Citation:

Jennings, D B. AND S T. Jarnagin. THE EMERGING USE OF LIDAR AS A TOOL FOR ASSESSING WATERSHED MORPHOLOGY. Presented at EPA Science Forum 2004, Washington, DC, June 1-3, 2004.

Impact/Purpose:

The objectives of this task are to:

Assess new remote sensing technology for applicability to landscape characterization; Integrate multiple sensor systems data for improved landscape characterization;

Coordinate future technological needs with other agencies' sensor development programs;

Apply existing remote sensing systems to varied landscape characterization needs; and

Conduct remote sensing applications research for habitat suitability, water resources, and terrestrial condition indicators.

Description:

Stream channel morphology is an integral component of the stream fluvial process and is inherently related to the stability of stream aquatic ecology. Numerous studies have shown that changes in stream channel geometry are related to changes in biotic integrity. In urbanizing landscapes, the most prevalent impact on stream morphology is due to impervious surfaces, roads, rooftops, etc. - and their related storm sewers. These features focus surface water runoff into the receiving streams, increase the volume and velocity of peak flows and thereby increase the number of erosional flooding events. Sedimentation due to stream channel incision and/or stream bank erosion are the primary causes of stream degradation related to stream channel change.

Past research into stream morphology issues has primarily relied on field survey techniques. The field surveys, though highly accurate, are labor intensive efforts that provide sparse information for volumetric analysis or longitudinal stream profiles. The lack of data density is problematic with respect to determining the systematic effects of landscape development upon the entirety of the stream channel. What is necessary is a survey vehicle that can detect the complete 3-dimensional component of the stream channel length. LIDAR (LIght Detection And Ranging) remote sensing technology has emerged over the past ten years as a viable remote sensing modeling tool for analyzing topographic change. LIDAR utilizes laser pulse technology to produce digital elevation models (DEM) with sub-meter postings. Combining repeat LIDAR collects with repeat high-resolution imagery collects will used to determine the impact of landscape change on stream channel geometry in the Clarksburg Special Protection Area (CSPA) in Montgomery County, Maryland. The CSPA is a 35km2 area that is planned for sub-division and commercial development along with various best management practices (BMP) for stream mitigation purposes.

Our research partners are Montgomery County, Maryland and the United States Geological Survey (USGS) Water Research Division (WRD) in Baltimore, Maryland. This research is an example of a Federal-Local technology-transfer partnership where innovative strategies are researched at the Federal level and the results made available at a local level for neighborhood solutions. This research is a collaborative effort where local stakeholders are involved in both conducting the research and applying the results and the Federal agencies are involved offering expertise and capabilities not available at the local level.

A successful modeling effort would provide local environmental managers with a strategy for 1) determining the impacts of development on stream morphology as well as 2) determining the success of BMPs for mitigating channel erosion and sedimentation.

Record Details: