Bloomington, IN, United States
Bloomington, IN, United States

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Ayers J.,Indiana University Bloomington | Ficklin D.L.,Indiana University Bloomington | Ficklin D.L.,Center for Geospatial Data Analysis | Stewart I.T.,Santa Clara University | Strunk M.,Indiana University Bloomington
International Journal of Climatology | Year: 2016

This work presents updated hydrologic projections for the Upper Colorado River Basin (UCRB) using downscaled (approximately 12 km) General Circulation Model (GCM) output from Coupled Model Intercomparison Project – Phase 5 (CMIP5) with a comparison to CMIP3 GCMs. We use the Soil and Water Assessment Tool model to simulate the impacts of end-of-century climate change on the UCRB using 21 CMIP5 and 18 CMIP3 GCMs, collected into one CMIP5 ensemble and one CMIP3 ensemble, respectively. Previous CMIP3 studies have identified a drier climate for the UCRB because of projected increases in temperature and decreases/little change in precipitation. Hydrologic simulations from CMIP5 inputs suggest wetter conditions than simulations based on CMIP3 inputs, yet drier conditions than the historical climate. Both ensembles lead to timing shifts in peak streamflow during the snowmelt season from changes in snowmelt, but the higher CMIP5 projected precipitation leads to, on average, peak streamflows 200–300 m3 s−1 larger (25–40% difference) than the CMIP3 projections. This difference is largely generated in the northern UCRB region, where CMIP5 simulations project much more significant increases in streamflow than CMIP3. This increase is largely due to an overall larger rise in precipitation in the CMIP5 ensemble (57% of the total UCRB area) compared to the CMIP3 ensemble (5%). Even with projected increases in precipitation, snowmelt is projected to decrease dramatically throughout the UCRB for both ensembles. The increases in precipitation and decreases in snowmelt leads to significant differences in hydrologic flux components between the CMIP3 and CMIP5 ensembles, such as end-of-century rises in soil water content and evapotranspiration in the CMIP5 ensemble compared to the CMIP3 ensemble. The difference between the dry CMIP3 and the somewhat wetter CMIP5 projections may be critical for water management in the already over-allocated UCRB. © 2016 Royal Meteorological Society

Ficklin D.L.,Indiana University Bloomington | Ficklin D.L.,Center for Geospatial Data Analysis | Robeson S.M.,Indiana University Bloomington | Knouft J.H.,Saint Louis University
Geophysical Research Letters | Year: 2016

Characterizing the impacts of climatic change on hydrologic processes is critical for managing freshwater systems. Specifically, there is a need to evaluate how the two major components of streamflow, baseflow and stormflow, have responded to recent trends in climate. We derive baseflow and stormflow for 674 sites throughout the United States from 1980 to 2010 to examine their associations with precipitation, potential evapotranspiration, and maximum/minimum temperature. The northeastern (NE) and southwestern (SW) United States display consistent trends in baseflow and stormflow: increasing during fall and winter in the NE and decreasing during all seasons in the SW. Trends elsewhere and at other times of the year are more variable but still associated with changes in climate. Counter to expectations, baseflow and stormflow trends throughout the United States tend to change concurrently. These trends are primarily associated with precipitation trends, but increases in PET are influential and likely to become important in the future. ©2016. American Geophysical Union. All Rights Reserved.

Zhang Q.,Indiana University Bloomington | Zhang Q.,Center for Geospatial Data Analysis | Ghanem H.,University of Jordan | Branam T.D.,Center for Geospatial Data Analysis | And 3 more authors.
Fuel | Year: 2016

Fixed scrubber sludge (FSS), is a coal-combustion byproduct composed of flue gas desulphurization sludge, fly ash, and quick lime. FSS has potential usages as structural fill and capping materials in mine land reclamation because of its low permeability and acid-neutralization capacity. Sediment cores extracted from an abandoned mine land reclamation site where FSS was used as a hydrologic barrier to groundwater recharge were analyzed in an effort to quantify the chemical phases (both primary and secondary) that constitute the FSS, and to evaluate any evidence of weathering that has occurred during the 18 years since emplacement. The primary solid phase is amorphous spheroids. Four different types were identified and their quantitative compositions were obtained, with SiO2, Al2O3, and FeO being the primary components. Of special concern was the occurrence and mobility of trace elements within the solid phases. Sequential extractions using different chemical reagents were conducted to analyze the concentrations of As, B, Ba, Cd, Cr, Cu, Ni, Pb, and Zn in different fractions as indications of mobility. The highest concentration of the trace elements was contained in the residual fraction, which is consistent with the amorphous spheroids being very resistant to chemical weathering. The results also suggest that the mobility of the trace elements decrease in the following order: B, Cu > Cd, Zn, Pb, Cr > Ba > Ni > As. Comparison of samples collected from the weathered edges and unweathered portions of the FSS layer reveal that a more aggressive weathering environment exists at the upper boundary of the FSS, where it is in contact with oxygenated soil water. The quantitative chemical compositions, distribution of trace elements, as well as evidence of how trace elements are released provide background data for the development a reactive transport model to simulate long-term effects of placing FSS in the natural environment; and particularly in areas that are being subjected to abandoned mine land reclamation. © 2016 Elsevier Ltd. All rights reserved.

Ficklin D.L.,Indiana University | Ficklin D.L.,Center for Geospatial Data Analysis | Barnhart B.L.,U.S. Department of Agriculture | Knouft J.H.,Saint Louis University | And 4 more authors.
Hydrology and Earth System Sciences | Year: 2014

Water temperature is a primary physical factor regulating the persistence and distribution of aquatic taxa. Considering projected increases in air temperature and changes in precipitation in the coming century, accurate assessment of suitable thermal habitats in freshwater systems is critical for predicting aquatic species' responses to changes in climate and for guiding adaptation strategies. We use a hydrologic model coupled with a stream temperature model and downscaled general circulation model outputs to explore the spatially and temporally varying changes in stream temperature for the late 21st century at the subbasin and ecological province scale for the Columbia River basin (CRB). On average, stream temperatures are projected to increase 3.5 °C for the spring, 5.2 °C for the summer, 2.7 °C for the fall, and 1.6 °C for the winter. While results indicate changes in stream temperature are correlated with changes in air temperature, our results also capture the important, and often ignored, influence of hydrological processes on changes in stream temperature. Decreases in future snowcover will result in increased thermal sensitivity within regions that were previously buffered by the cooling effect of flow originating as snowmelt. Other hydrological components, such as precipitation, surface runoff, lateral soil water flow, and groundwater inflow, are negatively correlated to increases in stream temperature depending on the ecological province and season. At the ecological province scale, the largest increase in annual stream temperature was within the Mountain Snake ecological province, which is characterized by migratory coldwater fish species. Stream temperature changes varied seasonally with the largest projected stream temperature increases occurring during the spring and summer for all ecological provinces. Our results indicate that stream temperatures are driven by local processes and ultimately require a physically explicit modeling approach to accurately characterize the habitat regulating the distribution and diversity of aquatic taxa.

Ficklin D.L.,Indiana University | Ficklin D.L.,Center for Geospatial Data Analysis | Letsinger S.L.,Center for Geospatial Data Analysis | Stewart I.T.,Santa Clara University | Maurer E.P.,Santa Clara University
Hydrology Research | Year: 2016

Most recent climate change impact studies are using Coupled Model Intercomparison Project Phase 5 (CMIP5) projections to replace older generation CMIP3 projections. Here we evaluate whether differences between projections based on comparable high emission pathways of a seven-member general circulation model CMIP3 versus CMIP5 ensemble change our understanding of the expected hydrologic impacts. This work focuses on the important snowmelt-dominated mountain runoffgenerating regions of the western United States (WUS; Upper Colorado River Basin (UCRB), Columbia River Basin (CRB), and Sierra Nevada (SN) Basins). Significant declines in snowmelt, and shifts in streamflow timing owing to warmer, wetter CMIP5 projections match or exceed those based on CMIP3 throughout the WUS. CMIP3- And CMIP5-based projections, while generally in agreement about hydroclimatic changes, differ in some important aspects for key regions. The most important is the UCRB, where CMIP5-based projections suggest increases in future streamflows. Comparable hydrologic projections result from similar underlying climate signals in CMIP3 and CMIP5 output for the CRB and SN, suggesting that previous work completed in these basins based on CMIP3 projections is likely still useful. However, UCRB hydrologic projections based on CMIP5 output suggest that a re-evaluation of future impacts on water resources is warranted. © IWA Publishing 2016.

Naylor S.,Center for Geospatial Data Analysis | Olyphant G.A.,Indiana University | Branam T.D.,Indiana Geological Survey
Joint Mining Reclamation Conf. 2010 - 27th Meeting of the ASMR, 12th Pennsylvania Abandoned Mine Reclamation Conf. and 4th Appalachian Regional Reforestation Initiative Mined Land Reforestation Conf. | Year: 2010

The use of coal combustion by-products (CCBs) in mine reclamation has been advocated by some because of their low permeability and potential to generate alkalinity. However, others have argued that these benefits are outweighed by the potential for leaching of trace elements that can enter ground and surface waters. In 1996, an abandoned mine land (AML) site in southwestern Indiana was reclaimed using ponded ash as structural fill in highwall cuts, and fixated scrubber sludge (FSS) as capping material over pyritic refuse. Prereclamation and post-reclamation monitoring of surface water discharge from the site, groundwater elevations and chemistry, as well as soil moisture fluctuations in the unsaturated zone have provided a basis for evaluating the effects of CCBs on the hydrochemistry of the site and potential for off-site impacts. Limited recharge through the FSS is supported by barometric efficiency changes in the refuse aquifer, the presence of perched water measured in monitoring wells installed on the cap, and minimal fluctuations in soil moisture within and immediately below the cap. Reductions in oxygenated rainwater reaching the refuse are indicated by groundwater chemistry data, collected from the refuse aquifer between 1995 and 2007, which show an increase in pH along with decreasing trends in total acidity, specific conductivity (SpC), and arsenic. Concentrations of boron, a trace element commonly associated with CCBs, have declined to near pre-reclamation levels at most sites (~1 mg/L) after an increase immediately following reclamation. Although arsenic concentrations at 14 μg/L (EPA maximum contaminant level, or MCL, is 10 μg/L) along with boron (14 mg/L) remain slightly elevated in groundwater associated with ash-filled lakes, improvements in surface water quality leaving the site include significant reductions in total mineral acidity and total iron concentrations, while trace metal concentrations remain below EPA MCLs. Copyright © (2010) by the American Society of Mining and Reclamation.

Martin L.C.,Indiana University | Branam T.D.,Center for Geospatial Data Analysis | Naylor S.,Center for Geospatial Data Analysis | Olyphant G.A.,Center for Geospatial Data Analysis
29th Annual National Conference of the American Society of Mining and Reclamation 2012, ASMR 2012 | Year: 2012

Coal combustion byproducts (CCBs) have potential as structural fill and capping materials in abandoned mine land (AML) reclamation because of their acid-neutralization capacity. However, the potential for these materials to leach constituents of potential concern (COPCs) into groundwater hinders their use by AML program managers. In 1996, the Midwestern AML site in southwestern Indiana was reclaimed using fixated scrubber sludge (FSS) cap composed of flue gas desulphurization sludge, fly ash, and lime. The cap was placed over a pyritic refuse deposit, an unreclaimed spoil ridge, and highwall lakes that were filled with ponded ash. Post reclamation analyses of groundwater chemistry showed that alkalinity and pH levels increased below the cap, indicating that the CCBs helped to neutralize the preexisting acid mine water. Concentrations of COPCs initially increased below the cap, but dropped back to near or below pre-reclamation values over the past 10 years. For example, boron that initially increased to 13,000 μg/L decreased to pre-reclamation values (300 μg/L) with time. X-ray diffractometry was conducted on core samples containing FSS and ponded ash collected from the site in 2011 to identify mineralogical changes since emplacement. Oxidation of hannebachite (calcium sulfite hemihydrate) produced gypsum and calcite in the upper 1 to 4 cm of the 1 to 3 m thick FSS cap. No oxidation zone was observed at the bottom of the cap. Sediment cores of ponded ash reveal little change with depth, possibly because leaching had already occurred as a result of stockpiling at the power plant. The results of this study indicate that FSS did contribute COPCs, including boron, molybdenum, chromium, and arsenic, to groundwater for short periods and in the immediate vicinity of emplacement. Nevertheless, a lack of significant oxidation and declining trends in groundwater contamination represent long-term favorable outcomes for use of CCBs in AML reclamation.

Ficklin D.L.,Indiana University | Ficklin D.L.,Center for Geospatial Data Analysis | Maxwell J.T.,Indiana University | Letsinger S.L.,Center for Geospatial Data Analysis | Gholizadeh H.,Indiana University
Environmental Research Letters | Year: 2015

We present high spatial-resolution trends of the Palmer drought severity index (PDSI), potential evapotranspiration (PET), and selected climate variables from 1979-2013 for the contiguous United States in order to gain an understanding of recent drought trends and their climatic forcings. Based on a spatial grouping analysis, four regions of increasing (upper Midwest, Louisiana, southeastern United States (US), and western US) and decreasing (New England, Pacific Northwest, upper Great Plains, and Ohio River Valley) drought trends based on Mann-Kendall Z values were found. Within these regions, partial correlation and multiple regression for trends in climate variables and PDSI were performed to examine potential climatic controls on these droughts. As expected, there was a US-wide concurrence on drought forcing by precipitation. However, there was correspondence of recent PET trends with recent drought trends in many regions. For regions with an increase in recent droughts, average air temperature was generally the second most important variable after precipitation in determining recent drought trends. Across the regions where recent drought trends are decreasing, there was no clear ranking of climate-variable importance, where trends in average temperature, specific humidity and net radiation all played significant regional roles in determining recent drought trends. Deconstructing the trends in drought show that, while there are regions in the US showing positive and negative trends in drought conditions, the climate forcings for these drought trends are regionally specific. The results of this study allow for the interpretation of the role of the changing hydroclimatic cycle in recent drought trends, which also have implications for the current and impending results of climate change. © 2015 IOP Publishing Ltd.

Ficklin D.L.,Indiana University | Ficklin D.L.,Center for Geospatial Data Analysis | Letsinger S.L.,Center for Geospatial Data Analysis | Gholizadeh H.,Indiana University | Maxwell J.T.,Indiana University
Computers and Geosciences | Year: 2015

Calculating the Palmer Drought Severity Index (PDSI) using the Thornthwaite potential evapotranspiration (PET) method has come under recent scrutiny for overestimating drought conditions when air temperatures exceed the historical baseline. With increasing air temperatures around the world, calculating the PDSI using the Thornthwaite PET method may no longer be the appropriate option. Therefore, various researchers have called for the use of the physically-based Penman-Monteith PET method to estimate PDSI. We present an addition to the PDSI tool developed by Jacobi et al. (2013) that includes an option to use the Penman-Monteith method to calculate PET as an input to the PDSI calculations. Comparisons with a global PDSI dataset also estimated using the Penman-Monteith method indicate good spatial correlation. This addition to the Jacobi et al. (2013) tool allows users to easily calculate a suite of Palmer drought indices using Penman-Monteith potential evapotranspiration for current and future drought projections at any spatial scale. © 2015 Elsevier Ltd.

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