2015

Abstract to be uploaded later

Anonymous — Thu, 23 Aug 2018 19:57:34 +0000

Abstract to be uploaded later Anonymous (not verified) Thu, 08/23/2018 - 13:57 Farrokh Shoaei

Shoaei, Farrokh ¹ ; Crimaldi, John P. ²

¹ ��ƷSM��ӰƬ
² ��ƷSM��ӰƬ

Abstract to be uploaded later.

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How The West Was Lost

Anonymous — Thu, 23 Aug 2018 19:31:19 +0000

How The West Was Lost Anonymous (not verified) Thu, 08/23/2018 - 13:31 Jay Famiglietti

Famiglietti, Jay ¹

¹ NASA Jet Propulsion Laboratory

Just as the settling and development of the arid American West was fueled by harnessing its available fresh water, the growing lack of water availability may well be its undoing. California?s epic drought is just the latest example of what is shaping up to be the new normal out west. In this presentation I review how groundwater depletion in the western United States is threatening to greatly undermine the region?s water security. Case studies from California and the Colorado River basin are examined. Implications for conjunctive water management are discussed.

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Hydrologic Simulations In Two Subcatchments Of The Boulder Creek Watershed

Anonymous — Mon, 13 Aug 2018 18:22:53 +0000

Hydrologic Simulations In Two Subcatchments Of The Boulder Creek Watershed Anonymous (not verified) Mon, 08/13/2018 - 12:22 Qinghuan Zhang

Zhang, Qinghuan ¹ ; Williams, Mark ² ; Cowie, Rory ³

¹ Geography & INSTAAR, ��ƷSM��ӰƬ
² Geography & INSTAAR, ��ƷSM��ӰƬ
³ Geography & INSTAAR, ��ƷSM��ӰƬ

Hydrologic modeling is necessary in predicting discharge, especially in mountainous areas where the measurements are hard to realize. The Variable Infiltration Capacity (VIC) model was applied to two sub-catchments of the Boulder Creek watershed, Como Creek and Fourmile Creek watersheds, and generated good results. The former catchment straddles subalpine and lower alpine zones, and has barely been influenced by human activities; the latter catchment is located in a montane zone, and has extensive logging and homes. The results showed that surface discharge in both of these two catchments was dominated by baseflow. However, discharge after the year 2010 in Fourmile Creek watershed is more irregular, which may be impacted by the forest fire. The 2010 Fourmile Canyon Fire influenced vegetation and soil conditions, indicating that using the same parameters before the fire can not give reliable results. Another reason comes from climate forcing data. The climate data before the year 2010 was from Maurer's dataset (Maurer et al., 2002), whereas the climate forcing data after the year 2010 was collected from Western Regional Climate Center, Boulder Station. The predicted discharge from the year 1990 to 1995, and 2011 to 2014 were shown in Figures 1 and 2. The unpredictable discharge after the year 2010 means that geological transformations are as important as climate forcing when using the VIC model.

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An Approach For Assessing The Drought-Resilience Of Colorado'S Transbasin Water Diversions

Anonymous — Mon, 13 Aug 2018 18:21:21 +0000

An Approach For Assessing The Drought-Resilience Of Colorado'S Transbasin Water Diversions Anonymous (not verified) Mon, 08/13/2018 - 12:21 David Yates , Kathleen A Miller

Yates, David ¹ ; Miller, Kathleen A ² ; Wilby, Robert L ³ ; Kaatz, Laurna ⁴

² Presenting Author

¹ NCAR
² NCAR
³ Loughborough University
⁴ Denver Water

Drought episodes and climate change may threaten water supplies for cities and farms along Colorado?s Front Range by reducing their ability to divert water across the Continental Divide from the Upper Colorado River Basin. Large uncertainties surround climate model projections for future precipitation for the region, but there is consensus amongst the models that air temperatures will rise, implying possible earlier and shorter melt seasons and related changes in watershed conditions. Hence, future water resource planning must be sufficiently flexible to accommodate multiple, uncertain, and interacting stressors on the water system. A multi-step decision support process was developed and applied to the physically and legally complex case of Colorado?s transbasin water diversions. We illustrate our approach by simulating the performance of an existing drought-response measure, the Shoshone Call Relaxation Agreement (SCRA) using the Water Evaluation and Planning (WEAP) hydrologic cycle and water systems modelling tool and the Statistical DownScaling Model (SDSM-DC) stochastic climate scenario generator. Scenarios relevant to the decision community were analyzed and results indicate that this drought management measure would provide only a small benefit in offsetting the impacts of a shift to a warmer and drier future climate coupled with related environmental changes. The analysis demonstrates the importance of engaging water managers in the development of credible and computationally efficient decision support tools that accurately capture the physical, legal and contractual dimensions of their climate risk management problems.

Yates, David, Kathleen A. Miller, Robert L. Wilby and Laurna Kaatz, 2015. Decision-centric adaptation appraisal for water management across Colorado?s Continental Divide, Climate Risk Management. In press.

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The Brief, Tumultuous Life Of Logjams In Rocky Mountain National Park

Anonymous — Mon, 13 Aug 2018 18:20:16 +0000

The Brief, Tumultuous Life Of Logjams In Rocky Mountain National Park Anonymous (not verified) Mon, 08/13/2018 - 12:20 Ellen Wohl

Wohl, Ellen ¹

¹ Colorado State University

Channel-spanning logjams occur on rivers throughout Rocky Mountain National Park. Each jam creates a backwater area in which finer sediment and organic matter are deposited. Jams thus slow the downstream movement of water, sediment, and nutrients. The backwater at a jam provides insect and fish habitat, so the logjams increase habitat abundance and diversity within streams. By creating obstructions to flow, logjams also enhance overbank flows that spread across the floodplain, depositing fine sediment and organic matter, eroding secondary channels, and creating further aquatic and riparian habitat. Finally, jams enhance exchanges of water between the stream and the subsurface, which mediates fluctuations in water temperature, provides subsurface habitat for aquatic invertebrates, and makes nutrients such as nitrogen available to stream organisms. Understanding the spatial distribution and persistence of logjams is thus important for managing river corridors in the park.

In 2008, I tagged all of the logs in each of 5 large jams with the intent of returning each year to measure exchanges of wood (loss of existing pieces, addition of new pieces). However, 3 of the jams completely disappeared within the next 2 years. In 2010, I began an annual survey of all the channel-spanning logjams on the main rivers in Wild Basin (North St. Vrain, Hunters, Cony, and Ouzel Creeks). In 2012 I added the portion of Glacier Creek between Black and Mills Lakes. Results thus far indicate that the combined effects of fluctuations through time and space in forest mortality (blowdowns, wildfires) and in peak flows (snowmelt and rainfall floods) create substantial variations in the number and size of logjams on rivers within the national park.

Wohl, E. and Beckman, N., 2014, Controls on the longitudinal distribution of channel-spanning logjams in the Colorado Front Range, USA: River Research and Applications, v. 30, p. 112-131.
Wohl, E. and Beckman, N.D., 2014, Leaky rivers: Implications of the loss of longitudinal fluvial disconnectivity in headwater streams: Geomorphology, v. 205, p. 27-35.

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Age And Origin Of Waters: What Hydrogen And Oxygen Isotopes In A Glacierized Catchment Can Tell Us

Anonymous — Mon, 13 Aug 2018 18:19:26 +0000

Age And Origin Of Waters: What Hydrogen And Oxygen Isotopes In A Glacierized Catchment Can Tell Us Anonymous (not verified) Mon, 08/13/2018 - 12:19 Alāna M. Wilson

Wilson, Alāna M. ¹ ; Williams, Mark W. ²

¹ Geography & INSTAAR, ��ƷSM��ӰƬ
² Geography & INSTAAR, ��ƷSM��ӰƬ

New results from tritium (H3) analysis of waters from the Langtang Valley, Nepal offer insight into the relative ages of different source waters in the glacierized catchment. Since tritium in the environment is primarily attributed to nuclear fallout in the 1950s and 1960s and its half-life is around 12 years, the presence of tritium in surface waters provides age-constraints on when it arrived as precipitation. The ambient value in new snow in the Langtang Valley, Nepal was measured at 2.2 Tritium Units (TU) in November of 2013. High-elevation groundwater in the catchment had a tritium value of 4.55 TU, and lower elevation springs had vaues between 3.4 and 3.8 TU, while geothermally-influenced hotspring waters had values of 2.0 and 2.5 TU. Ice at the termini of three glaciers was found to be tritium-dead meaning the ice formation pre-dates the nuclear testing era, however surface waters from the Langtang River had values of 4 TU or more in November 2013 and 3 TU or more in January 2014. This decline in tritium values between November and January is indicative of a shift towards baseflow that may be more strongly controlled by tritium-dead glacier melt than the November river water.

Concentrations of the oxygen-18 isotope (δ18O) in precipitation are dependent on temperature and distance traveled from the moisture source. Snow during the pre-monsoon season of 2012, arriving from the south, had δ18O concentrations of -5? to -9? while rain during the same time period had concentrations of -3?. Post-monsoon snow in 2013, likely delivered by the Westerlies, had an δ18O concentration of -27?. Values of δ18O measured in glacier ice varied between -16? and -20?, suggesting a monsoon season source that is intermediate to the pre- and post-monsoon precipitation samples that were measured.

Isotopes of hydrogen and oxygen offer insight into age and origin of surface waters and their sources. This information is explored further in order to estimate the contribution of different source waters to river streamflow.

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High-Rate Injection Is Associated With The Increase In U.S. Mid-Continent Seismicity

Anonymous — Mon, 13 Aug 2018 18:18:29 +0000

High-Rate Injection Is Associated With The Increase In U.S. Mid-Continent Seismicity Anonymous (not verified) Mon, 08/13/2018 - 12:18 Matthew Weingarten

Weingarten, Matthew ¹ ; Ge, Shemin ²

¹ University of Colorado-Boulder
² University of Colorado-Boulder

An unprecedented increase in earthquakes in the central and eastern US (CEUS) began in 2009. Many of these earthquakes have been documented as likely induced by wastewater injection. To better understand the likelihood of an induced seismic event from a given injection well, we compare the location and timing of earthquakes and injection operational parameters across the CEUS. We compiled a database of more than 187,000 injection wells in the CEUS, both active and inactive. In combination with the Advanced National Seismic System's (ANSS) comprehensive earthquake catalog from 1973 through December 2014, we use spatial and temporal filtering methods to discriminate injection wells that may be associated with earthquakes from those that are not. Our goal was to understand whether or not well operational parameters such as injection rate, cumulative injected volume, injection pressure and injection depth affect the likelihood that a well is spatiotemporally associated with an earthquake.

We found more than 15,000 wells (~10% of all wells) that may be associated with earthquakes in the CEUS. Our spatiotemporal filter succeeded in capturing every suspected case of induced seismicity that we are aware of. We also found that the likelihood of an injection well being associated with an earthquake was dominantly controlled a well's injection rate. High-rate injection wells, injecting more than 300,000 barrels/month, are preferentially associated with earthquakes. The highest rate injection wells, wells injecting more than 1,000,000 barrels/month, were nearly twice as likely to be associated with earthquakes as wells injecting at lower rates. This phenomenon was observed over a wide range of geologic and hydrogeologic provinces in states such as Oklahoma, Colorado, New Mexico and Arkansas. Operational parameters such as cumulative injected volume, injection pressure and injection depth do not show a clear trend towards an increased likelihood of spatiotemporal association with an earthquake.

In all, we found that, since 2001, the entire rate increase of U.S. mid-continent seismicity was associated with injection wells. The year of 2014 was especially remarkable; 98% (658 of the 671) M3.0+ earthquakes in the U.S. mid-continent were associated with injection wells. Given that injection rate appears to affect the likelihood of wells being associated with earthquakes, industry or regulators can use this parameter to lower the likelihood of earthquakes associated with injection wells.

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Incorporating Deeply Uncertain Factors Into The Many Objective Search Process: Improving Adaptation To Environmental Change

Anonymous — Mon, 13 Aug 2018 18:17:14 +0000

Incorporating Deeply Uncertain Factors Into The Many Objective Search Process: Improving Adaptation To Environmental Change Anonymous (not verified) Mon, 08/13/2018 - 12:17 Abigail Watson

Watson, Abigail ¹ ; Kasprzyk, Joseph ²

¹ CU-Boulder
² CU-Boulder

Increasingly, decision support systems seek to provide structured robust decision-making support for stakeholders and decision makers under the context of deep uncertainty. Deep uncertainty refers to situations in which stakeholders or decision makers do not know, or cannot fully agree upon, the full suite of risk factors within a planning problem (e.g., environmental change and corresponding socioeconomic effects). This presentation first briefly reviews robust optimization and scenario approaches that have been proposed to plan for systems under deep uncertainty. One recently introduced framework, Many Objective Robust Decision Making (MORDM), combines two techniques: evolutionary algorithm search and robust decision making methods. Evolutionary algorithm search is used to generate planning alternatives, and robust decision making methods are used to sample performance over a large range of plausible factors and, subsequently, choose a robust solution. Within MORDM, Pareto approximate tradeoff sets of solutions are used to balance objectives and examine alternatives.

However, MORDM does not currently incorporate the deeply uncertain scenario information into the search process itself. In this presentation, we highlight several avenues for doing so, that are focused on modifying the suite of uncertain data that is selected within the search process. Visualizations that compare tradeoff sets across different sets of assumptions can be used to guide decision makers? learning and, ultimately, their selection of several candidate solutions for further planning. For example, the baseline assumptions about probability distributions can be compared to optimization results under severe events to determine adaptive management strategies. A case study of water planning in the Lower Rio Grande Valley (LRGV) in Texas is used to demonstrate the approach. Our LRGV results compare baseline optimization with new solution sets that examine optimal management strategies under low inflow, high evaporation, and high demand scenarios that mimic possible scenarios of water management under climate change.

Ultimately, our approach seeks to provide another level of understanding presently unavailable to decision makers and stakeholders. By examining how planning strategies change under the proposed optimization framework, we show the impact of deep uncertainty assumptions of future hydrologic and socioeconomic decisions on the best strategies for mitigating undesirable change in the LRGV problem.

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The Center For Water, Earth Science And Technology (CWEST)

Anonymous — Mon, 13 Aug 2018 18:16:10 +0000

The Center For Water, Earth Science And Technology (CWEST) Anonymous (not verified) Mon, 08/13/2018 - 12:16 Lauren J Tomkinson

Tomkinson, Lauren J ¹

¹ INSTAAR

The Center for Water, Earth Science and Technology (CWEST) is a scientific and educational partnership between the U.S. Geological Survey (USGS) and ��ƷSM��ӰƬ. Housed within the Institute of Arctic and Alpine Research (INSTAAR), CWEST enhances the many successful and ongoing collaborations taking place between INSAAR, other CU researchers and researchers at the USGS including the National Research Program and its Earth Surface Dynamics Program. Through facilitation and coordination, CWEST supports (a) research and educational opportunities for undergraduate and graduate students involving both organizations, (b) the sharing of facilities, (c) joint USGS-CU research proposals and (d) joint training opportunities in areas related to water, environmental science, computer modeling and more.

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Streams, Soils, Strategies And (Stressed Out?) Survivors - Ecohydrology In Seasonally Dry Climates

Anonymous — Mon, 13 Aug 2018 18:15:01 +0000

Streams, Soils, Strategies And (Stressed Out?) Survivors - Ecohydrology In Seasonally Dry Climates Anonymous (not verified) Mon, 08/13/2018 - 12:15 Sally Thompson

Thompson, Sally ¹

¹ University of California, Berkeley

Seasonally dry ecosystems (or SDEs) include Mediterranean, Monsoonal and Tropically Dry climates. SDEs occur worldwide and share a pronounced contrast in precipitation between a wet season, and a dry season in which little to no rain falls. Water availability in SDEs during the dry season is dependent on carry-over storage from the rainy season. This can lead to a pronounced bimodality in water availability, which poses several challenges - to those who study these systems, and to the organisms that inhabit them. I want to hit on 3 of these challenges: 1. Predictions about soils and streams: existing stochastic ecohydrologic theory requires that rainfall statistics be stationary in time in order to make a prediction about flow duration curves and soil moisture PDFs. Such predictions support risk-based approaches to understanding stream and terrestrial water supplies. Through simple depletion arguments, we extend these theories to SDEs and identify how the wet season controls water availability in the dry season. 2. Optimal strategies for plants: Plants in SDEs adopt an almost bewildering array of leaf phenological strategies (phenology in this case refers to the timing of when leaves appear on the plant, and under what conditions leaves will be shed). Simple models can be used to evaluate the conditions under which different strategies allow more carbon fixation over the growing season, and might offer insight into why so many different modes of behavior co-exist. 3. Surviving the drought: Strategies are only good up to a point - after which plants are exposed to severe water stress. Field observations suggest that water stress experienced by oak trees in the California drought to date is becoming extreme, but variable, amongst species, locations and individuals. Whether stress predicts mortality remains a critical challenge for linking theory to predictions of change.

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