Presentation on theme: "2012 NHD/WBD Stewardhsip Conference – 3/29/2012. Provide framework for appropriate levels of rigor, consistency and cooperation Report by Stewards."— Presentation transcript:
Provide framework for appropriate levels of rigor, consistency and cooperation Report by Stewards and collaborators on their experiences Consolidate these into a set of best practices for lidar based delineations Establish a set of recommendations for the resulting update of the NHD and WBD Inform analysis of the benefit cost ratio for developing 3-dimentional hydrography network and hydrologic boundaries from lidar sources
The project carried out a nation-wide critical inventory of practices in: 1. Lidar collection and processing 2. Hydrography extraction 3. Standardization of the extracted data Workgroup members provided copious information about their home entity practices. Member contributions available thru MyUSGS collaboration platform, NHD/LIDAR/ workspace.
A Workflow for NHD Update from Lidar, Craig Ducey Building High-Resolution DEM and WBD Coverages From Overlapping LiDAR Point Clouds of Varying Resolutions in New Jersey, Jeffrey Hoffman Lessons From the Development of New York City’s Water Supply Watershed Hydrography Model, Ricardo Lopez- Torrijos A Community Approach for Hydrologic Enforcement of Topography Data, Brian Quinn Find at AWRA’s www.awra.org/proceedings/Spring2012/, or ask the author for a copy.www.awra.org/proceedings/Spring2012/
Enhancing LiDAR for Improved Watershed Modeling, Mark Ellard Wetlands Correction Factors for LiDAR Digital Elevation Models, Sandra Fox Automated Hydrologic Enforcement of High Resolution Topography, Brian Gelder Creating Local Resolution NHD: An Examination of Similarities and Differences in Three State Projects, Susan Phelps. Hydrographic Feature Extraction and Hydrological Modeling Based on LiDAR Point Cloud, Ping Yang Find at AWRA’s www.awra.org/proceedings/Spring2012/, or ask the author for a copy.www.awra.org/proceedings/Spring2012/
a. Federal minimum lidar acquisition specifications [v13: Nominal Pulse Spacing (NPS) of 1-2 meters] need to be improved when targeting areas with challenging ground cover patterns
b. To support subsequent work, metadata needs to be standardized, fully addressing data collection and processing
c. Protocols for the use of orthophotography and other ancillary datasets need to be developed, so that they support hydrography and watershed delineations impacted by a mismatch of temporal and spatial registration, including those stemming from horizontal and vertical accuracy relationships
d. Flow frequency, catchment area methods, protocols for the identification of a stream, and those for determining stream initiation points need further refinement.
e. The role played by underground urban and transportation related storm water infrastructure needs to be better understood and receive increased focus.
If not working directly with the lidar point cloud, refer to the bare-earth surface as lidar-derived
Conclusions are valid for any high resolution bare earth surface, irrespective of the technology used to measure the elevations.
Produce a summary report of the workgroup’s findings. In project design, evaluate carefully the project area boundary to ensure complete elevation data coverage.
Develop metrics to measure relative level of effort, and then a blue book guide for project costing and design, providing project costs according to each set of recommended specifications. Improve the tools for conflation of attributes to newly compiled vector data. Clarify expectations for submissions of NHD updates based on lidar. Clarify guidelines for WBD delineation.
Provide recommendations on storage of information used to incorporate storm water features into the stream network, and on update and hosting of other linear event information
The vertical integration of elevation and NHD/WBD needs to resolve issues with: Collection of underground infrastructure. Flow routing determination in flat areas. Determination of threshold source contributing area for stream initiation. Review process and feedback loops.
Resolve issues with: Vertical matching of vectors meeting existing streams at the project’s edge. Integration with non Z-enabled stream data in the NHD repository.