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The development of water resources to satisfy urban water needs has had serious impacts on freshwater ecosystem integrity and on valuable ecosystem services, but positive trends are emerging that point the way toward a solution. We demonstrate this through case studies of water resource development in and around five large urban areas: Los Angeles, Phoenix, New York, San Antonio, and Atlanta. Providing freshwater ecosystems with the water flows necessary to sustain their health, while meeting the other challenges of urban water management, will require greatly increased water productivity in conjunction with improvements in the degree to which planning and management take ecosystem needs into account. There is great...
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Note: The contents of this map are still under development and are being made available for illustration purposes only. These data are not to be used without permission by the map author. Risk of altered ecologically significant components of the flow regime due to human impacts. The SARP Flow Alteration Assessment provides a regional characterization of the distribution and risk of altered flow regimes at the NHDPlus segment scale. The human impacts include runoff from impervious surfaces, evaporative losses from artificial water bodies, and surface water use. Impacts of these activities on selected ecologically significant components of the flow regime are given in the attached document. These flow components...
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Accruate mapping of tidal wetlands is vital for effective conservation and restoration of these valued habitats, and good mapping is key to strategic planning for coastal resilience. Tidal wetlands are defined by regular inundation by the tides; therefore, mapping of tidal wetlands should be based on knowledge of tidal water levels and the land areas inundated by the tides. We developed this tidal wetland mapping following that principle. Briefly, we used a method developed in Oregon that combines NOAA’s extreme water level models with high-resolution LIDAR digital elevation models (DEMs) to map areas subject to tidal inundation. We refined the mapping using additional data sources such as the National Wetland...
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Data provided from the Virginia Department of Environmental Quality (DEQ) including simulated values of 72 hydrologic metrics, or indicators of hydrologic alteration (IHA), 37 fish metrics, and 64 benthic invertebrate metrics were reviewed to assess significant flow-ecology relations that may be developed. Hydrologic alteration was represented by simulation of streamflow record for a pre-water-withdrawal condition (baseline) without dams or developed land, compared to the simulated recent-flow condition (2008) including withdrawals, dams and altered landscape to calculate a percent-alteration of flow. Biological samples used represent a median condition of the biological community from 1972 to 2010. This study reviewed...
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This database is the result of an extensive literature search aimed at identifying documents relevant to the emerging field of dam removal science. In total the database contains 214 citations that contain empirical monitoring information associated with 181 different dam removals across the United States and abroad. Data includes publications through 2016 and supplemented with the U.S. Army Corps of Engineers National Inventory of Dams database, U.S. Geological Survey National Water Information System and aerial photos to estimate locations when coordinates were not provided. Publications were located using the Web of Science, Google Scholar, and Clearinghouse for Dam Removal Information.
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Note: This item is being used in a data pipeline that supports the Dam Removal Information Portal. We recommend users directly access the American River's Dam Removal Database from Figshare: https://doi.org/10.6084/m9.figshare.5234068. In the last century, the U.S. led the world in dam building for many purposes, including hydropower, irrigation, flood control and water storage. While dams can benefit society, they also cause considerable harm to rivers. Dams have depleted fisheries, degraded river ecosystems, and altered recreational opportunities on nearly all of our nation’s rivers. Today, many dams that were once at the epicenter of a community’s livelihood are now old, unsafe or no longer serving their intended...
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This CSV file contains 21 dam metrics representing stream fragmentation and flow alteration for nearly 2.3 million stream reaches in the conterminous USA. Dam metrics fall into four main categories: segment-based, count and density, distance-based, and cumulative reservoir storage (described below). These data were developed using spatially verified large dam locations (n=49,468) primarily from the National Anthropogenic Barrier Dataset (NABD) that were spatially linked to the National Hydrography Dataset Plus version 1 (NHDPlusV1). These dam metrics have been summarized using the unique identifier field native to the NHDPlusV1 (COMID) which can be used to join this table to spatial layers and data tables of the...
Categories: Data; Types: Citation; Tags: 2015 National Assessment, 2015 National Assessment, 2015 National Assessment, Alabama, Arizona, All tags...
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To identify the degree of hydrologic alteration of streams in the Mississippi Alluvial Plain (MAP), we used random forest (RF) regression methods (Breiman, 2001) to model the relation between six selected streamflow characteristics and explanatory variables (such as drainage area, precipitation, soils, and other watershed characteristics). RFs were chosen for this study because they have been proven to be more robust and accurate than traditional linear regression methods (Carlisle and others, 2010; Lawler and others, 2006; Prasad and others, 2006; Cutler and others, 2007). Estimated expected monthly mean streamflow from the RF models were compared to observed monthly mean streamflow at 68 sites located within the...
Flow regulation effects on floodplain forests in the semi-arid western United States are moderately well understood, whereas effects associated with changes in floodplain land use are poorly documented. We mapped land cover patterns from recent aerial photos and applied a classification scheme to mainstem alluvial floodplains in 10 subjectively selected 4th order hydrologic units (subbasins) in the Upper Colorado River Basin (UCRB) in order to document land use patterns (floodplain development) and assess their effects on Fremont cottonwood forest (CF) regeneration. Three of the mainstem rivers were unregulated, five were moderately regulated and two were highly regulated. We classified polygons as Undeveloped (with...
Riparian cottonwood (Populus deltoides) forests form the one of the most extensive deciduous forest ecosystems in arid regions of the western United States. However, cottonwood populations are threatened by flow alteration and channel degradation caused by dams, water diversions, and groundwater pumping. We developed a stochastic, density-dependent, population model to (1) consolidate information concerning cottonwood population dynamics in a conceptual and analytical framework, (2) determine whether complex forest stand dynamics can be predicted from basic cottonwood vital rates and river hydrology, and (3) aid in planning prescribed floods by projecting how altered flow regimes might affect populations. The model...


    map background search result map search result map Draft - Risk of Alteration of Magnitude of Extreme Low and Base Flows Dam Metrics Representing Stream Fragmentation and Flow Alteration for the Conterminous United States Linked to the NHDPLUSV1 Fish and Benthic Macroinvertebrate Flow-Ecology Regression Summary Statistics for Virginia American Rivers Dam Removal Database PRMS_Model_IHA_Metrics_Median_Future_Difference USGS Dam Removal Science Database v3.0 Basin Characteristics and Climate Data Used in Random Forest Models to Determine Hydrologic Alteration in the Mississippi Alluvial Plain West Coast USA Current and Historical Estuary Extent Fish and Benthic Macroinvertebrate Flow-Ecology Regression Summary Statistics for Virginia Basin Characteristics and Climate Data Used in Random Forest Models to Determine Hydrologic Alteration in the Mississippi Alluvial Plain West Coast USA Current and Historical Estuary Extent PRMS_Model_IHA_Metrics_Median_Future_Difference Draft - Risk of Alteration of Magnitude of Extreme Low and Base Flows Dam Metrics Representing Stream Fragmentation and Flow Alteration for the Conterminous United States Linked to the NHDPLUSV1 USGS Dam Removal Science Database v3.0 American Rivers Dam Removal Database