Research Record: Journal of the Transportation Research Board, 2018
Sea level in coastal New England is projected to rise 3.9–6.6 ft (1.2–2.0 m) by the year 2100. Ma... more Sea level in coastal New England is projected to rise 3.9–6.6 ft (1.2–2.0 m) by the year 2100. Many climate-change vulnerability and adaptation studies have investigated surface-water flooding from sea-level rise (SLR) on coastal-road infrastructure, but few have focused on rising groundwater. Groundwater modeling in New Hampshire’s Seacoast Region has shown that SLR-induced groundwater rise will occur three to four times farther inland than surface-water flooding, potentially impacting 23% of the region’s roads. Pavement service-life has been shown to decrease when the unbound layers become saturated. In areas where groundwater is projected to rise with SLR, pavements with groundwater 5.0 ft (1.5 m) deep or less are at risk of premature failure as groundwater moves into the pavement’s underlying unbound layers. In this study, groundwater hydrology and multi-layer elastic pavement analysis were used to identify two case-study sites in coastal New Hampshire that are predicted to expe...
Transportation Research Record: Journal of the Transportation Research Board, 2017
Coastal communities with road infrastructure close to the shoreline are vulnerable to the effects... more Coastal communities with road infrastructure close to the shoreline are vulnerable to the effects of sea level rise caused by climate change. The sea level in coastal New Hampshire is projected to rise by 3.9 to 6.6 ft (1.2 to 2.0 m) by 2100. Climate change vulnerability and adaptation studies have focused on surface water flooding caused by sea level rise; however, little attention has been given to the effects of climate change on groundwater. Groundwater is expected to rise with sea level rise and will intersect the unbound layers of coastal road infrastructure, thus reducing the service life of pavement. Vulnerability studies are an essential part of adaptation planning, and pavement engineers are looking for methods to identify roads that may experience premature failure. In this study, a regional groundwater flow model of coastal New Hampshire was used to identify road infrastructure for which rising groundwater will move into the unbound materials during the design life of th...
... Nantucket Island, Massachusetts By JAYNE FIFIELD KNOTT and JULIO C. OLIMPIO Prepared in coope... more ... Nantucket Island, Massachusetts By JAYNE FIFIELD KNOTT and JULIO C. OLIMPIO Prepared in cooperation with the Commonwealth of Massachusetts Water Resources Commission, Division of Water Resources US . ... 4. Tritium . I . Olimpio, Julio C. II . Massachusetts. ...
Because of their profound influence on water movement and nutrient cycling in salt marshes, the t... more Because of their profound influence on water movement and nutrient cycling in salt marshes, the two key physical properties of hydraulic conductivity and compressibility were studied in the Great Sippewissett Marsh and in the Ebben Creek Marsh in Massachusetts. Hydraulic conductivity was the most variable property: most frequently observed conductivities were of the order of 10−3 cm s−1 in both marshes, but extremes ranged from about 10−1 to 10−5 cm s−1. Compressibility was much less variable, and contributed of the order of 10−3 cm−1 to the specific storativity of marsh sediment, making compression a major mechanism for changes in water storage in the sediment. Surface sediments frequently exhibited below‐average conductivity, in contrast to freshwater bog peats which are usually most conductive at the surface. These measured properties may be applied to estimate the importance of many critical processes, such as the extent of infiltration occurring on the marsh surface, the hydrol...
Climate change poses a threat to the performance and resiliency of flexible pavement systems arou... more Climate change poses a threat to the performance and resiliency of flexible pavement systems around the world and can lead to inadequate designs or shortened service life which, in turn, tax the already limited budgets of transportation agencies and increase user costs. This paper aims to provide a high-level overview of three common approaches (scenario-based, asset-based and hybrid) that can be used to incorporate climate change in pavement design and rehabilitation practices. Examples of each approach for a flexible pavement system are presented along with a discussion of their advantages and limitations. Additionally, select results from a pavement life cycle assessment (LCA) case-study comparing the use of simulated future climate projections instead of historical observed climate data is included to demonstrate impacts on maintenance and rehabilitation budgeting and planning. Current knowledge gaps and research needs are identified and discussed to promote future collaboration towards designing and maintaining more resilient flexible pavements under a changing climate.
Greenhouse gas emissions have caused global temperatures to rise since the mid-20th century accom... more Greenhouse gas emissions have caused global temperatures to rise since the mid-20th century accompanied by sea-level rise (SLR). Temperature increases and SLR-induced groundwater rise have been shown to cause premature pavement failure in many roadway structures. Hybrid bottom-up/top-down (hybrid) adaptation approaches have shown promise by initially investigating an asset’s response to incremental environmental change and then identifying the timing of critical effects for budgetary planning. This improves practitioners’ understanding of the asset’s climate resiliency and informs adaptation-plan development to minimize both cost and risk. In this study, a hybrid approach to pavement adaptation with climate-change-induced temperature and groundwater rise is demonstrated at a case-study site in coastal New Hampshire. The hot-mix-asphalt (HMA) thickness that achieves a minimum of 85% reliability is calculated for 70 combinations of incremental temperature and groundwater rise. Increas...
Transportation Research Record: Journal of the Transportation Research Board, 2019
Pavements are vulnerable to reduced life with climate-change-induced temperature rise. Greenhouse... more Pavements are vulnerable to reduced life with climate-change-induced temperature rise. Greenhouse gas emissions have caused an increase in global temperatures since the mid-20th century and the warming is projected to accelerate. Many studies have characterized this risk with a top-down approach in which climate-change scenarios are chosen and applied to predict pavement-life reduction. This approach is useful in identifying possible pavement futures but may miss short-term or seasonal pavement-response trends that are essential for adaptation planning. A bottom-up approach focuses on a pavement’s response to incremental temperature change resulting in a more complete understanding of temperature-induced pavement damage. In this study, a hybrid bottom-up/top-down approach was used to quantify the impact of changing pavement seasons and temperatures on pavement life with incremental temperature rise from 0 to 5°C at a site in coastal New Hampshire. Changes in season length, seasonal ...
ABSTRACT Knott, J.F.; Jacobs, J.M.; Daniel, J.S., and Kirshen, P., 2019. Modeling groundwater ris... more ABSTRACT Knott, J.F.; Jacobs, J.M.; Daniel, J.S., and Kirshen, P., 2019. Modeling groundwater rise caused by sea-level rise in coastal New Hampshire. Journal of Coastal Research, 35(1), 143–157. Coconut Creek (Florida), ISSN 0749-0208. Coastal communities with low topography are vulnerable from sea-level rise (SLR) caused by climate change and glacial isostasy. Coastal groundwater will rise with sea level, affecting water quality, the structural integrity of infrastructure, and natural ecosystem health. SLR-induced groundwater rise has been studied in coastal areas of high aquifer transmissivity. In this regional study, SLR-induced groundwater rise is investigated in a coastal area characterized by shallow unconsolidated deposits overlying fractured bedrock, typical of the glaciated NE. A numerical groundwater-flow model is used with groundwater observations and withdrawals, LIDAR topography, and surface-water hydrology to investigate SLR-induced changes in groundwater levels in New Hampshire's coastal region. The SLR groundwater signal is detected more than three times farther inland than projected tidal flooding from SLR. The projected mean groundwater rise relative to SLR is 66% between 0 and 1 km, 34% between 1 and 2 km, 18% between 2 and 3 km, 7% between 3 and 4 km, and 3% between 4 and 5 km of the coastline, with large variability around the mean. The largest magnitude of SLR-induced groundwater rise occurs in the marine and estuarine deposits and peninsulas with tidal water bodies on three sides. Groundwater rise is dampened near streams. Groundwater inundation is projected to contribute 48% of the total inundated area from both SLR-induced groundwater rise and marine tidal flooding in the city of Portsmouth, with consequences for built and natural resources. Freshwater wetlands are projected to expand 3% by the year 2030, increasing to 25% by the end of the century, coupled with water-depth increases.
Transportation Research Record: Journal of the Transportation Research Board, 2018
Sea level in coastal New England is projected to rise 3.9–6.6 ft (1.2–2.0 m) by the year 2100. Ma... more Sea level in coastal New England is projected to rise 3.9–6.6 ft (1.2–2.0 m) by the year 2100. Many climate-change vulnerability and adaptation studies have investigated surface-water flooding from sea-level rise (SLR) on coastal-road infrastructure, but few have focused on rising groundwater. Groundwater modeling in New Hampshire’s Seacoast Region has shown that SLR-induced groundwater rise will occur three to four times farther inland than surface-water flooding, potentially impacting 23% of the region’s roads. Pavement service-life has been shown to decrease when the unbound layers become saturated. In areas where groundwater is projected to rise with SLR, pavements with groundwater 5.0 ft (1.5 m) deep or less are at risk of premature failure as groundwater moves into the pavement’s underlying unbound layers. In this study, groundwater hydrology and multi-layer elastic pavement analysis were used to identify two case-study sites in coastal New Hampshire that are predicted to expe...
Transportation Research Record: Journal of the Transportation Research Board, 2017
Coastal communities with road infrastructure close to the shoreline are vulnerable to the effects... more Coastal communities with road infrastructure close to the shoreline are vulnerable to the effects of sea level rise caused by climate change. The sea level in coastal New Hampshire is projected to rise by 3.9 to 6.6 ft (1.2 to 2.0 m) by 2100. Climate change vulnerability and adaptation studies have focused on surface water flooding caused by sea level rise; however, little attention has been given to the effects of climate change on groundwater. Groundwater is expected to rise with sea level rise and will intersect the unbound layers of coastal road infrastructure, thus reducing the service life of pavement. Vulnerability studies are an essential part of adaptation planning, and pavement engineers are looking for methods to identify roads that may experience premature failure. In this study, a regional groundwater flow model of coastal New Hampshire was used to identify road infrastructure for which rising groundwater will move into the unbound materials during the design life of th...
... Nantucket Island, Massachusetts By JAYNE FIFIELD KNOTT and JULIO C. OLIMPIO Prepared in coope... more ... Nantucket Island, Massachusetts By JAYNE FIFIELD KNOTT and JULIO C. OLIMPIO Prepared in cooperation with the Commonwealth of Massachusetts Water Resources Commission, Division of Water Resources US . ... 4. Tritium . I . Olimpio, Julio C. II . Massachusetts. ...
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