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Ecological thresholds that lead to alternative community states can be exceeded through gradual perturbation or as a result of sudden disturbance. Many Great Plains streams have experienced dramatic changes in their hydrologic regime resulting from water and landuse changes that began as early as 1880. These changes, combined with the presence of many invasive species, have substantially altered the fish communities in this area. We quantified temporal changes in fish communities in 3 large river basins in relation to putative anthropogenic stressors, including increased sediment supply derived from row-crop agriculture (beginning in 1880), habitat fragmentation caused by reservoir construction (beginning in the...
We determined changes in willow (Salixspp.) cover in two valleys of the eastern slope of Rocky Mountain National Park,Colorado, USA, and related these changes to suspected causative factors. Changes in vegetation were inferred from digital maps generated from aerial photo-interpretation and field surveys conducted with a global positioning system. The decrease in riparian shrub cover was approximately 20% in both valleys over the period between 1937/46 and 1996, while the decline in tall willow (> 2 m tall) cover was estimated to be approximately 55%in both valleys. Suppressed willows (< 1.5 m tall) were predominantly located in areas affected by flooding and in areas where major river reductions were observed....
Interest in the utilization of forest biomass for energy is growing. A search into existing forest biomass harvesting and regeneration guidelines was carried out to identify how biomass energy can be environmentally sustainable. Findings have shown that there are only a few guidelines that specifically address harvesting and regenerating biomass for bioenergy or other bio-based products. Of these few, there are guidelines developed for dedicated energy plantations such as the Scottish Agricultural College guidelines, as well as some Finnish and Swedish guidelines recommending management practices for both timber and biomass extraction. Most of the existing small woody material guidelines emphasize the retention,...
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The U.S. Geological Survey (USGS) is providing an online map of potentiometric-surface altitude contours in the Magothy and Jameco aquifers on Long Island, New York, April-May 2013. USGS serves this map and geospatial data as a REST Open Map Service (as well as HTTP, JSON, KML, and shapefile), so end-users can use the map and data on mobile and web clients. A companion report, U.S. Geological Survey Scientific Investigations Map 3326 (Como and others, 2015; http://dx.doi.org/10.3133/sim3326) further describes data collection and map preparation and presents 68x22 in. PDF versions, 4 sheets, scale 1:125,000. This polyline shapefile consists of digital contours that represent the potentiometric-surface...
Riparian ecosystems in the south-western United States have undergone extensive physical and biological changes, due, in part, to alteration of natural flow regimes and suppression of fluvial processes. Many riparian ecosystem restoration projects are achieving success because they recognize the importance of restoring the hydrologic regime. In other words, these projects are restoring flows of water and sediment in sufficient quantities and with appropriate temporal and spatial patterns. Other projects have proceeded without recognition of the need to incorporate environmental stream flow requirements into management plans. To increase success rate of riparian ecosystem restoration, this paper describes some changes...
Aim: To test the hypothesis that anthropogenic alteration of stream-flow regimes is a key driver of compositional shifts from native to introduced riparian plant species. Location: The arid south-western United States; 24 river reaches in the Gila and Lower Colorado drainage basins of Arizona. Methods: We compared the abundance of three dominant woody riparian taxa (native Populus fremontii and Salix gooddingii, and introduced Tamarix) between river reaches that varied in stream-flow permanence (perennial vs. intermittent), presence or absence of an upstream flow-regulating dam, and presence or absence of municipal effluent as a stream water source. Results: Populus and Salix were the dominant pioneer trees along...
The denitrifier method to determine the dual isotopic composition (δ15N and δ18O) of nitrate is well suited for studies of nitrogen contributions to streams during runoff events. This method requires only 70 nmol of NO3 − and enables high throughput of samples. We studied nitrate sources to a headwater stream during snowmelt by generating a high-temporal resolution dataset at the Sleepers River Research Watershed in Vermont, USA. In the earliest phase of runoff, stream NO3 − concentrations were highest and stream discharge, NO3 − concentrations, and δ18O of NO3 − generally tracked one another during diurnal melting. The isotopic composition of stream NO3 − varied in-between atmospheric and groundwater NO3 − end...
We use a spatially explicit landscape model to investigate the potential role of rainfall on shrub?grass transitions in the Jornada Basin of southern New Mexico during the past century. In long-term simulations (1915?1998) along a 2700 m transect running from a dry lake bed to the foothills of a small mountain, we test two hypotheses: (i) that wetter winters and drier summers may have facilitated shrub encroachment in grasslands, and (ii) that increases in large precipitation events may have increased soil water recharge at deeper layers, thus favoring shrub establishment and growth. Our model simulations generally support the hypothesis that wetter winters and drier summers may have played a key role, but we are...
The study presents the potential use of existing common data sources such as a soil database, and techniques such as a pedotransfer function and a non-linear parameter estimator to calibrate and validate a hydrologic model to design subsurface drainage systems for Iowa's tile landscapes. A field scale deterministic hydrological model, DRAINMOD has been calibrated and validated for two soils: Webster soil cultivated with continuous corn (WEBS_CC) and Canisteo soil cultivated with corn–soybean rotation (CANI_CS). The cumulative subsurface drainage over the calibration and validation years from 1990 to 2003 was predicted 2% higher than the observed subsurface drainage for WEBS_CC (coefficient of mass residual CRM =...
Many headwater streams in the midwestern United States were channelized for agricultural drainage. Conservation practices are implemented to reduce nutrient, pesticide, and sediment loadings within these altered streams. The impact of these practices is not well understood because their ecological impacts have not been evaluated and the relationships between water chemistry and fishes are not well understood. We evaluated relationships between water chemistry and fish communities within channelized headwater streams of Cedar Creek, Indiana, and Upper Big Walnut Creek, Ohio. Measurements of water chemistry, hydrology, and fishes have been collected from 20 sites beginning in 2005. Multiple regression analyses indicated...
Although our current (1990) knowledge of hydrologic and hydraulic processes is based on many years of study, there are river environments where these processes are complex and poorly understood. One of these environments is in mountainous areas, which cover about 25 percent of the United States. Use of conventional hydrologic and hydraulic techniques in mountain-river environments may produce erroneous results and interpretations in a wide spectrum of water-resources investigations. An ongoing U.S. Geological Survey research project is being conducted to improve the understanding of hydrologic and hydraulic processes of mountainous areas and to improve the results of subsequent hydrologic investigations. Future...
Slope wetlands generally occur at breaks in slope where discharging ground water maintains moist soil conditions. They often are found on the perimeter of highly permeable alluvial fans, but there have been no detailed hydrologic studies of these particular wetlands. We combined stream and spring flow measurements with five years of water-level and piezometric data to understand the hydrology of a 1.6 ha slope wetland at the base of a 5.2 ha alluvial fan in the central Rocky Mountains of Colorado. Step changes in streamflow inputs resulting from an upstream water diversion helped confirm the linkages inferred from the hydrometric data. Nearly 30% of the streamflow along a 180-m reach on the alluvial fan was lost...
The U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) model was applied to basins in 14 different hydroclimatic regions to determine the sensitivity and variability of the freshwater resources of the United States in the face of current climate-change projections. Rather than attempting to choose a most likely scenario from the results of the Intergovernmental Panel on Climate Change, an ensemble of climate simulations from five models under three emissions scenarios each was used to drive the basin models. Climate-change scenarios were generated for PRMS by modifying historical precipitation and temperature inputs; mean monthly climate change was derived by calculating changes in mean climates...
Encyclopedia of Water Science provides instant access to the most effective procedures in agricultural water engineering, unveiling a wide spectrum of design concepts, methodologies, and solutions for enhanced performance of water quality, treatment, conservation, and irrigation methods, as well as improved water efficiency in agricultural programs. Online version features quarterly updates, keyword searchability, color graphics, and customized content views.
A study was conducted to understand the contributions of tile flow and baseflow to total nitrate-N (NO3-N) loadings in two subsurface (tile)-drained watersheds, namely the Big Ditch (BD) and the Upper Embarras River (UER) watersheds in Illinois. Two stream sections were selected in the watersheds and rectangular cutthroat flumes were installed at the upstream and downstream ends of the stream sections to calculate the flow mass balance for separating baseflow. The stream section at BD site had two tile outlets draining into it. The stream section at UER watershed did not have any tile drain. Tile flow was also measured along with stream flow. Water samples were collected not only from the stream sections using auto-samplers...
Abstract (from http://link.springer.com/article/10.1007/s00382-015-2845-1): Humidity is important to climate impacts in hydrology, agriculture, ecology, energy demand, and human health and comfort. Nonetheless humidity is not available in some widely-used archives of statistically downscaled climate projections for the western U.S. In this work the Localized Constructed Analogs (LOCA) statistical downscaling method is used to downscale specific humidity to a 1°/16° grid over the conterminous U.S. and the results compared to observations. LOCA reproduces observed monthly climatological values with a mean error of ~0.5 % and RMS error of ~2 %. Extreme (1-day in 1- and 20-years) maximum values (relevant to human health...
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In 2021 and 2022, the U.S. Geological Survey (USGS), in cooperation with the Idaho Department of Water Resources (IDWR), drilled and constructed well SEP 16 (431900112593601) approximately 6 miles south-southeast of Big Southern Butte in Butte County, Idaho. The purpose of the well installation was to collect geologic, geophysical, and hydrologic data. On July 13, 2022, the USGS Idaho National Laboratory Project Office (INLPO) collected select geophysical logs within the cased well including natural gamma, neutron, neutron porosity, and gamma-gamma dual density logs. Gyroscopic deviation data were also collected during geophysical surveying to account for the horizontal and vertical displacement of the well. On...
The Green River is a major tributary of the Colorado River with a drainage area of 115 770 km2 in Colorado, Utah and Wyoming. The influence of Flaming Gorge Dam on sediment transport and the potential for future channel change were studied using comparative analysis of historical aerial photographs from 1952 to 1987 and geographical information systems, published sediment (1951-86) and discharge (1965-87) records, and sediment data collected during 1986-8. Since the closure of the dam in 1964, new equilibrium channel widths were apparently achieved by 1974 in the reach 161-279 km below Flaming Gorge Reservoir and by 1981 in the reach 465-509 km below the reservoir. Recent high flows have resulted in an increase...
This paper considers the risk of drought and develops drought scenarios for use in the study of severe sustained drought in the Southwestern United States. The focus is on the Colorado River Basin and regions to which Colorado River water is exported, especially southern California, which depends on water from the Colorado River. Drought scenarios are developed using estimates of unimpaired historic streamflow as well as reconstructions of streamflow based on tree ring widths. Drought scenarios in the Colorado River Basin are defined on the basis of annual flow at Lees Ferry. The risk, in terms of return period, of the drought scenarios developed, is assessed using stochastic models. Published in Journal of the...
We compared short-term effects of lug-soled boot trampling disturbance on water infiltration and soil erodibility on coarse-textured soils covered by a mixture of fine gravel and coarse sand over weak cyanobacterially-dominated biological soil crusts. Trampling significantly reduced final infiltration rate and total infiltration and increased sediment generation from small (0.5 m2) rainfall simulation plots (p<0.01). Trampling had no effect on time to runoff or time to peak runoff. Trampling had similar effects at sites with both low and very low levels of cyanobacterial biomass, as indicated chlorophyll a concentrations. We concluded that trampling effects are relatively independent of differences in the relatively...
map background search result map search result map Potentiometric Surface Contours of the Magothy and Jameco Aquifers, April-May 2013 Drilling, construction, geophysical, water quality, and aquifer test data for well SEP 16, Butte County, Idaho Potentiometric Surface Contours of the Magothy and Jameco Aquifers, April-May 2013