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Sorted by (Issue date descending, Date of update descending, Date of creation descending, Number of collection descending) Add the result to your favourites Refine your searchNational Water Model, Part 1: Science and Products
This lesson provides an introduction to the benefits, important input (forcing data), and key products of the National Water Model. Both official and evolving products are presented. The lesson uses the flooding associated with Hurricane Harvey in August 2017 to demonstrate key products.Dam Failure Concepts and Modeling
This lesson provides an in-depth case study to illustrate principles of dam failure modeling and examines some of the critical data inputs and outputs. Output is provided from the U.S. Army Corps of Engineers HEC-RAS model for simulated failures of a large dam. Several simulations are presented that show the impact from varying the size of the breach and the time it takes the breach to fully develop. The lesson also summarizes several infamous large dam failures from around the world and the impacts from other factors are such as reservoir shape and size, the age of the dam, and the material u ...Reservoir Pool Elevation: Considerations for Long-term Asset Management and Planning
Long-term management of critical water resources infrastructure needs to incorporate projected changes to environmental conditions. Reservoirs form the heart of water resource assets. Long-range plans for the repair, replacement, maintenance and renovation of these facilities depend on accurate projections of reservoir pool elevations. Environmental conditions, in turn, dictate the magnitude and timing of inflows and outflows from reservoirs, and thus the resulting water surface elevation. This lesson explores the factors that affect reservoir pool elevation and the considerations and challeng ...Met 101: Introduction to the Atmosphere
This lesson provides an overview of Earth’s atmosphere, its vertical structure, the fundamental forces acting on air, and how the atmosphere's composition affects the colors we see in the sky. The lesson also includes information about how Earth receives energy from the Sun as solar and infrared radiation, and the mechanisms for transferring heat around the globe. Learners will be introduced to the components of Earth’s water cycle, and also briefly explore the main types of systems used to observe the atmosphere.Climate and Water Resources Management, Part 1: Climate Variability and Change
Climate is changing at unprecedented rates in recorded history. A variety of lines of evidence demonstrate that climate change is likely to affect the hydrologic cycle and thus create new challenges in water management. This requires that climate change information be included in water and water-related resources planning, operations, and management. Climate and Water Resources Management, Part 1: Climate Variability and Change describes the terminology, global evidence, regional manifestations, and basic science of global climate variability and anthropogenic change, with a focus on water res ...Climate Variability and Change for Water Resources Management - International Edition
Climate is changing at unprecedented rates in recorded history. A variety of lines of evidence demonstrate that climate change is likely to affect the hydrologic cycle and thus create new challenges in water management. This requires that climate change information be included in water and water-related resources planning, operations, and management. Climate Variability and Change for Water Resources Management - International Edition describes the terminology, global evidence, regional manifestations, and basic science of global climate variability and anthropogenic change, with a focus on wa ...Overview of Watershed and Channel Sedimentation
This lesson provides an overview of the primary influences of watershed and channel sedimentation. In a short narrated portion of the lesson, we explore a section of the Rio Grande watershed and channel in New Mexico using Google Earth imagery, river profiles, and graphic animations. We highlight features of the upland catchments, the river channel, and the Elephant Butte Reservoir. We then demonstrate how environmental factors (climate, geography, land use changes, reservoirs) impact the supply and movement of sediments for the Rio Grande and other rivers. The focus is on the three primary pr ...Primary Influences on Water Temperature for Inland Streams
This lesson explores the primary influences, or drivers, on water temperature of inland streams and rivers. We use a simulated flight, or flyover, where we look down at the features of the South Boise River in Idaho. An unregulated as well as a regulated reach of the river are explored (above and below the Anderson Ranch Reservoir), with a look at cross sections of the river and its environment at key locations during the flyover. We explore how environmental factors (climate, geography, stream morphology) impact water temperatures. Then, after defining the factors that affect water temperatur ...Snowmelt Processes: International Edition
Snowmelt is an integral component of the hydrologic forecasting process in many parts of the world. Here, we examine the influences of environmental conditions on snowfall distribution, snowpack structure, snowpack-environment energy exchange, and finally, the rate and amount of snowmelt itself. The fate of snowmelt water after it reaches the ground is also explored.Flash Flood Processes: International Edition
Flash floods can occur in nearly any area of the world. A rainfall-induced flash flood is a truly hydrometeorological event: one that depends on both hydrologic and meteorological conditions. Forecasting flash floods involves a detailed understanding of the local hydrologic features and continual monitoring of the current meteorological situation. This module examines both the hydrologic and meteorological processes that often contribute to the development of flash flooding. Common tools and technologies that are used in flash flood monitoring and forecasting, from manual gauging systems to co ...Flood Forecasting Case Study: International Edition
This module allows users to explore the flood forecasting process by assuming the role of a visiting hydrologist intern at the National Hydrologic Service in Main Country. Fictional senior hydrologists guide the intern through an idealized flooding event that takes place over Main Country's Mainstem river basin and its tributary basins, each with varying landscapes and observation systems. Users will examine how these variations impact the quality and type of forecast that can be achieved. Users will also learn about common problems encountered in flood forecasting, and how to adjust forecasts ...Runoff Processes: International Edition
The Runoff Processes module offers a thorough introduction to the runoff processes critical for flood and water supply prediction. This module explains key terminology and concepts including the following: types of runoff, paths through which water becomes runoff, basin and soil properties that influence runoff, and numerical runoff modeling. Examples of popular runoff models are also discussed.Unit Hydrograph Theory: International Edition
The role of unit hydrograph theory in the flood prediction process is to provide an estimate of streamflow that results from a given amount precipitation. A unit hydrograph shows the temporal change in flow, or discharge, per excess unit of precipitation runoff. This module offers a thorough introduction to the use of unit hydrographs and the application of unit hydrograph theory in flood prediction. Key terminology and assumptions, the process of creating a unit hydrograph and application of unit hydrograph theory to forecast situations are all explored through comprehensive animations and in ...Distributed Hydrologic Models for Flow Forecasts - Part 2
Distributed Hydrologic Models for Flow Forecasts Part 2 is the second release in a two-part series focused on the science of distributed models and their applicability to different flow forecasting situations. Presented by Dr. Dennis Johnson, the module provides a more detailed look at the processes and mechanisms involved in distributed hydrologic models. It examines the rainfall/runoff component, snowmelt, overland flow routing, and channel response in a basin as represented in a distributed model. Calibration issues and situations in which distributed hydrologic models might be most appropr ...River Ice Processes - Short Version
This module provides information on flooding associated with river ice jams. Based on a presentation by Dr. Kate White, a nationally-recognized expert on river ice, this webcast explores basic river ice processes including the formation, growth, breakup, and transport of river ice and how it can become jammed, triggering floods. This shorter version of the previously published module "River Ice Processes", has less focus on the US National Weather Service, making it more broadly applicable, including to an international audience.Understanding the Hydrologic Cycle: International Edition
This module helps students gain a basic understanding of the elements of the hydrologic cycle. The hydrologic cycle is the continuous movement and phase change of liquid water, ice, and water vapor above, on, under and through the earth's surface. This module examines the basic concepts of the hydrologic cycle including water distribution, atmospheric water, surface water, groundwater, and snowpack/snowmelt.Distributed Hydrologic Models for Flow Forecasts - Part 1
Distributed Hydrologic Models for Flow Forecasts – Part 1 provides a basic description of distributed hydrologic models and how they work. This module is the first in a two-part series focused on the science of distributed models and their applicability in different situations. Presented by Dr. Dennis Johnson, the module begins with a review of hydrologic models, and then examines the differences between lumped and distributed models. It explains how lumped models may be distributed by subdividing the basin and suggests when distributed hydrologic models are most appropriate. Other topics cove ...Weather and the Built Environment
This short course provides broadcast meteorologists, educators, and the public with an overview of the evolution of our modern urban environment with a focus on impacts on the urban watershed, air quality, and climate. This course complements the course Watersheds: Connecting Weather to the Environment and both are part of the Earth Gauge™ environmental curriculum for weathercasters and educators. This curriculum is being developed by the National Environmental Education Foundation (NEEF). [See http://www.earthgauge.net/wp/] Unit 1, Where We Live, takes a look at past and current U.S. growth p ...River Forecasting Case Study
This module takes the learner through the considerations for the river forecasting decisions associated with the remnants of Hurricane Ivan on 17-19 September, 2004 for the Susquehanna River system in Pennsylvania and New York. The module assists the learner with applying the concepts covered in the foundation topics of the Basic Hydrologic Sciences course. Some of the specific topics pertinent to this case are soil conditions, the impact of QPF on runoff, runoff models, runoff processes, routed flow and stage-discharge relationships. Observations of upstream conditions and comparisons to hist ...Snowmelt Processes
This module helps the student develop an understanding of the contribution of snowmelt in the hydrologic forecasting process. The module first explains the influences of wind, sun, terrain, and vegetation on snow water distribution and then discusses the evolution of snowpack characteristics. From there, the student will learn about energy exchanges between the snow and the atmosphere and how that affects how quickly and how completely snow will melt. Finally, an explanation is presented of water flow through snow and the fate of that water when it reaches the ground surface. The lesson will b ...Flash Flood Case Studies
This module takes the learner through seven case studies of flash flood events that occurred in the conterminous U.S. between 2003 and 2006. The cases covered include: * 30-31 August 2003: Chase & Lyon Counties, KS * 16-17 September 2004: Macon County, NC * 31 July 2006: Santa Catalina Mountains near Tucson, AZ * 25 December 2003: Fire burn area near San Bernardino, CA * 30 August 2004: Urban flash flood in Richmond, VA * 19-20 August 2003: Urban flash flood in Las Vegas, NV * 9 October 2005: Cheshire County, NH This module assists the learner in applying the concepts covered in the foundation ...River Ice Processes
The “River Ice Processes” module provides information on flooding associated with river ice jams. In this webcast, Dr. Kate White, nationally-recognized expert on river ice, explores basic river ice processes including the formation, growth, breakup, and transport of river ice and how it can become jammed, triggering floods. In addition, Dr. White covers the current, state-of-the-art ice jam forecasting, and current ice-modeling research and development being conducted by the U.S. Army Corps of Engineers. As a foundation topic for the Basic Hydrologic Science course, this module may be taken o ...Flash Flood Processes
According to NOAA’s National Weather Service, a flash flood is a life-threatening flood that begins within 6 hours--and often within 3 hours--of a causative event. That causative event can be intense rainfall, the failure of a dam, levee, or other structure that is impounding water, or the sudden rise of water level associated with river ice jams. The “Flash Flood Processes” module offers an introduction to the distinguishing features of flash floods, the underlying hydrologic influences and the use of flash flood guidance (FFG) products. Through use of rich illustrations, animations, and inte ...Runoff Processes
The Runoff Processes module offers a thorough introduction to the runoff processes critical for flood and water supply prediction. Through the use of rich illustrations, animations, and interactions, this module explains key terminology and concepts including paths to runoff, basin and soil properties and runoff modeling. It also provides an introduction to the National Weather Service River Forecast System (NWSRFS). As a foundation topic for the Basic Hydrologic Science course, this module may be taken on its own or used as a supporting topic to provide factual scientific information to stude ...Understanding the Hydrologic Cycle
This module helps students gain a basic understanding of the elements of the hydrologic cycle. Making use of illustrations, animations, and interactions, this module examines the basic concepts of the hydrologic cycle including water distribution, atmospheric water, surface water, groundwater, and snowpack/snowmelt.Unit Hydrograph Theory
The role of unit hydrograph theory in the flood prediction process is to provide an estimate of streamflow given the precipitation. A unit hydrograph shows the temporal change in flow, or discharge, per unit of runoff from excess precipitation. In other words, the unit hydrograph shows how the flow of a stream will be affected over time by the addition of one unit of runoff. This module offers a thorough introduction to the use of unit hydrographs and the application of unit hydrograph theory in flood prediction. Through use of rich illustrations, animations, and interactions, this module expl ...
Operational hydrology report (OHR), 24. Level and discharge measurements under difficult conditions
The report, approved by Commission for Hydrology at its seventh session in 1984, constitutes valuable guidance for hydrologists on measuring river flow under difficult conditions and supplements the Guide to hydrological practices (WMO-No. 168) and the Manual on stream gauging (WMO-No. 519).
Operational hydrology report (OHR), 23. Intercomparison of models of snowmelt runoff
This report contains the full results of the WMO project on intercomparison of models of snowmelt runoff which was initiated in 1976 and completed in 1983.
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