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Diverse seismicity-prone geologic systems are located in Texas, USA. These systems include areas of tectonically natural earthquakes and areas with induced seismicity stemming from multiple factors. Some systems are geologically and operationally simple, such as the Fort Worth Basin, where multiple lines of peer-reviewed evidence indicate that earthquakes have been induced by injection of oil-field wastewater above the geologic basement, and the Eagle Ford region, where earthquakes have been induced principally by hydraulic fracturing activities. Other systems are far more complex, such as the Texas Panhandle, where natural seismicity and induced seismicity coexist, and the Delaware Basin, where wastewater disposal both above and below shale targets and hydraulic fracturing coexist with induced seismic events. Although cases of induced seismicity were documented in Texas as early as the 1980s, the public’s attention and formal regulatory actions occurred after substantial increases in seismicity were observed proximal to unconventional hydrocarbon reservoir development in the Dallas–Fort Worth metropolitan area. These actions, intended to mitigate induced seismicity, included creation of the Texas-funded TexNet Earthquake Monitoring Program in 2015 and the formation of the industry-sponsored Center for Integrated Seismicity Research in 2016, implementing policy changes by the Railroad Commission of Texas, and altering field activities by the petroleum industry. A public-private partnership was established in Texas for monitoring earthquakes, conducting research on causation and evolving risk, and developing approaches for mitigation. This partnership between stakeholders represents a major concerted effort to address the evolving environmental hazards of induced seismicity. Even with these actions, however, the total number of earthquakes with ML ≥ 2.0 cataloged in Texas reached a record high of 2601 in 2022, representing more than double the number of earthquakes that occurred in 2020 and more than eight times the number that occurred in 2017. This chapter provides a recent history of seismicity in specific areas of Texas and the monitoring, research, and regulatory actions taken to mitigate induced seismicity.

This chapter does not have an abstract CONTEXT OF THIS REGIONAL ISSUE National and global fossil fuel–based energy systems have been designed into modern life for communities to function and achieve their potentials. These systems currently support services such as transportation, electricity generation, comfort heating, and agricultural production. Around the mid-2000s, the combination of industrial-scale hydraulic stimulation (known as hydraulic fracturing) and steerable (horizontal) drilling techniques came into their own; oil and gas production increased, and the energy outlook in the United States has not been the same. For the first time, these technological approaches (sometimes referred to as “unconventional” drilling and production techniques) allowed the oil and gas industry to increase production from low-permeability shales and low-permeability or “tight” sandstones, significantly altering the global energy supply and changing the geopolitical relationship between the United States and the rest of the world. Figure 1 shows nearly 100 years of oil production in the United States, with the sharp rise in the early 2000s as evidence of the influence of new technology, including hydraulic fracturing...

As more pressure is exerted onto water sources, hydrologic systems may be altered in ways that are difficult to predict. In Texas, water deficits can become widespread as sources are strained beyond capacity. For smaller communities, such as Boerne, Texas, water management and planning is a way to prepare. The supply-demand water balance in Boerne is conceptualized through causal loop diagrams and system dynamics modeling. Through stakeholder engagement, xeriscaping, rainwater harvesting, and smart meters were chosen as interventions, each varied in adoption levels. The resulting 125 combinations were analyzed under three scenarios: a base case assuming maximum supply of water is firm, and two responses to a meteorological drought. Results show that the city can effectively forestall a deficit. Different combinations of adoptions can achieve the same goal, giving the city optionality in choosing strategies that are best suited for its needs and constraints. Rainwater harvesting was found to be the dominant intervention influencing demand, but its influence is reduced in the two drought scenarios. Xeriscaping was the second most influential intervention and smart meters for irrigation had no effect on demand. The approach used in this study highlights the interdependency between community adoption of conservation strategies and the importance of considering these relationships using systems modeling.

Studies on the role of geomorphology on vegetation structure at the basin scale are rarely available and less likely in the future due to access, funding, and potential health risks. Our goal is to determine the primary abiotic controlling factor(s) on shrub canopy structure using a dataset of approximately 23 million individual shrubs, generated using remote sensing and ground-truthing by Young et al. (in Remote Sens 9(5):16, https://doi.org/10.3390/rs9050458 , 2017). We posit that landscape position and local-scale geomorphic features in a desert alluvial fan environment will influence canopy volume and shrub spacing of creosote bush Larrea tridentata. We relate selected characteristics (canopy volume and spatial distribution) of identified L. tridentata to aspect and surface geomorphology at each shrub location. Statistical analyses included K-S testing, distribution fitting, and several generalized linear models (GLMs). The study was located in Eldorado Valley, Nevada, USA. Aspect and surface age have demonstrable influences on both shrub canopy volume and shrub spacing for all 5 geomorphic surfaces studied, with the highest median canopy volumes on east-facing surface (0.758 m3) almost 5 × larger than the lowest median volumes (0.152 m3) on the WNW-facing surfaces; variability in shrub volume was also higher on east-facing than west-facing surfaces. Shrub spacing on alluvial flat and fan skirt surfaces (2.418 and 2.333 m, respectively) were larger than older alluvial fan, fan piedmont and fan remnant surfaces (1.776, 1.837 and 1.892 m, respectively). Results show a significant relationship between shrub spacing and canopy volume by aspect and geomorphic surface, indicating a threshold at which biotic effects on canopy structure from intra-species competition transition to abiotic effects governed by geomorphic and climatological factors.

Projecting landscape impacts from energy development is essential to land management decisions. We forecast landscape alteration resulting from oil and gas well-pad construction across the economically important Permian Basin of Texas and New Mexico, USA, by projecting current landscape trends through 2050. We modeled three landscape-impact scenarios (low, medium, and high) using recent (2008–2017) trends in well-pad construction and energy production. The results of low-, medium-, and high-impact scenarios suggest that ~60,000, ~180,000, and ~430,000 new well pads could be constructed, potentially causing ~1000, ~2800, and ~6700 km2 of new direct landscape alteration. Almost two-thirds of all new well pads will be constructed within the geologic boundaries of the Delaware and Midland Basins. This translates into a 40, 120, and 300% increase in direct landscape alteration compared with direct alteration from existing well pads. We found that indirect effects (from edges) could increase by twofold, and that the ratio between indirect and direct alteration could decline by half as alteration intensifies and overlaps with existing alteration. The Chihuahuan Desert occupies the largest portion of the study area, and is projected to experience the largest area of alteration from future well-pad construction in the Permian Basin; the degree of direct alteration could increase by 70, 200, and 500% in this desert region, under low-, medium-, and high-impact scenarios. These scenarios can be used to design proactive conservation strategies to reduce landscape impacts from future oil and gas development.

It is well known that microtopography associated with ice wedge polygons drives pronounced, meter-scale spatial gradients in hydrologic and ecological processes on the tundra. However, high-resolution maps of polygonal geomorphology are rarely available, due to the complexity and subtlety of ice wedge polygon relief at landscape scales. Here we present a sub-meter resolution map of >106 discrete ice wedge polygons across a ~1200 km2 landscape, delineated within a lidar-derived digital elevation model. The delineation procedure relies on a convolutional neural network paired with a set of common image processing operations and permits explicit measurement of relative elevation at the center of each ice wedge polygon. The resulting map visualizes meter- to kilometer-scale spatial gradients in polygonal geomorphology across an extensive landscape with unprecedented detail. This high-resolution inventory of polygonal geomorphology provides rich spatial context for extrapolating observations of environmental processes across the landscape. The map also represents an extensive baseline dataset for quantifying contemporary land surface deformation (i.e., thermokarst) at the survey area, through future topographic surveys., Measurement(s)ice wedge polygon • landTechnology Type(s)computational modeling technique • LidarSample Characteristic - EnvironmenttundraSample Characteristic - LocationState of Alaska Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11871369

Soil organic matter (SOM) is a critical ecosystem variable regulated by interacting physical, chemical and biological processes. Collaborative efforts to integrate perspectives, data, and models from interdisciplinary research and observation networks can significantly advance predictive understanding of SOM. We outline how integrating three networks – the Long‐Term Ecological Research, with a focus on ecological dynamics, the Critical Zone Observatories with strengths in landscape/geologic context, and the National Ecological Observatory Network with standardized multi‐scale measurements—can advance SOM knowledge. This integration requires improved data dissemination and sharing, coordinated data collection activities, and enhanced collaboration between empiricists and modelers within and across networks.

The increasing trend on water use for hydraulic fracturing (HF) in multiple plays across the U.S. has raised the need to improve the HF water management model. Such approaches require good-quality datasets, particularly in water-stressed regions. In this work, we presented a QA/QC framework for HF data using an outlier detection methodology based on five univariate techniques: two interquartile ranges at 95 and 90% (PCTL95, PCTL90), the median absolute deviation (MAD) and Z score with thresholds of two and three times the standard deviation (2STD, 3STD). The cleaning techniques were tested using multiple variables from two data sources centered on the Eagle Ford play (EFP), Texas, for the period 2011–2017. Results suggest that the PCTL95 and MAD techniques are the best choices to remove long-tailed statistical distributions of different variables, classifying the minimum number of records as outliers. Overall, outliers represent 13–23% of the total HF water volume in the EFP. In addition, outliers highly impacted minimum and maximum HF water use values (min–max range of 0–47 m3/m and 5.3–24.6 m3/m of frac length, before and after the outlier removal process, respectively), that are frequently used as a proxy to develop future water–energy scenarios in early-stage plays. The data and framework presented here can be extended to other plays to improve water footprint estimates with similar conditions.

Recent advances in hydraulic fracturing, in conjunction with horizontal drilling, have enabled large-scale extraction of natural gas and oil from shale formations. Despite its advances and enormous economic benefits, opportunities remain to increase hydraulic fracturing efficiency and minimize potential environmental impacts. This review specifically examines three key themes associated with development and utilization of hydraulic fracturing fluids: 1) characteristics and behavior of fracturing fluids, 2) understanding and predicting migration and fate of fracturing fluids, 3) technologies to reduce environmental impact of fracturing fluids. The paper discusses key and new techniques and findings on rheology of hydrogel-based fluids, high fidelity simulation of propagation transport, potential environmental impacts, geosynthetics in mitigating contamination, and greener fracturing fluids. It is indicated that future development relies on advances in understanding of physical processes, modeling capabilities, and monitoring techniques.

Water resources development and landscape alteration exert marked impacts on water-cycle dynamics, including areas subjected to hydraulic fracturing (HF) for exploitation of unconventional oil and gas resources found in shale or tight sandstones. Here we apply a conceptual framework for linking baseflow analysis to changes in water demands from different sectors (e.g. oil/gas extraction, irrigation, and municipal consumption) and climatic variability in the semiarid Eagle Ford play in Texas, USA. We hypothesize that, in water-limited regions, baseflow ( Q b ) changes are partly due (along with climate variability) to groundwater abstraction. For a more realistic assessment, the analysis was conducted in two different sets of unregulated catchments, located outside and inside the Eagle Ford play. Three periods were considered in the analysis related to HF activities: pre-development (1980–2000), moderate (2001–2008) and intensive (2009–2015) periods. Results indicate that in the Eagle Ford play region, temporal changes in baseflow cannot be directly related to the increase in hydraulic fracturing. Instead, substantial baseflow declines during the intensive period of hydraulic fracturing represent the aggregated effects from the combination of: (1) a historical exceptional drought during 2011–2012; (2) increased groundwater-based irrigation; and (3) an intensive hydraulic fracturing activity.

Biological soil crusts (hereafter, “biocrusts”) dominate soil surfaces in nearly all dryland environments. To better understand the influence of water content on carbon (C) exchange, we assessed the ability of dual-probe heat-pulse (DPHP) sensors, installed vertically and angled, to measure changes in near-surface water content. Four DPHP sensors were installed in each of two research plots (eight sensors total) that differed by temperature treatment (control and heated). Responses were compared to horizontally installed water content measurements made with three frequency-domain reflectometry (FDR) sensors in each plot at 5-cm depth. The study was conducted near Moab, Utah, from April through September 2009. Results showed significant differences between sensor technologies: peak water content differences from the DPHP sensors were approximately three times higher than those from the FDR sensors; some of the differences can be explained by the targeted monitoring of biocrust material in the shorter DPHP sensor and by potential signal loss from horizontally installed FDR sensors, or by an oversampling of deeper soil. C-exchange estimates using the DPHP sensors showed a net C loss of 69 and 76 g C m−2 in control and heated plots, respectively. The study illustrates the potential for using the more sensitive data from shallow installations for estimating C exchange in biocrusts.

Several studies have developed costs of monitoring; however the costs are typically applied to generic sites and use a set of pre-selected monitoring approaches. In this study we use analytical models of leakage cases to assess the cost of leakage detection for sites with specified properties and assess the value of different monitoring approaches. We assume that leakage occurs at former production wells that have been plugged and abandoned (P&A). We compare pressure-based monitoring (PBM) and geochemical-based monitoring (GBM) techniques under the same economic constraints and to increase the spatial monitoring coverage. Then the project economics using probable correctness model provides estimates of the number of required PBM and GBM wells and their coverage ratio according to a defined annual budget. It was concluded that PBM technique has a better coverage over P&A wells than GBM technique and therefore is more cost-efficient.

At the Cranfield CO 2 enhanced oil recovery (CO 2 -EOR) site, a localized area of high concentrations of CO 2 (up to 44%) and CH 4 (up to 47%) in soil gas was detected near a plugged and abandoned well. The complexity of attributing this anomaly, especially in a CO 2 -EOR setting, underscores the need for careful attribution techniques and provides rare and valuable experiential knowledge on attributing blind anomalies. An extensive geochemical monitoring program utilizing process-based soil gas ratios, stable and radioactive isotopes of CO 2 and CH 4 , light hydrocarbon concentrations, noble gases, and perfluorocarbon and sulfur hexafluoride tracers was undertaken from 2009 through 2014. The goals were to attribute source, assess the usefulness of various attribution techniques, and begin to develop a framework for attribution in complex CO 2 -EOR settings. Initial process-based assessment indicated an “exogenous” source meaning that it was not the result of natural in-situ processes (Romanak et al., 2012). We report on the additional analyses used to determine the degree to which the anomaly was related to CO 2 injection. This work included characterization of potential non-reservoir gas sources within the overburden using mud-gas samples collected during a new drill and downhole fluids collected from wells within the field. Two hydrocarbon gas sources, one within the reservoir (Tuscaloosa) and one in the above-zone (Wilcox) were geochemically distinct. Stable carbon isotopes (δ 13 C) of CH 4 in the anomaly were similar to those of the reservoir, but stable hydrogen isotopes (δD) indicated that anomalous gases originate from an undetermined microbial source rather than either of the subsurface gas reservoirs. Hydrocarbon geochemical parameters were therefore not only useful for attribution, but were also found to have a high potential for leading to inaccurate conclusions because of alteration via CH 4 oxidation. Noble gases and introduced tracers proved least effective for attribution in this case. The most useful indicator was radioactive isotopes of CO 2 and CH 4 , which contained > 100% modern carbon indicating a negligible input, if any, from the reservoir.

Projecting landscape impacts from energy development is essential to land management decisions. We forecast landscape alteration resulting from oil and gas well-pad construction across the economically important Permian Basin of Texas and New Mexico, USA, by projecting current landscape trends through 2050. We modeled three landscape-impact scenarios (low, medium, and high) using recent (2008-2017) trends in well-pad construction and energy production. The results of low-, medium-, and high-impact scenarios suggest that ~60,000, ~180,000, and ~430,000 new well pads could be constructed, potentially causing ~1000, ~2800, and ~6700 km

Most soil hydraulic information used in Earth System Models (ESMs) is derived from pedo-transfer functions that use easy-to-measure soil attributes to estimate hydraulic parameters. This parameterization relies heavily on soil texture, but overlooks the critical role of soil structure originated by soil biophysical activity. Soil structure omission is pervasive also in sampling and measurement methods used to train pedotransfer functions. Here we show how systematic inclusion of salient soil structural features of biophysical origin affect local and global hydrologic and climatic responses. Locally, including soil structure in models significantly alters infiltration-runoff partitioning and recharge in wet and vegetated regions. Globally, the coarse spatial resolution of ESMs and their inability to simulate intense and short rainfall events mask effects of soil structure on surface fluxes and climate. Results suggest that although soil structure affects local hydrologic response, its implications on global-scale climate remains elusive in current ESMs., Nature Communications, 11 (1), ISSN:2041-1723

BACKGROUND It is unknown whether this burden of disease of lower respiratory tract infections is comparable across the Canadian Arctic. The objectives of this surveillance study were to compare the rates of hospital admission for lower respiratory tract infection and the severity of infection across Arctic Canada, and to describe the responsible viruses. METHODS We performed a prospective multicentre surveillance study of infants less than 1 year of age admitted in 2009 with lower respiratory tract infection to all hospitals (5 regional, 4 tertiary) in the Northwest Territories, Nunavut and Nunavik to assess for regional differences. Nasopharyngeal aspirates were processed by means of a polymerase chain reaction respiratory viral panel, testing for 20 respiratory viruses and influenza A (H1N1). The role of coinfection was assessed by means of regression analysis for length of stay (short: 14 d). Outcomes compared included rates of lower respiratory tract infection, respiratory syncytial virus infection, transfer to tertiary hospital and severe lower respiratory tract infection (respiratory failure, intubation and mechanical ventilation, and/or cardiopulmonary resuscitation). RESULTS There were 348 admissions for lower respiratory tract infection in the population of interest in 2009. Rates of admission per 1000 live births varied significantly, from 39 in the Northwest Territories to 456 in Nunavik (p < 0.001). The rates of tertiary admissions and severe lower respiratory tract infection per 1000 live births in the Northwest Territories were 5.6 and 1.4, respectively, compared to 55.9 and 17.1, respectively, in Nunavut and 52.0 and 20.0, respectively, in Nunavik (p ≤ 0.001). Respiratory syncytial virus was the most common virus identified (124 cases [41.6% of those tested]), and coinfection was detected in 51 cases (41.1%) of infection with this virus. Longer length of stay was associated with coinfection (odds ratio [OR] 2.64) and underlying risk factors (OR 4.39). Length of stay decreased by 32.2% for every 30-day increase in age (OR 0.68). INTERPRETATION Nunavut and Nunavik have very elevated rates of lower respiratory tract infection, with severe outcomes. Respiratory syncytial virus was the most common virus identified, and coinfection was associated with longer length of stay. Targeted public health interventions are required to reduce the burden of disease for infants residing in these Arctic regions.

BACKGROUND The purpose of the study was to examine the effects of the “Yes You Can!” (YYC) curriculum on sexual knowledge and behavioral intent of program participants. METHODS Participants included students ages 10-14 from schools in a northeast US urban area. Yes You Can! program lessons were designed to support healthy relationships. The curriculum was taught by trained instructors. The testing instrument was a 30-item questionnaire, which included sexual knowledge and intent items. Students completed the questionnaire before program implementation, immediately following intervention, and a third time at follow-up. Data were analyzed using analysis of covariance. Pretest knowledge scores were used as the covariate for the knowledge analyses. Pretest intent scores were used as the covariate for the intent analyses. RESULTS Results showed the intervention group had less intent to engage in sexual intercourse than the control group at post-test (p < .001) and at follow-up (p < .001). Similarly, the intervention group had higher knowledge scores than the control group at post-test (p < .001) and at follow-up (p < .001). CONCLUSIONS Results indicate that the YYC program had a statistically significant, positive impact on knowledge and sexual intent. These variables are important precursors to actual behavior. Future research should examine the effects of the program on changes in sexual behavior.

A numerical model is presented to test whether a hillslope diffusion approach can simulate the topographic evolution of some recently developed high-centred ice-wedge polygons south of Prudhoe Bay, Alaska. The polygons are adjacent to a highway whose construction appears to have triggered their geomorphic transition. The model is calibrated using a light detection and ranging data-set that captures both the high-centred polygons and some neighbouring low-centred polygons that appear to be unaffected by thermokarst. The latter are used to represent initial conditions. Model simulations are analysed to estimate potential fluxes of soil from polygon edges into troughs and the loss of depressional water storage during development of the high-centred polygons. Overall, a match between the topography of simulated and observed high-centred polygons suggests that diffusive hillslope processes represent a feasible mechanism driving polygon transition. Rates of soil displacement inferred from optimised simulations, moreover, are within the range previously observed in permafrost terrain with a similar climate. Direct observations of the soil velocity profile in actively transitioning polygons would help resolve whether and to what extent hillslope processes, as opposed to pure thaw-related subsidence at the polygon edges, drive the development of high-centred forms in natural systems. Copyright © 2016 John Wiley & Sons, Ltd.

A one-dimensional vertical numerical model for coupled water flow and heat transport in soil and snow was modified to include all three phases of water: vapor, liquid, and ice. The top boundary condition in the model is driven by incoming precipitation and the surface energy balance. The model was applied to three different terrestrial systems: A warm desert bare lysimeter soil in Boulder City, NV; a cool mixed-grass rangeland soil near Laramie, WY; and a snow-dominated mountainous forest soil about 50 km west of Laramie, WY. Comparison of measured and calculated soil water contents with depth yielded modeling efficiency (ME) values (maximum range: -8< ME = 1) of 0.32 = ME = 0.75 for the bare soil, 0.05 = ME = 0.30 for the rangeland soil, and 0.06 = ME = 0.37 for the forest soil. Results for soil temperature with depth were 0.87 = ME = 0.91 for the bare soil, 0.92 = ME = 0.94 for the rangeland soil, and 0.85 = ME = 0.88 for the forest soil. The model described the mass change in the bare soil lysimeter due to outgoing evaporation with moderate accuracy (ME = 0.41, based on 4 yr of data and using weekly evaporation rates). Snow height for the rangeland soil and the forest soil was captured reasonably well (ME = 0.57 for both sites based on 5 yr of data for each site). The model is physics based, with few empirical parameters, making it applicable to a wide range of terrestrial ecosystems.

As population and economies continue to grow on a global scale, so too does the demand for energy. To improve reliability and independence of energy supplies, the U.S. and many other countries are seeking internally-sourced renewable energy; solar is one such renewable-energy source that meets these criteria. However, all energy sources exert some environmental impacts. In the case of solar, direct impacts stem mostly from alteration of land needed to host infrastructure. Understanding the environmental upside and downside potential of solar energy systems allows a more comprehensive, side-by-side comparison with different energy sources. In this article, we focus on the solar energy potential of West Texas, USA, a large arid to semi-arid region with a rural population and favorable climatic conditions. Texas is an interesting and important region to study given its unregulated and independent grid operation and the additional (and substantial) sources of regionally produced energy. Herein, we assess the geographic and environmental attributes, constraints to (e.g., incoming solar radiation, slope, habitats, ecoregion, water availability, etc.), and the potential environmental impacts on land resources from utility-scale installations of different types of solar energy generation systems. Our assessment points to the balance needed to expand solar energy to gain flexibility in energy sourcing on the one hand, while carefully considering future locations and technology to avoid regional impacts to land and environmental resources.

We present a workflow for rapid delineation and microtopographic characterization of ice wedge polygons within high-resolution digital elevation models. The workflow, which is extensible to other forms of remotely sensed imagery, incorporates a convolutional neural network to detect pixels representing troughs. A watershed transformation is then used to segment imagery into discrete polygons. Regions of non-polygonal terrain are partitioned out using a simple post-processing procedure. Results from training and validation sites at Barrow and Prudhoe Bay, Alaska demonstrate robust performance in diverse tundra landscapes. The methodology permits fast, spatially extensive measurements of polygonal microtopography and trough network geometry.

Soil moisture sensors infer volumetric soil water content (SWC) from other properties of the bulk porous media. The CS655 water content reflectometer is a relatively new, low-frequency electromagnetic sensor that determines relative permittivity () using the two-way travel period and voltage attenuation of the applied signal along two 12-cm rods. This measured attenuation is quadratically related to bulk electrical conductivity (EC). Along with an onboard thermistor, the CS655 allows a more robust correction of propagation time and , which its predecessors, the CS615 and CS616, lacked. However, with new sensors it is necessary to quantify their practical accuracy in the field. Here, we present an overview of the CS655 sensor and an evaluation under both laboratory and field conditions, using five surface soils (0–10-cm depth) in the laboratory and gravimetric samples collected in the field. Overall, a site-specific calibration using a two-term linearization of the SWC– function reduced the root mean square error (RMSE) of the factory-derived SWC of 0.073 and 0.043 m m during batch and infiltration experiments, respectively, to 0.025 and 0.028 m m. Results further indicate that a soil-specific calibration additionally reduced the RMSE to

In this paper, we present and analyze a global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database, for the first time. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and USA. In addition to its global spatial coverage, the collected infiltration curves cover a time span of research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use were gathered along with the infiltration data, which makes the database valuable for the development of pedo-transfer functions for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements (~76 %) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on the land use is available for 76 % of experimental sites with agricultural land use as the dominant type (~40 %). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for use by public domain only and can be copied freely by referencing it. Supplementary data are available at doi:10.1594/PANGAEA.885492. Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend/update the SWIG by uploading new data to it.

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial was a large, randomized controlled trial of cancer screening that also evolved over time into a unique epidemiologic cohort. Vast quantities of data have been collected since the beginning of the trial in 1993. Screening data was obtained through 2006. Questionnaire-based risk factor data (collected at baseline and at other points in the trial), vital status, cancer diagnoses and treatment, biospecimen data and additional ancillary efforts continue to be collected. Accurate data collection and efficient management methods are required to ensure high-quality data and valid and consistent analyses of trial outcomes. Information Management Services (IMS) was and continues to be responsible for processing and converting the collected raw PLCO data into comprehensive and accessible datasets. IMS also continues to provide a wide spectrum of analytic support including support for trial monitoring, data sharing, and epidemiologic research. In this paper, we describe the data processing and management requirements from the analytic team perspective, highlighting the various data sources and their complexity. We also illustrate the construction of usable analytic data files and discuss the wide range of analytic support provided. Instructions for accessing PLCO data also are provided.

We assess the spatial and geomorphic fragmentation from the recent Eagle Ford Shale play in La Salle County, Texas, USA. Wells and pipelines were overlaid onto base maps of land cover, soil properties, vegetation assemblages, and hydrologic units. Changes to continuity of different ecoregions and supporting landscapes were assessed using the Landscape Fragmentation Tool (a third-party ArcGIS extension) as quantified by land area and continuity of core landscape areas (i.e., those degraded by "edge effects"). Results show decreases in core areas (8.7%; ~33,290 ha) and increases in landscape patches (0.2%; ~640 ha), edges (1.8%; ~6940 ha), and perforated areas (4.2%; ~16230 ha). Pipeline construction dominates landscape disturbance, followed by drilling and injection pads (85, 15, and 0.03% of disturbed area, respectively). An increased potential for soil loss is indicated, with 51% (~5790 ha) of all disturbance regimes occurring on soils with low water-transmission rates (depth to impermeable layer less than 50 cm) and a high surface runoff potential (hydrologic soil group D). Additionally, 88% (~10,020 ha) of all disturbances occurred on soils with a wind erodibility index of approximately 19 kt/km(2)/year (0.19 kt/ha/year) or higher, resulting in an estimated potential of 2 million tons of soil loss per year. Results demonstrate that infrastructure placement is occurring on soils susceptible to erosion while reducing and splitting core areas potentially vital to ecosystem services.

Surfactants can reduce soil water retention by changing the surface tension of water and the contact angle between the liquid and solid phases. As a result, water flow and solute transport in unsaturated soil may be altered in the presence of surfactants. In this study, the effects of a representative nonionic surfactant, Triton X-100, on coupled water flow and nonreactive solute transport during unsaturated flow conditions were evaluated. Batch reactor experiments were conducted to measure the surfactant sorption characteristics, while unsaturated transport experiments were performed in columns packed with 40–270 mesh Ottawa sand at five initial water contents. Following the introduction of surfactant solution, the rate of water percolation through the sand increased; however, this period of rapid water drainage was followed by decreased water percolation due to the reduction in soil water content and the corresponding decrease in unsaturated hydraulic conductivity behind the surfactant front. The observed changes in water percolation occurred sequentially, and resulted in faster nonreactive solute transport than was observed in the absence of surfactant. A one-dimensional mathematical model accurately described coupled water flow, surfactant, and solute transport under most experimental conditions. Differences between model predictions and experimental data were observed in the column study performed at the lowest water content (0.115 cm3/cm3), which was attributed to surfactant adsorption at the air-water interface. These findings demonstrate the potential influence of surfactants additives on unsaturated water flow and solute transport in soils, and demonstrate a methodology to couple these processes in a predictive modeling tool.

Diorhabda carinulata (northern tamarisk beetle) has been released in the western United States as a biological control agent for the invasive plant Tamarix spp. (tamarisk). A few studies have been conducted analysing the effects of beetle defoliation on tamarisk water consumption, but predefoliation and post-defoliation comparison based on field data is scarce. The question of whether beetles substantially alter tamarisk water consumption is still open for discussion. In this study, an eddy covariance station and groundwater monitoring well were installed in a tamarisk stand along the Virgin River near Mesquite, NV, in 2010 to observe the impacts of tamarisk defoliation on evapotranspiration (ET) and groundwater levels. ET was calculated using the eddy covariance method and the White method and supported by Landsat remote sensing estimates. Data collected in 2010 established a baseline since the beetles arrived at the site in late 2010 and started feeding on foliage causing tamarisk trees to turn to brown during 2011. Repeated defoliations in 2011 and 2012 show that post-defoliation ET values and magnitude of diurnal groundwater-level fluctuations decreased compared with the predefoliation values. Estimated annual ET and annual average daily groundwater fluctuations were reduced by 18% and 35%, respectively. However, the magnitude of effects of defoliation was dependent on the growth stage of tamarisk at the time of defoliation. Also, ET recovered within a month as tamarisk established new leaves. Results from this study suggest that long-term changes in ET are highly dependent on repeated defoliation occurrences over several years. Copyright © 2015 John Wiley & Sons, Ltd.

Background More than half of US states have legalized medical marijuana. Several states have also legalized it for recreational use. In spite of states' actions, marijuana remains illegal under federal law. It remains to be seen, however, if the Trump administration will enforce federal law in states that have legalized marijuana. For now, it appears the move toward state legalization of marijuana will increase. Because of its legal status, research concerning the medical benefits of marijuana has been limited. Methods We reviewed the literature pertaining to medical use and legalization of marijuana. Results Available research shows that marijuana can benefit some conditions. There are also concerns about harmful effects on both individual and public health and whether legalization will lead to increased marijuana use among youth. Each of these elements has implications for school-based drug education programs. Researchers have shown that the 10 states with the highest rate of past month marijuana use by youth all have legalized recreational and/or medical use of marijuana, whereas none of the 10 states with the lowest rate of past month marijuana use by youth, has legalized marijuana. In the debate over legalization schools can potentially serve as a community resource, providing accurate information concerning marijuana. Conclusions Teachers and parents should continue to discourage young people from using marijuana (as well as alcohol, tobacco, and other drugs).

The Southwestern United States desert serves as the host for several threatened and endangered species, one of which is the desert tortoise (Gopherus agassizii). The goal of this study was to develop a fine-scale, remote-sensing-based approach that indicates favorable burrow locations for G. agassizii in the Boulder City (Nevada) Conservation Easement area (35,500 ha). This was done by analyzing airborne LiDAR data (5–7 points/m2) and color imagery (four bands, 0.15-m resolution) and determining the percent vegetation cover; shrub height and area; Normalized Difference Vegetation Index (NDVI); and several geomorphic characteristics including slope, azimuth, and roughness. Other field data used herein include estimates of canopy area and species richness using 1271 line transects, and shrub height and canopy area using plant-specific measurements of ~200 plants. Larrea tridentata and Ambrosia dumosa shrubs were identified using an algorithm that obtained an optimum combination of NDVI and average reflectance of the four bands (IR, R, G, and B) from pixels in each image. The results, which identified more than 65 million shrubs across the study area, indicate that percent vegetation cover from aerial imagery across the site (13.92%) compared favorably (14.52%) to the estimate obtained from line transects, though the LiDAR method yielded shrub heights approximately 60% those of measured shrub heights. Landscape and plant properties were combined with known locations of tortoise burrows, as visually observed in 2014. Masks were created using roughness coefficient, slope percent, azimuth of burrow openings, elevation, and percent vegetation cover to isolate areas more likely to host burrows. Combined, the masks isolated 55% of the total survey area, which will help target future field surveys. Overall, the approach provides areas where tortoise burrows are more likely to be found, though additional ecological data would help refine the overall method.

Evapotranspiration (ET) dominates water fluxes in arid and semiarid ecosystems. The partitioning of ET into transpiration (T) and evaporation (E) has drawn increasing attention, particularly with respect to quantifying the control of shrub cover on water budget studies. The main objective of this study was to simulate the effects of shrub coverage spatial patterns on water partitioning into T and E and its relation to the simulation cell sizes. Correlation lengths of spatially distributed shrub cover in fine resolution grid cells were used to distinguish spatial patterns (i.e. patchiness) of shrub distributions. We then aggregated the fine resolution grid cells into larger cells of various hierarchies, calculated the potential T of each large cell as a portion of potential ET in the aggregated cell, and simulated the partitioning of actual ET into T and E. Results illustrated that simulated T increases with aggregated cell size, while E rate and total E do not change significantly (i.e. T/ET increases with aggregated cell size). The spatial distribution of shrub pattern influences the partitioning of ET: T increases with decreasing correlation length of shrub spatial pattern. Significant differences in T/ET are linked to the different correlation lengths, as a result of the highly non-linear relationship between potential T and % shrub cover, which indirectly take into account subsurface lateral flows in the root zone. Copyright © 2014 John Wiley & Sons, Ltd.