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The article focuses on the papers published in the journal Geology Today. The answer to the question, why do we say 4.7 on the Richter scale and not 4.7 Richters, from the seismologist Roger Musson points out that when Richter designed the magnitude scale he did so by analogy with the magnitude scale used by astronomers for stars. The term "Richter scale" was later coined by Californian journalists and is not a scientific term and no seismologist would use the phrase when talking to another seismologist. The destruction of coal, another kind of underground activity is taking place in Colorado. U.S. where coal is burning uncontrolled, is unusual occurrence.

This paper draws from a dataset focusing on two rural communities in Colorado (USA). Data collection occurred over two periods: late‐2019 and again during COVID‐19 lockdowns in mid‐2020. The communities differed demographically: one had a growing minoritized population, especially among its youth; the other was overwhelmingly white. The paper troubles the concept of subjective wellbeing (SWB) as it asks about the productive potentials of discomfort, with assistance from such concepts as colorblind ideology, motivated reasoning, and network homophily. While important to think about so‐called positive emotional states in the context of community development, we must also ask questions like, "SWB for who and at whose expense?" How respondents thought about individual‐ and community‐level SWB had much to do with the social networks they were in. I also explore why the community that fared pandemic‐related disruptions, from a SWB standpoint, better than the other performed worse during this same period from an economic (material) standpoint. Sociological factors explain these dynamics, which are leveraged to enhance our understanding of how to conceptualize community development in productive ways. In sum, I argue that certain expressions of discomfort have value and are therefore necessary for creating resilient, flourishing, and, ultimately, just communities. [ABSTRACT FROM AUTHOR]

Ground‐level ozone (O3) was unusually high in northern Colorado in the summer of 2021 with maximum daily 8‐hr average (MDA8) concentrations 6 to 8 parts‐per‐billion by volume (ppbv) higher than in 2019, 2020, or 2022. One or more of the monitors on the Colorado Front Range exceeded the 2015 U.S. National Ambient Air Quality Standard (NAAQS) of 70 ppbv on 66 of the 122 days from 1 June to 30 September, and this record number of exceedances coincided with the near daily presence of dispersed smoke haze from wildfires in Arizona, California, and the Pacific Northwest. In this paper, we use regulatory and non‐regulatory surface O3 and PM2.5 measurements in conjunction with ground‐based lidar observations to estimate how much O3 was associated with the wildfire smoke. Analyses of the surface measurements suggest that pyrogenic O3 transported to northern Colorado with the smoke increased the surface concentrations in northern Colorado by an average of 8 ppbv in July, 3 ppbv in August, and 2 ppbv in September. Analysis of the lidar measurements showed these contributions to be as large as 12 ppbv on some days. Production of O3 from reactions of pyrogenic VOCs and locally emitted NOx appears to have been minimal (<3 ppbv) in the Boulder area, but may have been much larger in the suburbs southwest of downtown Denver. Plain Language Summary: Northern Colorado experienced unusually poor air quality in the summer of 2021 with frequent high ozone (O3) episodes and hazy skies caused by smoke from wildfires in Arizona, California, and the Pacific Northwest. In this study, we use surface and lidar measurements to explore the connection between the two. Our analysis suggests that the unusually high O3 was caused primarily by a combination of O3 transported to Colorado with the wildfire smoke and enhancement of local photochemical production by unusually clear skies and warm temperatures coupled with weak winds that led to localized O3 accumulations and fewer than normal thunderstorms that might otherwise have dispersed the O3. Production of O3 by reactions of locally emitted NOx with VOCs in the wildfire smoke may also have been significant in Southwest Denver. Key Points: The impacts of the 2021 western wildfires on ozone in the Denver metropolitan area and rural northern Colorado in 2021 are examinedOzone transported in the smoke from distant wildfires increased the 8‐hr concentrations in northern Colorado by an average of 8 ppbv in JulyUnusual meteorology, including fewer thunderstorms, allowed ozone produced locally to accumulate along the foothills west of Denver [ABSTRACT FROM AUTHOR]

This paper examines the amenity value of legalized marijuana by analyzing the impact of marijuana legalization on migration to Colorado. Colorado is the pioneering state in this area having legalized medical marijuana in 2000 and recreational marijuana in 2012. We test whether potential migrants to Colorado view legalized marijuana as a positive or negative local amenity. We use the synthetic control methodology to examine in‐ and out‐migration to/from Colorado versus migration to/from counterfactual versions of Colorado that have not legalized marijuana. We find strong evidence that potential migrants view legalized marijuana as a positive amenity with in‐migration significantly higher in Colorado compared with synthetic‐Colorado after the writing of the Ogden memo in 2009 that effectively allowed state laws already in place to be activated, and additionally after marijuana was legalized in 2013 for recreational use. When we employ permutation methods to assess the statistical likelihood of our results given our sample, we find that Colorado is a clear and significant outlier. We find no evidence for changes in out‐migration from Colorado suggesting that marijuana legalization did not change the equilibrium for individuals already living in the state. [ABSTRACT FROM AUTHOR]

This paper draws from a dataset focusing on two rural communities in Colorado (USA). Data collection occurred over two periods: late‐2019 and again during COVID‐19 lockdowns in mid‐2020. The communities differed demographically: one had a growing minoritized population, especially among its youth; the other was overwhelmingly white. The paper troubles the concept of subjective wellbeing (SWB) as it asks about the productive potentials of discomfort, with assistance from such concepts as colorblind ideology, motivated reasoning, and network homophily. While important to think about so‐called positive emotional states in the context of community development, we must also ask questions like, "SWB for who and at whose expense?" How respondents thought about individual‐ and community‐level SWB had much to do with the social networks they were in. I also explore why the community that fared pandemic‐related disruptions, from a SWB standpoint, better than the other performed worse during this same period from an economic (material) standpoint. Sociological factors explain these dynamics, which are leveraged to enhance our understanding of how to conceptualize community development in productive ways. In sum, I argue that certain expressions of discomfort have value and are therefore necessary for creating resilient, flourishing, and, ultimately, just communities. [ABSTRACT FROM AUTHOR]

Major cities located in the Colorado River Basin (CRB) rely on incentive‐based policies to address water use and supply reliability challenges, through programs provided by cities themselves, by state and federal agencies, and by NGOs. This review examines water use trends across cities, the phenomena of declining per capita use, and finds that most large cities have adopted municipal rate structures designed to incentivize lower use. A number of urban areas provide incentives to use gray water and effluent for outdoor use and to harvest rainwater. Incentive‐based programs to protect watershed health have become a water supply strategy implemented through programs and partnerships across the CRB. The paper concludes by reviewing the ways that incentive‐based urban water policies are being evaluated, and by providing guidelines for designing and evaluating programs to reduce urban use and protect watersheds that provide urban supplies. [ABSTRACT FROM AUTHOR]

When advocating for policy change, coalitions rely on various elements and strategies of policy narratives, including emotions. However, past research on the Narrative Policy Framework, and more broadly on the policy process, has largely ignored the role of emotions. This paper argues that emotions, such as anger and fear, are central to how coalitions advocate for policy change. It explores the role of anger and fear in policy narratives by examining the oral testimony (n = 474) given over four legislative committee hearings in March 2019 concerning Colorado Senate Bill 19‐181. This bill changed the mission of the Colorado Oil and Gas Conservation Commission to prioritize protecting the environment and public health over oil and gas development. This research finds the coalition that successfully supported the bill used anger towards the oil and gas industry, while those that opposed the bill relied more on fear of the uncertain consequences of the bill. It also finds the coalition that opposed the bill relied on self‐characterization as heroes and victims, which was a failed strategy. The implications for this research on the Narrative Policy Framework and, more broadly, for the policy process and advocacy are discussed. [ABSTRACT FROM AUTHOR]

As wildfires increase in both severity and frequency, understanding the role of risk saliency on human behaviors in the face of fire risks becomes paramount. While research has shown that homebuyers capitalize wildfire risk following a fire, studies of the role that risk saliency plays on residential development is limited. This paper aims to fill this gap by studying the link between wildfire risk saliency and the rate of residential development in wildfire‐prone areas, by treating recent wildfires as conditionally exogenous shocks to saliency. Using geospatial data on residential development in Colorado, we show that saliency shocks due to wildfire lead to statistically significant reductions in the rate of new development in wildfire risk zones that last upwards of 5 years, a result that is robust to a number of alternative explanations. We explore the policy implications of these findings, noting that education on fire risks may curtail some but not all of the development in these high wildfire‐risk areas due to the rapid growth of development in these regions. [ABSTRACT FROM AUTHOR]

Background and Objectives: Lesbian, gay, bisexual, and questioning (LGBQ) youth are at greater risk of problematic alcohol use than their heterosexual peers, yet there is a dearth of research examining variability in alcohol use among youth that simultaneously accounts for sexual orientation and gender identity. This paper examines the relationship between alcohol use and intersecting identities of sexual orientation and gender while accounting for this population's disproportionate experiences of depression and dating and sexual violence. Methods: The study used a representative sample (n = 27,621) of high school students. Logistic regressions were used to determine if earlier age at first drink, 30‐day alcohol use, and binge drinking were significantly related to intersectional sexual orientation and gender identity. Secondary models added depression, dating violence, and sexual violence to analyses to determine if they explained any of the variance in alcohol use variables in LGBQ and transgender youth. Results: Transgender youth who identified as heterosexual or questioning their sexual orientation were at greatest risk for early initiation of alcohol use and binge drinking. These relationships between intersectional identity and alcohol use became nonsignificant when depression, dating violence, and sexual violence were added to the models. Conclusions and Scientific Significance: This is the first study to examine relationships between intersecting identities of sexual orientation and gender identity and alcohol use among youth. Risky alcohol use among transgender youth may be attributed to experiences of depression, dating violence, and sexual violence impacting these populations. Interventions should focus on reducing transgender youth exposure to violence. [ABSTRACT FROM AUTHOR]

This special issue contains papers from the Fourteenth Copper Mountain Conference on Multigrid Methods, held in the Colorado Rocky Mountains on March 22–27, 2009. The papers address a variety of applications and cover a breadth of topics, ranging from theory to high-performance computing. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A new automated method to retrieve charge layer polarity from flashes, named Chargepol, is presented in this paper. Using data from the NASA Lightning Mapping Array (LMA) deployed during the Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign in Cordoba, Argentina, from November 2018 to April 2019, this method estimates the polarity of vertical charge distributions and their altitudes and thicknesses (or vertical depth) using the very‐high frequency (VHF) source emissions detected by LMAs. When this method is applied to LMA data for extended periods of time, it is capable of inferring a storm's bulk electrical charge structure throughout its life cycle. This method reliably predicted the polarity of charge within which lightning flashes propagated and was validated in comparison to methods that require manual assignment of polarities via visual inspection of VHF lightning sources. Examples of normal and anomalous charge structures retrieved using Chargepol for storms in Central Argentina during RELAMPAGO are presented for the first time. Application of Chargepol to five months of LMA data in Central Argentina and several locations in the United States allowed for the characterization of the charge structure in these regions and for a reliable comparison using the same methodology. About 13.3% of Cordoba thunderstorms were defined by an anomalous charge structure, slightly higher than in Oklahoma (12.5%) and West Texas (11.1%), higher than Alabama (7.3%), and considerably lower than in Colorado (82.6%). Some of the Cordoba anomalous thunderstorms presented enhanced low‐level positive charge, a feature rarely if ever observed in Colorado thunderstorms. Key Points: A new automated method to estimate the polarity, altitude, and vertical depth of charge layers from flashes is presentedThunderstorm charge structures in Central Argentina are characterized from months of Lightning Mapping Array (LMA) data, with 13.3% anomalous charge structureCordoba anomalously charged thunderstorms have a distinct charge altitude distribution when compared to those in Colorado [ABSTRACT FROM AUTHOR]

Forested areas exhibit high spatial variability in the distribution of snow water equivalent (SWE). Previous work has focused on forested areas with respect to snow accumulation in adjacent clearings. There is generally less snow in forested areas with greater variability relative to open areas due to the influence of tree canopies. However, the length scale of the transition from open areas to forested conditions is uncertain. Hence, the goal of this paper is to determine the length scales associated with forest boundary effects on SWE accumulation distribution patterns within forest stands. To accomplish this, we utilize a unique ground‐penetrating radar data set collected during the NASA SnowEx campaign on Grand Mesa, Colorado, in February 2017 to determine spatial SWE distribution patterns of areas under canopy and in clearings, and the length scales of transitions between these patterns (i.e., the size of within‐stand boundary areas). We define within‐stand boundary areas as the transitional zone from a clearing to relatively stable SWE distribution, or background distribution patterns, within forest stands. The largest within‐stand boundary effect occurred on the leeward side of stands with a mean extent of 44 m, or 4.3 mean canopy heights. In contrast, windward within‐stand boundary effects showed a mean extent of 28 m, or 3.7 mean canopy heights. We present a conceptual framework of the complex wind dynamics that occur in forest stands to explain the within‐stand boundary effects on SWE distribution. Future investigations could improve understanding of this complex process and associated driving variables. Key Points: Boundary effects extend into forested areas 3.7 and 4.3 mean canopy heights on windward and leeward sides of stands, respectivelyThese effects are a result of complex wind dynamics including eddies and spatially varying effective roughness near forest boundariesSWE variability is significantly different in forest boundary affected areas relative to background under canopy variability [ABSTRACT FROM AUTHOR]

Future reduction in mountain snowpack due to anthropogenic climate change poses a threat to many snow‐adapted species worldwide. Mountain topography exerts a strong control on snowpack not only due to elevation but also through the effect of slope and aspect on the surface energy balance. We develop high‐resolution projections of snowpack in order to provide improved, physically based estimates of the spatial distribution of future snowpack to inform species conservation efforts for the wolverine (Gulo gulo) in two study areas in the Rocky Mountains: one in Montana with known den sites and one in Colorado with recent wolverine activity and potential for reintroduction. Here we assess springtime snowpack loss in actual and potential denning areas under five future climate scenarios for the mid‐21st century. Snowpack in April and May is likely to persist into the mid‐21st century in the upper half of current denning elevations in all but the warmest future climate scenario, while large declines are projected for the lower half of the denning elevations. We gain new insight into the influence of topographical aspect on future snowpack and quantify the potential for enhanced snow persistence on north and east facing slopes under future scenarios that is only revealed in simulations where terrain slopes are resolved. Plain Language Summary: Climate change and its effect on snow are a threat to high mountain ecosystems and species worldwide. The future of mountain snowpack is complex, with multiple drivers, and with a strong elevation dependence. What has received much less attention is the dependence on topographical aspect—how will the snowpack on north facing versus south facing slopes respond differently under climate change. In this paper we develop snow projections motivated by a conservation issue for the wolverine: the future of the springtime snowpack at elevations of observed and potential wolverine denning for two study areas in the Rocky Mountains by the mid‐21st century. While there is significant snowpack loss in the lower half of denning elevations, the upper denning elevations retain springtime snowpack, supporting conservation actions through midcentury in these regions. Key Points: Early spring snowpack declines sharply in the lower half of wolverine den elevations studied but persists through midcentury higher upSpringtime snowpack is less affected by climate change on north and east facing slopes leading to potential for climate refugiaHigh‐resolution modeling that resolves topographical aspect may provide useful information to support conservation decisions [ABSTRACT FROM AUTHOR]

Summary: Tracer studies are a commonly used tool to develop and test Einstein‐type stochastic bedload transport models. The movements of these tracers are controlled by many factors including grain characteristics, hydrologic forcing, and channel morphology. Although the influence of these sediment storage zones related to morphological features (e.g., bars, pools, riffles) have long been observed to "trap" bedload particles in transport, this influence has not been adequately quantified. In this paper we explore the influence of channel morphology on particle travel distances through the development of a Bayesian survival process model. This model simulates particle path length distributions using a location‐specific "trapping probability" parameter (pi), which is estimated using the starting and ending locations of bedload tracers. We test this model using a field tracer study from Halfmoon Creek, Colorado. We find that (1) the model is able to adequately recreate the observed multi‐modal path length distributions, (2) particles tend to accumulate in trapping zones, especially during large floods, and (3) particles entrained near a trapping zone will travel a shorter distance than one that is further away. Particle starting positions can affect path lengths by as much as a factor of two, which we confirm by modelling "starting‐location‐specific" path length probability distributions. This study highlights the importance of considering both tracer locations and channel topography in examinations of field tracer studies. © 2020 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Much of the research on tax and expenditure limitations (TELs) focuses on the impact that limits have on the size of the public sector or the distribution of expenditures at the state and local levels. While these results shed light on the extent to which TELs succeed in reducing government spending, they do not have much to say about the impact of TELs on government budgeting or financial planning, despite the fact that voters support TELs in the hope of reducing government inefficiency (Courant, Gramlich, and Rubinfeld 1980; Ladd and Wilson 1982). This paper examines the effect of TELs on the stability of government revenues; sound tax policy entails controlling the volatility of revenues in order to plan more effectively for the future. Using panel data from Colorado's Division of Local Government as well as the Census Bureau's Annual Survey of State and Local Government Finances, this paper examines the impact of Colorado's 1992 Taxpayer's Bill of Rights (TABOR) on local government finances. Results from difference-in-difference estimation suggest that TELs increase revenue and expenditure volatility. [ABSTRACT FROM AUTHOR]

Estimation of epidemic onset timing is an important component of controlling the spread of seasonal infectious diseases within community healthcare sites. The Above Local Elevated Respiratory Illness Threshold (ALERT) algorithm uses a threshold-based approach to suggest incidence levels that historically have indicated the transition from endemic to epidemic activity. In this paper, we present the first detailed overview of the computational approach underlying the algorithm. In the motivating example section, we evaluate the performance of ALERT in determining the onset of increased respiratory virus incidence using laboratory testing data from the Children's Hospital of Colorado. At a threshold of 10 cases per week, ALERT-selected intervention periods performed better than the observed hospital site periods (2004/2005-2012/2013) and a CUSUM method. Additional simulation studies show how data properties may effect ALERT performance on novel data. We found that the conditions under which ALERT showed ideal performance generally included high seasonality and low off-season incidence. [ABSTRACT FROM AUTHOR]

Reliable estimation of the volume and timing of snowmelt runoff is vital for water supply and flood forecasting in snow‐dominated regions. Snowmelt is often simulated using temperature‐index (TI) models due to their applicability in data‐sparse environments. Previous research has shown that a modified‐TI model, which uses a radiation‐derived proxy temperature instead of air temperature as its surrogate for available energy, can produce more accurate snow‐covered area (SCA) maps than a traditional TI model. However, it is unclear whether the improved SCA maps are associated with improved snow water equivalent (SWE) estimation across the watershed or improved snowmelt‐derived streamflow simulation. This paper evaluates whether a modified‐TI model produces better streamflow estimates than a TI model when they are used within a fully distributed hydrologic model. It further evaluates the performance of the two models when they are calibrated using either point SWE measurements or SCA maps. The Senator Beck Basin in Colorado is used as the study site because its surface is largely bedrock, which reduces the role of infiltration and emphasizes the role of the SWE pattern on streamflow generation. Streamflow is simulated using both models for 6 years. The modified‐TI model produces more accurate streamflow estimates (including flow volume and peak flow rate) than the TI model, likely because the modified‐TI model better reproduces the SWE pattern across the watershed. Both models also produce better performance when calibrated with SCA maps instead of point SWE data, likely because the SCA maps better constrain the space‐time pattern of SWE. [ABSTRACT FROM AUTHOR]

Existing literature on energy boomtowns includes numerous statements that women are more severely "impacted" than men (if the same communities. It is possible to draw hypothesis from other literatures. however, that imply that women may do less poorly than men, or even that the women may do less poorly than men, or even that the women could benefit from rapid growth. The present paper examines data on social integration, alienation, and overall social-psychological adjustment from a sample of four western Colorado energy communities, one of which has become a boomtown. the paper finds very little support for the proposition that the women would perceive themselves as being more negatively affected than the men of the boomtown: nor, however, does it discover evidence that the energy boom has led to a net personal benefit for the women. The boomtown women were highly unlikely to receive a direct economic benefit from development, and the data from one scale total suggest that the hypothesis of negative impacts among newcomer women (as well as among newcomer men) may deserve further attention. Particularly among long-time residents, however, the present study's data suggest that women may actually be adapting more successfully to boomtown living than are men. [ABSTRACT FROM AUTHOR]

Rapid, widespread changes in public perceptions and behaviors have the potential to influence conservation outcomes. However, few studies have documented whether and how such shifts occur throughout the span of a conservation initiative. We examined the 2020 ballot initiative to reintroduce wolves into Colorado, which passed with less support than prior surveys had estimated. We conducted a postelection survey of Colorado residents using the same methods as our preelection survey to compare responses between surveys and to official election results. Reported voting in favor of wolf reintroduction in the postelection survey decreased in comparison to voting intentions shared in the preelection survey, but not enough to reflect the actual vote. While bias from survey methods and/or sampling contributed to differences, we also found evidence that public perception changed. Specifically, beliefs about the potential for negative impacts of wolves increased, while beliefs about the potential for positive impacts of wolves decreased. Our findings highlight the need to conduct longitudinal monitoring of public perception given perceptions may be highly fluid as different entities attempt to sway voters. In addition, to better understand evolving perceptions, survey methods and sampling need to be improved. We find evidence of rapid, widespread public perspective change in response to a conservation initiative: the ballot initiative to reintroduce wolves to Colorado. We also find evidence that online panel surveys can overestimate public support for conservation causes, particularly in rural areas. [ABSTRACT FROM AUTHOR]

Recent growth in the number of school choice programs across the country has ignited debate on the stratifying effects of these programs. In the context of interdistrict open enrollment, this paper analyzes-both theoretically and empirically-how choice programs affect stratification levels through the mechanisms of (i) the relative characteristics of program participants and nonparticipants and (ii) the schooling choices of different groups of program participants. The theoretical analysis uses Monte Carlo simulation techniques to analyze a hypothetical world where interdistrict choice is available to students in three school districts that are allowed to vary in student composition, the type of students who take advantage of the interdistrict choice program, and schooling choices of students who open enroll. The results of these simulations provide an understanding of the conditions under which an interdistrict open enrollment program leads to increases, decreases, or no changes in stratification levels. The empirical analysis uses data from the universe of students attending Colorado public schools in 2009-10 to examine how the state's interdistrict choice program affects stratification levels. It also analyzes the factors responsible for any increases or decreases in stratification and finds both participation patterns and differences in schooling decisions across groups to play important roles. The paper concludes with a discussion of its implications for research and policy. [ABSTRACT FROM AUTHOR]

Geostatistical models are often used to predict spatial variables of interest, but the parameters involved in the spatial correlation function usually cannot be well estimated even if the sample size is large enough under a fixed domain. This would result in the spatial predictor being inaccurate and unstable. In this paper, we apply a data perturbation technique to obtain a new spatial predictor, which is not only continuous but also differentiable with respect to the response variables even after plugging-in the estimated model parameters. Therefore, it is more stable. Moreover, it is known that different spatial predictors obtained from different methods generally have different levels of performance under different circumstances. To mitigate the uncertainties inherent in a selection process, in this paper, we propose an estimation method of weights based on Stein's unbiased risk estimate to combine candidate stabilized spatial predictors, leading to a versatile spatial predictor that is adaptive to the underlying spatial process. Validity for the proposed spatial prediction method is justified both numerically and theoretically. Furthermore, an application of a real data set for the precipitation levels in the Colorado State is also presented. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND Adolescent overweight and obesity are serious health risks, with prevalence varying by sociodemographic group. Studies link children's weight status and sex/race-ethnic differences with meeting recommendations for physical activity and diet. But, research examining the intersection of sociodemographic characteristics, behavior, and weight status is limited. This paper aims to identify sociodemographic differences in the association between adolescent weight status and meeting 6 national obesity-related recommendations. METHODS In 2011-2012, the Healthy Kids Colorado Survey was administered to all Denver high school students. Using descriptive and multivariate modeling, we examined subgroup associations between students' self-reported weight status and physical activity and diet. RESULTS Students (N = 6652) who met at least 1 recommendation were less likely to be at an unhealthy weight (OR = 0.87); also true for students who met at least 1 physical activity recommendation (OR = 0.80). However, the association varied across subgroups. The association between weight status and meeting at least 1 nutritional recommendation (OR = 0.91) was inconsistent across subgroups. Unexpected patterns also emerged in subgroup associations between meeting specific recommendations and weight status. CONCLUSIONS Identifying subgroup differences in meeting recommendations and the association with weight status is important in identifying high risk groups and improving policy and programs that target childhood obesity prevention. [ABSTRACT FROM AUTHOR]

Abstract: Groundwater is a critical input to agricultural production across the globe. Current groundwater pumping rates frequently exceed recharge, often by a substantial amount, leading to groundwater depletion and potential declines in agricultural profits over time. As a result, many regions reliant on irrigated agriculture have proposed policies to manage groundwater use. Even when gains from aquifer management exist, there is little information about how policies affect individual producers sharing the resource. In this paper, we investigate the variability of groundwater management policy impacts across heterogeneous agricultural producers. To measure these impacts, we develop a hydroeconomic model that captures the important role of well capacity, productivity of water, and weather uncertainty. We use the model to simulate the impacts of groundwater management policies on producers in the High Plains aquifer of eastern Colorado and compare outcomes to a no‐policy baseline. The management policies considered include a pumping fee, a quantity restriction, and an irrigated acreage fee. We find that well capacity and soil type affect policy impacts but in ways that can qualitatively differ across policy type. Model results have important implications for the distributional impacts and political acceptability of groundwater management policies. [ABSTRACT FROM AUTHOR]

The ability to reallocate water to higher‐value uses during drought is an increasingly important "soft‐path" tool for managing water resources in an uncertain future. In most of the Western United States, state‐level water market institutions that enable reallocation also impose substantial transaction costs on market participants related to regulatory approval and litigation. These transaction costs can be prohibitive for many participants in terms of both costs and lengthy approval periods, limiting transfers and reducing allocation efficiency, particularly during drought crises periods. This manuscript describes a mechanism to reduce transaction costs by adapting an existing form of informal leases to facilitate quicker and less expensive transfers among market participants. Instead of navigating the formal approval process to lease a water right, informal leases are financial contracts for conservation that enable more junior holders of existing rights to divert water during drought, thereby allowing the formal transfer approval process to be bypassed. The informal leasing approach is tested in the Upper Colorado River Basin, where drought and institutional barriers to transfers lead to frequent shortages for urban rights holders along Colorado's Front Range. Informal leases are facilitated via option contracts that include adaptive triggers and that define volumes of additional, compensatory, releases designed to mitigate impacts to instream flows and third parties. Results suggest that more rapid reallocation of water via informal leases could have resulted in up to $222 million in additional benefits for urban rights holders during the historical period 1950–2013. Plain Language Summary: In much of the developed world, there is little ability to sustainably manage water resources by building more dams or digging new wells. Water stressed regions are increasingly adapting to droughts through agreements to conserve or reallocate water between members of the community. In some places, markets make this easier by allowing users to buy and sell water. However, in most of the Western U.S., the legal system that approves these transactions makes them very costly and time consuming, reducing the benefits from trade. In particular, it is very hard to buy and sell short‐term leases. Here, we propose a new type of leasing contract, "informal leases," that avoid the legal system by relying on contractual agreements between water users. Instead of buying water via the legal system water users pay other users to conserve, coordinated through simple index contracts. When these contracts are designed correctly, they can perfectly recreate the effect of a formal water sale, for a fraction of the price. In this manuscript, we show how contracts for informal leases can be designed and evaluated, creating savings for water buyers/sellers, additional revenue for their neighbors, and a win/win response to environmental stress (for everyone except the lawyers). Key Points: Transaction costs related to regulatory approval are a significant impediment to water market leases in the Western United StatesInformal leases enable rapid short‐term water reallocation during drought while reducing transaction costsThe State of Colorado could have accrued $222 million in benefits using informal leases to reallocate water from irrigators to urban users [ABSTRACT FROM AUTHOR]

What is the relationship between the design of regulations and levels of individual compliance? To answer this question, Crawford and Ostrom's institutional grammar tool is used to deconstruct regulations governing the aquaculture industry in Colorado, USA. Compliance with the deconstructed regulatory components is then assessed based on the perceptions of the appropriateness of the regulations, involvement in designing the regulations, and intrinsic and extrinsic motivations. The findings suggest that levels of compliance with regulations vary across and within individuals regarding various aspects of the regulatory components. As expected, the level of compliance is affected by the perceived appropriateness of regulations, participation in designing the regulations, and feelings of guilt and fear of social disapproval. Furthermore, there is a strong degree of interdependence among the written components, as identified by the institutional grammar tool, in affecting compliance levels. The paper contributes to the regulation and compliance literature by illustrating the utility of the institutional grammar tool in understanding regulatory content, applying a new Q-Sort technique for measuring individual levels of compliance, and providing a rare exploration into feelings of guilt and fear outside of the laboratory setting. [ABSTRACT FROM AUTHOR]

This paper analyzes Colorado corn producers' preferences over both private- and environmental public-good production system attributes, and tests the robustness of alternative data reconstruction and estimation techniques. Irrigated corn production practices are characterized by intensive water and chemical use, resulting in nonpoint source pollution to water bodies as well as soil erosion problems. Data from a stated preference survey are employed to analyze key attributes of experimentally configured irrigation systems, proposed as alternatives to current practices. Panel mixed logit estimations (and several alternative fixed parameter specifications) uncover consistently positive preferences for profit, risk reduction, and, importantly, systems with less environmental impact in terms of nitrate leaching and soil erosion. The analysis also finds evidence of preference heterogeneity and a complementary relationship between the two environmental attributes. Analysis of this kind can be used by policy makers to predict behavioral responses associated with introduction of new technologies, or to assess welfare implications of agricultural policy changes and stricter environmental regulations. Dans le présent article, nous avons analysé les préférences des producteurs de maïs du Colorado concernant les attributs des systèmes de production de biens environnementaux publics et privés et avons vérifié la robustesse des techniques de rechange pour la reconstruction et l'estimation des données. Les pratiques de production de maïs irrigué sont caractérisées par l'utilisation intensive d'eau et de produits chimiques qui entraîne une pollution diffuse des plans d'eau ainsi que des problèmes d'érosion du sol. Nous avons utilisé des données tirées d'un sondage sur les préférences déclarées pour analyser les principaux attributs des systèmes d'irrigation expérimentaux proposés comme solutions de rechange aux pratiques actuelles. Les estimations du modèle mixte logit (et plusieurs spécifications de paramètres fixes) ont permis de découvrir des préférences uniformément positives concernant les profits, la réduction des risques et les systèmes ayant moins d'impact environnemental du point de vue du lessivage des nitrates et de l'érosion du sol. L'analyse a également montré l'hétérogénéité des préférences et l'existence d'un lien complémentaire entre les deux attributs environnementaux. Les décideurs pourraient utiliser ce genre d'analyse pour prévoir les réactions comportementales liées à l'introduction de nouvelles technologies ou pour évaluer les répercussions des changements de politique agricole et des règlements environnementaux plus stricts sur le bien-être. [ABSTRACT FROM AUTHOR]

The article highlights the Twelfth Copper Mountain Conference on Multigrid Methods that was held from April 3-8, 2005 in Colorado Rocky Mountains. Ten research papers were introduced at the convention, covering from theory to high-performance computing. Among the sponsors of the event were Front Range Scientific Computation Inc., U.S. Department of Energy and International Business Machines Corp.

In this paper, I frame immigrant “illegality” as a local-scale technique of neoliberal governmentality. Drawing on recent work of anthropologists, I present illegality as a racialized, spatialized social condition which operates as governmentality by marginalizing and criminalizing immigrants, loosening the US border and forcing it into local spaces, and impacting immigrants’ everyday lives and mobility. The paper then draws on a case study of Leadville, Colorado, to illustrate the utility of this framework. In Leadville, we see how through illegality neoliberalism seeps through scales. Illegality disciplines immigrant labor in service of the neoliberal order, turns all residents into surveillers of immigrants’ subordinate sociospatial position, and masks contradictions within neoliberalism that arise particularly at the local scale. I argue that conceptualizing illegality as a governmentality technique provides a powerful tool for understanding changing state spatiality, especially ways in which neoliberalism is diffused and embedded into local economic, political, and social processes. [ABSTRACT FROM AUTHOR]

Most studies of mega-events such as Olympic Games find a relatively small impact on the cities that host them. One reason given for this finding is that the event displaces tourists who otherwise would have come to the city. This paper documents such displacement by showing that expenditure at ski resorts in Colorado rose as a result of the 2002 Winter Olympic Games. In addition to supporting previous studies, the spillover effect suggests that cities and states that gain from spillovers might want to support bids for events by nearby cities. [ABSTRACT FROM AUTHOR]

Despite improved fiscal accounting systems, many district leaders continue to struggle with how to report and use fiscal data for the purpose of strategic resource decisions. This paper proposes the creation and use of school spending profiles as a way to communicate more complete and comparable school spending information. The proposed school spending profile provides not only a complete picture of school expenditures reflecting real costs, but it also indicates spending relative to each school's mix of student needs. Data from Denver Public Schools (DPS) illustrate how profiles can provide dashboard indicators useful for district leadership. Key assumptions and implications are considered. [ABSTRACT FROM AUTHOR]

Private markets constantly assess project investment opportunities across a spectrum of such possibilities. The market's perspective on the boundary of viable projects, however, may be more limited than socially optimal due to informational constraints. In the case of economic development projects in particular, this boundary could be extended by public researchers. This paper constructs a method to estimate the private and social value-added of such research, providing a new means to understand and assess the public/private sector interface. The framework uses agents’ evolving subjective perceptions through Bayesian updating to value research information, along with methods to estimate functional forms and relative optima. Two case studies of regional development research on value-added agriculture in Colorado highlight the utility of the approach. [ABSTRACT FROM AUTHOR]

A new fossil leaf beetle species, Pulchritudo attenboroughi (Chrysomelidae, Sagrinae), is described from the Eocene Green River Formation in Colorado and is the second known fossil representative of this subfamily from North America. The fossil stands out by its remarkable preservation of elytral patterns. Such sharp and high‐contrast preservation of exoskeletal colouration is extremely rare in the fossil record of beetles and unique in its definition and fidelity. Sagrinae currently do not occur in North America, but two extant species are present in tropical and subtropical South America, one of which is similar in several aspects to the new fossil. Many extant Sagrinae live in a warm, humid climate similar to that suggested for the Early Eocene Climatic Optimum of the Green River Formation. [ABSTRACT FROM AUTHOR]

Strong professional priorities, evolving Affordable Care Act requirements, and a significantly limited public health nursing workforce prompted the University of Colorado College of Nursing to collaborate with the School of Public Health to implement one of the first Doctor of Nursing Practice/Master of Public Health dual degree programs in the nation. Federal grant funding supported the development, implementation, and evaluation of this unique post‐baccalaureate dual degree program, for which there were no roadmaps, models, or best practices to follow. Several key issues emerged that serve as lessons learned in creating a new, novel higher education pathway for Advanced Public Health Nursing. This paper highlights two of those: (1) marketing, admission, and matriculation across two programs, and (2) enhancing curricula through distance coursework and interprofessional education. When collaboration with a school of public health is possible, the Doctor of Nursing Practice/Master of Public Health dual degree is an efficient way to prepare public health nurses' with the highest level of public health knowledge, practice, and leadership expertise. [ABSTRACT FROM AUTHOR]

We describe a new Eocene fossil assassin bug, Aphelicophontes danjuddi gen. et sp. nov. (Reduviidae: Harpactorinae), from the Green River Formation of Colorado. The specimens informing this description are extraordinarily preserved, particularly in the external and internal structures of the adult male genitalia. We discuss implications of the new species for the systematics and evolutionary history of the group, as well as the strength of phylogenetic signal in harpactorine genitalia. [ABSTRACT FROM AUTHOR]

A new family, five new genera, and nine new species of fossil damselflies (Insecta, Odonata, Zygoptera, Calopterygida) from the USA are described, seven from the Eocene Fossil Lake deposits and one from Lake Uinta deposits, both from the Green River Formation, and an additional specimen from the Wind River Formation of Wyoming and Colorado. Namely, Carlea eocenica gen. et sp. nov. (in Carleidae fam. nov.), Labandeiraia riveri sp. nov., Labandeiraia browni sp. nov., Eodysphaea magnifica gen. et sp. nov., Litheuphaea sp. cf. coloradensis Petrulevičius et al., 2007, Zacallites cockerelli sp. nov., Dysagrion integrum sp. nov., Tenebragrion shermani gen. et sp. nov., Tynskysagrion brookeae gen. et sp. nov., and Oreodysagrion tenebris gen. et sp. nov. Epallagoidea and Amphipterygoidea are most common while Calopterygoidea, Coenagrionoidae and Lestoidea damselflies are less diverse. Genera of zygopteran Dysagrionidae are known from Europe and North America, further supporting the hypothesis of Palaeogene terrestrial interchange. Representatives of Epallagoidea and Amphipterygoidea in the Green River Formation confirm that warm conditions occurred at the time of deposition. [ABSTRACT FROM AUTHOR]

Our ability to test probabilistic models linking clast movements to bedload diffusion is most limited by basic field data, because measuring transport statistics during natural floods is difficult. We embedded accelerometers and gyroscopes into artificial cobbles, and measured transport during 28 daily snowmelt floods in Halfmoon Creek, Colorado, USA. The tracers captured ≈6 orders of temporal magnitude of rest durations in one data set for the first time. Motions and rests suggest a scaling transition around ≈12.5 min from subdiffusion to superdiffusion with increasing shear stress and timescale. We interpret that diurnal hydrograph cyclicity may cause another diffusion scaling break at ≈12 h. Shear stress controls and scaling uncertainties may explain differences in diffusion exponents found in several field data sets, suggesting that gravel superdiffusion scaling may be relatively universal over minutes to seasons. Methodologically, "smartrocks" can quantify field transport probabilities previously only possible in laboratory experiments. Plain Language Summary: During floods in mountain streams, gravel moves downstream but also spreads out. Predicting this spreading—called diffusion—is useful for river restoration and for assessing flood risks. We used "smartrocks" containing accelerometers and batteries to measure exactly when individual sediment grains moved during a month‐long flood in the Rocky Mountains of Colorado. The data were used to calibrate various equations to improve predictions of gravel diffusion during future floods. Key Points: Sensor‐embedded cobble tracers quantify bedload rest and hop durations during a ≈month‐long 10‐year flood in a natural mountain streamShear stress is quantified as a first‐order control on bedload diffusionA single field data set resolves scaling transitions from subdiffusion to superdiffusion with increasing shear stress and timescale [ABSTRACT FROM AUTHOR]

The successes of introduced populations in novel habitats often provide powerful examples of evolution and adaptation. In the 1950s, opossum shrimp (Mysis diluviana) individuals from Clearwater Lake in Minnesota, USA were transported and introduced to Twin Lakes in Colorado, USA by fisheries managers to supplement food sources for trout. Mysis were subsequently introduced from Twin Lakes into numerous lakes throughout Colorado. Because managers kept detailed records of the timing of the introductions, we had the opportunity to test for evolutionary divergence within a known time interval. Here, we used reduced representation genomic data to investigate patterns of genetic diversity, test for genetic divergence between populations, and for evidence of adaptive evolution within the introduced populations in Colorado. We found very low levels of genetic diversity across all populations, with evidence for some genetic divergence between the Minnesota source population and the introduced populations in Colorado. There was little differentiation among the Colorado populations, consistent with the known provenance of a single founding population, with the exception of the population from Gross Reservoir, Colorado. Demographic modeling suggests that at least one undocumented introduction from an unknown source population hybridized with the population in Gross Reservoir. Despite the overall low genetic diversity we observed, FST outlier and environmental association analyses identified multiple loci exhibiting signatures of selection and adaptive variation related to elevation and lake depth. The success of introduced species is thought to be limited by genetic variation, but our results imply that populations with limited genetic variation can become established in a wide range of novel environments. From an applied perspective, the observed patterns of divergence between populations suggest that genetic analysis can be a useful forensic tool to determine likely sources of invasive species. [ABSTRACT FROM AUTHOR]

Understanding the suitable habitat of endangered species is crucial for agencies such as the Bureau of Land Management to plan management and conservation. However, few species distribution models are directly validated, potentially limiting their application in management. In preparation for a Species Status Assessment of clay‐loving wild buckwheat (Eriogonum pelinophilum), an endangered subshrub found in southwest Colorado, we ran a series of species distribution models to estimate the species' potential occupied habitat and validated these models in the field. A 1‐meter resolution digital elevation model derived from LiDAR and a high‐resolution geology mapping helped identify biologically relevant characteristics of the species' habitat. We employed a weighted ensemble model based on two Random Forest and one Boosted Regression Tree model, and discrimination performance of the ensemble model was high (AUC‐PR = 0.793). We then conducted a systematic field survey of model habitat suitability predictions, during which we discovered 55 new subpopulations of the species and demonstrated that new species observations were strongly associated with model predictions (p <.0001, Cliff's delta = 0.575). We further refined our original models by incorporating the additional species occurrences collected in the field survey, a new explanatory variable, and a more diverse set of models. These iterative changes marginally improved performance of the ensemble model (AUC‐PR = 0.825). Direct validation of species distribution models is extremely rare, and our field survey provides strong validation of our model results. This helps increase confidence to utilize predictions in planning. The final model predictions greatly improve the Bureau of Land Management's understanding of the species' habitat and increase our ability to consider potential habitat in planning land use activities such as road development and travel management. [ABSTRACT FROM AUTHOR]

Purpose: To describe the planning and development of alternate care site (ACS) trainings for community COVID care delivery. Methods: A timeline of activities by the core training team is presented from the lens of the State of Colorado Emergency Operations, leading to the pilot test of a templated training that was completed during the first week of June 2020. Lessons learned and training topics are described. Conclusion: This case study of the Colorado experience developing training for community‐based COVID care delivery sites can inform other public health planners creating the same in their locales. And, public access materials from this project may supplement training for both public health and community health nurse educators. [ABSTRACT FROM AUTHOR]

The papers in this section were given as a panel on Religious Naturalism at the American Academy of Religion in Denver in November 2001. The panelists included Jerome Stone, Gordon Kaufman, Ursula Goodenough, Charley Hardwick, and Donald Crosby. This introduction briefly describes the panelists, lists three questions the panelists were asked to consider, and names other current and past religious naturalists. [ABSTRACT FROM AUTHOR]

Cooperative management of shared groundwater resources in the High Plains region of the United States is critical to support sustainable agricultural‐based economies. This research uses a repeat‐sample survey of agricultural producers in the states of Colorado and Nebraska to analyze how seasonal changes and variation in stress and salience influence support for groundwater management. We find that support for groundwater management tends to be lower in the fall, when agricultural producers are engaged in harvest activities. The results also reveal that changes in the salience of commodity prices and water availability can drive changes in support for groundwater management. [ABSTRACT FROM AUTHOR]

Ancient magnetization(s), often recorded by hematite (Fe2O3), provide key paleomagnetic constraints on plate interactions through time. Primary remanent magnetizations may be modified or overprinted by secondary processes that complicate interpretations of paleomagnetic data. Hematite (U‐Th)/He (hematite He) dating has the potential to resolve when secondary magnetizations were acquired. Here, we compare hematite He data and paleomagnetic results in Paleoproterozoic crystalline rocks, meters below a major nonconformity in the Colorado Front Range, USA. Prior work and new rock magnetic data indicate that pervasive hematite alteration records a secondary chemical remanent magnetization (CRM) during the Permo‐Carboniferous Reverse Superchron, coincident with the Ancestral Rocky Mountain orogeny. We target minor hematite‐coated faults cutting basement for (U‐Th)/He analyses because they are of sufficient hematite purity to yield geologically meaningful dates. Two samples yield overlapping and scattered individual hematite He dates ranging from ∼138 to 27 Ma (n = 33), significantly younger than the age of the late Paleozoic CRM. Scanning electron microscopy, electron probe microanalysis, and Raman spectroscopy indicate that aliquots have variable grain size distributions and fluorocarbonate impurities. Thermal history models support hematite on fault surfaces mineralized coeval with CRM acquisition during the late Paleozoic, and hematite He data scatter reflects variable He loss during Mesozoic burial owing to differences in grain size distribution from fault slip comminution and in chemistry among aliquots. Our results underscore the differences in temperature sensitivity and sampling requirements between paleomagnetic and hematite He investigations and illustrate that hematite He dates will usually be younger than preserved remanent magnetizations. Plain Language Summary: Minerals such as hematite are capable of recording the direction of the Earth's magnetic field during formation and this paleomagnetic information helps geoscientists estimate the age of rocks and the past motions of tectonic plates. During geologic events like mountain‐building, primary paleomagnetic signatures in rocks may be modified or replaced by new, secondary paleomagnetic recordings. Such secondary magnetizations can be challenging to interpret, especially if the age of these magnetizations is unknown. (U‐Th)/He analysis, a form of radiometric dating, may aid paleomagnetic studies by revealing the age of minerals that carry secondary magnetizations. In this study, we compare hematite (U‐Th)/He data and a secondary magnetization carried by hematite from Colorado's Front Range and find that (U‐Th)/He dates are scattered and considerably younger than the reported age of the secondary magnetization. We interpret the variability of hematite (U‐Th)/He dates to reflect differences between aliquots relating to crystal size and the presence of non‐hematite minerals. Our results suggest that the (U‐Th)/He system was partially to fully reset by a more recent phase of burial and associated reheating that was not hot enough to fully reset the paleomagnetic system. We conclude that (U‐Th)/He and paleomagnetic investigations in hematite may not record the same geologic events. Key Points: We compare new hematite (U‐Th)/He dates with previously published paleomagnetic data from the same exposure of crystalline basement rockHematite (U‐Th)/He dates are younger than the inferred timing of magnetization and imply partial He loss since magnetization acquisition(U‐Th)/He dates may not relate to remanence acquisition because of differences in sampling requirements and temperature sensitivity [ABSTRACT FROM AUTHOR]

This paper investigates the beliefs and framing strategies of interest groups during a period of policy change and the factors explaining policy change. We develop propositions to explore questions concerning policy change primarily from the advocacy coalition framework as well as from other theorie. The propositions are tested by examining the promulgation of a Colorado regulation requiring the disclosure of chemicals used in hydraulic fracturing. Using coded data of documents published by organizations involved in the rulemaking process, we find divergence between industry and environmental groups on their beliefs concerning hydraulic fracturing, as well as their portraying themselves and each other as heroes, victims, and villains, but some convergence on their more specific beliefs concerning disclosure of chemicals. Interviews point to the importance of policy entrepreneurs, timing, a negotiated agreement, and learning for explaining policy change. The findings provide both theoretical and methodological insights into how and why policy changes. [ABSTRACT FROM AUTHOR]

BSTRACT [ABSTRACT FROM AUTHOR]

The retreat of cliffs may constitute the dominant erosional response to base-level fall in arid settings underlain by horizontally-bedded sedimentary rock. These vertical cliffs typically loom above a relatively straight bedrock slope ('plinth') that is mantled with a thin layer of sediment and perched near the angle of repose. In detail, a plinth consists of a system of quasi-parallel ridges and channels. We ask how the sediment supplied from a retreating cliff influences the erosion of the plinth hillslopes and channels, and how this affects the rate of cliff retreat. Motivated by field observations and high-resolution topographic data from two sites in western Colorado, we develop a two-dimensional (2D), rules-based numerical model to simulate the erosion of channels draining a plinth and diffusive erosion of the intervening interfluves. In this model, retreat of a cliffband occurs when the height of the vertical cliff exceeds a threshold due to incision by channels on the plinth below. Debris derived from cliff retreat is distributed over the model plinth according to the local topography and distance from the source. This debris then weathers in place, and importantly can act to reduce local bedrock erosion rates, protecting both the plinth and ultimately the cliff from erosion. In this paper, we focus on two sets of numerical model experiments. In one suite, we regulate the rate of rockfall to limit the cliff retreat rate; in most cases, this results in complete loss of the plinth by erosion. In a second suite, we do not impose a limit on the cliff retreat rate, but instead vary the weathering rate of the rockfall debris. These runs result in temporally steady cliff-plinth forms and retreat rates; both depend on the weathering rate of the debris. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Reliable predictions of sediment transport and river morphology in response to variations in natural and human-induced drivers are necessary for river engineering and management. Because engineering and management applications may span a wide range of space and time scales, a broad spectrum of modeling approaches has been developed, ranging from suspended-sediment 'rating curves' to complex three-dimensional morphodynamic models. Suspended sediment rating curves are an attractive approach for evaluating changes in multi-year sediment budgets resulting from changes in flow regimes because they are simple to implement, computationally efficient, and the empirical parameters can be estimated from quantities that are commonly measured in the field (i.e., suspended sediment concentration and water discharge). However, the standard rating curve approach assumes a unique suspended sediment concentration for a given water discharge. This assumption is not valid in rivers where sediment supply varies enough to cause changes in particle size or changes in areal coverage of sediment on the bed; both of these changes cause variations in suspended sediment concentration for a given water discharge. More complex numerical models of hydraulics and morphodynamics have been developed to address such physical changes of the bed. This additional complexity comes at a cost in terms of computations as well as the type and amount of data required for model setup, calibration, and testing. Moreover, application of the resulting sediment-transport models may require observations of bed-sediment boundary conditions that require extensive (and expensive) observations or, alternatively, require the use of an additional model (subject to its own errors) merely to predict the bed-sediment boundary conditions for use by the transport model. In this paper we present a hybrid approach that combines aspects of the rating curve method and the more complex morphodynamic models. Our primary objective was to develop an approach complex enough to capture the processes related to sediment supply limitation but simple enough to allow for rapid calculations of multi-year sediment budgets. The approach relies on empirical relations between suspended sediment concentration and discharge but on a particle size specific basis and also tracks and incorporates the particle size distribution of the bed sediment. We have applied this approach to the Colorado River below Glen Canyon Dam (GCD), a reach that is particularly suited to such an approach because it is substantially sediment supply limited such that transport rates are strongly dependent on both water discharge and sediment supply. The results confirm the ability of the approach to simulate the effects of supply limitation, including periods of accumulation and bed fining as well as erosion and bed coarsening, using a very simple formulation. Although more empirical in nature than standard one-dimensional morphodynamic models, this alternative approach is attractive because its simplicity allows for rapid evaluation of multi-year sediment budgets under a range of flow regimes and sediment supply conditions, and also because it requires substantially less data for model setup and use. [ABSTRACT FROM AUTHOR]

Most growth models implicitly assume that test scores have been vertically scaled. What may not be widely appreciated are the different choices that must be made when creating a vertical score scale. In this paper empirical patterns of growth in student achievement are compared as a function of different approaches to creating a vertical scale. Longitudinal item-level data from a standardized reading test are analyzed for two cohorts of students between Grades 3 and 6 and Grades 4 and 7 for the entire state of Colorado from 2003 to 2006. Eight different vertical scales were established on the basis of choices made for three key variables: Item Response Theory modeling approach, linking approach, and ability estimation approach. It is shown that interpretations of empirical growth patterns appear to depend upon the extent to which a vertical scale has been effectively “stretched” or “compressed” by the psychometric decisions made to establish it. While all of the vertical scales considered show patterns of decelerating growth across grade levels, there is little evidence of scale shrinkage. [ABSTRACT FROM AUTHOR]

Electric utilities have typically enjoyed a close and cooperative relationship with the state regulatory bodies that oversee them. In 2001, the Colorado Public Utilities Commission mandated that the largest Colorado utility build a wind power plant as part of its conventional generating capacity, despite the utility's vigorous objections. Local environmental groups, intervening in a form of rule making called Integrated Resource Planning, succeeded in overturning regulatory capture. This paper explains this anomalous case and highlights the role of knowledge and learning in the outcome. The case shows the opportunities and limitations of using contested technical knowledge to push for institutional learning. The case also suggests the importance of repeated policy processes. Wind energy advocates perceived that they had acquired participation equity, ownership in the process akin to Kingdon's “softening up,” which led policy makers to take their arguments more seriously, opening up the possibility of institutional learning. [ABSTRACT FROM AUTHOR]

This paper describes the results of the investigation of a shallow urban lake before, and a second year after, restoration to determine the effects of aeration and bottom-sediment removal on the trophic state and environmental variables controlling the lake's phytoplankton, macrovertebrates and zooplankton compositions. The anthropogenic eutrophic process of the lake is characterized by increased nutrient concentrations from urban run-off inputs. This addition triggers a chain of events that start with a massive increase in the growth of primary producers, as these are generally growth-limited by nutrients in freshwater ecosystems. Although the lake was artificially mixed, nuisance cyanobacteria were dominant as primary producers the second year after restoration, during the summers of 2004 and 2005, until this population collapsed and were replaced by diatoms after periods of high winds, rainfall and a decreased temperature. The absence of macrophytes in the main basin because of the removal of bottom sediment had a major effect on macroinvertebrates and zooplankton. Daphnia sp. was the dominant zooplankton species before restoration, being replaced by Bosmina sp., possibly because of the lack of refuge by macrophytes. As an alternative, Bosmina sp. used the surface blooms of cyanobacteria in summer as refuge from grazing by planktivorous fish. The greatest disturbance on the macroinvertebrate community richness and evenness was the decline of scrapers and shredders, because of the lack of macrophytes after removal of the lake bottom sediment. [ABSTRACT FROM AUTHOR]

Public land designations are often primarily political decisions that may also have substantial local economic impacts. This paper econometrically estimates the visitation effect of the conversion of National Monuments to National Parks through the eight designation changes that have occurred between 1979 and 2000. The study finds robust and significant impacts of such conversions, yielding 11,642 additional visitors annually, even after controlling for likely site acreage expansion and other site visitation trends. Furthermore, these new visitors do not appear to occur at the expense of visitation at alternative sites. Using these findings, the paper explores the local economic impact of the Great Sand Dunes conversion on Colorado's San Luis Valley. [ABSTRACT FROM AUTHOR]