Extracting Valley And Flowing Channel Networks From LiDAR Data

As an important geomorphologic and hydrologic feature, drainage network in a basin is composed of unchannelized valley and channel.  From the perspective of flow duration in channel, channels are categorized into perennial stream and ephemeral stream.  It is critical to understand the physical controls on flow durations in streams for projecting climate change impacts on streamflow and stream ecosystems.  However, little research has been conducted to model the expansion and contraction of flowing channels due to the limited monitoring data on the dynamics of flowing streams.  In this presentation, Light Detection and Ranging (LiDAR) data is utilized to identify valley network and flowing channel network.  The totally valley network is identified by crenulation of contours generated from ground elevation from LiDAR.  A method based on the point density of ground and vegetation LiDAR returns is developed to differentiate dry and flowing channels.  The developed method is applied to a drainage basin for mapping the dry and flowing channels.