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Ellen Douglas

University of Massachusetts, Boston, Environmental, Earth and Ocean Sciences, Faculty Member

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Papers by Ellen Douglas

1 Freshwater Availability Anomalies and Outbreak of Internal War: Results from a Global Spatial Time Series Analysis1

We investigated the relationship between water availability and internal war outbreak. This work ... more We investigated the relationship between water availability and internal war outbreak. This work constitutes the first test of climate-security connections utilizing global subnational time series data. We created harmonized spatial time series databases on a subnational global grid of internal war, renewable freshwater surface water resources (in the form of runoff), rainfall deviations and population for the period 1980-2002. We utilize national-level data on infant mortality, political institutions, and trade openness as controls. We find that at the global scale there is a highly significant relationship between rainfall deviations and the likelihood of outbreak of a high-intensity internal war. When rainfall is significantly below normal, the likelihood of conflict outbreak is significantly elevated in the subsequent year. We do not find a similar effect for the mean annual runoff at the global scale, but find some evidence at the continental scale. We also find no significant ...

A statistical analysis of extreme rainfall in Massachusetts, New Hampshire and Maine and updated estimates of the 100-year storm

Cost-Efficient and Storm Surge-sensitive Bridge Design for Coastal Maine

Climatic variation felt through changing weather patterns is having increasingly acute effects on... more Climatic variation felt through changing weather patterns is having increasingly acute effects on Maine’s transportation infrastructure. Acute risk occurs as a result of events, such as storms and flooding, while chronic risk surrounds longer range changes due to climate over time. It is acute risk that results in an increased need for disaster designation and response, increased risk of collateral property damage, and threats to safety of the traveling public. This type of risk can be mitigated by early preparation. Because of uncertainty about the future of climate and weather variability, chronic risk is much harder to gauge. This uncertainty can create paralysis in an agency charged with making and justifying long-term, fiscally-responsible decisions around the safety and efficiency of public travel. But long life cycles of most transportation infrastructure demand adaptation via early preparation to protect significant taxpayer investments into the reasonably foreseeable future...

A probabilistic approach for assessing the vulnerability of transportation infrastructure to flooding from sea level rise and storm surge

Fate of Nutrients During the Composting of Yard and Agricultural Wastes

Principal Findings and Significance: Results to date (continued in FY 1994): The pH of the compos... more Principal Findings and Significance: Results to date (continued in FY 1994): The pH of the composting waste ranged from 8.0 to 9.0. Measurements of pH collected over the sampling time showed approximate ranges from 4.5 to 5.5 in the forested and cleared areas, which is typical of forest soils in this area. In the composting area, pH measurements steadily increased, with ranges of 6.0 to 7.5 in the soil adjacent to the windrow and 7.0 to 8.0 beneath the windrow. Measurements of electrical conductivity show this same effect, with measurements in the forested and cleared areas very similar, approximately 50 to 75 mS/cm, while measurements in the composting area were very elevated, approximately 1000 mS/cm beneath the windrow. These field parameters clearly indicate the movement of contaminants from the composting waste into the nearby soil.

A Biogeomorphological Model of Stream Health for Mountain Streams in Northearn Georgia, U

As human population encroaches on every corner of the planet, streams and the aquatic habitats th... more As human population encroaches on every corner of the planet, streams and the aquatic habitats that depend on them are becoming increasingly stressed. Numerous studies have assessed how an undisturbed stream differs in physical attributes from a disturbed stream or how benthic macroinvertebrate assemblages change with increased human contact. In this study, both geomorphic and biologic data are employed in a logistic regression analysis to discriminate anthropogenically-disturbed streams from undisturbed streams in northern Georgia, U.S. We found that physical variables alone do not predict impairment as powerfully as the integrated physical-biological model. In addition, benthic macroinvertebrate taxa were found to predict with greater power and accuracy than the commonly-used macroinvertebrate metrics. Key geomorphic predictors included reach-averaged percent embedded and reach-averaged residual pool depth. Important biologic predictors were: number of clinger taxa, percent EPT (E...

Integrated Analysis of the Value of Wetland Services in Coastal Adaptation; Methodology and Case Study of Hampton-Seabrook Estuary, New Hampshire

Our research objective is to carry out an integrated assessment of the economic and social values... more Our research objective is to carry out an integrated assessment of the economic and social values of wetland ecosystem services as part of adaptation strategies to coastal climate change, specifically sea level rise and associated increases in erosion and coastal flooding. The work was carried out in three communities on the Hampton-Seabrook Estuary (HSE), New Hampshire; Hampton, Hampton Falls, and Seabrook. The HSE is an approximately 8 mile long barrier beach system with extensive back-barrier tidal wetlands. An inlet conducts tidal waters into and out of the estuary and drains the upland areas of this coastal watershed. The inlet is narrow (about 1000 feet across) and shallow (about 20 feet), and consists primarily of coarse grained sands in the center channel and progressively finer sediments to the banks. The sediment transport is high in the inlet and back bay, requiring regular dredging to maintain the navigation channels PDA, 2013). The mouth is characterized by a north jetty that extends about 0.2 miles into the ocean, and a half-jetty to the south side that is overtopped at high tides. Ocean waves are important to the sediment transport along the adjacent Hampton and Seabrook beaches, but are attenuated near the mouth by strong refraction away from the main channel and wave breaking over rocky outcrops offshore of the mouth and along the south side of the inlet. Inside the back bay, the wave field is generally small owing to the narrow inlet and limited fetch and thus surface wave velocities do not contribute to the circulation in the estuary.

Trends in floods and low flows in the United States: impact of spatial correlation

Journal of Hydrology, 2000

Trends in¯ood and low¯ows in the US were evaluated using a regional average Kendall's S trend tes... more Trends in¯ood and low¯ows in the US were evaluated using a regional average Kendall's S trend test at two spatial scales and over two timeframes. Field signi®cance was assessed using a bootstrap methodology to account for the observed regional cross-correlation of stream¯ows. Using a 5% signi®cance level, we found no evidence of trends in¯ood¯ows but did ®nd evidence of upward trends in low¯ows at the larger scale in the Midwest and at the smaller scale in the Ohio, the north central and the upper Midwest regions. A dramatically different interpretation would have been achieved if regional cross-correlation had been ignored. In that case, statistically signi®cant trends would have been found in all but two of the low¯ow analyses and in two-thirds of the¯ood¯ow analyses. We show that the cross-correlation of¯ow records dramatically reduces the effective number of samples available for trend assessment. We also found that low¯ow time series exhibit signi®cant temporal persistence. Even when the serial correlation was removed from the time series, signi®cant trends in low¯ow series were apparent, though the number of signi®cant trends decreased.

Probabilistic Behavior of Floods of Record in the United States

Journal of Hydrologic Engineering, 2006

Literature on the probability distribution function ͑PDF͒ of annual maximum flood discharges is e... more Literature on the probability distribution function ͑PDF͒ of annual maximum flood discharges is extensive, yet the literature on the PDF of the flood of record ͑FOR͒ is sparse. This is partially due to two facts: ͑1͒ the PDF for record events is more complex than the PDF for annual maxima; and ͑2͒ data sets for observed FORs are much smaller than for the annual maximum flood series from which they derive. We show that, if annual floods arise from a generalized extreme values ͑GEV͒ distribution, then the FOR also arises from another GEV distribution, which we term GEV max. We also derive the moments and L-moments for the PDF of GEV max. Using record flood observations at over 1,500 basins in the United States, we compared theoretical and empirical properties of observed values of the FOR. We found that, at both regional and national scales, the FOR values are on average more extreme than would be expected if they occurred randomly, and that they tend to form spatial clusters.

Freshwater availability anomalies and outbreak of internal war: Results from a global spatial time series analysis

We investigated the relationship between water availability and internal war outbreak. This work ... more We investigated the relationship between water availability and internal war outbreak. This work constitutes the first test of climate-security connections utilizing global subnational time series data. We created harmonized spatial time series databases on a subnational global grid of internal war, renewable freshwater surface water resources (in the form of runoff), rainfall deviations and population for the period 1980-2002. We utilize national-level data on infant mortality, political institutions, and trade openness as controls. We find that at the global scale there is a highly significant relationship between rainfall deviations and the likelihood of outbreak of a high-intensity internal war. When rainfall is significantly below normal, the likelihood of conflict outbreak is significantly elevated in the subsequent year. We do not find a similar effect for the mean annual runoff at the global scale, but find some evidence at the continental scale. We also find no significant relationship between rainfall deviations and the onset of low-intensity internal wars. The capacity to geographically reference social science and biogeophysical data sets will create new opportunities for hypothesis testing with respect to the sources of internal conflict in the fast of climate change invariability

The Behavior of the Flood of Record in the United States

ABSTRACT The literature on the probability distribution function (pdf) of annual maximum flood di... more ABSTRACT The literature on the probability distribution function (pdf) of annual maximum flood discharges is extensive, yet the literature on the pdf of the flood of record is sparse. This is partially due to two facts: 1) the pdf for record events is more complex than the pdf for annual maxima, and 2) datasets for observed floods of record are much smaller than the annual maximum flood series from which they derive. We show that if annual floods arise from a generalized extreme value (GEV) distribution, then the flood of record also arises from another GEV distribution, which we term GEVmax. Using GEVmax, we explore the exceedence probability of observed floods of record across the U.S. In many regions, and over the U.S. as a whole, floods of record are on average more extreme than would be expected if they occurred randomly. We found instances where more extreme floods of record are spatially clustered and can be related to storm events that appear to have produced floods of record over large areas. We also found that the timing of record floods in the U.S. is related to sunspot cycles. Finally, we developed a multivariate regression model for estimating the flood of record from climatic, basin and geomorphologic information.

Impact of Streamflow Persistence on Hydrologic Design

Journal of Hydrologic Engineering, 2002

Conventional methods for estimating the average return period, E(T), and failure risk, R, general... more Conventional methods for estimating the average return period, E(T), and failure risk, R, generally ignore the impact of persistence in annual streamflows on associated probabilistic statements and streamflow statistics. Recent evaluations of streamflow observations indicate statistically significant serial correlations ͑persistence͒ associated with annual low flows in the United States. We define the average occurrence interval E(T) as the expected time to the first event, and we present a method for estimating E(T) and R in the presence of persistence. We show that for observed ranges of persistence, E(T) can be nearly 100% greater and R more than 20% lower than conventional estimates. This implies that the expected design life of a system is longer when persistence is taken into account. Also, by ignoring persistence, low flow quantiles may be underestimated by 50% or more. An evaluation of the effect of persistence on drought risk estimation across the U.S. is presented.

Is Precipitation in Northern New England Becoming More Extreme? Statistical Analysis of Extreme Rainfall

The objective of this study was to investigate the presence of trends in extreme precipitation. (... more The objective of this study was to investigate the presence of trends in extreme precipitation. (denoted MAXP and defined as the annual maximum daily precipitation depth) time series for coastal northern New England and to assess changes in the magnitude of the socalled "100-year storm". MAXP depths from 48 stations with long, continuous records in Maine, New Hampshire and Massachusetts were analyzed. At those same stations, the number of daily precipitation depths ≥ 2 inches (denoted as GT2in) was also quantified for each year. The seasonally-averaged MAXP was found to be fairly uniform throughout the year, but the frequency of MAXP is highest during August through October, the typical hurricane season in New England. The presence of trends in MAXP and GT2in was evaluated over four time frames (1954-2005, 1954-2008, 1970-2005 and 1970-2008) This study as well as recent record-breaking events in northern New England strongly suggests the need for updating of design storm e...

An analysis of the allocation of Yakima River water in terms of sustainability and economic efficiency

Decades of agricultural growth has led to the over appropriation of Yakima water and the ecologic... more Decades of agricultural growth has led to the over appropriation of Yakima water and the ecological integrity of the basin has been compromised. We evaluate the impact of current water allocation on the natural flow regime of the Yakima River using the Indicators of Hydrologic Alteration/Range of Variability Analysis and by quantifying indicators of ecosurplus and ecodeficit. We analyze the sustainability of the current water allocation scheme based on a range of sustainability criteria, from weak to strong to environmentally sustainable. Economic efficiency is assessed by describing the current allocation framework and suggesting ways to make it more efficient. Our IHA/RVA analysis suggests that the allocation of water in the Yakima River has resulted in a highly altered flow regime. Ecodeficit is far in excess of ecosurplus. We conclude that this allocation scheme is weakly sustainable, if sustainable at all, in its current framework. The allocation of water is also not economical...

Mapping the links between water, poverty and food security

A method for forming an as-cast hole by using a core involves forming an undercut and casting by ... more A method for forming an as-cast hole by using a core involves forming an undercut and casting by using a core die which is slidable at an angle with respect to mold closing and opening directions. At the same time, an as-cast hole with an axial direction different from the slide direction of the core die is formed. To form the as-cast hole, a floating core is slidably disposed in the core die for movement in the axial direction of the as-cast hole. An apparatus for practicing the method includes a stationary die, a movable die and the core die containing the slidable floating core.

Session D3 - Physical and biological assessment of the Eel River Headwaters restoration sites in Plymouth, MA

The role of stakeholders in Murray-Darling Basin water management: How do irrigators make water use decisions and how can this influence water policy?

Session B4- Freshwater fish and aquatic macroinvertebrate biomonitoring of the Eel River Headwaters Restoration sites in Plymouth, Massachusetts

Modeling regional landslide susceptibility using dynamic soil moisture profiles

Journal of Mountain Science

A landslide susceptibility mapping study was performed using dynamic hillslope hydrology. The mod... more A landslide susceptibility mapping study was performed using dynamic hillslope hydrology. The modified infinite slope stability model that directly includes vadose zone soil moisture (SM) was applied at Cleveland Corral, California, US and Krishnabhir, Dhading, Nepal. The variable infiltration capacity (VIC-3L) model simulated vadose zone soil moisture and the wetness index hydrologic model simulated groundwater (GW). The GW model predictions had a 75% NASH-Sutcliffe efficiency when compared to California’s in-situ GW measurements. The model performed best during the wet season. Using predicted GW and VIC-3L vadose zone SM, the developed landslide susceptibility maps showed very good agreement with mapped landslides at each study region. Previous quasi-dynamic model predictions of Nepal’s hazardous areas during extreme rainfall events were enhanced to improve the spatial characterization and provide the timing of hazardous conditions.

Simulating the Impacts and Assessing the Vulnerability of the Central Artery/Tunnel System to Sea Level Rise and Increased Coastal Flooding

Journal of Extreme Events, 2017

Highway tunnels along the coast are critical infrastructure and represent one of the more sensiti... more Highway tunnels along the coast are critical infrastructure and represent one of the more sensitive components of a transportation network to coastal flooding. By their very nature, large portions of these tunnels are beneath present sea level and the tunnel entrances and the equipment necessary to operate the tunnels such as vent buildings may or may not be above present flood thresholds. The Central Artery/Tunnel (CA/T) system in coastal Boston, Massachusetts USA is a vital link in the regional transportation network and is comprised of more than 160 lane-miles (more than half of them in tunnels), 6 interchanges and 200 bridges. While not examined here, the CA/T system relies upon other infrastructure systems to fully function, such as the electrical grid. The ADvanced CIRCulation model (ADCIRC) coupled with the Simulating WAves Nearshore (SWAN) Model was used for storm surge modeling. SLR scenarios were selected for four distinct time periods (2013, 2030, 2070, and 2100) to brack...

1 Freshwater Availability Anomalies and Outbreak of Internal War: Results from a Global Spatial Time Series Analysis1

We investigated the relationship between water availability and internal war outbreak. This work ... more We investigated the relationship between water availability and internal war outbreak. This work constitutes the first test of climate-security connections utilizing global subnational time series data. We created harmonized spatial time series databases on a subnational global grid of internal war, renewable freshwater surface water resources (in the form of runoff), rainfall deviations and population for the period 1980-2002. We utilize national-level data on infant mortality, political institutions, and trade openness as controls. We find that at the global scale there is a highly significant relationship between rainfall deviations and the likelihood of outbreak of a high-intensity internal war. When rainfall is significantly below normal, the likelihood of conflict outbreak is significantly elevated in the subsequent year. We do not find a similar effect for the mean annual runoff at the global scale, but find some evidence at the continental scale. We also find no significant ...

A statistical analysis of extreme rainfall in Massachusetts, New Hampshire and Maine and updated estimates of the 100-year storm

Cost-Efficient and Storm Surge-sensitive Bridge Design for Coastal Maine

Climatic variation felt through changing weather patterns is having increasingly acute effects on... more Climatic variation felt through changing weather patterns is having increasingly acute effects on Maine’s transportation infrastructure. Acute risk occurs as a result of events, such as storms and flooding, while chronic risk surrounds longer range changes due to climate over time. It is acute risk that results in an increased need for disaster designation and response, increased risk of collateral property damage, and threats to safety of the traveling public. This type of risk can be mitigated by early preparation. Because of uncertainty about the future of climate and weather variability, chronic risk is much harder to gauge. This uncertainty can create paralysis in an agency charged with making and justifying long-term, fiscally-responsible decisions around the safety and efficiency of public travel. But long life cycles of most transportation infrastructure demand adaptation via early preparation to protect significant taxpayer investments into the reasonably foreseeable future...

A probabilistic approach for assessing the vulnerability of transportation infrastructure to flooding from sea level rise and storm surge

Fate of Nutrients During the Composting of Yard and Agricultural Wastes

Principal Findings and Significance: Results to date (continued in FY 1994): The pH of the compos... more Principal Findings and Significance: Results to date (continued in FY 1994): The pH of the composting waste ranged from 8.0 to 9.0. Measurements of pH collected over the sampling time showed approximate ranges from 4.5 to 5.5 in the forested and cleared areas, which is typical of forest soils in this area. In the composting area, pH measurements steadily increased, with ranges of 6.0 to 7.5 in the soil adjacent to the windrow and 7.0 to 8.0 beneath the windrow. Measurements of electrical conductivity show this same effect, with measurements in the forested and cleared areas very similar, approximately 50 to 75 mS/cm, while measurements in the composting area were very elevated, approximately 1000 mS/cm beneath the windrow. These field parameters clearly indicate the movement of contaminants from the composting waste into the nearby soil.

A Biogeomorphological Model of Stream Health for Mountain Streams in Northearn Georgia, U

As human population encroaches on every corner of the planet, streams and the aquatic habitats th... more As human population encroaches on every corner of the planet, streams and the aquatic habitats that depend on them are becoming increasingly stressed. Numerous studies have assessed how an undisturbed stream differs in physical attributes from a disturbed stream or how benthic macroinvertebrate assemblages change with increased human contact. In this study, both geomorphic and biologic data are employed in a logistic regression analysis to discriminate anthropogenically-disturbed streams from undisturbed streams in northern Georgia, U.S. We found that physical variables alone do not predict impairment as powerfully as the integrated physical-biological model. In addition, benthic macroinvertebrate taxa were found to predict with greater power and accuracy than the commonly-used macroinvertebrate metrics. Key geomorphic predictors included reach-averaged percent embedded and reach-averaged residual pool depth. Important biologic predictors were: number of clinger taxa, percent EPT (E...

Integrated Analysis of the Value of Wetland Services in Coastal Adaptation; Methodology and Case Study of Hampton-Seabrook Estuary, New Hampshire

Our research objective is to carry out an integrated assessment of the economic and social values... more Our research objective is to carry out an integrated assessment of the economic and social values of wetland ecosystem services as part of adaptation strategies to coastal climate change, specifically sea level rise and associated increases in erosion and coastal flooding. The work was carried out in three communities on the Hampton-Seabrook Estuary (HSE), New Hampshire; Hampton, Hampton Falls, and Seabrook. The HSE is an approximately 8 mile long barrier beach system with extensive back-barrier tidal wetlands. An inlet conducts tidal waters into and out of the estuary and drains the upland areas of this coastal watershed. The inlet is narrow (about 1000 feet across) and shallow (about 20 feet), and consists primarily of coarse grained sands in the center channel and progressively finer sediments to the banks. The sediment transport is high in the inlet and back bay, requiring regular dredging to maintain the navigation channels PDA, 2013). The mouth is characterized by a north jetty that extends about 0.2 miles into the ocean, and a half-jetty to the south side that is overtopped at high tides. Ocean waves are important to the sediment transport along the adjacent Hampton and Seabrook beaches, but are attenuated near the mouth by strong refraction away from the main channel and wave breaking over rocky outcrops offshore of the mouth and along the south side of the inlet. Inside the back bay, the wave field is generally small owing to the narrow inlet and limited fetch and thus surface wave velocities do not contribute to the circulation in the estuary.

Trends in floods and low flows in the United States: impact of spatial correlation

Journal of Hydrology, 2000

Trends in¯ood and low¯ows in the US were evaluated using a regional average Kendall's S trend tes... more Trends in¯ood and low¯ows in the US were evaluated using a regional average Kendall's S trend test at two spatial scales and over two timeframes. Field signi®cance was assessed using a bootstrap methodology to account for the observed regional cross-correlation of stream¯ows. Using a 5% signi®cance level, we found no evidence of trends in¯ood¯ows but did ®nd evidence of upward trends in low¯ows at the larger scale in the Midwest and at the smaller scale in the Ohio, the north central and the upper Midwest regions. A dramatically different interpretation would have been achieved if regional cross-correlation had been ignored. In that case, statistically signi®cant trends would have been found in all but two of the low¯ow analyses and in two-thirds of the¯ood¯ow analyses. We show that the cross-correlation of¯ow records dramatically reduces the effective number of samples available for trend assessment. We also found that low¯ow time series exhibit signi®cant temporal persistence. Even when the serial correlation was removed from the time series, signi®cant trends in low¯ow series were apparent, though the number of signi®cant trends decreased.

Probabilistic Behavior of Floods of Record in the United States

Journal of Hydrologic Engineering, 2006

Literature on the probability distribution function ͑PDF͒ of annual maximum flood discharges is e... more Literature on the probability distribution function ͑PDF͒ of annual maximum flood discharges is extensive, yet the literature on the PDF of the flood of record ͑FOR͒ is sparse. This is partially due to two facts: ͑1͒ the PDF for record events is more complex than the PDF for annual maxima; and ͑2͒ data sets for observed FORs are much smaller than for the annual maximum flood series from which they derive. We show that, if annual floods arise from a generalized extreme values ͑GEV͒ distribution, then the FOR also arises from another GEV distribution, which we term GEV max. We also derive the moments and L-moments for the PDF of GEV max. Using record flood observations at over 1,500 basins in the United States, we compared theoretical and empirical properties of observed values of the FOR. We found that, at both regional and national scales, the FOR values are on average more extreme than would be expected if they occurred randomly, and that they tend to form spatial clusters.

Freshwater availability anomalies and outbreak of internal war: Results from a global spatial time series analysis

We investigated the relationship between water availability and internal war outbreak. This work ... more We investigated the relationship between water availability and internal war outbreak. This work constitutes the first test of climate-security connections utilizing global subnational time series data. We created harmonized spatial time series databases on a subnational global grid of internal war, renewable freshwater surface water resources (in the form of runoff), rainfall deviations and population for the period 1980-2002. We utilize national-level data on infant mortality, political institutions, and trade openness as controls. We find that at the global scale there is a highly significant relationship between rainfall deviations and the likelihood of outbreak of a high-intensity internal war. When rainfall is significantly below normal, the likelihood of conflict outbreak is significantly elevated in the subsequent year. We do not find a similar effect for the mean annual runoff at the global scale, but find some evidence at the continental scale. We also find no significant relationship between rainfall deviations and the onset of low-intensity internal wars. The capacity to geographically reference social science and biogeophysical data sets will create new opportunities for hypothesis testing with respect to the sources of internal conflict in the fast of climate change invariability

The Behavior of the Flood of Record in the United States

ABSTRACT The literature on the probability distribution function (pdf) of annual maximum flood di... more ABSTRACT The literature on the probability distribution function (pdf) of annual maximum flood discharges is extensive, yet the literature on the pdf of the flood of record is sparse. This is partially due to two facts: 1) the pdf for record events is more complex than the pdf for annual maxima, and 2) datasets for observed floods of record are much smaller than the annual maximum flood series from which they derive. We show that if annual floods arise from a generalized extreme value (GEV) distribution, then the flood of record also arises from another GEV distribution, which we term GEVmax. Using GEVmax, we explore the exceedence probability of observed floods of record across the U.S. In many regions, and over the U.S. as a whole, floods of record are on average more extreme than would be expected if they occurred randomly. We found instances where more extreme floods of record are spatially clustered and can be related to storm events that appear to have produced floods of record over large areas. We also found that the timing of record floods in the U.S. is related to sunspot cycles. Finally, we developed a multivariate regression model for estimating the flood of record from climatic, basin and geomorphologic information.

Impact of Streamflow Persistence on Hydrologic Design

Journal of Hydrologic Engineering, 2002

Conventional methods for estimating the average return period, E(T), and failure risk, R, general... more Conventional methods for estimating the average return period, E(T), and failure risk, R, generally ignore the impact of persistence in annual streamflows on associated probabilistic statements and streamflow statistics. Recent evaluations of streamflow observations indicate statistically significant serial correlations ͑persistence͒ associated with annual low flows in the United States. We define the average occurrence interval E(T) as the expected time to the first event, and we present a method for estimating E(T) and R in the presence of persistence. We show that for observed ranges of persistence, E(T) can be nearly 100% greater and R more than 20% lower than conventional estimates. This implies that the expected design life of a system is longer when persistence is taken into account. Also, by ignoring persistence, low flow quantiles may be underestimated by 50% or more. An evaluation of the effect of persistence on drought risk estimation across the U.S. is presented.

Is Precipitation in Northern New England Becoming More Extreme? Statistical Analysis of Extreme Rainfall

The objective of this study was to investigate the presence of trends in extreme precipitation. (... more The objective of this study was to investigate the presence of trends in extreme precipitation. (denoted MAXP and defined as the annual maximum daily precipitation depth) time series for coastal northern New England and to assess changes in the magnitude of the socalled "100-year storm". MAXP depths from 48 stations with long, continuous records in Maine, New Hampshire and Massachusetts were analyzed. At those same stations, the number of daily precipitation depths ≥ 2 inches (denoted as GT2in) was also quantified for each year. The seasonally-averaged MAXP was found to be fairly uniform throughout the year, but the frequency of MAXP is highest during August through October, the typical hurricane season in New England. The presence of trends in MAXP and GT2in was evaluated over four time frames (1954-2005, 1954-2008, 1970-2005 and 1970-2008) This study as well as recent record-breaking events in northern New England strongly suggests the need for updating of design storm e...

An analysis of the allocation of Yakima River water in terms of sustainability and economic efficiency

Decades of agricultural growth has led to the over appropriation of Yakima water and the ecologic... more Decades of agricultural growth has led to the over appropriation of Yakima water and the ecological integrity of the basin has been compromised. We evaluate the impact of current water allocation on the natural flow regime of the Yakima River using the Indicators of Hydrologic Alteration/Range of Variability Analysis and by quantifying indicators of ecosurplus and ecodeficit. We analyze the sustainability of the current water allocation scheme based on a range of sustainability criteria, from weak to strong to environmentally sustainable. Economic efficiency is assessed by describing the current allocation framework and suggesting ways to make it more efficient. Our IHA/RVA analysis suggests that the allocation of water in the Yakima River has resulted in a highly altered flow regime. Ecodeficit is far in excess of ecosurplus. We conclude that this allocation scheme is weakly sustainable, if sustainable at all, in its current framework. The allocation of water is also not economical...

Mapping the links between water, poverty and food security

A method for forming an as-cast hole by using a core involves forming an undercut and casting by ... more A method for forming an as-cast hole by using a core involves forming an undercut and casting by using a core die which is slidable at an angle with respect to mold closing and opening directions. At the same time, an as-cast hole with an axial direction different from the slide direction of the core die is formed. To form the as-cast hole, a floating core is slidably disposed in the core die for movement in the axial direction of the as-cast hole. An apparatus for practicing the method includes a stationary die, a movable die and the core die containing the slidable floating core.

Session D3 - Physical and biological assessment of the Eel River Headwaters restoration sites in Plymouth, MA

The role of stakeholders in Murray-Darling Basin water management: How do irrigators make water use decisions and how can this influence water policy?

Session B4- Freshwater fish and aquatic macroinvertebrate biomonitoring of the Eel River Headwaters Restoration sites in Plymouth, Massachusetts

Modeling regional landslide susceptibility using dynamic soil moisture profiles

Journal of Mountain Science

A landslide susceptibility mapping study was performed using dynamic hillslope hydrology. The mod... more A landslide susceptibility mapping study was performed using dynamic hillslope hydrology. The modified infinite slope stability model that directly includes vadose zone soil moisture (SM) was applied at Cleveland Corral, California, US and Krishnabhir, Dhading, Nepal. The variable infiltration capacity (VIC-3L) model simulated vadose zone soil moisture and the wetness index hydrologic model simulated groundwater (GW). The GW model predictions had a 75% NASH-Sutcliffe efficiency when compared to California’s in-situ GW measurements. The model performed best during the wet season. Using predicted GW and VIC-3L vadose zone SM, the developed landslide susceptibility maps showed very good agreement with mapped landslides at each study region. Previous quasi-dynamic model predictions of Nepal’s hazardous areas during extreme rainfall events were enhanced to improve the spatial characterization and provide the timing of hazardous conditions.

Simulating the Impacts and Assessing the Vulnerability of the Central Artery/Tunnel System to Sea Level Rise and Increased Coastal Flooding

Journal of Extreme Events, 2017

Highway tunnels along the coast are critical infrastructure and represent one of the more sensiti... more Highway tunnels along the coast are critical infrastructure and represent one of the more sensitive components of a transportation network to coastal flooding. By their very nature, large portions of these tunnels are beneath present sea level and the tunnel entrances and the equipment necessary to operate the tunnels such as vent buildings may or may not be above present flood thresholds. The Central Artery/Tunnel (CA/T) system in coastal Boston, Massachusetts USA is a vital link in the regional transportation network and is comprised of more than 160 lane-miles (more than half of them in tunnels), 6 interchanges and 200 bridges. While not examined here, the CA/T system relies upon other infrastructure systems to fully function, such as the electrical grid. The ADvanced CIRCulation model (ADCIRC) coupled with the Simulating WAves Nearshore (SWAN) Model was used for storm surge modeling. SLR scenarios were selected for four distinct time periods (2013, 2030, 2070, and 2100) to brack...