Scientific Investigations Report 2009–5202
AbstractDuring 2006–09, the U.S. Geological Survey, in cooperation with the National Atlas of the United States®, produced a 1:1,000,000-scale (1:1M) hydrography dataset comprising streams and waterbodies for the entire United States, including Puerto Rico and the U.S. Virgin Islands, for inclusion in the recompiled National Atlas. This report documents the methods used to select, simplify, and refine features in the 1:100,000-scale (1:100K) (1:63,360-scale in Alaska) National Hydrography Dataset to create the national 1:1M hydrography dataset. Custom tools and semi-automated processes were created to facilitate generalization of the 1:100K National Hydrography Dataset (1:63,360-scale in Alaska) to 1:1M on the basis of existing small-scale hydrography datasets. The first step in creating the new 1:1M dataset was to address feature selection and optimal data density in the streams network. Several existing methods were evaluated. The production method that was established for selecting features for inclusion in the 1:1M dataset uses a combination of the existing attributes and network in the National Hydrography Dataset and several of the concepts from the methods evaluated. The process for creating the 1:1M waterbodies dataset required a similar approach to that used for the streams dataset. Geometric simplification of features was the next step. Stream reaches and waterbodies indicated in the feature selection process were exported as new feature classes and then simplified using a geographic information system tool. The final step was refinement of the 1:1M streams and waterbodies. Refinement was done through the use of additional geographic information system tools. |
First posted September 30, 2009 For additional information contact: Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge. |
Gary, R.H., Wilson, Z.D., Archuleta, C.M., Thompson, F.E., and Vrabel, Joseph, 2009, Production of a national 1:1,000,000-scale hydrography dataset for the United States—Feature selection, simplification, and refinement: U.S. Geological Survey Scientific Investigations Report 2009–5202, 22 p. Revised May 2010.
Abstract
Introduction
Feature Selection
Simplification
Refinement
Summary
Selected References
Glossary