Related Experiment Video
Updated: Jul 12, 2025
12:44
Watershed Planning within a Quantitative Scenario Analysis Framework
Published on: July 24, 2016
8.1K
Restructuring and serving web-accessible streamflow data from the NOAA National Water Model historic simulations.
J Michael Johnson1,2, David L Blodgett3, Keith C Clarke4
1Lynker, Fort Collins, CO, USA. jjohnson@lynker.com.
Scientific Data
|October 20, 2023
Summary
The National Water Model (NWM) data restructuring process enables efficient streamflow time series access. New datasets and an R package improve usability for hydrological research.
Area of Science:
- Hydrology
- Environmental Science
- Data Science
Background:
- The National Oceanic and Atmospheric Administration's National Water Model (NWM) provides operational forecasts of the U.S. water cycle.
- Existing NWM data structures present significant technical challenges for accessing historical streamflow time series due to large file volumes per timestep.
- Extracting a single location's streamflow data can involve managing hundreds of thousands of files, totaling terabytes of data.
Purpose of the Study:
- To develop and present a reproducible method for restructuring NWM streamflow files for efficient time series access.
- To provide publicly accessible, restructured datasets for multiple NWM versions (1.2, 2.0, and 2.1).
- To introduce an R package designed to simplify and expedite data retrieval from these restructured datasets.
Main Methods:
- Developed a reproducible process to restructure sequential NWM streamflow files.
- Created restructured datasets for NWM versions 1.2, 2.0, and 2.1, covering extensive historical periods.
- Hosted restructured datasets on an OPeNDAP-enabled THREDDS data server for public access.
- Developed an R package to facilitate data retrieval and analysis.
Main Results:
- Successfully restructured NWM streamflow data, enabling efficient time series extraction.
- Provided accessible datasets for NWM versions 1.2 (1993-2018), 2.0 (1993-2020), and 2.1 (1979-2022).
- Analysis indicated that the latest NWM version is not universally optimal for all locations.
- The R package demonstrated effectiveness in expediting data retrieval for various use-cases.
Conclusions:
- The developed restructuring process and accessible datasets significantly reduce barriers to utilizing NWM historical streamflow data.
- The R package offers a valuable tool for researchers and practitioners working with NWM data.
- Users should consider specific location needs when selecting NWM versions, as newer versions may not always provide superior results.
Related Concept Videos
01:30Typical Model Studies
365
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
365
01:12Modeling and Similitude
271
Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale...
271
01:21Design Example: Creating a Hydraulic Model of a Dam Spillway
207
Scaled hydraulic models of dam spillways provide a practical way to replicate and study the intricate flow dynamics of these structures. Often built to a 1:15 ratio, these models allow for observing critical water behavior, such as velocity distribution, flow patterns, and energy dissipation.
207
01:24Rapidly Varying Flow
66
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
66
01:18Streamlines, Streaklines, and Pathlines
1.3K
A streamline represents the trajectory that is always tangent to the fluid's velocity vector at any given point. The velocity of a fluid particle is always directed along the streamline, ensuring the particle continuously follows the streamline's path. Streamlines are particularly useful for visualizing the overall direction of flow in a fluid system, and they provide an instantaneous representation of the flow's velocity field. In steady flow, where conditions do not change over...
1.3K
01:17Design Example: Analyzing Capacity Contours for Flood Risk Assessment
52
Flood risk assessment involves careful planning and analysis to ensure the safety of communities near water retention structures. Capacity contours are a vital tool in this process, as they illustrate the potential spread of water at specific levels in a given area. In the context of building a bund across a small valley, these contours play a critical role in evaluating the safety of nearby residential areas.In this example, the bund is intended to store stormwater in the valley. The engineers...
52