Geology topics

Keith C. Clarke

Publications and source records attributed to Keith C. Clarke.

3 recordsLinked to original sources

USGS2023

Restructuring and serving web-accessible streamflow data from the NOAA National Water Model historic simulations

In 2016, the National Oceanic and Atmospheric Administration deployed the first iteration of an operational National Water Model (NWM) to forecast the water cycle in the continental United States. With many versions, an hourly, multi-decadal historic simulation is made available to the public. In all released to date, the files containing simulated streamflow contain a snapshot of model conditions across the entire domain for a single timestep which makes accessing time series a technical and resource-intensive challenge. In the most recent release, extracting a complete streamflow time series for a single location requires managing 367,920 files (~16.2 TB). In this work we describe a reproducible process for restructuring a sequential set of NWM steamflow files for efficient time series access and provide restructured datasets for versions 1.2 (1993–2018), 2.0 (1993–2020), and 2.1 (1979–2022). These datasets have been made accessible via an OPeNDAP enabled THREDDS data server for public use and a brief analysis highlights the latest version of the model should not be assumed best for all locations. Lastly we describe an R package that expedites data retrieval with examples for multiple use-cases.

Nature, Scientific Data↗

USGS1996

Methods and techniques for rigorous calibration of a cellular automaton model of urban growth

Several lessons about the process of calibration were learned during development of a self-modifying cellular automaton model to predict urban growth. This model, part of a global change research project on human-induced land transformations, was used to predict the spatial extent of urban growth 100 years into the future. The context of the prediction was to evaluate urban environmental disturbances such as land use conversion, urban heat island intensification, and greenhouse gas generation. Using data for the San Francisco Bay area as a test case, methods were developed, including interactive and statistical versions of the model, animation and visualization tools, automated testing methods, and Monte Carlo simulations. This presentation will enumerate, analyze, and discuss the lessons learned during the extensive process of model calibration. Experience with the methods developed may have broader use in assisting the rigorous calibration for other CA models, and perhaps those coupled environmental models with an extensive spatial data component. These methods are now under test as the project moves to a new data set for the Washington, D.C.-Baltimore area.

Conference Paper↗

USGS1996

Communicating scientific findings to the general public

The Human Induced Land Transformation project (HILT), part of the U.S. Geological Survey Global Change Research Program, has generated considerable public interest during the first two phases of the project: the data assembly and visualization phase carried out for the San Francisco Bay area; and the model building and calibration phase. The third phase, now underway for the Washington/Baltimore region, is a large scale test of the model's portability to another urban area. The modeling community has been kept informed of progress and findings of the HILT project through conventional academic outlets such as conference and journal publications as well as through more popular outlets such as newspaper, television, and a World Wide Web site. The program, sample data and documentation of the model will be available for downloading to those with an Internet connection. While recognizing that not all research has the same degree of public appeal as this project, additional effort was invested to establish contacts, publicize, and distribute the historical visualizations and model predictions generated by this work in the media, publishing, and in education. In this paper, we will cover the lessons learned in publicizing HILT, the techniques used and the criteria evolved for successful involvement of the general public in the modeling of land cover transitions.

Conference Paper↗